The big news in breast cancer research this week (so far anyway) is the results of a new study that shows a drug used to treat or prevent osteoporosis can also reduce the risk of breast cancer.

This study called ‘Study of Tamoxifen and Raloxifene’ or ‘STAR’ involved close to 20,000 post-menopausal women. These women were randomly assign to be in one of two groups. One group were given tamoxifen - used to treat women with estrogen-receptor-positive cancer and to prevent it in high risk women - the other raloxifene. Raloxifene is sold by Eli Lilly as Evista and is used to treat and prevent osteoporosis. The study lasted five years.

The results show that women taking raloxifene reduced their chances of getting invasive breast cancer by 50%, about the same amount of protection as taking tamoxifen.

Both drugs, tamoxifen and raloxifene, are ’selective estrogen response modulators’ which behave like estrogen in some parts of the body, but not in others.

The women in the raloxifene group tended to have less side effects than the women in the other group.

Raloxifene has not be approved by the FDA to be used to prevent cancer, but Eli Lilly will most likely petition the FDA so that it can be used by high-risk, post-menopausal women to reduce their risk of developing breast cancer.

(Technorati Tags: breast cancer, raloxifene, tamoxifen, estrogen)