Aromatase inhibitors better than tamoxifen

Aromatase inhibitors, which lower the amount of estrogen in the body, are more effective in preventing breast cancer than tamoxifen, U.S. researchers said.

Two separate meta-analyses of worldwide clinical trials tested tamoxifen against aromatase inhibitor drugs in post-menopausal women with early breast cancer, and each reached the same conclusion: aromatase inhibitors are more effective in preventing breast cancer from coming back.

Tamoxifen and aromatase inhibitors are widely used to prevent recurrence of, or to treat, tumors that are estrogen-receptor positive, which comprise 70 percent to 80 percent of all breast cancers.

Tamoxifen is a good drug, but it looks like aromatase inhibitors may be somewhat better, Dr. James Ingle of the Mayo Clinic in Rochester, Minn., said in a statement.

The importance of these findings can be seen from the fact that 80,000 to 90,000 women in the United States alone are using endocrine therapy this year, while a 3 percent difference in cancer recurrence may not seem like much, it can mean that several thousand women could be spared from a breast cancer recurrence.

The joint analyses are being presented at the Cancer Therapy & Research Center-American Association for Cancer Research 31st annual San Antonio Breast Cancer Symposium.