Medical Policy

Policy Num:      11.003.135
Policy Name:     Genetic Biomarker Testing (Including Liquid Biopsy) for Targeted Treatment in Advanced Cancer
Policy ID:          [11.003.135]  [Ac / B / M+ / P+]  [2.04.151]

Last Review:      January 20, 2026
Next Review:     January 20, 2027
 

Related Policies:

11.003.030 - Germline Genetic Testing for Hereditary Breast/Ovarian Cancer Syndrome and Other High-Risk Cancers (BRCA1, BRCA2, PALB2) 
11.003.026 - Comprehensive Genomic Profiling for Selecting Targeted Cancer Therapies
11.003.089 - Circulating Tumor DNA and Circulating Tumor Cells for Cancer Management (Liquid Biopsy)

11.003.140 - Somatic Biomarker Testing for Immune Checkpoint Inhibitor Therapy (BRAF, MSI/MMR, PD-L1, TMB)  
11.003.035 - Assays of Genetic Expression in Tumor Tissue as a Technique to Determine Prognosis in Patients with Breast Cancer

11.003.063 - BCR-ABL1 Testing in Chronic Myelogenous Leukemia and Acute Lymphoblastic Leukemia

05.001.012 - Trastuzumab
05.001.024 - Ado-Trastuzumab Emtansine (Trastuzumab-DM1) for Treatment of HER2-Positive Malignancies
05.001.034 - Tropomyosin Receptor Kinase Inhibitors for Locally Advanced or Metastatic Solid Tumors Harboring an NTRK Gene Fusion

 Genetic Biomarker Testing (Including Liquid Biopsy) for Targeted Treatment in Advanced Cancer

Summary

Description

Multiple biomarkers are being evaluated to select treatment with an FDA-approved targeted treatments for patients with unresectable, recurrent, relapsed, refractory, advanced or metastatic cancer. These include tissue-based testing as well as circulating tumor DNA and circulating tumor cell testing (known as liquid biopsy).

The objective of this evidence review is to examine whether genetic biomarker testing for BRCA1, BRCA2 , PIK3CA, ESR1, BRAF, EGFR, EZH2, HER2, FOLR1, FLT3, CLDN18, FGFR3, PDGFRA, TP53, KRAS, NRAS, IDH1, IDH2, HLA, KIT, MET, homologous recombination deficiency (HDR), and homologous recombination repair (HRR) gene variants, ALK, ROS1, RET, FGFR2, PDGFR, NTRK, Philadelphia chromosome rearrangements or fusions, and other molecular signatures, such as, PD-L1, MSI/MMR, and TMB status, in tumor tissue, or circulating tumor DNA improves the net health outcome in patients with unresectable, recurrent, relapsed, refractory, advanced or metastatic cancer who are considering targeted therapy (Table 1).

Table PG1. Gene Variants Found in DNA for Targeted Therapy

  ATC: anaplastic thyroid cancer; CRC: colorectal cancer; HRD: homologous recombination deficiency; HRR: homologous recombination repair; NSCLC: non-small cell lung cancer; TMB: tumor mutational burden. a Genomic instability score

Summary of Evidence

For individuals with unresectable, recurrent, relapsed, refractory, advanced, or metastatic cancer who are being considered for targeted therapy with an FDA-approved drug consistent with the labeled indication , the evidence includes FDA-approved therapeutics with National Comprehensive Cancer Network (NCCN) recommendations of 2A or higher and was not extensively evaluated. The evidence includes the pivotal studies leading to the FDA and National Comprehensive Cancer Network (NCCN) recommendations.

Additional Information

Not applicable.

Objective

The objective of this evidence review is to summarize the evidence and guidelines on genetic biomarker testing using tissue biopsy, circulating tumor DNA testing, or circulating tumor cells to select targeted treatment for individuals with unresectable, recurrent, relapsed, refractory, advanced, or metastatic cancer.

Policy Statements

ALK Testing

Analysis of tumor tissue for somatic rearrangement variants of the anaplastic lymphoma kinase (ALK) gene in tissue may be considered medically necessary to select treatment with an U.S. Food and Drug Administration (FDA)-approved ALK inhibitor therapy (eg, crizotinib [Xalkori], ceritinib [Zykadia], alectinib [Alecensa], brigatinib [Alunbrig], or lorlatinib [Lorbrena]) in individuals with advanced lung adenocarcinoma or in whom an adenocarcinoma component cannot be excluded, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

BRAF Testing

Analysis of tumor tissue for the somatic BRAF V600E variant may be considered medically necessary to select treatment with an FDA-approved BRAF and/or MEK inhibitor therapy (eg, dabrafenib [Tafinlar] and trametinib [Mekinist]), in individuals with advanced lung adenocarcinoma, in whom an adenocarcinoma component cannot be excluded, colorectal cancer (CRC) or metastatic CRC, glioma, anaplastic thyroid cancer (ATC), unresectable or metastatic melanoma, or resected stage III melanoma, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

Testing for BRAF V600 variants or BRAF fusion rearrangements (e.g., KIAA1549::BRAF) in individuals with relapsed or refractory pediatric low-grade glioma may be considered medically necessary to select individuals for targeted treatment with tovorafenib.

Testing for BRAF V600 variants or BRAF fusion rearrangements for all other individuals with glioma to select targeted treatment is considered investigational.

BRCA1 and BRCA2 Testing

Genetic testing for BRCA1 or BRCA2 germline variants may be considered medically necessary to select treatment with PARP inhibitors (eg, olaparib [Lynparza] and talazoparib [Talzenna]) for human epidermal receptor 2 (HER2)-negative metastatic and early stage, high-risk breast cancer, individuals with metastatic castrate-resistant prostate cancer (mCRPC), and advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer.

Somatic BRCA1/2 variant analysis using tumor tissue may be considered medically necessary for individuals with advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer, mCRPC, and prostate cancer to select treatment with FDA-approved targeted therapies.

Claudin 18 (CLDN18) Testing

CLDN18 testing may be considered medically necessary to select treatment with FDA-approved targeted therapies in individuals with locally advanced unresectable or metastatic human epidermal growth factor receptor 2 (HER2)-negative gastric or gastroesophageal junction adenocarcinoma whose tumors are claudin (CLDN) 18.2 positive as determined by an FDA-approved test.

EGFR Testing

Analysis of tumor tissue for somatic variants in exons 18 through 21 (eg, G719X, L858R, T790M, S6781, L861Q) within the epidermal growth factor receptor (EGFR) gene, may be considered medically necessary to select treatment with a FDA-approved therapy (eg, erlotinib [Tarceva] alone or in combination with ramucirumab [Cyramza], gefitinib [Iressa], afatinib [Gilotrif], dacomitinib [Vizimpro], or osimertinib [Tagrisso]) in individuals with advanced lung adenocarcinoma, large cell carcinoma, advanced squamous-cell non-small-cell lung cancer (NSCLC), and NSCLC not otherwise specified, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

Analysis of tumor tissue for somatic variants in exon 20 (eg, insertion mutations) within the EGFR gene, may be considered medically necessary to select treatment with an FDA-approved therapy (eg, mobocertinib [Exkivity]) in individuals with NSCLC, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

Somatic EGFR variant analysis using tumor tissue may be considered medically necessary to select treatment with FDA-approved targeted therapies for individuals with metastatic colorectal cancer (CRC), if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

ESR1 Testing

Analysis of tissue somatic variants of the ESR1 gene using an FDA-approved companion diagnostic tissue test to detect tumor DNA may be considered medically necessary as an alternative to a liquid biopsy (see Policy Guidelines) to select treatment with an FDA-approved with elacestrant (Orserdu) in individuals with estrogen receptor-positive, HER2-negative advanced or metastatic breast cancer with disease progression following at least 1 line of endocrine therapy, if the individual does not have any FDA-labeled contraindications to the requested agent and both the agent and tissue test are intended to be used consistently with their FDA-approved labels.

EZH2 Testing

EZH2 testing of tumor tissue biopsy specimens may be considered medically necessary to select treatment with tazemetostat (Tazverik) in individuals with relapsed or refractory follicular lymphoma whose tumors are positive for an EZH2 variant as detected by an FDA-approved test and who have received at least 2 prior systemic therapies.

FGFR2 Testing

FGFR2 testing of tumor tissue biopsy specimens may be considered medically necessary to select treatment with pemigatinib (Pemazyre) in individuals with previously treated, unresectable locally advanced or metastatic cholangiocarcinoma with a fibroblast growth factor receptor 2 (FGFR2) fusion or other rearrangement as detected by an FDA-approved test.

FGFR3 Testing

FGFR3 testing of tumor tissue biopsy specimens may be considered medically necessary to select treatment with erdafitinib (Balversa) in individuals with locally advanced or metastatic urothelial carcinoma and progressed during or following at least one line of prior platinum-containing chemotherapy including within 12 months of neoadjuvant or adjuvant platinum-containing chemotherapy.

FLT3 Testing

Somatic testing using blood or bone marrow specimens for FLT3gene variants or internal tandem duplication (ITD)-positive as detected by an FDA-approved test to select treatment for acute myeloid leukemia (AML) with FDA-approved targeted therapies may be considered medically necessary if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

FOLR1 Testing

FOLR1 testing of tumor tissue biopsy specimens may be considered medically necessary to select treatment with FDA-approved targeted therapies for individuals with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer, who have received one to three prior systemic treatment regimens.

HER2 Testing

HER2 testing of tumor tissue biopsy specimens may be considered medically necessary to select treatment with FDA-approved therapies for individuals with metastatic solid tumors.

