SOURCE: Manson JE, Aragaki AK, Rossouw JE, et al. JAMA 2017;318:927-938.
Hormone replacement therapy (HRT) reached its peak in the late 1990s based on observational data that suggested improvements in cardiovascular health, cognition, genitourinary health, and other factors. That changed drastically following the HERS trial and the Women’s Health Initiative (WHI), both of which found not only no cardiovascular benefit associated with HRT but increased adversities such as breast cancer and venous thrombosis.
Women were enrolled in the WHI from 1993-1998, and have been followed through 2014, so clinicians can look at the long-term effects of their treatments for the six or seven years they participated in the trial through that date. There was no difference in all-cause mortality or cancer-related mortality between treated and untreated patients over 18 years of follow-up. It has been noted that younger women (age 50-59 years) in the WHI had a favorable outcome for all-cause mortality during the trial. This trend continued through the 18-year follow-up (hazard ratio for mortality, 0.87; confidence interval, 0.76-1.00).
For women who currently use or have used hormone replacement for menopausal symptoms, these data should be reassuring that their symptom relief does not come at a cost of increased total or cancer-related mortality.