Therapy for Breast Cancer: Questions and Answers
Researchers have been evaluating breast cancer to find how best to treat this disease. Special attention is given to find ways to prevent breast cancer from returning after primary treatment.
It once was thought that breast cancer spreads (metastasizes) first to nearby tissue and underarm lymph nodes prior to spreading to other parts of the body. It is now believed that cancer cells may break away from the primary tumor in the breast and begin to metastasize although the disease may be in an early stage.
Adjuvant therapy is treatment given in addition to the primary cancer treatments to kill any cancer cells that may have spread, even if it cannot be detected by radiologic or laboratory tests. Studies have shown that adjuvant therapy for breast cancer may increase the chance of long-term survival by preventing the cancer from returning.
What are the primary types of therapy are used for breast cancer?
Primary therapy for breast cancer normally involves lumpectomy and radiation therapy or modified radical mastectomy. A lumpectomy is the removal of the primary breast tumor and a small amount of surrounding tissue. Generally, most of the underarm lymph nodes are also removed. A lumpectomy is followed by radiation treatment to the breast. A modified radical mastectomy is the removal of the whole breast, most of the lymph nodes under the arm, and often the lining over the chest muscles. The smaller of the two chest muscles is sometimes taken out to help in removing the lymph nodes.
Doctors are testing and evaluating a new procedure, called sentinel node biopsy, where only a single lymph node is removed and tested to see if the breast cancer has spread to lymph nodes under the arm. Clinical trials are being done to determine the function of this procedure in the treatment of breast cancer.
What are the primary types of therapy used for breast cancer?
The main purpose of adjuvant therapy is to destroy any cancer cells that may have spread, treatment is usually systemic (uses substances that travel through the bloodstream, reaching and affecting cancer cells all over the body). Adjuvant therapy for breast cancer includes chemotherapy or hormone therapy, either alone or in combination:
Adjuvant chemotherapy is the use of drugs to kill cancer cells. Research has shown that using chemotherapy as adjuvant therapy for early stage breast cancer helps to prevent the original cancer from returning. Adjuvant chemotherapy usually combines anticancer drugs, which has shown to be more successful than a single anticancer drug.
Adjuvant hormone therapy deprives cancer cells of the female hormone estrogen, which some breast cancer cells require to grow. Usually, adjuvant hormone therapy is treatment with the drug tamoxifen. Research has shown that when tamoxifen is used as adjuvant therapy for early stage breast cancer, it helps to prevent the original cancer from returning and also helps to prevent new cancers developing in the other breast.
The ovaries are the primary source of estrogen before menopause. For premenopausal women with breast cancer, adjuvant hormone therapy can include tamoxifen to deprive the cancer cells of estrogen. Drugs to stop the production of estrogen by the ovaries are under investigation. Also, surgery may be performed to remove the ovaries.
What do prognostic factors have to do with adjuvant therapy?
Prognostic factors are characteristics of breast tumors that help predict whether the disease is likely to return. These factors are used by Doctors when they are trying to determine which patients might benefit from adjuvant therapy.
Several prognostic factors are commonly used to plan breast cancer treatment:
- Tumor size
- Lymph node involvement
- Hormone receptor status
- Histologic grade
- Proliferative capacity of a tumor
- Oncogene activation
Who is given adjuvant therapy?
Although prognostic factors provide critical information about the risk of breast cancer returning, they do not allow doctors to predict exactly who will be cured by primary therapy and who may gain additional help from adjuvant therapy. Decisions about adjuvant therapy for breast cancer must be made on an individual basis, taking into account the prognostic factors described above, the woman’s menopausal status (whether she has gone through menopause), her general health, and her personal preference. This complicated decision-making process is best carried out by consulting our doctor who specializes in cancer treatment.
When should adjuvant therapy be started?
Adjuvant therapy typically begins inside 6 weeks after surgery, based on the results of clinical trials in which the therapy was started within that time period. Doctors do not know how effective adjuvant therapy is in reducing the chance of cancer returning when treatment is started at a later time.
How is adjuvant therapy given, and how long does it last?
Chemotherapy is given by mouth or by injection into a blood vessel. Either way, the drugs enter the bloodstream and travel throughout the body. Chemotherapy is given in cycles: a treatment period followed by a recovery period, then another treatment period, and so on. Most patients receive treatment in an outpatient part of the hospital or at Texas Breast Care. Adjuvant chemotherapy typically lasts for 3 to 6 months.
In adjuvant hormone therapy, tamoxifen is taken orally. Tamoxifen enters the bloodstream and travels all through the body. Most women take tamoxifen every day for 5 years. Studies have shown that taking tamoxifen longer than 5 years is not any more effective. Premenopausal women may receive hormones by injection to suppress ovarian function. Otherwise, surgery can be performed to remove the ovaries.
What are some of the side effects of adjuvant therapy?
The side effects of chemotherapy depend mainly on the drugs the patient receives. As with other types of treatment, side effects differ from person to person. Most of the time, anticancer drugs affect rapidly dividing cells. These include blood cells, which fight infection, cause the blood to clot, and carry oxygen to all parts of the body. When blood cells are affected by anticancer drugs, patients are more likely to get infections, bruise or bleed easily, and may have less energy during treatment and for some time afterward. Cells in hair follicles and cells that line the digestive tract also divide rapidly. As a result of chemotherapy, patients may lose their hair and may have other side effects, such as loss of appetite, nausea, vomiting, diarrhea, or mouth sores.
Doctors can prescribe medications to help control nausea and vomiting caused by chemotherapy. They also keep an eye on patients for any signs of other problems and may change the dose or schedule of treatment if problems arise. Also, doctors advise women who have a lowered resistance to infection because of low blood cell counts to avoid crowds and people who are sick or have colds. The side effects of chemotherapy are generally a short-term problem. They slowly dissipate during the recovery part of the chemotherapy cycle or after the treatment is completed.
Usually, the side effects of tamoxifen are much like some of the symptoms of menopause. The most common side effects are hot flashes, vaginal discharge, and nausea. Just like with menopause, not all women who take tamoxifen have these symptoms. Most of these side effects will not need medical attention.
Our doctors carefully monitor women taking tamoxifen for any signs of more serious side effects. Women taking tamoxifen, particularly those who are receiving chemotherapy along with tamoxifen, have a greater risk of developing a blood clot. The risk of having a blood clot due to tamoxifen is similar to the risk of a blood clot when taking estrogen replacement therapy. Women taking tamoxifen also have an increased risk of stroke.
Among women who have not had a hysterectomy (surgery to remove the uterus), the risk of developing endometrial cancer (cancer of the lining of the uterus) and uterine sarcoma (cancer of the muscular wall of the uterus) is increased in those taking tamoxifen. Women who take tamoxifen should talk with their doctor about having regular pelvic exams, and should be examined promptly if they have pelvic pain or any abnormal vaginal bleeding.
Studies have revealed that the risks of adjuvant therapy for breast cancer are outweighed by the benefit of the treatment-increasing the chance of survival. It is important for women to share any concerns they may have about their treatment or side effects with our doctor or other health care provider.
How are doctors and scientists trying to answer questions about adjuvant therapy for breast cancer?
Doctors and scientists are conducting clinical trials to gain knowledge of how to treat breast cancer more effectively. In these studies, researchers compare two or more groups of patients who receive different treatments. These studies can illustrate whether new treatments are more or less effective than standard ones and how the side effects compare.