Hormone therapy and breast cancer risk 10 years after the WHI.

Ten years after the publication of the first Women's Health Initiative (WHI) report, a substantial decrease in hormone replacement therapy (HRT) has been observed world-wide. Fear of developing breast cancer represents one of the reasons for an important shift toward alternatives for treatment of menopause symptoms or abstention from therapy altogether. Many publications in the scientific and lay press have emphasized the magnitude of the relative risk of breast cancer but have not focused on excess or attributable risk. Since the original report of the WHI study, new information has been published on risk factors for breast cancer related to hormone therapy use. Accordingly, we believe it important to review current data and examine excess rather than relative or absolute risk. A balanced perspective on excess risk determined from existing data suggests that the benefits of HRT for quality of life can outweigh the risks in management of a large number of postmenopausal women. In addition, alternative strategies for relief of menopausal symptoms are not as effective as HRT in treating the climacteric symptoms.