Long term use of statins increases the risk of breast cancer

This study was published in Cancer Epidemiology, Biomarkers and Prevention 2013 Jul 5

Study title and authors:
Long-term statin use and risk of ductal and lobular breast cancer among women 55-74 years of age.

McDougall JA, Malone KE, Daling JR, Cushing-Haugen KL, Porter PL, Li CI.
Epidemiology, Fred Hutchinson Cancer Research Center.

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/23833125

This study investigated the relationship between long term statin use and the risk of breast cancer. The study included 916 women with invasive ductal carcinoma breast cancer and 1,068 women with invasive lobular carcinoma breast cancer who were compared with 902 women free of breast cancer. The women were aged between 55-74 years.

The study found:
(a) Current users of statins for 10 years or longer had a 1.83-fold increased risk of invasive ductal carcinoma breast cancer compared to women who had never used statins.
(b) Current users of statins for 10 years or longer had a 1.97-fold increased risk of invasive lobular carcinoma breast cancer compared to women who had never used statins.

McDougall concluded: "Long-term use of statins was associated with increased risks of both invasive ductal carcinoma and invasive lobular carcinoma".