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.Cholesterol-lowering statin drugs can almost halve the risk of colon cancer, even in people with a family history of the disease, a joint Israeli-US study has shown. 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.
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 Technion-Israel Institute of Technology. The results of the study appeared in the May 26 New England Journal of Medicine.
Statin drugs, such as Zocor, Pravachol or Lipitor, are typically used for lowering cholesterol and have been shown to be effective at preventing cardiovascular disease. Data was based on the Molecular Epidemiology of Colorectal Cancer study, a population-based case-control study of colorectal cancer in northern Israel.
The results were shown for the first time by an Israeli team, which was headed by epidemiology Prof. Gad Rennert of the Technion’s Rappaport Medical Faculty, Clalit Health Services’ National Cancer Control Center and Carmel Hospital in Haifa, with participation by Prof. Stephen Gruber and colleagues at the University of Michigan.
The researchers analyzed 1,953 Israelis 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 Haifa team conducted personal interviews with the patients, divided equally into matched groups that either received statins for five years or did not and were backed up by computerized prescription records.
Most of the patients were Jews of Ashkenazi origin, a group in which colorectal cancer is more common, but there were also Jews of Sephardi origin and Arabs in both groups. Adjustments were made for age, sex, the use or non-use of aspirin or other NSAIDS, ethnic group, first-degree history of colorectal cancer, vegetable consumption, exercise and high cholesterol.
The patients 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.
Even considering all these additional factors, statins were still associated with a 47 percent reduced risk of colorectal cancer.
Rennert said that when the team compared the results with those of 21 patients who used a non-statin cholesterol-lowering drug named bezafibrate, unlike the statins, this medication did not prove to lower the risk of colorectal cancer.
“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,” said study co-author Dr. Stephen Gruber, of the University of Michigan in Ann Arbor Medical School.
According to the Technion’s Rennert, the results of the study raise the possibility in the future of preventing cancer by using statins among the general population or among segments of the population with high risk.
“It’s very encouraging that the medicine which has found to be effective against colon cancer is also efficient against heart disease, a fact that increases the chances in the future that it will be considered as a preventive drug against chronic diseases,” he said.
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.
The article appeared in the journal accompanied with an editorial by physicians at the US National Cancer Institute advocating immediate prospective studies to confirm the findings. The editorial says it is premature to recommend taking statins to prevent colorectal cancer, as prospective therapeutic clinical trials are still needed.
“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,” said Gruber.