Homologous Recombination Repair (HRR) Gene Testing

Somatic testing using tissue biopsy for homologous recombination repair (HRR) gene variants (BRCA1, BRCA2, ATM, BARD1, BRIP1, CDK12, CHEK1, CHEK2, FANCL, PALB2, RAD51B, RAD51C, RAD51D, and RAD54L) to select treatment for mCRPC with FDA-approved targeted therapies may be considered medically necessary.

Homologous Recombination Deficiency (HRD) Gene Testing

Homologous recombination deficiency (HRD) analysis of tumor tissue may be considered medically necessary to select treatment with FDA-approved targeted therapies for individuals with advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer.

Human Leukocyte Antigen (HLA) Testing

HLA testing of tumor tissue biopsy specimens may be considered medically necessary to select treatment with tebentafusp-tebn (Kimmtrak) for individuals with unresectable or metastatic uveal melanoma.

IDH1 and IDH2 Testing

Testing for IDH1 or IDH2 gene variants in individuals with glioma (i.e., grade 2 astrocytoma or oligodendroglioma following surgery including biopsy, sub-total resection, or gross total resection) may be considered medically necessary to select individuals for targeted treatment with vorasidenib.

Testing for IDH1 or IDH2 gene variants in individuals with relapsed or refractory acute myeloid leukemia (AML) or individuals that are 75 years or older, or who have comorbidities that preclude use of intensive induction chemotherapy and are newly diagnosed with AML may be considered medically necessary to select individuals for targeted treatment with FDA-approved therapies that are consistent with the labeled indication.

Testing for IDH1 gene variants in individuals with relapsed or refractory myelodysplastic syndromes or locally advanced or metastatic cholangiocarcinoma may be considered medically necessary to select individuals for targeted treatment with ivosidenib in concordance with the labeled indication.

KIT Testing

Testing for KIT gene variants in individuals with aggressive systemic mastocytosis (ASM) without the D816V c-Kit mutation or with c-Kit mutational status unknown may be considered medically necessary to select individuals for targeted treatment with imatinib mesylate (Gleevec).

MET Exon 14 Skipping Alteration

Analysis of tumor tissue for somatic alterations in tissue that leads to MET exon 14 skipping may be considered medically necessary to select treatment with capmatinib (Tabrecta) in individuals with metastatic NSCLC, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label (see Policy Guidelines).

Mismatch Repair/Microsatellite Instability Testing

For individuals with unresectable or metastatic solid tumors who receive mismatch repair/microsatellite instability tumor tissue testing to select treatment may be considered medically necessary for FDA-approved immune checkpoint inhibitors with NCCN recommendations of 2A or higher and the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

Neurotrophic Receptor Tyrosine Kinase (NTRK) Gene Fusion Testing

NTRK gene fusion testing may be considered medically necessary for individuals with recurrent unresectable (local or regional) or stage IV breast cancer to select individuals for treatment with FDA-approved therapies.

Analysis of tumor tissue for NTRK gene fusions may be considered medically necessary to select treatment with TRK inhibitor therapy (e.g., larotrectinib [Vitrakvi] or entrectinib [Rozlytrek]) in individuals with metastatic NSCLC, metastatic CRC, unresectable or metastatic melanoma, glioma, and individuals with advanced epithelial ovarian, fallopian tube, primary peritoneal cancer, or other solid tumors, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label (see Policy Guidelines).

PDGFRA Testing

Analysis of tumor tissue for somatic variants of the PDGFRA gene (eg, D842V) may be considered medically necessary to select treatment with avapritinib (Ayvakit) in individuals with unresectable or metastatic gastrointestinal stromal tumor (GIST).

PDGFRB Testing

Analysis of tumor tissue for somatic gene rearrangements of the PDGFRB gene (eg, FIP1L1-PDGFRα) may be considered medically necessary to select treatment with imatinib mesylate (Gleevec) in individuals with myelodysplastic/myeloproliferative diseases (MDS/MPD).

PIK3CA Testing

PIK3CA testing may be considered medically necessary to select treatment with alpelisib (Piqray) in individuals with hormone receptor-positive, HER2-negative advanced or metastatic breast cancer who have progressed on or after an endocrine-based regimen (see Policy Guidelines).

Programmed Cell Death Ligand-1 Testing

For individuals with unresectable or metastatic solid tumors who receive programmed cell death ligand-1 (PD-L1) tumor tissue testing to select treatment may be considered medically necessary for FDA-approved immune checkpoint inhibitors with NCCN recommendations of 2A or higher and the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

RAS (KRAS and NRAS) Testing

Analysis of tumor tissue for somatic variants of the KRAS gene (eg, G12C) may be considered medically necessary to select treatment with sotorasib (Lumakras) in individuals with advanced lung adenocarcinoma or in whom an adenocarcinoma component cannot be excluded, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

KRAS and NRAS testing of tumor tissue biopsy specimens may be considered medically necessary for individuals with metastatic colorectal cancer (CRC) to select individuals for treatment with U.S. Food and Drug Administration (FDA)-approved therapies.

RET Testing

Analysis of tumor tissue for somatic alterations in the RET gene may be considered medically necessary to select treatment with RET inhibitor therapy (e.g., pralsetinib [Gavreto] or selpercatinib [Retevmo]) in individuals with advanced or metastatic NSCLC, CRC, medullary thyroid cancer, thyroid cancer, or any other solid tumors, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

ROS1 Testing

Analysis of tumor tissue for somatic rearrangement variants of the ROS1 gene may be considered medically necessary to select treatment with an FDA-approved ROS1 inhibitor therapy (eg, crizotinib [Xalkori] ) in individuals with advanced lung adenocarcinoma or in whom an adenocarcinoma component cannot be excluded, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

TP53 Testing

Analysis of tumor tissue for a somatic deletion of chromosome 17p (TP53 gene) may be considered medically necessary to select treatment with venetoclax (Venclexta) in individuals with chronic lymphocytic leukemia (CLL).

Tumor Mutational Burden Testing

For individuals with unresectable or metastatic solid tumors who receive tumor mutational burden tumor (TMB) tissue testing to select treatment may be considered medically necessary for FDA-approved immune checkpoint inhibitors with NCCN recommendations of 2A or higher and the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label.

All other uses of genetic biomarker analysis for somatic variants to select treatment with FDA-approved targeted therapies, outlined in Table 1, for individuals with unresectable, recurrent, relapsed, refractory, advanced, or metastatic cancer are considered investigational.

Circulating Tumor DNA Testing (Liquid Biopsy)

Analysis of plasma for somatic rearrangement variants of the ALK gene using an FDA-approved companion diagnostic plasma test to detect ctDNA may be considered medically necessary as an alternative to tissue biopsy (see Policy Guidelines) to select treatment with an FDA-approved ALK inhibitor therapy in individuals with non-small cell lung cancer (NSCLC) (eg, alectinib [Alcensa]), if the individual does not have any FDA-labeled contraindications to the requested agent and both the agent and ctDNA test are intended to be used consistently with their FDA-approved labels (see Policy Guidelines).

Analysis of plasma (liquid biopsy) for the somatic BRAF V600E variants using an FDA-approved companion diagnostic plasma test to detect ctDNA may be considered medically necessary as an alternative to tissue biopsy (see Policy Guidelines) to select treatment with an FDA-approved therapy in individuals with metastatic CRC and NSCLC, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label (see Policy Guidelines).

BRCA1/2 variant analysis using circulating tumor DNA (liquid biopsy) may be considered medically necessary for individuals with advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer to select treatment with FDA-approved targeted therapies when tissue-based analysis is not clinically feasible.

At diagnosis, analysis of plasma for somatic variants in exons 19 through 21 (eg, exon 19 deletions, L858R, T790M) within the EGFR gene, using an FDA-approved companion diagnostic plasma test to detect circulating tumor DNA (ctDNA) may be considered medically necessary as an alternative to tissue biopsy (see Policy Guidelines) to select treatment with an FDA-approved therapy in individuals with advanced lung adenocarcinoma, large cell carcinoma, advanced squamous cell NSCLC, and NSCLC not otherwise specified, if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label (see Policy Guidelines).

At progression, analysis of plasma for the EGFR T790M resistance variant for targeted therapy with osimertinib using an FDA-approved companion diagnostic plasma test to detect ctDNA may be considered medically necessary in individuals with advanced lung adenocarcinoma, large cell carcinoma, advanced squamous cell NSCLC, and NSCLC not otherwise specified, when tissue biopsy to obtain new tissue is not feasible (eg, in those who do not have enough tissue for standard molecular testing using formalin-fixed paraffin-embedded tissue, do not have a biopsy-amenable lesion, or cannot undergo biopsy), and when the individual does not have any FDA-labeled contraindications to osimertinib and it is intended to be used consistently with the FDA-approved label (see Policy Guidelines).

ESR1 testing using ctDNA to detect variants (liquid biopsy) may be considered medically necessary to predict treatment response to elacestrant (Orserdu) in individuals with estrogen receptor-positive, HER2-negative advanced or metastatic breast cancer with disease progression following at least 1 line of endocrine therapy (see Policy Guidelines).

Somatic testing using circulating tumor DNA testing (liquid biopsy) for BRCA1, BRCA2, and ATM variants to select treatment for mCRPC with FDA-approved targeted therapies may be considered medically necessary.

Analysis of plasma for somatic alteration that leads to MET exon 14 skipping using an FDA-approved companion diagnostic plasma test to detect ctDNA may be considered medically necessary as an alternative to tissue biopsy (see Policy Guidelines) to select treatment with MET inhibitor therapy (eg, capmatinib [Tabrecta]) in individuals with NSCLC, if the individual does not have any FDA-labeled contraindications to the requested agent and both the agent and ctDNA test are intended to be used consistently with their FDA-approved labels (see Policy Guidelines).

