Postmenopausal estrogen, cancer and other considerations.

The female hormone estrogen is widely prescribed to postmenopausal women. Its major documented benefit is prevention of bone mineral loss, which is a major risk factor for fracture in the elderly. Its clearly documented risk is promotion of cancer of the endometrium. There is a growing body of data that suggests that postmenopausal estrogen therapy reduces the risk of cardiovascular disease. This benefit, if real, may be lost when a cyclic progestin is added to reduce the risk of cancer. Further studies are needed to provide a firmer basis for balancing these risks and benefits.