Germline genetic testing for CDH1 variants to identify individuals with or at risk for hereditary diffuse gastric cancer (HDGC) may be considered medically necessary for individuals meeting the following criteria (see Policy Guidelines):
A diagnosis of diffuse gastric cancer (DGC) before age 50 years; OR
A diagnosis of DGC at any age in individuals of Maori ethnicity, or with a personal or family history of cleft/lip palate; OR
A diagnosis of bilateral lobular breast cancer before age 70 years; OR
Personal or family history of both DGC and lobular breast cancer, one diagnosed before age 70 years; OR
Two 1st- or 2nd-degree relatives (see Policy Guidelines) with a diagnosis of gastric cancer at any age, one DGC; OR
Two 1st- or 2nd-degree relatives (see Policy Guidelines) with a diagnosis of lobular breast cancer before 50 years of age.
Germline genetic testing for CDH1 variants in individuals not meeting the above criteria is considered investigational.
Germline genetic testing for CTNNA1 variants to identify individuals with or at risk for HDGC is considered investigational (see Policy Guidelines).
