The Oncotype DX® Breast Cancer Assay is a diagnostic test that assesses a patient’s tumor tissue at a molecular level. It analyzes the activity of a specific group of genes to predict the likelihood of chemotherapy benefit and recurrence risk in early-stage, estrogen-receptor-positive, invasive breast cancer.
Oncotype DX® Colon Cancer Assay is a new multigene expression test that also examines the activity of specific genes in a patient’s tumor sample to assess the likelihood of recurrence following surgery to remove stage II colon cancer. Both tests provide individualized information concerning the biological makeup of the patient’s tumor, helping to guide important treatment decisions.
HER2-neu testing may also be conducted for advanced cancer of the stomach or the junction where the esophagus meets the stomach (gastroesophageal junction), as the FDA has approved treatment with trastuzumab in combination with specific chemotherapy agents for these HER2-neu positive cancers.
In patients diagnosed with invasive breast cancer, a tumor sample is typically tested to determine hormone receptor status of estrogen and progesterone as well as whether there is overexpression of the gene HER2-neu. Such testing provides important prognostic information concerning how aggressive the tumor may be and in guiding treatment decisions.
Patients with estrogen- and/or progesterone-positive breast cancers may benefit from anti-hormone therapy as part of their treatment, such as with tamoxifen or aromatase inhibitors. Those whose tumors are HER2-neu positive may be candidates for treatment with anti-HER2 agents, such as trastuzumab (Herceptin®), which targets the HER2-neu protein.
