An advisory panel to the Food and Drug Administration (FDA) has recommended that the agency approve the anti-osteoporosis drug raloxifene (Evista) for the prevention of breast cancer in postmenopausal women at high risk of the disease.

The panel, the FDA Oncology Drugs Advisory Committee (ODAC), also recommended approval for raloxifene's use to prevent breast cancer in women with osteoporosis. The committee's vote on this latter recommendation was close, 8-6, while the margin of the vote for the high-risk indication was somewhat larger, 10-4.

The recommendations stem from the results of four clinical trials, including the pivotal NCI-supported STAR trial, which showed that raloxifene was as effective as tamoxifen at reducing breast cancer risk in postmenopausal women at increased risk for the disease but with a generally better safety profile. Tamoxifen is the only drug that has received FDA approval for breast cancer prevention.

Dr. Peter Greenwald, director of NCI's Division of Cancer Prevention, said he was pleased with the recommendation. Should FDA follow ODAC's recommendation, he said, it will provide an important new option for breast cancer prevention that women can discuss with their physicians.

"This is a positive step for women's health and for cancer prevention," he said.

Some breast cancer advocacy groups, however, were disappointed in the recommendation, arguing that the benefits of tamoxifen or raloxifene don't outweigh their risks.

In their presentation to ODAC, FDA's own reviewers concluded it was "especially important" that raloxifene's risk/benefit ratio be carefully considered based on the available trial results.

In the STAR trial, both raloxifene and tamoxifen reduced the risk of invasive breast cancer by approximately 50 percent. Women on raloxifene were less likely to develop blood clots, endometrial cancer, and cataracts compared with women on tamoxifen, although not all were statistically significant reductions. Also, raloxifene did not decrease the risk of noninvasive breast cancer compared with tamoxifen.

The three other clinical trial results reviewed by the committee found that raloxifene was associated with a decreased risk of breast cancer in postmenopausal women, but none of these trials included that measure as a primary endpoint.

Although FDA often follows the advice of its advisory committees, it is not bound to do so. According to one media report, Eli Lilly, which manufactures raloxifene, said it expects a decision from the agency by September.