Analysis of plasma for NTRK gene fusions using an FDA-approved companion diagnostic plasma test to detect ctDNA may be considered medically necessary as an alternative to tissue biopsy (see Policy Guidelines) to select treatment with TRK inhibitor therapy (e.g., larotrectinib [Vitrakvi] or entrectinib [Rozlytrek]) in individuals with metastatic NSCLC, metastatic CRC, unresectable or metastatic melanoma, glioma, and individuals with advanced epithelial ovarian, fallopian tube, primary peritoneal cancer, or other solid tumors, if the individual does not have any FDA-labeled contraindications to the requested agent and both the agent and ctDNA test are intended to be used consistently with their FDA-approved labels (see Policy Guidelines).

PIK3CA testing using ctDNA (liquid biopsy) specimens may be considered medically necessary to select treatment with alpelisib (Piqray) in individuals with hormone receptor-positive, HER2 negative advanced or metastatic breast cancer who have progressed on or after an endocrine-based regimen (see Policy Guidelines).

• When tumor tissue is available, use of tissue for testing is preferred but is not required.

• When tumor tissue is available, use of tissue for testing is preferred but is not required (see Circulating Tumor DNA Testing below).

Analysis of plasma (liquid biopsy) for somatic variants of the KRAS (eg, G12C) and RAS variants using an FDA-approved companion diagnostic plasma test to detect circulating tumor (ctDNA) may be considered medically necessary as an alternative to tissue biopsy (see Policy Guidelines) to select treatment with an FDA-approved therapy in individuals with metastatic CRC if the individual does not have any FDA-labeled contraindications to the requested agent and the agent is intended to be used consistently with the FDA-approved label (see Policy Guidelines).

Analysis of plasma for somatic variants of the KRAS gene (eg, G12C) using an FDA-approved companion diagnostic plasma test to detect ctDNA may be considered medically necessary as an alternative to tissue biopsy (see Policy Guidelines) to select treatment with sotorasib (Lumakras) in individuals with advanced lung adenocarcinoma or in whom an adenocarcinoma component cannot be excluded, if the individual does not have any FDA-labeled contraindications to the requested agent and both the agent and ctDNA test are intended to be used consistently with their FDA-approved labels (see Policy Guidelines).

Analysis of plasma for somatic alterations of the RET gene using plasma specimens to detect ctDNA is considered investigational as an alternative to tissue biopsy (see Policy Guidelines) to select treatment with RET inhibitor therapy (eg, selpercatinib [Retevmo], pralsetinib [Gavreto]) in individuals with advanced or metastatic NSCLC, CRC, medullary thyroid cancer, thyroid cancer, or any other solid tumors.

Analysis of plasma for somatic rearrangement variants of the ROS1 gene to detect ctDNA may be considered medically necessary as an alternative to tissue biopsy (see Policy Guidelines) to select treatment with ROS1 inhibitor therapy (eg, crizotinib [Xalkori] or entrectinib ) in individuals with NSCLC.

All other uses of somatic testing using circulating tumor DNA testing (liquid biopsy) to guide cancer targeted therapy are considered investigational.

Plasma Testing When Tissue is Insufficient

Plasma tests for oncogenic driver variants deemed medically necessary on tissue biopsy may be considered medically necessary to select treatment with targeted therapy for individuals meeting the following criteria:

• Individual does not have sufficient tissue for standard molecular testing using formalin-fixed paraffin-embedded tissue; AND

• Follow-up tissue-based analysis is planned should no driver variant be identified via plasma testing.

Testing for other variants may become available between policy updates.

Other

Testing for other variants may become available between policy updates.

Policy Guidelines

See U.S. Food and Drug Administration labels, clinical trials, and National Comprehensive Cancer Network (NCCN) guidelines for specific population descriptions. Descriptions varied slightly across sources. Plans may need to alter local coverage medical policy to conform to state law regarding coverage of biomarker testing.

This policy does not address germline testing for inherited risk of developing cancer.

The use of ado-trastuzumab emtansine is addressed separately in evidence review 05.001.024. For expanded panel testing, see evidence review 11.003.026. The use of circulating tumor DNA and circulating tumor cells are addressed separately in evidence review 11.003.089 and 11.003.026.

Testing for other variants may become available between policy updates.

FDA approves tests in between policy review cycles. As such, newly approved tests might need to be considered per local Plan discretion. For guidance on testing criteria between policy updates, refer to the FDA's List of Cleared or Approved Companion Diagnostic Devices (In Vitro and Imaging Tools) (https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools) for an updated list of FDA-approved tumor markers and consult the most current version of NCCN management algorithms.

Note: Extensive evidence review is not included for somatic tests of individual genes (not gene panels) associated with FDA-approved therapies with NCCN recommendations of 2A or higher. Additionally, while the FDA approval of companion diagnostic tests for genes might include tests that are conducted as panels, the FDA approval is for specific genes (such as driver variants) and not for all of the genes on the test panel. No evidence review is provided for somatic tests of individual genes that do not have associated FDA-approved therapies regardless of NCCN recommendations, as these off-label therapies are deemed investigational per the Blue Cross and Blue Shield Association Medical Policy Program Policies and Procedures.

This policy varies from NCCN-Pediatric CNS guidelines for pediatric gliomas, which endorse use of several off-label therapies. Plans might locally consider coverage of BRAF V600E testing to inform coverage of vemurafenib and ALK rearrangement testing to inform coverage of lorlatinib and alectinib. The NCCN guidelines for CNS cancers also endorse off-label use of ivosidenib in recurrent or progressive adult oligodendroglioma after radiotherapy and chemotherapy harboring IDH1 variants. NCCN notes that IDH variant testing is required for the workup of all gliomas, as IDH variant status defines WHO grade 2 and 3 astrocytomas and oligodendrogliomas, and grade 4 astrocytomas. The presence of these variants distinguishes lower-grade gliomas from glioblastomas, which are IDH wild-type. IDH-mutant gliomas are considered adult-type diffuse gliomas and are addressed in the NCCN non-pediatric CNS cancer guidelines. This review does not address genetic testing for purposes of diagnosis or staging in melanoma or glioma.

Targeted Therapy

Targeted therapy is a type of precision or personalized medicine that treats cancer by targeting specific features, changes, mutations (variants), or substances in or on cancer cells.

There are many kinds of targeted therapies. They are designed to stop cancer cells from growing and spreading while limiting damage to normal, healthy cells. Each type works in a specific way. For example, they might:

• Target specific biomarkers (genes and proteins that help cancer cells survive and grow).

• Change the tissue or environment that cancer cells grow in.

• Target other types of cells that help a cancer grow, like blood vessel cells.

Targeted therapy definition: treatment with drugs that interact with or block the synthesis of specific cellular components characteristic of the individual’s disease to stop or interrupt the specific biochemical dysfunction involved in the progression of the disease.

Genetic therapy definition: techniques and strategies that include coding sequences and other conventional or radical means to transform or modify cells to treat or reverse disease conditions.

Paired Genetic Testing

Testing for genetic changes in tumor tissue assesses somatic changes. However, most somatic testing involves a paired blood analysis in order to distinguish whether findings in tumor tissue are acquired somatic changes or inherited germline changes. As such, simultaneous sequencing of tumor and normal tissue can recognize potential secondary germline changes that may identify risk for other cancers as well as identify risk for relatives. Thus, some laboratories offer concurrent full germline and somatic testing or paired tumor sequencing and germline sequencing, through large panels of germline and somatic variants. For paired panel testing involving germline components, see evidence review 11.003.064 - Genetic Cancer Susceptibility Panels Using Next Generation Sequencing. For paired panel testing involving somatic components, see evidence review 11.003.026 - Comprehensive Genomic Profiling for Selecting Targeted Cancer Therapies.

Repeat Genetic Testing

There may be utility in repeated testing of gene variants for determining targeted therapy or immunotherapy in individuals with NSCLC, prostate cancer, CRC, ovarian cancer, etc. as tumor molecular profiles may change with subsequent treatments and re-evaluation may be considered at time of cancer progression for treatment decision-making. For example, repeat testing (tissue or liquid based) at progression on or after targeted therapy with an FDA-approved drug may be considered to select patients for treatment with another FDA-approved therapy if an acquired resistance variant occurs that was not detected at initial diagnosis (Lin et al 2019; PMID 30425037). The American Society of Clinical Oncology (ASCO) currently suggests repeat genomic testing for individuals on targeted therapy with suspected acquired resistance, especially if choice of next-line therapy would be guided. The ASCO guidance is not tumor specific, and it cautions to consider clinical utility (Chakravarty et al, 2022; PMID 35175857).

Tissue-based Genetic Testing

Tissue biopsy testing uses tissue samples and assesses cancer DNA within the sampled tissue. The goal is to identify options for genome-informed treatment. Some providers will order a liquid biopsy test and a tissue biopsy test at the same time to hasten time to treatment. If the intent of concurrent testing is to follow an individual over time to monitor for resistance variants, then consideration could be given to doing tissue biopsy at diagnosis with the liquid biopsy to make sure that variants that are going to be followed longitudinally can be detected by the tissue biopsy.

Concurrent Somatic Liquid-Based and Tissue-Based Genetic Testing

Liquid biopsy testing uses blood samples and assesses cancer DNA and non-cancer DNA in the same blood sample. The goal is to identify options for genome-informed treatment. Some providers will order a liquid biopsy test and a tissue biopsy test at the same time to hasten time to treatment. If the intent of concurrent testing is to follow an individual over time to monitor for resistance variants, then consideration could be given to doing liquid biopsy at diagnosis with the tissue biopsy to make sure that variants that are going to be followed longitudinally can be detected by the liquid biopsy.

Recommended Testing Strategies

Individuals who meet criteria for genetic testing as outlined in the policy statements above should be tested for the variants specified.

