Breast cancer is a malignant (cancerous) growth that begins in the tissues of the breast. The American Cancer Society estimates that over the course of a lifetime, one in eight women will be diagnosed with breast cancer. When detected early, before the cancer has spread (called localized cancer), the 5-year survival rate for women with breast cancer is now 98 percent, compared to only 26 percent if the cancer has already spread.
Screening and Diagnosis
All women should check their breasts for lumps or other changes in texture; this self-examination process is a key personal screening tool. Your doctor may also check each breast for lumps and look for other problems. If you have a lump, your doctor will feel its size, shape, and texture. A hard, oddly shaped lump that feels firmly attached within the breast is more likely to be cancer.
Your doctor may order a mammogram (an X-ray picture of the breast) to view the tissues inside the breast. NCI recommends that women 40 years of age and older should have a screening mammogram at least every two years. Other breast imaging tools include magnetic resonance imaging (MRI) scans for detailed pictures of breast tissue and ultrasound, which sends out sound waves that bounce off tissues to create a picture. If your doctor finds something suspicious with any of these imaging methods, you may need to have a biopsy (testing of a tiny portion of breast tissue) to look for cancer cells.
In recent years, two therapies have revolutionized breast cancer treatment: tamoxifen (Nolvadex) and trastuzumab (Herceptin). Bernard Fisher, M.D., of the University of Pittsburgh, and Dennis J. Slamon, M.D., of UCLA, pioneered these treatments. (See a related story on the inside front cover of this issue.)
Dr. Fisher's research into how cancer spreads paved the way for today's understanding that cancer is a disease of the entire body and that its spread is not predictable. Dr. Fisher went on to show the effectiveness of adjuvant (supportive) chemotherapy and hormonal therapy with tamoxifen in treating breast cancer. Tamoxifen blocks the activity of the female hormone estrogen in the breast and can stop the growth of some breast tumors.
Dr. Slamon and his colleagues developed trastuzumab (Herceptin). Trastuzumab, a monoclonal antibody, was the first treatment to target the specific molecular changes in cells that make them cancerous. Because it targets only the cancer cells, trastuzumab causes fewer side effects than standard chemotherapy drugs, which can kill both cancer cells and normal cells.
Today, breast-conserving surgery (lumpectomy), followed by localized radiation therapy has replaced mastectomy (removal of the entire breast) as the preferred surgical approach for treating women with early-stage breast cancer. Combination chemo (therapy with more than one drug) has also become standard in the treatment of women with early stage breast cancer.