Trastuzumab may be considered medically necessary for the treatment of patients with breast cancer whose tumors overexpress the human epidermal growth factor receptor 2 (HER2) protein (HER2-positive breast cancer). The use of trastuzumab includes use as adjuvant therapy, neoadjuvant therapy, and treatment of metastatic disease.
Trastuzumab may be considered medically necessary, when used in combination with systemic chemotherapy, for the treatment of patients with advanced (locally advanced or metastatic) gastric cancer or gastroesophageal junction adenocarcinoma whose tumors overexpress the HER2 protein (HER2-positive cancer).
Trastuzumab is considered investigational for the treatment of all other conditions including, but not limited to, HER2-negative breast cancer and the following types of cancer, which may be HER2-positive: osteosarcoma, non-small-cell lung, ovarian, prostate, head and neck, esophageal (except as noted above), gastric (except as noted above), pancreatic, colorectal, endometrial, and urothelial.
