A popular class of cholesterol lowering drugs called "statins" does not increase the risk of breast cancer. A new study published in the journal Cancer shows that long-term use of statins may actually reduce risk of breast cancer in postmenopausal women.

Since their approval by the FDA in 1987, statins have demonstrated tremendous efficacy in lowering cholesterol and reducing morbidity of heart disease. But early rodent experiments and clinical trial reports suggested statins might increase the risk of breast cancer. Further studies continue to offer conflicting data on the risk of cancer, in large part due to the limited range of statin exposure duration and inadequate sample size.

Conversely, more recent laboratory data and population-based studies suggest that statins may actually reduce cancer risk. In light of this question regarding the safety of this increasingly important class of drugs, a team of researchers led by Dr. Denise M. Boudreau of the Center for Health Studies, Group Health Cooperative in Seattle, WA conducted a case-control study at the Fred Hutchinson Cancer Research Center to investigate associations between breast cancer and statin use. The researchers analyzed data from 975 postmenopausal women with breast cancer and 1007 women without the disease.

The authors found that among women currently using statins, there was no increased risk of breast cancer (odds ratio 1.0). Among long-term users (> 5 years), the risk of breast cancer actually decreased (odds ratio = 0.7).

The authors conclude, "Our results both provide reassurance on the safety of statin use among older women, and support the emerging evidence that statins may have a chemoprotective action on breast cancer risk."

SOURCE:
Cancer, June 1, 2004, published online April 26, 2004