Postmenopausal women reduce chance for tumor recurrence when breast cancer therapy is supplemented with aromatase inhibitors.
HEALTH Experts from the American Society of Clinical Oncology (ASCO) reviewed available clinical research and issued guidelines for oncologists. Aromatase inhibitor works by reducing estrogen production. Your adrenal glands produce a substance called androstenedione, which gets converted into estrogen in tissues such as fat and muscle, as well as in breast cancers themselves. The conversion requires an enzyme called aromatase. Aromatase inhibitors stop the conversion of androstenedione to estrogen, thereby lowering the amount of estrogen in the body. On the other hand, often prescribed tamoxifen blocks estrogen action specifically on cancer tumors that are estrogen-receptor positive.
New guidelines basically state that when following radiation, surgical or chemotherapy treatments, an aromatase inhibitor reduces cancer recurrence. This is evident whether, the aromatase inhibitor is used concurrently with, a replacement for, or within five years of beginning tamoxifen therapy. The treatment is ineffective in pre- or perimenopausal women. So a five-year course of tamoxifen is still recommended.
The three aromatase inhibitors that are currently on the market offer comparable benefits. However, they can cost over 17 times as much as tamoxifen. Generic amortize inhibitors have recently been made available, which should improve the cost disparity.
Hot flashes, muscle aches, headaches and fatigue are mild effects generally experienced by women taking aromatase inhibitors. Dr. Harold J. Burstein, co-chairman of the ASCO committee preparing the guidelines, reports: "Aromatase inhibitors are clearly associated with osteoporosis and with bone and joint [pain which can be prominent in some women]. They might also be associated with a greater risk of hypertension and high cholesterol."
More serious side effects have been reported with tamoxifen. These include cataracts, uterine cancer, blood clots and stroke.
Though the new breast cancer treatment guidelines replace those issued in 2002, 2003, and 2004, they basically support what has been practiced for some time by oncologists reading the same reports reviewed by the ASCO.
- Experts Issue New Guidelines on Breast Cancer Drugs, HealthDay, Bloomberg Businessweek
- Adjuvant therapy guide for breast cancer, Mayo Clinic
- American Society of Clinical Oncology Guidelines
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