An expert panel approved the expanded use of the osteoporosis drug Evista, believing it to be effective in preventing some breast cancers. If the FDA follows this advice, the drug will be legally sold as a cancer prevention agent to millions of women. Evista would serve as an alternative to the anti-estrogen drug tamoxifen, which has long been used to help prevent the recurrence of breast cancer. Breast cancer is the second leading cause of cancer death among women, and about 13% of women are estimated to develop breast cancer in their lifetime. Experts recommend giving postmenopausal women at high risk the option to use Evista. Studies show that Evista and tamoxifen are equally effective in reducing cancer risk in these women. However, women taking Evista are at a higher risk of serious blood clots and fatal strokes. The FDA analysis is inconclusive as to whether Evista’s potential benefits outweigh its risks. Some breast cancer advocacy groups oppose the approval, arguing that the government should focus more on finding the causes of breast cancer. Some experts suggest restricting the drug's marketing, especially to women at risk for cardiovascular disease.