This is a very comprehensive, well referenced report authored by the Life Extension Foundation. It concludes:
Given the preponderance of evidence, maturing women should feel confident that bioidentical hormone replacement, when appropriately prescribed, offers a safer and potentially even more effective alternative to conventional hormone replacement with non-bioidentical hormone drugs to help relieve menopausal symptoms and optimize long-term health. The addition of several proven nutrients to a bioidentical hormone regimen may help optimize estrogen metabolism and reduce cancer risk even further, offering an optimal, balanced approach to health maintenance.
http://www.lef.org/magazine/