A popular class of cholesterol-lowering drugs called "statins" does not increase the risk of breast cancer and may even reduce the risk, according to a new study led by researchers at the Center for Health Studies at Group Health Cooperative in Seattle and the Public Health Sciences Division.
Dr. Denise Boudreau, a Group Health investigator who conducted the study as part of her dissertation research at Fred Hutchinson, and colleagues found that long-term use of statins appeared to reduce the risk of breast cancer by 30 percent in postmenopausal women. "More research is needed, but these results are very encouraging," Boudreau said. The findings appear in the online edition of Cancer and will appear in print in the journal's June 1 issue.
Since their approval by the U.S. Food and Drug Administration in 1987, statins have demonstrated tremendous effectiveness in lowering cholesterol and reducing complications 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 use duration and the small numbers of women studied.
Conversely, more recent laboratory data and population-based studies suggest statins may actually reduce cancer risk. In light of this question regarding the safety of this increasingly important class of drugs, the researchers conducted a case-control study at Fred Hutchinson to investigate associations between breast cancer and statin use. The researchers analyzed data from 975 postmenopausal women with breast cancer and 1,007 women without the disease.
The authors found that among women currently using statins, there was no increased risk of breast cancer. Among long-term users, the risk of breast cancer actually decreased by about 30 percent.
Boudreau recently received a grant from the National Cancer Institute to further research statins and breast-cancer risk, including in younger women. At the Center for Health Studies, Boudreau also will look at the relationship between statin use and other site-specific cancers including those of the prostate and reproductive organs.
Coauthors included PHS investigators Dr. Kathi Malone and Dr. Janet Daling; Dr. Jaqueline Gardner and Dr. David Blough, University of Washington; and Dr. Susan Heckbert, Group Health Cooperative Center for Health Studies.