• When tumor tissue is available, use of tissue for testing of any/all variants and biomarkers outlined in this policy is recommended, but is not required in all situations. In certain situations, circulating tumor DNA testing (liquid biopsy) may be an option.

Genetics Nomenclature Update

The Human Genome Variation Society nomenclature is used to report information on variants found in DNA and serves as an international standard in DNA diagnostics. It is being implemented for genetic testing medical evidence review updates starting in 2017 (see Table PG2). The Society's nomenclature is recommended by the Human Variome Project, the HUman Genome Organization, and by the Human Genome Variation Society itself.

The American College of Medical Genetics and Genomics and the Association for Molecular Pathology standards and guidelines for interpretation of sequence variants represent expert opinion from both organizations, in addition to the College of American Pathologists. These recommendations primarily apply to genetic tests used in clinical laboratories, including genotyping, single genes, panels, exomes, and genomes. Table PG3 shows the recommended standard terminology- "pathogenic," "likely pathogenic," "uncertain significance," "likely benign," and "benign"- to describe variants identified that cause Mendelian disorders.

Table PG2. Nomenclature to Report on Variants Found in DNA

Table PG3. ACMG-AMP Standards and Guidelines for Variant Classification

  ACMG-AMP: American College of Medical Genetics and Genomics and the Association for Molecular Pathology.

Genetic Counseling

Genetic counseling is primarily aimed at patients who are at risk for inherited disorders, and experts recommend formal genetic counseling in most cases when genetic testing for an inherited condition is considered. The interpretation of the results of genetic tests and the understanding of risk factors can be very difficult and complex. Therefore, genetic counseling will assist individuals in understanding the possible benefits and harms of genetic testing, including the possible impact of the information on the individual’s family. Genetic counseling may alter the utilization of genetic testing substantially and may reduce inappropriate testing. Genetic counseling should be performed by an individual with experience and expertise in genetic medicine and genetic testing methods.

Coding

See the Codes table for details.

Benefit Application

BlueCard/National Account Issues

Some Plans may have contract or benefit exclusions for genetic testing.

Benefits are determined by the group contract, member benefit booklet, and/or individual subscriber certificate in effect at the time services were rendered.  Benefit products or negotiated coverages may have all or some of the services discussed in this medical policy excluded from their coverage.

As mandated by Law 79 of August 1st, 2020 medical necessity and coverage may be determined following NCCN Guidelines and/or Local/National Coverage Determinations superseeding this medical policy criteria. 

Background

ALK Gene

ALK is a tyrosine kinase (TK) that, in NSCLC, is aberrantly activated because of a chromosomal rearrangement that leads to a fusion gene and expression of a protein with constitutive TK activity that has been demonstrated to play a role in controlling cell proliferation. The EML4-ALK fusion gene results from an inversion within the short arm of chromosome 2.

The EML4-ALK rearrangement (“ALK-positive”) is detected in 3% to 6% of NSCLC patients, with the highest prevalence in never-smokers or light ex-smokers who have adenocarcinoma.

BRAF

RAF proteins are serine/threonine kinases that are downstream of RAS in the RAS-RAF-ERK-MAPK pathway. The most common variant locus is found in codon 600 of exon 15 (V600E) of the BRAF gene, causing constitutive hyperactivation, proliferation, differentiation, survival, and oncogenic transformation.^1,BRAF variants occur in approximately 1% of breast cancer cases.^2,Variants in the b-raf proto-oncogene, serine/threonine kinase (BRAF) kinase gene are common in tumors of patients with advanced melanoma and result in constitutive activation of a key signaling pathway (rapidly accelerated fibrosarcoma [RAF]-MEK-extracellular signal-regulated kinase [ERK] pathway) that is associated with oncogenic proliferation. In general, 50% to 70% of melanoma tumors harbor a BRAF variant; of these, 80% are positive for the BRAF V600E variant, and 16% are positive for BRAF V600K.^3, Thus, 45% to 60% of advanced melanoma patients may respond to a BRAF inhibitor targeted to this mutated kinase. There is considerable interest in targeted therapies that inhibit the RAF-MEK-ERK pathway, particularly in patients with high-grade and low-grade gliomas whose tumors are in locations that prevent full resection. Evidence from early-phase trials in patients with BRAF variant-positive melanoma with brain metastases have suggested some efficacy for brain tumor response with vemurafenib and dabrafenib indicating that these agents might be potential therapies for primary brain tumors. ^4,5, In this pathway, the BRAF gene is the most frequently mutated in NSCLC, in 1% to 3% of adenocarcinomas. Unlike melanoma, about 50% of the variants in NSCLC are non-V600E variants. ^6, Most BRAF variants occur more frequently in smokers.

BRCA Variant Testing

The prevalence of BRCA variants is approximately 0.2% to 0.3% in the general population.^7, The prevalence may be much higher for particular ethnic groups with characterized founder variants (eg, 2.5% [1/40] in the Ashkenazi Jewish population). Family history of breast and ovarian cancer is an important risk factor for the BRCA variant; additionally, age and ethnicity could be independent risk factors.

Several genetic syndromes with an autosomal dominant pattern of inheritance that features breast cancer have been identified.^8, Of these, hereditary breast and ovarian cancer (HBOC) and some cases of hereditary site-specific breast cancer have in common causative variants in BRCA (breast cancer susceptibility) genes. Families suspected of having HBOC syndrome are characterized by an increased susceptibility to breast cancer occurring at a young age, bilateral breast cancer, male breast cancer, ovarian cancer at any age, as well as cancer of the fallopian tube and primary peritoneal cancer. Other cancers, such as prostate cancer, pancreatic cancer, gastrointestinal cancers, melanoma, and laryngeal cancer, occur more frequently in HBOC families. Hereditary site-specific breast cancer families are characterized by early-onset breast cancer with or without male cases, but without ovarian cancer.

Germline variants in the BRCA1 and BRCA2 genes are responsible for the cancer susceptibility in most HBOC families, especially if ovarian cancer or male breast cancer are features.^9, However, in site-specific cancer, BRCA variants are responsible only for a proportion of affected families. BRCA gene variants are inherited in an autosomal dominant fashion through maternal or paternal lineage. It is possible to test for abnormalities in BRCA1 and BRCA2 genes to identify the specific variant in cancer cases and to identify family members at increased cancer risk. Family members without existing cancer who are found to have BRCA variants can consider preventive interventions for reducing risk and mortality.

Young age of onset of breast cancer, even in the absence of family history, is a risk factor for BRCA1 variants. Winchester (1996) estimated that hereditary breast cancers account for 36% to 85% of patients diagnosed before age 30.^10, In several studies, BRCA variants were independently predicted by early age at onset, being present in 6% to 10% of breast cancer cases diagnosed at ages younger than various premenopausal age cutoffs (age range, 35-50 years).^10,11,12,13, In cancer-prone families, the mean age of breast cancer diagnosis among women carrying BRCA1 or BRCA2 variants is in the 40s.^14, In the Ashkenazi Jewish population, Frank et al (2002) reported that 13% of 248 cases with no known family history and diagnosed before 50 years of age had BRCA variants.^11, In a similar study by Gershoni-Baruch et al (2000), 31% of Ashkenazi Jewish women, unselected for family history, diagnosed with breast cancer at younger than 42 years of age had BRCA variants.^15, Other studies have indicated that early age of breast cancer diagnosis is a significant predictor of BRCA variants in the absence of family history in this population.^16,17,18,

In patients with “triple-negative” breast cancer (ie, negative for expression of estrogen, progesterone, and overexpression of human epidermal growth factor receptor 2 [HER2] receptors), there is an increased prevalence of BRCA variants. Pathophysiologic research has suggested that the physiologic pathway for the development of triple-negative breast cancer is similar to that for BRCA-associated breast cancer.^19, Young et al (2009) studied 54 women with high-grade, triple-negative breast cancer with no family history of breast or ovarian cancer, representing a group that previously was not recommended for BRCA testing.^20, Six BRCA variants (5 BRCA1, 1 BRCA2) were found, for a variant rate of 11%. Finally, Gonzalez-Angulo et al (2011) in a study of 77 patients with triple-negative breast cancer, reported that 15 patients (19.5%) had BRCA variants (12 in BRCA1, 3 in BRCA2).^21,

CLDN18

Claudin-18 (CLDN18) is a transmembrane protein that forms tight junctions between epithelial cells and regulate the flow and movement of ions across epithelial cells. Overexpression of this protein is implicated in the development of various primary malignant tumors, such as gastric cancer/gastroesophageal junction (GC/GEJ) cancer, breast cancer, colon cancer, liver cancer, head and neck cancer, bronchial cancer, and non-small-cell lung cancer. ^22,23, More specifically, CLDN18.2 is an isoform that is exclusively expressed in the tight junctions of gastric mucosal cells and participates in the proliferation, differentiation and migration of tumor cells. Studies have reported that CLDN18.2 is expressed in approximately 70% of gastric cancers and up to 60% of pancreatic adenocarcinomas. ^24,

EGFR

EGFR, a receptor tyrosine kinase (TK), is frequently overexpressed and activated in NSCLC. Drugs that inhibit EGFR signaling either prevent ligand binding to the extracellular domain (monoclonal antibodies) or inhibit intracellular TK activity (small-molecule tyrosine kinase inhibitors [TKIs]). These targeted therapies dampen signal transduction through pathways downstream to the EGFR, such as the RAS/RAF/MAPK cascade. RAS proteins are G proteins that cycle between active and inactive forms in response to stimulation from cell surface receptors, such as EGFR, acting as binary switches between cell surface EGFR and downstream signaling pathways. These pathways are important in cancer cell proliferation, invasion, metastasis, and stimulation of neovascularization.

