- Current, but not past, use of menopausal hormone therapy (MHT) by postmenopausal women is associated with nearly doubled odds of any breast cancer.
- Current use of MHT is associated with even higher odds of:
- Estrogen-receptor (ER)+ disease.
- ER+, progesterone-receptor (PR)+ disease.
- ER+/PR+ and human epidermal growth factor receptor-2 (HER-2)-negative disease.
Why this matters
- Findings underscore recommendations to limit MHT use to the shortest time possible, and to women with severe symptoms.
- Cohort study comparing 399 registry-verified breast cancer cases with known receptor status with 324 cancer-free control patients enrolled in the New South Wales (NSW) Cancer Lifestyle and Evaluation of Risk (CLEAR) study.
- MHT use ascertained by questionnaire.
- Funding: Cancer Council NSW.
- Current (vs never) MHT use is associated with higher risk for breast cancer of any subtype (adjusted OR [aOR], 1.98; 95% CI, 1.27-3.11); past MHT use (vs never) is not.
- Current (vs never) MHT use is associated with even higher risks for these BC subtypes:
- ER+ subtype (aOR, 2.04; 95% CI, 1.28-3.24).
- ER+/PR+ subtype (aOR, 2.29; 95% CI, 1.41-3.72).
- ER+/PR+/HER2− subtype (aOR, 2.30; 95% CI, 1.42-3.73).
- Current MHT use is not associated with other ER, ER/PR, or ER/PR/HER2 subtypes.
- Observational design.