Breast Cancer Drug OKd for Use in Avoiding Recurrence

The Food and Drug Administration agreed Friday to allow a drug used against advanced breast cancer to be prescribed to prevent the disease from recurring in women who have been treated for early forms of the disease.

The agency approved the new use for letrozole, which can now be prescribed for postmenopausal women who have finished five years of treatment with tamoxifen.

The manufacturer, Novartis Pharmaceuticals, sells the drug under the name Femara. The drug is taken daily and costs about $210 a month, the company said.

The drug will offer new therapy to about 100,000 each year who complete tamoxifen treatment for breast cancer, said Dr. Diane Young, a Novartis vice president.

A clinical study of the drug showed it cut the risk of recurrence by half.

More than 5,000 women in North America and Europe participated in the study. They had the most common form of breast cancer and had completed the recommended five years of tamoxifen treatment.

The women were given either letrozole or a dummy pill. After nearly 2 1/2 years, 132 of those taking the placebo had a cancer recurrence, compared with 75 of those on letrozole. The study was stopped so women getting the placebo could be switched to letrozole.

The hormone estrogen fuels the growth of many breast cancers and can encourage a dormant cancer to begin growing again.

Tamoxifen, which blocks estrogen from connecting to cells, is recommended after early breast cancer is treated with surgery and chemotherapy. After five years or so the body can become resistant, and until now, no follow-up treatment has been available. Letrozole also blocks the effects of estrogen.

Hot flashes and arthritis were the most common side effects reported in the study.