Study: Drug May Prevent Breast Cancer

A new study shows that a drug used for years to treat breast cancer patients also may prevent the disease from occurring, according to a newspaper report.

The National Cancer Institute said its six-year study was the first to show that a drug can reduce the incidence of breast cancer, the Philadelphia Inquirer reported Sunday.

The study showed that the drug tamoxifen cut cancer rates by nearly half among women who were considered at risk of getting the disease.

The institute recently mailed letters announcing the breakthrough to the 13,000 women in the United States and Canada who participated in the study, the newspaper reported.

The results of the study--one of the largest cancer prevention trials ever undertaken--are to be made public Wednesday. Researchers would not discuss the results with the newspaper.

Women at risk of getting the disease because of family history, precancerous breast lesions or age were randomly assigned to five years on either a placebo pill or tamoxifen.

The drug, made by Wilmington, Del.-based Zeneca Pharmaceuticals, is widely used to prevent the spread or return of breast cancer.

According to the institute, the drug reduced the rate of expected breast cancers from 1 in 130 women to 1 in 236 during the study, the Inquirer reported.

However, tamoxifen also has been associated with increased risks for cancer in the uterine lining and for blood clots in the lungs.