The treatment of breast cancer may include surgery, radiation therapy and/or chemotherapy. For localized breast cancer (that is, breast cancer that is confined to the breast and the regional lymph nodes located under the arm and sternum, and has not spread through the bloodstream to distant sites sch as bone, liver, lung, or brain), surgery is the most important of these treatments.
Surgery usually entails removing the primary cancer in the breast, as well as some of the lymph nodes from under the arm (axillary lymph nodes). Removal of the primary tumor may be called tylectomy, lumpectomy, partial mastectomy, setmental resection, or segmental mastectomy. There is increasing interest in lymph node mapping (sentinal node biopsy) and selective removal of nodes to limit the extent of the underarm surgery and reduce the side effects of the procedure. The main side effect from the axillary operation is swelling or lymphedema of the arm, which is directly related to the extent of the dissection and whether or not it is necessary to irradiate the underarm area after the operation.
Patients who have early-stage breast cancers with a single site of cancer in the breast (that is, cancers that are not multifocal, or located in more than one area of the breast) are often candidates for breast-conserving therapy. The tumor is removed and the breast is otherwise left intact. This is feasible if it is possible to remove the tumor and have a good cosmetic result. Otherwise, it may be necessary to remove the entire breast. Procedures that remove the entire breast include simple, modified, total, and radical mastectomy. If this is done, it is often possible to reconstruct the breast using tissue flaps such as a muscle from the side of the back (latissimus dorsi flap) or the lower abdominal muscles (TRAM flap).
Radiation therapy is administered to the breast when the breast has been conserved. When the breast has been removed, but there is a high risk for recurrence because the cancer was large or was found close to the surgical margins or there was disease in axillary lymph nodes, the chest wall and regional lymph nodes are irradiated.
Systemic therapy is indicated for many patients with breast cancer to reduce the chance of the cancer recurring elsewhere in the body. Systemic therapy includes both chemotherapy and hormonal therapy. One or both types of systemic therapy may be recommended depending on the patient’s age, metastatic risk, medical condition, and whether the breast cancer contained hormonal receptors.