Association Between Menopausal Hormone Therapy and Cancer: A Nationwide Retrospective Cohort Study in South Korea
Menée à l'aide de données de l'Assurance maladie coréenne portant sur 276 890 femmes ménopausées et âgées d'au moins 40 ans (durée médiane de suivi : 7,9 ans), cette étude analyse l'association entre l'utilisation d'un traitement hormonal substitutif par type et le risque de cancer
Background: To investigate MHT(menopausal hormone therapy)’s overall cancer risks in postmenopausal women.
Methods: This retrospective cohort study used South Korea’s National Health Insurance System data, focusing on women aged 40 or older diagnosed with initial menopause (2011-2014), comparing an MHT group (≥6 months) to a propensity score-matched non-MHT group for cancer incidence until 2020.
Results: We matched 138,445 women per group, followed for a median 7.9 years. Breast (28%), thyroid (23%) and colorectal (8%) cancers predominated. MHT increased the overall cancer risk (hazard ratio [HR] 1.104, 95% confidence interval [CI] 1.064-1.145), especially estrogen plus progestogen therapy (EPT) (HR 1.172, 95% CI 1.119-1.227) and estrogen-alone therapy (ET) (HR 1.142, 95% CI 1.05-1.244), but not tibolone. Breast (HR 1.568, 95% CI 1.448-1.697), colorectal (HR 1.157, 95% CI 1.018-1.315), brain (HR 1.618, 95% CI 1.6-2.258), and renal (HR 1.378, 95% CI 1.053-1.803) cancers were more common in MHT; uterine cancer decreased (HR 0.865, 95% CI 0.763-0.981).
Conclusions: MHT increased overall cancer risk, with EPT and ET elevating risks, unlike tibolone. MHT users faced higher breast, brain, renal, and colorectal cancer risks, but lower uterine cancer risk. Impact: These findings suggest considering lower-potency progestogens in current estrogen/progestogen. This change might increase endometrial cancer risk but reduce breast cancer risk, potentially lowering overall cancer risk.
Cancer Epidemiology, Biomarkers & Prevention , résumé, 2026