Breast cancer: the role of hormone therapy

The possible association of estrogen (E) with or without progestin (P) and breast cancer has been addressed in many studies for several decades. The recent reported prospective double-blind Women's Health Initiative (WHI) study suggests that E + P increases the risk of breast cancer if a woman is an average of 63 years old when she begins replacement therapy. One third of the patients in this study were 70 to 79 years of age when E + P was begun--obviously several decades past menopausal. Retrospective and observational studies suggest protection or no increased risk. The WHI-E only study actually notes a 23% reduction in breast cancer compared with the placebo. It would appear from a review of the literature that if there is an increased risk for breast cancer with E or E + P, it is minimal.