Menopausal hormone therapy and mortality among endometrial cancer patients in the NIH-AARP Diet and Health Study.

Abstract

While menopausal hormone therapy (MHT) is an established endometrial cancer risk factor, its relationship with mortality among endometrial cancer patients is understudied. Within the NIH-AARP Diet and Health Study, we examined the associations of pre-diagnosis MHT use with 10-year all-cause and endometrial cancer-specific mortality among 890 endometrial cancer patients. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for tumor characteristics, treatment, and other risk factors. Endometrial cancer cases were diagnosed a median of 4.6years (range 0.0-10.1years) after the second risk factor questionnaire was completed. We identified a total of 241 deaths, of which 104 were due to endometrial cancer. Compared with non-MHT use, pre-diagnosis use of estrogen plus progestin therapy (EPT)-only was associated with lower 10-year all-cause (HR 0.65, 95% CI 0.43-0.99, based on 29 deaths) and endometrial cancer-specific mortality (HR 0.51, 95% CI 0.26-0.98, based on 11 deaths). Recency of MHT use, assessed approximately 5years prior to the endometrial cancer diagnosis, was associated with mortality. Compared with non-MHT users, former ET users had higher all-cause (HR 1.71, 95% CI 1.02-2.88, based on 18 deaths) and endometrial cancer-specific mortality (HR 2.17, 95% CI 0.96-4.90, based on 8 deaths), whereas current EPT users had nonsignificant lower risks of death. Based on small numbers, we observed that pre-diagnosis use of EPT was related to lower mortality among endometrial cancer patients. Future studies examining the biological mechanisms underlying this association are warranted.