Hormone replacement therapy. Current controversies.

Hormone replacement therapy has had a controversial history since its introduction for medical use several decades ago. Current evidence indicates that users of hormone replacement therapy have an increased risk of venous thromboembolism, stroke, and coronary heart disease compared to non-users. Among users, the risk of breast cancer is modestly increased. This effect becomes apparent after 4 to 5 years use and primarily with use of combination estrogen plus progestin products. The risk of colorectal cancer is decreased with use of hormone replacement therapy. In addition, the risk of osteopenia and osteoporosis is decreased as is the risk of osteoporotic fracture.