Treatment for breast cancer almost always begins with a decision about the type of surgery. The options are mastectomy, removing the entire affected breast; or lumpectomy, removing just the malignant lump and a margin of healthy tissue around all edges of the tumor. A lumpectomy also is called breast-conserving therapy, or BCC. When a lumpectomy is performed, it generally is followed by radiation therapy to prevent the cancer from recurring in the same breast. The goal of BCC is to maintain the cosmetic appearance of the breast without decreasing a woman's chance of surviving breast cancer.

Today, it is estimated that up to 80 percent of women with early-stage breast cancer can be treated with BCC. For these women, mastectomy and lumpectomy with radiation offer the same chance of long-term survival. However, women who undergo mastectomy have a slightly lower risk of breast-cancer recurrence.

A woman is considered a good candidate for lumpectomy if her tumor is localized to one area of the breast. Most women with breast cancer qualify as candidates for lumpectomy. However, there are other considerations:

• Cosmetic results may not be good in women who have relatively large lumps in small breasts.
• If there is more than one lump, there is concern that other areas of the breast could have cancer multifocal disease. In this case, a mastectomy is the preferred therapy.
• Women who are unwilling or unable to have follow-up radiation treatments are not good candidates for lumpectomy. Radiation typically is given five days a week for five to six weeks after surgery. Patients who live far from a hospital or medical center that provides radiation therapy may find it inconvenient or impossible to travel back and forth for daily treatment.
• Women who previously have had radiation therapy to their breast or chest area might not be able to undergo further breast radiation. In this case, mastectomy is the preferred therapy.

A mastectomy usually involves removing the breast and some lymph nodes located under the arm. After the lymph nodes are removed, they are examined by a pathologist to check for cancer cells. The information about the presence or absence of cancer cells in the axillary lymph nodes is essential in determining the patient's prognosis and the need for further therapy.

It's important to consult a plastic surgeon before surgery. This consultation can help women make a better decision about whether to have the reconstruction done immediately (during the surgery) or to later.

The number of days spent in the hospital varies. Occasionally, mastectomy without reconstruction may be performed as same-day surgery. After surgery, most women need to do special exercises to overcome stiffness and regain mobility in the arm on the side of the mastectomy.

The latest variation is a skin-sparing mastectomy, in which the breast tissue is removed through a circular incision around the nipple. The skin thus remains intact so that the breast can be reconstructed immediately by inserting an implant or fatty tissue taken from the abdomen, back or buttocks. With a skin-sparing mastectomy, a separate incision is needed to remove underarm lymph nodes.

Most breast-cancer surgery requires the removal of some axillary (underarm) lymph nodes to check for the presence of cancer cells. The most commonly performed procedure is called an axillary dissection — the removal of a wedge of fat from the underarm that usually contains between 10 and 15 lymph nodes. A newer method, called sentinel-node mapping, relies on identifying and removing only the one or two lymph nodes closest to the tumor. If no cancer is found in the sentinel nodes, then no more lymph nodes are removed. This procedure is under investigation. If further study reveals that sentinel-node biopsies are as sensitive as more extensive biopsies in detecting cancer in the axillary lymph nodes, then it likely will replace the current method of lymph-node removal. At this time, sentinel-node mapping should be performed only by an experienced surgeon who has performed many of these procedures before.

The lymph nodes can be removed in the course of a mastectomy. With lumpectomy, a separate incision usually is made to remove the wedge of fat that contains the nodes. Either way, most patients wake up from surgery to find a drain emerging from the underarm area to remove any fluid that accumulates.

After the lymph nodes are removed, they are examined under the microscope to check for the presence of cancer cells. The need for additional treatment after surgery depends on whether some nodes are positive for cancer.

Several potential complications are associated with lymph-node removal. The most serious is lymphedema, a swelling in the arm caused by the accumulation of fluid that doesn't drain properly. Lymphedema is very rare since the current surgical techniques involve the removal of fewer lymph nodes than the more extensive procedures of the past. Swelling can range from barely noticeable to an obvious enlargement of the arm. It can be either painless or painful. Sometimes, lymphedema is triggered by an infection, but other times, the cause is unknown. Some women develop it right away, and others develop it some time after surgery. In some cases, the lymphedema is transient and resolves on its own. In other cases, it may be a chronic problem. There are special exercises and precautions that can be followed after surgery to decrease the chance of developing lymphedema. Examples include wearing gloves whenever gardening, avoiding constricting clothing and jewelry and shaving your underarms with an electric razor. Treatments are available if lymphedema does occur.

Another potential complication is some loss of sensation under your arm. When the surgeon makes an incision in your skin, it can damage nerves in the area. The numbness won't affect the use of your arm, but you will have to be very careful when shaving because part of the area under your arm will lack sensation.

