Retrospective cohort study of association of statin use and risk of breast cancer among women with benign breast disease in Denmark

Statins have been suggested to protect against breast cancer risk, but the observational evidence is inconclusive. A nationwide retrospective cohort study in Denmark evaluated the association between statin use and breast cancer incidence among women aged 50 years or older at elevated risk of breast cancer due to a history of benign breast disease (BBD). Among 111,550 women with BBD, 7629 (6.8%) were diagnosed with breast cancer during median follow-up of 12.2 years. Overall statin use was not associated with breast cancer incidence (aHR 0.99; 95% CI 0.93-1.06). However long-term (≥ 10 years), high-intensity statin use was associated with lower risk of breast cancer (aHR 0.75; 95% CI 0.60-0.96). The authors conclude that the study did not find an association for overall statin use with breast cancer incidence among women with BBD. The inverse association with long-term-high-dose statin use requires further evaluation.