Statin use and risk of breast cancer

BACKGROUND. Findings that statins inhibited the Proliferation of breast cancer cells in vitro and in rodents have raised interest in whether the use of statins might decrease a woman's risk of developing breast cancer. We analyzed data from a Population-based case-control Study to evaluate the association between the use of statins and breast cancer risk. METHODS. Cases of incident invasive breast cancer in women 50 years of age or older and diagnosed from 1995-2001 were identified from Population-based cancer registries in Wisconsin, Massachusetts, and New Hampshire. Controls were randomly selected, within each state, from lists of licensed drivers and Medicare beneficiaries. Information on the use of statins and other breast cancer risk factors was ascertained from structured telephone interviews. RESULTS. Overall, breast cancer cases were not more likely than controls to have ever used slatins. Ever use of lipophilic statins as a group (simvastatin, lovastatin, and fluvastatin) and ever use of the hydrophilic statin pravastatin were also not associated with breast cancer risk. Ever use Of fluvastatin was associated with a decreased risk of breast cancer (odds ratio [OR], 0.5; 95% confidence interval, 0.3-0.8) but the magnitude of the ORs did not vary across categories of duration of use. CONCLUSIONS. The use of statins overall was not associated with breast cancer risk.