Breast Cancer (cont.)
Medical Treatment: Radiation, Chemotherapy, and Hormonal Therapy
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.
- Radiation therapy in breast cancer is usually external beam radiation, where the radiation is pointed at a specific area of the breast from the outside. Rarely internal radiation therapy is used, where radioactive pellets are implanted close to the cancer. Newer techniques of rapid partial breast radiation have been developed and may be appropriate in certain circumstances. The use of radiation treatment at the same time as surgery is done more in other countries that here, but continues to be explored.
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:
- Adjuvant chemotherapy is given to people who have had potentially curative treatment for their breast cancer, such as surgery and for whom radiation may be planned. The possibility that breast cancer cells may have spread microscopically away from the area operated upon or to be radiated is thought to be what results in the metastases developing at a later date. Adjuvant therapy is given to try to eliminate these hidden, but potentially still present cells to reduce the risk of relapse. The characteristics of the primary cancerous tumor both grossly, microscopically, and on chemical analysis help the doctor to judge what risk there is that such hidden cells could be present.
- Presurgical chemotherapy (known as neoadjuvant 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.
- Therapeutic chemotherapy is routinely administered to women with metastatic 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 (Femara) 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.
- Targeted therapy is a type of treatment that has been developed to directly work against some of the cellular changes that have been identified in breast cancers. Examples of targeted therapies include monoclonal antibodies against cancer cell-specific proteins.
Medically Reviewed by a Doctor on 12/18/2015
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