Postdiagnosis Statin Use Linked to Lower Breast Cancer Mortality

Postdiagnosis Statin Use Linked to Lower Breast Cancer Mortality

POSTDIAGNOSIS statin use was associated with a modest but measurable reduction in breast cancer-related deaths among women with early-stage disease, according to new findings from a large observational cohort study.

Study Design and Population

Using a target trial emulation approach, researchers evaluated data from 66,952 women diagnosed with Stage I–III breast cancer between 2000 and 2021. Participants were identified through comprehensive Danish national registries, including the Danish Breast Cancer Group’s clinical database and the Danish National Prescription Registry. Women with previous invasive breast cancer or prediagnosis use of cholesterol-lowering medication were excluded. Eligible patients were assigned to one of two treatment strategies: statin initiation within 36 months of diagnosis or no statin initiation. The study followed participants until death, emigration, or up to 10 years after diagnosis.

Breast Cancer Mortality and Statin Use

During 606,266 person-years of follow-up, 9,130 participants died from breast cancer and 19,679 from any cause. Among those who initiated statins, the 10-year breast cancer mortality risk was 11.8%, compared with 13.5% among noninitiators, a difference of 1.7% (95% CI: 0.5%–3.0%). Weighted analyses yielded an HR of 0.90 (95% CI: 0.85–0.95) for breast cancer mortality and 0.92 (95% CI: 0.85–1.00) for all-cause mortality, suggesting a small but statistically significant benefit.

Clinical Implications

These findings indicate that initiating statin therapy after a breast cancer diagnosis may confer a survival advantage beyond cardiovascular protection. The modest reduction in mortality supports the hypothesis that cholesterol metabolism contributes to tumor progression, aligning with emerging evidence that lipid pathways influence cancer biology. Given the widespread availability and established safety of statins, their potential role as adjunctive therapy in oncology warrants further clinical investigation through randomized trials. Such studies could clarify optimal timing, dosage, and patient selection to determine whether integrating statins into breast cancer management can improve long-term outcomes.

Reference: Harborg S et al. Postdiagnosis Statin Use and Breast Cancer Mortality. JAMA Netw Open. 2025;8(10):e2538737.