Somatic variants in the TK domain of the EGFR gene, notably small deletions in exon 19 and a point mutation in exon 21 (L858R, indicating substitution of leucine by arginine at codon position 858) are the most commonly found EGFR variants associated with sensitivity to EGFR TKIs ( afatinib, erlotinib, gefitinib). These variants are referred to as sensitizing variants. Almost all patients who initially respond to an EGFR TKI experience disease progression. The most common of these secondary variants, called resistance variants, involves the substitution of methionine for threonine at position 790 (T790M) on exon 20.

Fang et al (2013) reported EGFR variants (all L858R) in 3 (2%) of 146 consecutively treated Chinese patients with early-stage squamous cell carcinoma (SCC).^25, In a separate cohort of 63 Chinese patients with SCC who received erlotinib or gefitinib as second- or third-line treatment (63% never-smokers, 21% women), EGFR variant prevalence (all exon 19 deletion or L858R) was 23.8%. In a comprehensive analysis of 14 studies involving 2880 patients, Mitsudomi et al (2006) reported EGFR variants in 10% of men, 7% of non-Asian patients, 7% of current or former smokers, and 2% of patients with nonadenocarcinoma histologies.^26, Eberhard et al (2005)^27, observed EGFR variants in 6.4% of patients with SCC and Rosell et al (2009) ^28, observed EGFR variants in 11.5% of patients with large cell carcinomas. Both studies had small sample sizes. In 2 other studies, the acquired EGFR T790M variant has been estimated to be present in 50% to 60% of TKI-resistant cases in approximately 200 patients. ^29,30,

ESR1

Variants in estrogen receptor 1 (ESR1), which occur in approximately 10-20% of patients with metastatic estrogen receptor-positive breast cancer, confer resistance to endocrine therapy via constitutive activation of estrogen receptor-mediated growth activity.^31,32,

EZH2

Enhancer of zeste homolog 2 (EZH2) is a histone-lysine N-methyltrasnferase responsible for generating epigenetic markers that regulate gene function with the most common being trimethylation of Lys-27 in histone 3 (H3K27me3). ^33,EZH2 is overexpressed in numerous tumor types including melanoma, ovarian, breast, endometrial, bladder, renal cell, lung, and liver cancer, and is associated with aggressive disease, leading to its classification as an oncogene. It is commonly overexpressed or harbors gain-of-function mutations that enhance the catalytic activity within 25 percent of follicular lymphomas. ^34,

FGFR2 and FGFR3

The fibroblast growth factor receptor (FGFR) family is an integral signaling pathway for cellular activities, including proliferation, tissue repair, regeneration, chemotaxis, angiogenesis, differentiation, and survival. ^35, Thus, dysregulation of this pathway with alterations of these genes has been implicated in numerous cancers, including uroepithelial carcinoma (32–14.8%), colorectal carcinoma (31%), breast carcinoma (12.6–18%), gastric carcinoma (16.8–25.6%), endometrial carcinoma (13%), squamous lung carcinoma (6.8–13%), esophageal carcinoma (12.7%), ovarian carcinoma (9%), and lung adenocarcinoma (1.3%). Most of these abnormalities were gene amplifications (53.7–66%), followed by mutations (26–38.8%), and rearrangements/fusions (5.6–8%). The frequencies of aberration for FGFR2 and FGFR3 were 14.2–19% and 17.7–26%, respectively ^36,37,

FLT3 (ITD/TDK)

Internal tandem duplications (ITDs) of the FMS-like tyrosine kinase 3 (FLT3) gene occur in ∼25% to 30% of acute myeloid leukemia (AML) cases and results is more severe outcomes, including higher relapse rates and reduced overall survival, after standard of care treatment. ^38,39,40, Variants in FLT3 were found in 30 % of newly diagnosed AML patients, with FLT3-ITD variants occurring with a frequency of 24% and variants within the activation loop (FLT3-TKD mutations) occurring at a frequency of 7%.

FOLR1

Folate receptor alpha (FRα), encoded by the FOLR1 gene, is an attractive target for cancer therapeutics due to its high expression in several cancer types including lung, breast, and epithelial ovarian cancer (EOC) with overexpression in approximately 80% of EOCs. ^41,

Homologous Recombination Deficiency and Homologous Recombination Repair

DNA damage happens daily, and most are repaired to allow normal cell functioning. Double strand breaks (DSB) in the DNA are particularly damaging. Repair of DSB utilizes the homologous recombination repair (HRR) pathway. Many types of cancer, however, are unable to repair DNA damage. This leads to the accumulation of genetic errors, such as loss of DNA, rearrangements in the DNA, and loss of entire genes. The consequence of these errors is genomic instability. The loss of the HRR and associated genomic instability is called homologous recombination deficiency (HRD). HRD is associated with several types of cancer including ovarian cancer. ^42,43, HRD is associated with several types of cancer including prostate cancer, where estimates as high as 30% of metastatic castrate-resistant prostate cancer (mCRPC) tumors have genetic changes that result in the loss of DNA repair capacity.^43, Specific to prostate cancer, the National Comprehensive Cancer Network (NCCN) prostate cancer guideline gives examples of HRR genes (BRCA1, BRCA2, ATM, BARD1, BRIP1, CDK12, CHEK1, CHEK2, FANCL, PALB2, RAD51B, RAD51C, RAD51D, and RAD54L). ^44,Poly adenosine diphosphate-ribose polymerase (PARP) inhibitors are used to target tumor cells with alterations in the HRR genes BRCA1 and BRCA2.

In ovarian cancer targeted therapies, HRD-positive status is generally defined by either a deleterious or suspected deleterious BRCA mutation, and/or genomic instability. Myriad MyChoice^® is an FDA-approved companion diagnostic for the assessment of tumor genomic instability score (GIS) and the detection and classification of variants in the BRCA1 and BRCA2 genes, for the selection of patients who are eligible for targeted treatment. A patient’s Myriad HRD status is determined by detecting single nucleotide variants (SNVs), variants in homopolymer stretches, insertions and deletions (indels), and large rearrangements (LRs) in the BRCA1 and BRCA2 genes, and determining a genomic instability score (GIS) using DNA obtained from ovarian tumor tissue. A positive Myriad HRD Status result is due to either the presence of a pathogenic variant in BRCA1 and/or BRCA2 and/or a GIS above a defined threshold. ^45, Approximately 41% to 50% of epithelial ovarian cancers are estimated to exhibit HRD. Germline alterations in BRCA1 and BRCA2 genes have been identified in up to 17% of individuals diagnosed with epithelial ovarian cancer, and somatic mutations are found in an additional 7%. ^46,

Human Epidermal Growth Factor Receptor 2 Amplification/Overexpression

Human epidermal growth factor receptor 2 (HER2) is a member of the HER (EGFR) family of tyrosine kinase receptors and has no specific ligand. When activated, it forms dimers with other EGFR family members. Amplification of HER2 is detected in approximately 4% of patients with CRC, with higher prevalence in RAS/BRAF-wild type tumors (5% to 14%).^47, In addition to its role as a predictive marker for HER2-targeted therapy, HER2 amplification/overexpression is being investigated as a predictor of resistance to EGFR-targeting monoclonal antibodies.

Human Leukocyte Antigen

The human leukocyte antigen (HLA) is a complex system of genes in humans that encode cell-surface proteins responsible for the regulation of the immune system. HLA molecular pathways present tumor antigens to T-cells to facilitate the recognition of tumor cells by the immune system. HLA genes are highly polymorphic allowing them to fine-tune the immune response through multiple unique combinations. HLA variants are crucial for targeted therapy as these drugs are engineered to bind to specific HLA constructs to evoke an immune response against tumor cells. ^48,

IDH1 and IDH2

Mutations in isocitrate dehydrogenase-1 (IDH1) or -2 (IDH2) genes lead to aberrant accumulated production of D-2-hydroxyglutarate, disrupting gene expression and cellular differentiation. WHO grade 2 and 3 astrocytomas and oligodendrogliomas are defined by IDH mutations, distinguishing lower-grade gliomas from glioblastomas. IDH1 and IDH2 mutations are generally associated with a more favorable prognosis, and have been important biomarkers for stratification in clinical trials. IDH mutations are detected in over 50% of gliomas in patients aged 55 or older. ^49,

KIT

KIT, also known as c-KIT, is a tyrosine kinase expressed on the surface of cells and plays a significant role in cell survival, proliferation, and differentiation via signaling pathways. For instance, KIT signaling is required for melanocyte survival, and is involved in hematopoiesis and gametogenesis. Gain-of-function variants within this gene are highly associated with cancer as it is implicated in numerous signaling pathways, such as RAS-MAPK and PI-3K.KIT variants are present in 85% to 95% of gastrointestinal stromal tumors (GIST) and systemic mastocytosis cancers. ^50,

MET

MET alteration is one of the critical events for acquired resistance in EGFR-mutated adenocarcinomas refractory to EGFR TKIs. ^6,

Mismatch Repair Deficiency/Microsatellite Instability

Mismatch repair deficiency (dMMR) and high levels of microsatellite instability (MSI-H) describe cells that have alterations in certain genes involved in correcting errors made when DNA is replicated. dMMR tumors are characterized by a high tumor mutational load and potential responsiveness to anti-programmed cell death ligand-1 (PD-L1)-immunotherapy. Mismatch repair (MMR) deficiency is most common in colorectal cancer, other types of gastrointestinal cancer, and endometrial cancer, but it may also be found in other cancers including breast cancer.

