Many women have treatment in addition to surgery, which may include radiation therapy, chemotherapy, or hormonal therapy. The decision about which additional treatments are needed is based upon the stage and type of cancer, the presence of hormonal and/or HER-2/neu receptors, and patient health and preferences.
Radiation therapy is used to kill tumor cells if there are any left after surgery.
Radiation is a local treatment and therefore works only on tumor cells that are directly in its beam.
Radiation is used most often in people who have undergone conservative surgery such as lumpectomy. Conservative surgery is designed to leave as much of the breast tissue in place as possible.
Radiation therapy is usually given five days a week over five to six weeks. Each treatment takes only a few minutes.
Radiation therapy is painless and has relatively few side effects. However, it can irritate the skin or cause a burn similar to a bad sunburn in the area.
Chemotherapy consists of the administration of medications that kill cancer cells or stop them from growing. In breast cancer, three different chemotherapy strategies may be used:
1. Adjuvant chemotherapy is given to people who have had curative treatment for their breast cancer, such as surgery and radiation. It is given to reduce the possibility that the cancer will return.2. Presurgical chemotherapy is given to shrink a large tumor and/or to kill stray cancer cells. This increases the chances that surgery will get rid of the cancer completely.3. Therapeutic chemotherapy is routinely administered to women with breast cancer that has spread beyond the confines of the breast or local area.
Most chemotherapy agents are given through an IV line, but some are given as pills.
Chemotherapy is usually given in "cycles." Each cycle includes a period of intensive treatment lasting a few days or weeks followed by a week or two of recovery. Most people with breast cancer receive at least two, more often four, cycles of chemotherapy to begin with. Tests are then repeated to see what effect the therapy has had on the cancer.
Chemotherapy differs from radiation in that it treats the entire body and thus may target stray tumor cells that may have migrated from the breast area.
The side effects of chemotherapy are well known. Side effects depend on which drugs are used. Many of these drugs have side effects that include loss of hair, nausea and vomiting, loss of appetite, fatigue, and low blood cell counts. Low blood counts may cause patients to be more susceptible to infections, to feel sick and tired, or to bleed more easily than usual. Medications are available to treat or prevent many of these side effects.
Hormonal therapy may be given because breast cancers (especially those that have ample estrogen or progesterone receptors) are frequently sensitive to changes in hormones. Hormonal therapy may be given to prevent recurrence of a tumor or for treatment of existing disease.
In some cases, it is beneficial to suppress a woman's natural hormones with drugs; in others, it is beneficial to add hormones.
In premenopausal women, ovarian ablation (removal of the hormonal effects of the ovary) may be useful. This can be accomplished with medications that block the ovaries' ability to produce estrogens or by surgically removing the ovaries, or less commonly with radiation.
Until recently, tamoxifen (Nolvadex), an antiestrogen (a drug that blocks the effect of estrogen), has been the most commonly prescribed hormone treatment. It is used both for breast cancer prevention and for treatment.
Fulvestrant (Faslodex) is another drug that acts via the estrogen receptor, but instead of blocking it, this drug eliminates it. It can be effective if the breast cancer is no longer responding to tamoxifen. Fulvestrant is only given to women who are already in menopause and is approved for use in women with advanced breast cancer.
Toremifene (Fareston) is another anti-estrogen drug closely related to tamoxifen.
Aromatase inhibitors, which block the effect of a key hormone affecting the tumor, may be more effective than tamoxifen in the adjuvant setting. The drugs anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femera) have a different set of side effects and risks than tamoxifen.
Aromatase inhibitors are rapidly moving into first line hormonal therapy regimens. In addition, they are frequently used after two or more years of tamoxifen therapy.
Megace (megestrol acetate) is a drug similar to progesterone which may also be used as hormonal therapy.
Monoclonal antibodies are antibodies against proteins in or around a cancer cell. Antibodies recognize an "invader"—in this case, a cancer cell—and attack it.
Trastuzumab (Herceptin) is an antibody against the HER-2 protein, a protein responsible for cancer cell growth in many women with breast cancer (about 15-25% of breast cancers). Adding treatment with trastuzumab to chemotherapy given after surgery has been shown to lower the recurrence rate and death rate in women with HER2/neu-positive early breast cancers. Using trastuzumab along with chemotherapy has become standard adjuvant treatment for these women.
Lapatinib (Tykerb) is another drug that targets the HER2/neu protein and may be given combined with chemotherapy. It is used in women with HER2-positive breast cancer that is no longer helped by chemotherapy and trastuzumab.
Another monoclonal antibody, Bevacixumab (Avastin) has been shown to have activity in the treatment of breast cancer and is used in combination with chemotherapy. This drug targets the ability of cancers cells to form new blood vessels.
Surgery
Surgery is generally the first step after the diagnosis of breast cancer. The type of surgery is dependent upon the size and type of tumor and the patient's health and preferences.
Lumpectomy involves removal of the cancerous tissue and a surrounding area of normal tissue. This is not considered curative and should almost always be done in association with other therapy such as radiation therapy with or without chemotherapy or hormonal therapy.
At the time of lumpectomy, the axillary lymph nodes (the glands in the armpit) need to be evaluated for the spread of cancer. This can be done by either removing the lymph nodes or by sentinel node biopsy (biopsy of the closest lymph node to the tumor).
If a sentinel node biopsy is done at the time of lumpectomy, it may allow the surgeon to remove only some of the lymph nodes. In this procedure, a dye is injected into the area of the tumor. The path of the substance is then followed as it travels to the lymph nodes. The first node reached is the sentinel node. This node is considered most important to biopsy when evaluating the spread of the tumor.
If the sentinel node biopsy is positive, the surgeon will usually remove of all of the lymph nodes found in the axilla (armpit).
Simple mastectomy removes the entire breast but no other structures. If the cancer is invasive, this surgery alone will not cure it. It is a common treatment for DCIS, a noninvasive type of breast cancer.
Modified radical mastectomy removes the breast and the axillary (underarm) lymph nodes but does not remove the underlying muscle of the chest wall. Although additional chemotherapy or hormonal therapy is almost always offered, surgery alone is considered adequate to control the disease if it has not metastasized.
Radical mastectomy involves removal of the breast and the underlying chest wall muscles, as well as the underarm contents. This surgery is no longer done because current therapies are less disfiguring and have fewer complications.
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