But first drug helps prevent noninvasive disease more and has fewer side effects, study finds
MONDAY, April 19 (HealthDay News) -- The latest results from a landmark, long-running study find that both tamoxifen and raloxifene help prevent breast cancer in postmenopausal women, although some differences are starting to emerge between the two drugs.
Raloxifene (Evista), originally an osteoporosis drug, was less effective at preventing invasive breast cancer and more effective against noninvasive breast cancer than tamoxifen. But raloxifene compensated by having fewer side effects and a lower likelihood of causing uterine cancer than its older cousin. Both drugs work by interfering with the ability of estrogen to fuel tumor growth.
"The results of this update are good news for postmenopausal women. It reconfirms that both of these drugs are very reasonable options to consider to reduce the risk of breast cancer in postmenopausal women," said Dr. D. Lawrence Wickerham, associate chairman of the breast cancer group in the National Surgical Adjuvant Breast and Bowel Project (NSABP), a clinical trials cooperative group. "We are seeing some differences emerging, but both are effective."
Tamoxifen also stays in the body longer, offering protection for a longer time after women have stopped taking the drug, the study found.
"Both drugs still offer significant protection against breast cancer. The main difference with the longer-term follow-up is that the benefit of protection afforded by raloxifene looks like it's tailing [after women stop taking the drug], whereas the effect of tamoxifen persists," said Dr. Mary Daly, chairwoman of clinical genetics at Fox Chase Cancer Center in Philadelphia.
This also means the toxicities of tamoxifen persist after women stop taking that drug, she pointed out.
The findings were presented Monday at the American Association for Cancer Research annual meeting in
All rights reserved