Testing for dMMR and MSI is used to identify individuals most likely to respond to anti-PD-L1 therapy. Either MMR testing or MSI testing can be used to screen for MMR functional defects. MMR testing is performed using IHC for 4 MMR proteins (MLH1, MSH2, PMS2, and MSH6). Microsatellite instability testing is generally performed using polymerase chain reaction (PCR) for 5 biomarkers (MLH1, MSH2, MSH6, PMS1 and PMS2). High MSI is defined as 2 or more of the 5 biomarkers showing instability or more than 30% of the tested biomarkers showing instability depending on what panel is used. ^51,

Neurotrophic Receptor Tyrosine Kinase (NTRK) Gene Fusion Testing

The presence of NTRK gene fusion can be detected by multiple methods including next-generation sequencing, reverse transcription-polymerase chain reaction, fluorescence in situ hybridization and immunohistochemistry.^52, Next-generation sequencing provides the most comprehensive view of a large number of genes and may identify NTRK gene fusions as well as other actionable alterations, with minimal tissue needed. The fluorescence in situ hybridization using break-apart probes can detect gene rearrangements in DNA that may generate a fusion transcript. The immunohistochemistry techniques have generally been used in the research setting. Reverse transcription-polymerase chain reaction is designed to identify only known translocation partners and breakpoints and cannot identify novel breakpoints or novel fusion partners.

PIK3CA Testing

Alterations in the protein coding gene PIK3CA (Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Alpha) occur in approximately 40% of patients with hormone receptor (HR)-positive, HER2-negative breast cancer. ^53,

Platelet-Derived Growth Factor Receptor Alpha and Beta

Platelet-derived growth factor receptors (PDGF-R) are cell surface tyrosine kinase receptors and are members of the platelet-derived growth factor (PDGF) family. PDGF subunits α and β play important roles in regulating cell proliferation, cellular differentiation, cell growth and development with alterations in these genes being heavily implicated in oncogenesis. PDGFRA variants occur in approximately 10–15% of GISTs ^54,, however, PDGFRB rearrangements are rare with approximately 2% of myeloproliferative neoplasms containing these fusions. ^55,

Programmed Cell Death Ligand Protein-1

Programmed cell death ligand-1 is a transmembrane protein expressed on the surface of multiple tissue types, including many tumor cells. Blocking the PD-L1 protein may prevent cancer cells from inactivating T cells.

FDA-approved PD-L1 immune checkpoint inhibitors include atezolizumab, avelumab, durvalumab, nivolumab, and pembrolizumab.

RAS (KRAS and NRAS)

Cetuximab (Erbitux^®; ImClone Systems) and panitumumab (Vectibix^®; Amgen) are monoclonal antibodies that bind to the epidermal growth factor receptor (EGFR), preventing intrinsic ligand binding and activation of downstream signaling pathways vital for cancer cell proliferation, invasion, metastasis, and stimulation of neovascularization. The RAS-RAF-MAP kinase pathway is activated in the EGFR cascade. The RAS proteins are G proteins that cycle between active (RAS guanosine triphosphate) and inactive (RAS guanosine diphosphate) forms in response to stimulation from a cell surface receptor, such as EGFR, and they act as a binary switch between the cell surface EGFR and downstream signaling pathways. The KRAS gene can harbor oncogenic variants that result in a constitutively activated protein, independent of EGFR ligand binding, rendering antibodies to the upstream EGFR ineffective. Approximately 40% of colorectal cancers (CRCs) have KRAS variants in codons 12 and 13 in exon 2. Another proto-oncogene that acts downstream from KRAS-NRAS harbors oncogenic variants in codons 12, 13, or 61 that result in constitutive activation of the EGFR-mediated pathway. These variants are less common compared with KRAS, detected in 2% to 7% of CRC specimens. It is unclear whether NRAS variants predict poor response due to anti-EGFR monoclonal antibody therapy or are prognostic of poor CRC outcomes in general.

The KRAS gene (which encodes RAS proteins) can harbor oncogenic variants that result in a constitutively activated protein, independent of signaling from the EGFR, possibly rendering a tumor resistant to therapies that target the EGFR. Variants in the KRAS gene, mainly codons 12 and 13, have been reported in 20% to 30% of NSCLC, and occur most often in adenocarcinomas in heavy smokers. KRAS variants can be detected by direct sequencing, polymerase chain reaction technologies, or next-generation sequencing. EGFR, ALK, ROS1, and KRAS driver mutations are considered to be mutually exclusive.

A large body of literature has shown that metastatic CRC tumors with a variant in exon 2 (codon 12 or 13) of the KRAS gene do not respond to cetuximab or panitumumab therapy. More recent evidence has shown that variants in KRAS outside exon 2 (ie, in exons 3 [codons 59 and 61] and exon 4 [codons 117 and 146]) and variants in NRAS exon 2 (codons 12 and 13), exon 3 (codons 59 and 61), and exon 4 (codons 117 and 146) also predict a lack of response to these monoclonal antibodies. Variant testing of these exons outside the KRAS exon 2 is referred to as extended RAS testing.

Rearranged During Transfection

The REarranged during Transfection (RET) proto-oncogene encodes a receptor tyrosine kinase growth factor.^56, Translocations that result in fusion genes with several partners have been reported, and occur in about 5-10% of thyroid cancer cases (primarily papillary thyroid carcinoma), 1%-2% of non-small-cell lung cancer cases ^6,, and occurring in roughly 0.2% colorectal cancers.^57, RET fusions in breast cancer, occur in less than 1% of cases.^58,

ROS1

ROS1 codes for a receptor tyrosine kinase of the insulin receptor family and chromosomal rearrangements result in fusion genes. The prevalence of ROS1 fusions in NSCLC varies from 0.9% to 3.7%. ^6, Patients with ROS1 fusions are typically never-smokers with adenocarcinoma.

Tumor Mutational Burden

Tumor mutational burden (TMB) is a measure of gene mutations within cancer cells. Initially, assessments of TMB involved whole exome sequencing (WES). More recently, targeted next generation sequencing (NGS) panels are being adapted to estimate TMB. Currently FoundationOne CDx is the only U.S. Food and Drug Administration (FDA) approved panel for estimating TMB, but others are in development. ^59,

Tumor Protein p53

Tumor protein p53 (TP53) is a transcription factor protein that binds to DNA and regulates gene expression to prevent alterations of the genome. Accumulating evidence indicates that p53 is the most frequently mutated gene in human cancers and are commonly found in the ovary (47.27%), colon and rectum (44.55%), lung (40.8%), pancreas (38.53%), stomach (36.78%), urethra (35.01%), liver (29.17%), breast (26.44%), prostate (22.52%), bone (16.19%), thyroid (11.13%), hematopoietic and lymphatic (10.13%) and kidney (8.75%). ^60,61,

Circulating Tumor DNA

Normal and tumor cells release small fragments of DNA into the blood, which is referred to as cell-free DNA. Cell-free DNA from nonmalignant cells is released by apoptosis. Most cell-free tumor DNA is derived from apoptotic and/or necrotic tumor cells, either from the primary tumor, metastases, or CTCs. Unlike apoptosis, necrosis is considered a pathologic process and generates larger DNA fragments due to incomplete and random digestion of genomic DNA. The length or integrity of the circulating DNA can potentially distinguish between apoptotic and necrotic origin. Circulating tumor DNA can be used for genomic characterization of the tumor.

Regulatory Status

Clinical laboratories may develop and validate tests in-house and market them as a laboratory service; laboratory-developed tests must meet the general regulatory standards of the Clinical Laboratory Improvement Amendments. Laboratories that offer laboratory-developed tests must be licensed by the Clinical Laboratory Improvement Amendments for high-complexity testing. To date, the U.S. Food and Drug Administration has chosen not to require any regulatory review of these tests.

Table 1 summarizes available targeted treatments with FDA approval for unresectable, recurrent, relapsed, refractory, advanced, and/or metastatic cancer (including immunotherapy) and the FDA cleared or approved companion diagnostic tests associated with each. The information in Table 1 was current as of November 01, 2025. An up-to-date list of FDA cleared or approved companion diagnostics is available at https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools. As the FDA had decided that laboratory developed tests (LDT) are no longer under their purview, this table is not all encompassing of LDT that are capable of detecting genetic biomarker variants for targeted therapy.

Table 1. Targeted Treatments for Unresectable, Recurrent, Relapsed, Refractory, Advanced, and/or Metastatic Cancer and FDA Approved Companion Diagnostic Tests

  BLA: biologics license application; dMMR: mismatch repair deficient; FDA: U.S. Food & Drug Administration; MSI-H: microsatellite instability-high; N/A: not applicable; NCCN: National Comprehensive Cancer Network; NDA: new drug application; TMB: tumor mutational burden Source: 62, and 63, a PLA codes are for the diagnostic test only. CPT codes for genes will be listed in the coding table.

In August 2021, Genentech voluntarily withdrew accelerated approval of atezolizumab (Tecentriq) for use in patients with PD-L1 positive, triple-negative breast cancer following FDA assessment of confirmatory trial results.

Rationale

This evidence review was created in December 2020 and has been updated regularly with searches of the PubMed database. The most recent literature update was performed through November 1, 2025.

Evidence reviews assess whether a medical test is clinically useful. A useful test provides information to make a clinical management decision that improves the net health outcome. That is, the balance of benefits and harms is better when the test is used to manage the condition than when another test or no test is used to manage the condition.

The first step in assessing a medical test is to formulate the clinical context and purpose of the test. The test must be technically reliable, clinically valid, and clinically useful for that purpose. Evidence reviews assess the evidence on whether a test is clinically valid and clinically useful. Technical reliability is outside the scope of these reviews, and credible information on technical reliability is available from other sources.

