Clinical trial proves the ongoing benefit of tamoxifen

Reported by Susan Aldridge, PhD, medical journalist

The benefits of tamoxifen in preventing breast cancer continue after treatment has stopped.
Previous research has shown that tamoxifen can reduce the risk of hormone receptor positive breast cancer in women who are at risk. Now researchers for Cancer Research UK report on a follow up study, which reveals that the protective benefit of tamoxifen continues for several years after treatment stops.

A group of over 7,000 pre and postmenopausal women in seven countries who were at risk of breast cancer took either 20 mg of tamoxifen or a placebo every day for five years. After an average follow up of 96 months, there were 142 breast cancers among the tamoxifen group compared to 195 in the placebo group. Moreover, the side effects of tamoxifen stop after women cease taking it, according to this trial. Meanwhile, the researchers are looking an alternative drug, anastrozole, which may have fewer side effects than tamoxifen. Results from this trial are due in 2010 and will show if anastrozole has similar protective benefits against breast cancer.

Source
Journal of the National Cancer Institute 20th February 2007 Volume 99 pages 272-282