Breast cancer is the uncontrolled, abnormal growth of cells in the breast. Abnormal cell mutations develop into malignant tumors, which can invade nearby healthy breast tissue over time. Usually, breast cancer begins in the cells of the milk-producing glands (lobules) or the passages that drain milk (ducts). If not treated, the cancer can progress and spread to the lymph nodes under the arm and eventually may invade other parts of the body by way of the lymphatic system.
Invasive Breast Cancer
Invasive means that the cancer has “invaded” or spread to the surrounding breast tissues. Most invasive breast cancers start in the ducts (tubes that carry milk from the lobules to the nipple). Invasive breast cancer can spread to other parts of the body through the blood and lymph systems. Invasive breast cancer is also called infiltrating breast cancer.
Non-Invasive Ductal Breast Cancer & DCIS (Ductal Carcinoma In Situ)
Unlike invasive breast cancer, the tumor cells in DCIS are confined to the milk ducts within the breast. However, women who are diagnosed with DCIS have, on average, a 20-25 percent risk of a local recurrence of DCIS or invasive breast cancer at 10 years with surgery alone.i
Validation studies have already been performed on the Oncotype DX® Breast Cancer Assay for patients with pre-invasive or DCIS, node-negative and node-positive, estrogen-receptor-positive (ER+) breast cancer; for single gene reporting quantitative of ER (estrogen receptor), PR (progesterone receptor negative) and HER2 (human epidermal growth factor receptor 2) genes, and for patients treated with Tamoxifen or an Aromatase Inhibitor. The Oncotype DX breast cancer tests are currently commercially available. For detailed information please call: (866) ONCOTYPE or visit www.oncotypedx.com
iHughes et al, J Clin Oncol. 2009; 27:39