Actionable Insights Newsletter

Translating research to power whole health

Issue 6    |    August 2023

Comparing the safety of a new hormone therapy to traditional hormone therapies for menopause symptoms among women in the US

Large, multi-database study shows conjugated estrogens+bazedoxifene (CE/BZA) users may experience higher rates of endometrial cancer and endometrial hyperplasia and lower rates of breast cancer than users of other medications for menopause symptoms.

Enterprise Analytics Core domain(s): Oncology, quality of care

Summary

Background
Conjugated estrogens+bazedoxifene (CE/BZA), also known as Duavive or Duavee, is a medication approved in May 2014 that is used to treat menopause symptoms, including hot flashes and night sweats. Previous evidence suggests that certain hormone therapies increase the risk of cancers, stroke, and heart attack.

Objective
To assess the rates of endometrial cancer, endometrial hyperplasia (a pre-cancerous thickening of the uterine lining), breast cancer, and other outcomes, such as stroke and heart attack, among women using CE/BZA compared to women using estrogen + progestin combination hormone therapy (EP).

Methods
Carelon Research conducted a cohort study using data from five U.S. healthcare claims databases. These databases included data from over 92 million women. Women who started using CE/BZA or EP from 01 May 2014 to 30 August 2019 were included. EP users (N=94,531) were matched to CE/BZA users (n=10,603) based on medical and prescription history and demographic data. Incidence of endometrial cancer, endometrial hyperplasia, breast cancer, and other outcomes were calculated for each treatment group. Rate ratios and differences were pooled across databases using specialized statistical techniques.

Results

• The analysis included 10,596 CE/BZA users and 33,818 EP users.
  
• Rates of endometrial cancer and endometrial hyperplasia during follow-up were slightly higher among the CE/BZA users (endometrial cancer rate ratio (RR)=1.50; 95% CI: 0.79, 2.88, and endometrial hyperplasia RR=1.69; 95% CI: 0.51, 5.61), but there were very few cases of these outcomes in either group.
• CE/BZA users were less likely than EP users to experience breast cancer during follow-up. There were, on average, 9 fewer cases of breast cancer for every 10,000 patients per year in the CE/BZA group than in the EP group.
• Results for several additional outcomes, including stroke and heart attack, were slightly higher among CE/BZA users, but these associations were less precise.

Key takeaways