Topical tamoxifen may reduce side effects

CHICAGO, June 22 (UPI) -- U.S. researchers are conducting a clinical trial to see if a gel containing an active form of tamoxifen, which reduces breast cancer risk, is effective.

Principal investigator Dr. Seema Khan of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University and a surgical oncologist at Northwestern Memorial Hospital, says women with ductal carcinoma in situ are usually advised to take oral tamoxifen for five years. However, some women refuse tamoxifen because it has an increased risk of blood clots, uterine cancer and hot flashes.

Half of the women received the study gel and half the women received the oral tamoxifen.

"The gel is a way to minimize exposure to the rest of the body and concentrate the drug in the breast where it is needed," Khan says in a statement. "Delivery of the drug through the skin of the breast means there will be very little drug circulating through the bloodstream and the body. This should reduce the possibility of blood clots."

Khan says the trial is similar to delivery of estrogen via skin patch to avoid the risk of blood clots, and because the circulating levels of the topical drug are very low, the gel should be unlikely to cause other side effects such as hot flashes and the increased risk of uterine cancer.