Population Reference No. 1 

Biomarker Testing Using Tissue Biopsy to Select Targeted Treatment

Clinical Context and Test Purpose

Breast cancer treatment selection is informed by tumor type, grade, stage, patient performance status and preference, prior treatments, and the molecular characteristics of the tumor such as the presence of driver variants. One purpose of biomarker testing of individuals who have advanced cancer is to inform a decision regarding treatment selection (eg, whether to select a targeted treatment or standard treatment).

The following PICO was used to select literature to inform this review.

Populations

The relevant population of interest is individuals with unresectable, recurrent, relapsed, refractory, advanced, or metastatic cancer for whom the selection of treatment depends on the molecular characterization of the tumor.

Interventions

The technology being considered is genetic testing for biomarkers using tissue or liquid biopsy.

Comparators

Decisions about treatment in unresectable, recurrent, relapsed, refractory, advanced, or metastatic cancer are based on clinical characteristics.

Outcomes

The general outcomes of interest in oncology are overall survival, disease-specific survival, quality of life (QOL), treatment-related mortality and morbidity.

Beneficial outcomes resulting from a true-positive test result are prolonged survival, reduced toxicity, and improved QOL associated with receiving a more effective targeted therapy. Beneficial outcomes from a true negative result are prolonged survival associated with receiving chemotherapy in those without driver variants.

Harmful outcomes resulting from a false-negative test result include shorter survival from receiving less effective and more cytotoxic chemotherapy in those with driver variants; possible harmful outcomes resulting from a false-positive test result are a shorter survival from receiving potentially ineffective targeted treatment and delay in initiation of chemotherapy in those without driver variants.

The overall response rate (ORR) may be used as a surrogate endpoint reasonably likely to predict clinical benefit in individuals with refractory solid tumors. ORR can be measured by the proportion of individuals with best overall confirmed response of complete response) or partial response by the Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1),^64, or Response Assessment in Neuro-Oncology criteria,^65, as appropriate by a blinded and independent adjudication committee.

There are clearly defined quantitative thresholds for the follow-up of individuals in oncology trials. A general rule is a continuation of treatment until disease progression or unacceptable toxicity. Long-term follow-up outside of a study setting is conducted to determine survival status. The duration of follow-up for the outcomes of interest is 6 months and 1 year.

Study Selection Criteria

Methodologically credible studies were selected using the following principles:

• To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for randomized controlled trials (RCTs);

• In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.

• To assess long-term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.

• Studies with duplicative or overlapping populations were excluded.

Review of Evidence

Testing for GeneticVariants and Biomarkers for Selection of FDA-approved Targeted Therapies

For individuals with unresectable, recurrent, relapsed, refractory, advanced, or metastatic cancer who receive genetic biomarker testing of tumor tissue or circulating tumor DNA and are being considered for targeted therapy with an FDA-approved drug consistent with the labeled indication , the evidence includes FDA-approved therapeutics with National Comprehensive Cancer Network (NCCN) recommendations of 2A or higher and was not extensively evaluated. The evidence includes the pivotal studies leading to the FDA and National Comprehensive Cancer Network (NCCN) recommendations.

For individuals with unresectable, recurrent, relapsed, refractory, advanced, or metastatic cancer who are being considered for targeted therapy with an FDA-approved drug consistent with the labeled indication , the evidence includes FDA-approved therapeutics with National Comprehensive Cancer Network (NCCN) recommendations of 2A or higher and was not extensively evaluated. The evidence includes the pivotal studies leading to the FDA and National Comprehensive Cancer Network (NCCN) recommendations.

Summary of Evidence

For individuals with unresectable, recurrent, relapsed, refractory, advanced, or metastatic cancer who are being considered for targeted therapy with an FDA-approved drug consistent with the labeled indication , the evidence includes FDA-approved therapeutics with National Comprehensive Cancer Network (NCCN) recommendations of 2A or higher and was not extensively evaluated. The evidence includes the pivotal studies leading to the FDA and National Comprehensive Cancer Network (NCCN) recommendations.

Supplemental Information

The purpose of the following information is to provide reference material. Inclusion does not imply endorsement or alignment with the evidence review conclusions.

Practice Guidelines and Position Statements

Guidelines or position statements will be considered for inclusion in ‘Supplemental Information' if they were issued by, or jointly by, a US professional society, an international society with US representation, or National Institute for Health and Care Excellence (NICE). Priority will be given to guidelines that are informed by a systematic review, include strength of evidence ratings, and include a description of management of conflict of interest.

American College of Chest Physicians Guidelines

In 2013, the American College of Chest Physicians updated its evidence-based practice guidelines on the treatment of stage IV non-small-cell lung cancer (NSCLC).^66, Based on a review of the literature, improved response rates, progression-free survival, and toxicity profiles with first-line erlotinib or gefitinib compared with first-line platinum-based therapy in patients with EGFR variants, especially exon 19 deletion and L858R were reported. They recommended, “testing patients with NSCLC for EGFR mutations at the time of diagnosis whenever feasible, and treating with first-line EGFR TKIs [tyrosine kinase inhibitors] if mutation-positive.”

American Society of Clinical Oncology

In 2017, the American Society of Clinical Oncology along with American Society for Clinical Pathology, College of American Pathologists, and Association for Molecular Pathology published guidelines on molecular biomarkers for the evaluation of colorectal cancer. ^67, Table 2 summarizes the relevant guidelines.

Table 2. Summary of Recommendations

  EGFR: epidermal growth factor receptor; MLH1: mutL homolog 1;MMR: mismatch repair; QOE: quality of evidence; SOE: strength of evidence.

In 2021, the American Society of Clinical Oncology (ASCO) and Ontario Health published updated guidelines on therapy for stage IV NSCLC with driver alterations. ^68, The updated recommendations were based on a systematic review of randomized controlled trials from December 2015 to January 2020 and meeting abstracts from ASCO 2020. The recommendations include the following:

• All patients with nonsquamous NSCLC should have the results of testing for potentially targetable mutations (alterations) before implementing therapy for advanced lung cancer, regardless of smoking status, when possible.

• Targeted therapies against ROS1 fusions, BRAF V600E mutations, RET fusions, MET exon 14 skipping mutations, and NTRK fusions should be offered to patients, either as initial or second-line therapy when not given in the first-line setting.

• Chemotherapy is still an option at most stages.

The above guidelines were updated in 2023 to add amivantamab monotherapy and mobocertinib monotherapy for second-line treatment in advanced NSCLC with an EGFR exon 20 insertion, and sotorasib monotherapy for second-line treatment in advanced NSCLC with a KRAS-G12C mutation. ^69,

In 2022, the ASCO published a guideline on the management of stage III NSCLC.[Daly ME, Singh N, Ismaila N, et al. Management of.... (12): 1356-1384. PMID 34936470] The recommendations were based on a literature search of systematic reviews, meta-analyses, and randomized controlled trials published from 1990 through 2021. Relevant recommendations include the following:

• Presence of oncogenic driver alterations, available therapies, and patient characteristics should be taken into account.

• Patients with resected stage III NSCLC with EGFR exon 19 deletion or exon 21 L858R mutation may be offered adjuvant osimertinib after platinum-based chemotherapy.

In 2022, the American Society of Clinical Oncology published an updated guideline on biomarker testing to guide systemic therapy in patients with metastatic breast cancer.^70, The guideline recommended the following biomarker tests:

• PIK3CA (Type of recommendation: evidence-based; Evidence quality: high; Strength of recommendation: strong)

• Germline BRCA1 and BRCA2 (Type of recommendation: evidence-based; Evidence quality: high; Strength of recommendation: strong)

• PD-L1 (Type of recommendation: evidence-based; Evidence quality: intermediate; Strength of recommendation: strong)

• MSI-H/dMMR (Type of recommendation: informal consensus-based; Evidence quality: low; Strength of recommendation: moderate)

• TMB (Type of recommendation: informal consensus-based; Evidence quality: low; Strength of recommendation: moderate)

• NTRK fusions (Type of recommendation: informal consensus-based; Evidence quality: low; Strength of recommendation: moderate)

The following biomarker tests were not recommended by ASCO: PALB2, TROP2 expression, circulating tumor DNA, circulating tumor cell.

Detailed recommendations are as follows:

• Patients with locally recurrent unresectable or metastatic hormone receptor-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer who are candidates for a treatment regimen that includes a phosphatidylinositol 3-kinase inhibitor and a hormonal therapy should undergo testing for PIK3CA mutations using next-generation sequencing of tumor tissue or circulating tumor DNA (ctDNA) in plasma to determine their eligibility for treatment with the phosphatidylinositol 3-kinase inhibitor alpelisib plus fulvestrant. If no mutation is found in ctDNA, testing in tumor tissue, if available, should be used as this will detect a small number of additional patients with PIK3CA mutations (Type of recommendation: evidence-based, benefits outweigh harms; Evidence quality: high; Strength of recommendation: strong)

• Patients with metastatic HER2-negative breast cancer who are candidates for treatment with a poly (ADP-ribose) polymerase (PARP) inhibitor should undergo testing for germline BRCA1 and BRCA2 pathogenic or likely pathogenic mutations to determine their eligibility for treatment with the PARP inhibitors olaparib or talazoparib (Type of recommendation: evidence-based, benefits outweigh harms; Evidence quality: high; Strength of recommendation: strong).

• There is insufficient evidence to support a recommendation either for or against testing for a germline PALB2 pathogenic variant for the purpose of determining eligibility for treatment with PARP inhibitor therapy in the metastatic setting. This recommendation is independent of the indication for testing to assess cancer risk (Type: informal consensus; Evidence quality: low; Strength of recommendation: moderate).

