How is early-stage breast cancer treated?

Treatment of early-stage breast cancer often involves more than one approach. Surgery is usually the first step. Most women with early-stage breast cancer have a choice between 2 surgical treatments:

• Breast-sparing surgery, followed by radiation therapy — Breast-sparing surgery, also called breast-conserving surgery, includes lumpectomy (luhm-PEK-tuh-mee) and partial (or segmented) mastectomy (ma-STEK-tuh-mee). With lumpectomy, the tumor and some surrounding normal tissue are removed. With partial mastectomy, a portion of the breast containing the tumor is removed. Women who have breast-sparing surgery usually have lymph nodes under the arm removed. This may occur during the breast-sparing surgery or at a later time. Breast-sparing surgery keeps the breast intact — looking a lot like it did before surgery.

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• Mastectomy — With simple (total) mastectomy, the surgeon removes the whole breast that has cancer and possibly some of the lymph nodes under the arm. With modified radical mastectomy, the whole breast, plus many of the lymph nodes under the arm, the lining over the chest muscles, and, sometimes, part of the chest wall muscles are removed.

The goal of both surgeries is to remove all of the cancer from the breast. The doctor will also want to find out if the cancer has spread to nearby lymph nodes. With axillary lymph node dissection (ALND), some or all of the lymph nodes under your arm are removed. With sentinel lymph node (SLN) biopsy, a substance is injected near the tumor that allows the doctor to see which lymph node the substance flows to first. This is the sentinel lymph node. It is the first lymph node the cancer is likely to spread to. The sentinel lymph node is removed and looked at under a microscope. If cancer is not found, the other lymph nodes may be left in place. If cancer is found, more lymph nodes may be removed.
The lymph node status, along with test results, helps the doctor know what other treatments, called adjuvant (AY-juh-vuhnt) therapy, might also be prudent. The goal of adjuvant therapy after surgery is to kill any cancer cells that might be elsewhere in the body and to keep cancer from recurring.
See "Will I need treatment after surgery?" to learn about adjuvant therapy.