The American Cancer Society describes breast cancer as a tumor that originates in cells of the breast. It most often occurs in women, but is diagnosed in men as well. While the cancer is being staged, examination of hormone receptors is typically performed. Breast cancer cells can be estrogen receptor-positive or progesterone-receptor positive, and hormone therapy may be used as a treatment in these types of cancers.
SIgnificance
Breast cancer will develop in about one in eight American women, says Breastcancer.org, and in 2010, more than 200,000 women will be diagnosed with invasive breast cancer in the United States. According to the American Cancer Society, approximately two out of three breast cancers test estrogen-receptive, or ER-positive, or progesterone receptive, or PR-positive. Estrogen encourages the growth of ER- and PR-positive breast cancers.
Features
Hormone receptors may be present in breast cancer and will be mentioned in the pathology report. These receptors may be either estrogen or progesterone receptors, which means they respond to these hormones and send messages to the cancer cells. If hormone receptors are present, the cancer will likely have a good response to hormone therapy; a positive result for hormone receptor status is a good result, states Breastcancer.org.
Treatment
PR-positive breast cancer can be treated with a variety of treatments, including surgery, radiation and chemotherapy. Hormone receptor-positive breast cancer is also responsive to hormone therapy. According to Dr. Sandra Schnall from Breastcancer.org, if a breast cancer is either estrogen- or progesterone-positive, most hormonal therapies are thought to be effective, even if the estrogen receptors are negative. Oral medications include tamoxifen, toremifene, fulvestrant, aromatase inhibitors such as anastrazole, and Megace. Ovarian ablation is another hormone therapy option, says the American Cancer Society. This involves shutting down or removing the ovaries, the main sources of estrogen.
Effects
Side effects of hormone therapy for hormone-receptor positive breast cancer depend on the specific medication. Common side effects include fatigue, hot flashes, vaginal dryness, mood swings, mild nausea and weight gain. Some medications may increase the risk of bone thinning or osteoporosis, and certain kinds of cancers such as uterine sarcoma and endometrial cancer, according to the American Cancer Society.
Warning
Unexplained vaginal bleeding should be reported to a physician immediately, especially in women who are post-menopausal. While abnormal bleeding is not always symptomatic of cancer, the American Cancer Society states that this symptom should be reported to a physician immediately. Some hormone therapies may also increase the risk of developing blood clots, which can lead to stroke or heart attack. Having regular follow-ups with the health care team is important while on hormone therapy and after breast cancer treatment is over.
