Tuesday June 15 5:58 PM ET
Osteoporosis drug reduces breast cancer risk
NEW YORK, Jun 15 (Reuters Health) -- Older women who took the drug raloxifene (Evista) to reduce their risk of osteoporosis over a 3-year period
had a 76% reduction in their risk of invasive breast cancer, results of a study suggest.
If raloxifene's benefits continue over time, the drug ''may be a way of substantially reducing a woman's lifetime risk of breast cancer,'' said lead
researcher Dr. Steven R. Cummings of the University of California at San Francisco in a statement.
During the study, 7,705 postmenopausal women were randomly assigned to either 60 milligrams or 120 milligrams of raloxifene daily or (an inactive)
placebo.
Overall, about 1% of women taking a placebo developed invasive breast cancer compared with 0.2% of women taking raloxifene, according to a report
in the June 16th issue of The Journal of the American Medical Association.
The dose of raloxifene did not seem important, with women taking either dose having a reduction in breast cancer risk, according to Cummings.
''You don't often find changes of this magnitude in medicine,'' said Cummings in an interview with Reuters Health. ''If this reduced risk continues
over 10 years -- currently there is a one in nine chance of a woman getting breast cancer -- we could reduce the risk to 2 or 3 out of 100 over the
course of life.''
The trial, which was originally designed to look at the effects of raloxifene on fracture risk, will continue for a minimum of 8 years.
Women taking raloxifene had a higher risk of developing blood clots in the legs or lungs, but did not have an increased risk of endometrial cancer. In
contrast, tamoxifen, a similar type of estrogen-mimicking drug, does increase the risk of endometrial cancer, Cummings noted.
''The issue is, how long do these effects last?'' Cummings said. ''We're not yet ready to prescribe raloxifene for all postmenopausal women. For
those at risk of breast cancer and osteoporosis, or for whom these diseases are a source of worry, (treatment should be considered).''
Raloxifene is currently approved by the Food and Drug Administration for the prevention of osteoporosis, but not the prevention of breast cancer.
Tamoxifen, which has been studied much more extensively, is the only drug approved by the FDA for breast cancer prevention.
SOURCE: The Journal of the American Medical Association 1999;281:2189-2197, 2243-2244. |
