Prospective Analysis of Association between Statin Use and Breast Cancer Risk in the Women's Health Initiative
A partir des données de la cohorte "Women's Health Initiative" incluant 154 587 femmes âgées de 50 à 79 ans, cette étude prospective évalue l'association entre l'utilisation de statines et le risque de cancer du sein
Background: Statins are a class of cholesterol lowering drugs that affect many intracellular pathways which may have implications for chemo prevention against cancer. Epidemiological data on statins and breast cancer is conflicting. We analyzed updated data from the Women's Health Initiative (WHI) to assess the relationship between statins and breast cancer risk. Methods: The population included 154,587 post-menopausal women ages 50-79 years, with 7,430 pathologically confirmed cases of breast cancer identified over an average of 10.8 (SD 3.3) years. Information on statins was collected at baseline and years 1, 3, 6, and 9. Self- and interviewer-administered questionnaires were used to collect information on risk factors. Cox proportional hazards regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) to evaluate the relationship between statin use and cancer risk. Statistical tests were two-sided. Results: Statins were used by 11,584 (7.5%) women at baseline. The annualized rate of breast cancer was 0.42% among statin users and 0.42% among nonusers. The multivariable adjusted HR of breast cancer for users versus non-users was 0.94 (95% C.I. 0.83-1.06). In the multivariable adjusted time-dependent model, the HR for simvastatin was 0.87 (95% CI, 0.71-1.07). There was no significant trend by overall duration of use (p value for trend 0.68). There was no effect of tumor stage, grade or hormone receptor status. Conclusion: Overall statins were not associated with breast cancer risk. Impact: Our study adds to the literature suggesting no relationship between statins and breast cancer risk.