Study: Arimidex May Replace Tamoxifen as Gold Standard of Treatment

A new drug for breast cancer patients, Arimidex, may replace tamoxifen as the gold standard in treatment and may even prevent the disease, according to researchers at Cancer Research UK.

Arimidex (anastrozole) has the potential to prevent or delay up to 80 percent of breast tumors in most postmenopausal women who are considered high risk, the researchers reported..

Taxoxifen has been shown to reduce the risk of contralateral cancer (breast cancer occurring in the second breast after primary cancer has been treated in first breast) by 50 percent. Findings from this new study have shown that Arimidex has the potential to reduce the risk of contralateral cancer by up to 80 percent.

Arimidex inhibits the production of estrogen and does it more effectively than tamoxifen in breast cancer patients who respond to hormone treatment, the researchers said.

Another advantage of Arimidex is that it has fewer side effects than tamoxifen, which can cause an increased risk of endometrial cancer, vaginal bleeding, hot flashes and blood clots.

The study, published in The Lancet, tracked more than 9,000 postmenopausal women in 21 countries for almost three years. One third of the women were given Arimidex, one third were given tamoxifen and one third were given a combination of the two drugs.

Although the study was designed to treat women with existing breast cancer, researchers found a reduction in contralateral breast cancer, reported Joan Houghton, senior lecturer and co-author of the study.

"Therefore there is the suggestion that anastrozole would also be a good drug to use as a preventative agent, especially as side effects are reduced," said Houghton.

The study only compared tamoxifen and Arimidex in women with newly diagnosed breast cancer. There is no research that shows that patients already taking tamoxifen would benefit by changing drugs.

Other sources: Cancer Researck UK