After surgery, the pathology report will provide information for staging the cancer, a process that helps to determine whether any further treatment is needed after surgery and to predict the outlook for a cure. Here's a summary of the stages of breast cancer:

Stage O: Carcinoma in situ. Cancer has not spread beyond the ducts in the breast.

Stage I: The tumor is two centimeters (about one inch) or less in diameter and it has not spread to the underarm (axillary) lymph nodes or to any other sites.

Stage II: Tumor is larger than two centimeters, or cancer cells are detected in movable (not fixed) axillary lymph nodes on the same side of the body as the breast mass. If the cancer-containing lymph nodes are fixed — meaning they are attached to the skin or underlying tissue — then the cancer is stage III.

Stage III: The tumor may be any size, but it has spread to fixed lymph nodes. If a tumor involves the skin or chest wall or has spread to the lymph nodes located underneath the breast on the same side of the body as the tumor, it automatically is at least stage III, no matter what the size.

Stage IV: Any tumor that has spread to any other site beyond the local area of the breast (for example, to internal organs or bones), no matter what the size.

The lower the stage, the better the outlook for survival.

Radiation therapy (sometimes called radiotherapy) almost always is recommended after lumpectomy to destroy any cancer cells left behind and to prevent local recurrences in the breast. Without radiation therapy, the odds of a local recurrence increase by about 25 percent. These recurrences can predict cancer spread to other parts of the body, especially when they occur within the first three years after surgery. Radiation therapy is also sometimes recommended after mastectomy, depending on the size and other characteristics of the breast tumor.

Although many patients worry that radiation treatment can cause cancer, this is extremely rare with today's high-tech machines. There is no risk of becoming radioactive or losing your hair due to radiation treatments. Fatigue is a common side effect of radiation, and many women experience swelling or a sensation of heaviness of the breast. Most of these changes in the breast are temporary and will go away within a few months to a year. Some women, however, notice that their breasts are smaller and firmer after the treatment, and this can be permanent. Radiation therapy is not given to pregnant women because it can cause birth defects.

After surgery, certain patients will be offered chemotherapy (anti-cancer drugs) to improve their chance of survival. In other cases, chemotherapy may be recommended before surgery to shrink the tumor before it is removed. Before recommending chemotherapy, your doctor will consider the stage of your cancer and the prognosis. If your cancer recurs, chemotherapy usually is recommended. If chemotherapy is necessary, treatment typically is given over a period of three to six months. The drugs can be given by injection or in pill form. Treatment can be given once every three or four weeks to allow patients to recuperate in between. Most chemotherapy for breast cancer involves a combination of three drugs, but the specific combination depends on the individual case.

Chemotherapy commonly causes side effects, but the severity and type of symptoms experienced varies with each person and with the type of drugs given, the dosage of the drugs and the length of time the patient is treated. Fatigue is the most common side effect associated with chemotherapy. The gastrointestinal tract often is damaged temporarily by the chemotherapy drugs, so nausea, vomiting, mouth sores and decreased appetite are common. Many patients also experience hair loss and menstrual irregularities. Chemotherapy also can increase your risk of infection (by decreasing the number of your infection-fighting white-blood cells), fatigue (by decreasing the number of red blood cells, among other reasons) and bleeding (by causing your platelet counts to drop).

It's important to keep in mind that these side effects are treatable. A variety of medications are available to minimize nausea and vomiting. In addition, several medications are available to stimulate the production of blood cells, which can be inhibited by chemotherapy.

Hormonal therapy works by inhibiting tumor growth that is stimulated by hormones. Tumors that are estrogen- or progesterone-receptor positive are more likely to respond to hormonal therapy than are tumors without these hormone receptors. By blocking the receptors, the growth of a hormone-receptor positive tumor can be slowed. The estrogen receptor is the most important hormonal receptor in breast cancer. It is inhibited by tamoxifen , which is an anti-estrogen drug. Tamoxifen has side effects, such as hot flashes, and it increases your risk of forming blood clots and developing uterine cancer. However, most women are able to tolerate tamoxifen without difficulty.

Tamoxifen has been shown to be effective in decreasing the risk of breast cancer for high-risk women, and it now has FDA-approval to be used for this purpose. A recent major research trial, called the PI study, demonstrated that women who had increased risk of breast cancer because of age (greater than 60) or other risk factors were nearly 50 percent less likely to develop breast cancer after taking tamoxifen.

A P2 study is now underway. This trial, known as the STAR trial, is comparing the effectiveness of tamoxifen and a related drug, raloxifene, in the prevention of breast cancer in postmenopausal women at high risk of breast cancer. The most common use of tamoxifen, however, is to decrease the risk of cancer recurrence after breast-cancer surgery.

Anastrozole, letrozole and exemestane are other hormonal therapies. They currently are recommended in certain cases for women who have breast cancer that has spread to other parts of the body, such as the bones, liver and lung.