  • Small single-arm studies show that oral PARP inhibitor therapy demonstrates high response rates in MBC encoding DNA repair defects, such as germline PALB2 pathogenic variants and somatic BRCA1/2 mutations. It should also be noted that the randomized PARP inhibitor trials made no direct comparison with taxanes, anthracyclines, or platinums; comparative efficacy against these compounds is unknown.
    There are insufficient data at present to recommend routine testing of tumors for homologous recombination deficiency to guide therapy for MBC (Type: informal consensus; Evidence quality: low; Strength of recommendation: moderate).

• Patients with locally recurrent unresectable or metastatic hormone receptor-negative and HER2-negative breast cancer who are candidates for a treatment regimen that includes an immune checkpoint inhibitor (ICI) should undergo testing for expression of programmed cell death ligand-1 in the tumor and immune cells with a US Food and Drug Administration–approved test to determine eligibility for treatment with the ICI pembrolizumab plus chemotherapy (Type of recommendation: evidence based, benefits outweigh harms; Evidence quality: intermediate; Strength of recommendation: strong).

• Patients with metastatic cancer who are candidates for a treatment regimen that includes an ICI should undergo testing for deficient mismatch repair/microsatellite instability-high to determine eligibility for dostarlimab-gxly or pembrolizumab (Type of recommendation: informal consensus; Evidence quality: low; Strength of recommendation: moderate).

• Patients with metastatic cancer who are candidates for treatment with an ICI should undergo testing for tumor mutational burden to determine eligibility for pembrolizumab monotherapy (Type of recommendation: informal consensus; Evidence quality: low; Strength of recommendation: moderate).

• Clinicians may test for NTRK fusions in patients with metastatic cancer who are candidates for a treatment regimen that includes a TRK inhibitor to determine eligibility for larotrectinib or entrectinib (Type of recommendation: informal consensus; Evidence quality: low; Strength of recommendation: moderate).

• There are insufficient data to recommend routine testing of tumors for TROP2 expression to guide therapy with an anti-TROP2 antibody-drug conjugate for hormone receptor-negative, HER2-negative MBC (Type of recommendation: informal consensus; Evidence quality: low; Strength of recommendation: moderate).

• There are insufficient data to recommend routine use of ctDNA to monitor response to therapy among patients with MBC (Type of recommendation: informal consensus; Evidence quality: low; Strength of recommendation: moderate).

• There are insufficient data to recommend routine use of circulating tumor cells to monitor response to therapy among patients with MBC (Type of recommendation: informal consensus; Evidence quality: low; Strength of recommendation: moderate).

In 2022, the American Society of Clinical Oncology published a provisional clinical opinion on the appropriate use of tumor genomic testing in patients with metastatic or advanced solid tumors. ^71,

Provisional Clinical Opinion

Informal consensus is based on the review of existing approved testing and therapy combinations, available marker prevalence data, and expert opinion. As no formal systematic review of the clinical trial evidence was conducted for this provisional clinical opinion (PCO), and all the recommendations are based on the informal consensus of the expert panel, no recommendation-by-recommendation
statement of evidence quality is provided.

Section 1: Framework for decision making on multigene panel–based genomic sequencing with disease-specific approved markers.

1. PCO 1.1. Genomic testing should be performed for patients with metastatic or advanced solid tumors with adequate performance status in the following two clinical scenarios:

   1. When there are genomic biomarker–linked therapies approved by regulatory agencies for their cancer.

   2. When considering a treatment for which there are specific genomic biomarker–based contraindications or exclusions (strength of recommendation: strong).

Section 3: Testing for gene fusions and exon skipping variants

1. PCO 3.1. In patients with metastatic or advanced solid tumors, fusion testing should be performed if there are fusion-targeted therapies with regulatory approval for that specific disease (strength of recommendation: strong).

2. PCO 3.2.1. NTRK fusion testing should be performed in patients with metastatic or advanced solid tumors who may be candidates for TRK-inhibitor therapy, considering the prevalence of NTRK fusions in individual tumor types (strength of recommendation: strong).

3. PCO 3.2.2. Testing for other fusions is recommended in patients with metastatic or advanced solid tumors if no oncogenic driver alterations are identified on large panel DNA sequencing (strength of recommendation: moderate).

Section 4: Framework for decision making on panel tests with no approved disease-specific markers.

1. PCO 4.1. Genomic testing should be considered to determine candidacy for tumor-agnostic therapies in patients with metastatic or advanced solid tumors without approved genomic biomarker–linked therapies (strength of recommendation: moderate).

2. PCO 4.2. For tumors with actionable genomic alterations without approved genomic biomarker–linked targeted therapies, patient participation in clinical trials is encouraged after considering the expected efficacy of available standard-of-care options (strength of recommendation: strong).

3. PCO 4.3. Off-label and off-study use of genomic biomarker–linked therapies approved in other diseases is not recommended when a clinical trial is available or without clinical evidence of meaningful efficacy (strength of recommendation: strong).

A rapid update to the ASCO guideline was published in March 2023 to address ESR1 testing (which was not recommended in the previous version).^72, The guideline recommended routine testing for ESR1 mutations at the time of disease recurrence or progression while receiving endocrine therapy, with or without a concomitant CDK4/6 inhibitor, in patients with estrogen receptor-positive, HER2-negative metastatic breast cancer (Type of recommendation: evidence-based; Evidence quality: high; Strength of recommendation: strong). Testing should be performed with blood or tissue obtained at the time of progression, as ESR1 alterations develop via selective pressure from treatment and are unlikely to be detected in the primary tumor. Blood-based ctDNA is preferred due to greater sensitivity.

American Urological Assocation/Society of Urologic Oncology

In 2023, the American Urological Assocation and the Society of Urologic Oncology published amended guidelines on advanced prostate cancer. ^73, The guidelines included the following relevant recommendation (level of evidence) on the treatment of mCRPC:

• In patients with mCRPC, clinicians should offer germline (if not already performed) and somatic genetic testing to identify DNA repair deficiency, microsatellite instability (MSI) status, tumor mutational burden, and other potential mutations that may inform prognosis and familial cancer risk, as well as direct potential targeted therapies.(Clinical Principle)

College of American Pathology

In 2013, the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology published evidence-based guidelines for molecular testing to select patients with lung cancer for treatment with EGFR and ALK TKI therapy. ^74, Based on excellent quality evidence (category A), the guidelines recommended EGFR variant and ALK rearrangement testing in patients with lung adenocarcinoma regardless of clinical characteristics (eg, smoking history).

In 2018, updated guidelines were published and added new EGFR and ALK recommendations. ^75,ROS1 testing is recommended for all patients with lung adenocarcinoma irrespective of clinical characteristics (strong recommendation). BRAF, RET, HER2, KRAS, and MET testing are not recommended as routine stand-alone tests, but may be considered as part of a larger testing panel or if EGFR, ALK, and ROS1 are negative (expert consensus opinion).

The 2018 guidelines issued jointly by the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology have recommended the following:

“One set of genes must be offered by all laboratories that test lung cancers, as an absolute minimum: EGFR, ALK, and ROS1. A second group of genes should be included in any expanded panel that is offered for lung cancer patients: BRAF, MET, RET, ERBB2 (HER2), and KRAS, if adequate material is available. KRAS testing may also be offered as a single-gene test to exclude patients from expanded panel testing. All other genes are considered investigational at the time of publication.”

U.S. Preventive Services Task Force Recommendations

Not applicable.

Medicare National Coverage

In January 2020, the Centers for Medicare and Medicaid Services (CMS) determined that next-generation sequencing (NGS) is covered for patients with breast or ovarian cancer when the diagnostic test is performed in a Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory AND the test has approval or clearance by the U.S. Food and Drug Administration (CAG-00450R).^76,

CMS states that local Medicare carriers may determine coverage of NGS for management of the patient for any cancer diagnosis with a clinical indication and risk factor for germline testing of hereditary cancers when performed in a CLIA-certified laboratory.

The Centers for Medicare & Medicaid Services (CMS) National Coverage Determination on Next Generation Sequencing (90.2) states ^77,:

"Effective for services performed on or after March 16, 2018, [CMS] has determined that Next Generation Sequencing (NGS) as a diagnostic laboratory test is reasonable and necessary and covered nationally, when performed in a Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory, when ordered by a treating physician, and when all of the following requirements are met:

a. Patient has:

1. either recurrent, relapsed, refractory, metastatic, or advanced stage III or IV cancer; and

2. not been previously tested with the same test using NGS for the same cancer genetic content; and

3. decided to seek further cancer treatment (e.g., therapeutic chemotherapy).

b. The diagnostic laboratory test using NGS must have:

1. Food & Drug Administration (FDA) approval or clearance as a companion in vitro diagnostic; and,

2. an FDA-approved or -cleared indication for use in that patient’s cancer; and,

3. results provided to the treating physician for management of the patient using a report template to specify treatment options."

Regarding liquid biopsies, the memo states, "The NCD does not limit coverage to how to prepare a sample for performing a diagnostic laboratory test using NGS. Commenters submitted published articles on liquid biopsies (also referred to as circulating tumor DNA (ctDNA) or plasma cell-free DNA (cfDNA) tests). We reviewed and included in the evidence and analysis of 4 studies on liquid biopsies. At this time, liquid-based multi-gene sequencing panel tests are left to contractor discretion if certain patient criteria are met."

Ongoing and Unpublished Clinical Trials

Some currently unpublished trials that might influence this review are listed in Table 3.

Table 3. Summary of Key Trials

  NCT: national clinical trial. a Denotes industry-sponsored or cosponsored trial.

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77. Centers for Medicare & Medicaid Services. 2020. National Coverage Determination 90.2: Next Generation Sequencing. https://www.cms.gov/medicare-coverage-database/view/ncd.aspx?NCDId=372&ncdver=2&NCAId=296&bc=ACAAAAAACAAA&. Accessed October 30, 2025.

Codes

Policy History