Statins Decrease Risk of Colon Cancer
Colon Cancer and Statins
People who took a type of cholesterol-lowering drug for five years had nearly half the risk of developing colon cancer, even when they had a family history of the disease or other risk factors, according to researchers at the University of Michigan Comprehensive Cancer Center. Results of the study appear in the May 26 New England Journal of Medicine.
Statins, such as Zocor, Pravachol or Lipitor, are typically used for lowering cholesterol and have been shown to be effective at preventing cardiovascular disease.
"This is an important piece of the puzzle. This piece helps bring together evidence that statins may have the potential to prevent chronic diseases other than heart disease, and helps us consider ways to study these powerful drugs for more than one purpose," says study author Stephen Gruber, M.D., Ph.D., M.P.H., associate professor of internal medicine and human genetics at the U-M Medical School and associate professor of epidemiology at the U-M School of Public Health.
Data was based on the Molecular Epidemiology of Colorectal Cancer study, a population-based case-control study of colorectal cancer in northern Israel. The researchers analyzed 1,953 people with colorectal cancer and 2,015 control subjects who did not have colon cancer. All study participants were asked to recall every medication they had used for at least five years. Statin use was determined based on this list and validated against prescription records from the health care provider.
The people without colon cancer were nearly twice as likely to report taking statins for at least five years, compared to the people with a history of colon cancer, 11.6 percent vs. 6.1 percent.
Researchers analyzed the data taking into account increased or decreased risk associated with demographic factors such as age, sex and ethnic background, and with lifestyle factors such as taking aspirin, participating in sports and eating vegetables. They also considered family history of colon cancer, which increases a person's risk.
Even considering all these additional factors, statins were still associated with a 47 percent reduced risk of colorectal cancer.
It's not known or well understood why statins show a protective effect against cancer. Recent research has suggested a similar connection between statins and other types of cancer, including breast, prostate, pancreatic and esophageal cancers. Researchers suspect something in the cholesterol pathway may affect a person's risk of colon cancer.
"Statins also have anti-inflammatory properties that might be relevant for cancer. That may explain why they appear to work in other cancers besides colon cancer," says study lead author Jenny Poynter, M.P.H., a graduate student in the U-M School of Public Health.
But the researchers caution, it's not advisable for everyone to begin taking statins to prevent cancer.
"We are now working to identify those groups who are likely to benefit most. In order to proceed to clinical trials, it is important to know who is most likely to benefit, and who isn't," says Gruber, co-director of the biomedical prevention program at the U-M Comprehensive Cancer Center.
Nearly 105,000 people will be diagnosed with colon cancer in the United States this year, according to the American Cancer Society, and some 56,000 will die from the disease.
In addition to Gruber and Poynter, U-M study authors are Peter Higgins, M.D., Ph.D., lecturer in gastroenterology; Joel Greenson, M.D., assistant professor of pathology; and Joseph Bonner, a programmer analyst in internal medicine. Other authors are Ronit Almog, M.D., M.P.H.; Hedy Rennert, M.P.H., Marcelo Low, M.P.H., and Gad Rennert, M.D., Ph.D., all from the Technion-Israel Institute of Technology and Clalit Health Services National Cancer Control Center in Haifa, Israel.
Funding for the study is from the National Cancer Institute, the Ravitz Foundation and the National Institutes of Health.
For more information on colorectal cancer, visit www.cancer.med.umich.edu/learn/coloninfo.htm or call the Cancer AnswerLine at 800-865-1125.
Reference: New England Journal of Medicine, Vol. 352, No. 21, pp. 2184-92
U-M News - ANN ARBOR, Mich.