Background: Statins have anticancer activity in various cell types, including colon cancer cells. Although epidemiologic data on the relationship between statin use and the risk of colorectal cancer are limited, one case-control study reported a 50% reduction in colorectal cancer risk among statin users. We conducted a population-based case-control study to assess this association with respect to statin type, dose, and duration of use.
Methods: Case patients with adenocarcinoma of the colon or rectum were ascertained from participating hospitals in Massachusetts and the Massachusetts Cancer Registry from January 1, 2001, through November 30, 2004. Age-, sex-, and precinct-matched control subjects were chosen from Massachusetts town lists. Information on statin use and other relevant data were obtained by telephone interview. We used multivariable conditional logistic regression models to estimate odds ratios (ORs). All tests for statistical significance were two-sided.
Results: Among 1809 case patients and 1809 matched control subjects, regular use of statins for at least 3 months was not associated with the risk of colorectal cancer (OR = 0.92, 95% confidence interval [CI] = 0.78 to 1.09). There was no consistent trend across dose or duration of use (e.g., for > or = 10 years of use, OR = 0.86, 95% CI = 0.51 to 1.45). The risk of stage IV cancer was, however, statistically significantly lower among statin users than among nonusers (OR = 0.49, 95% CI = 0.26 to 0.91). There was no evidence of an interaction between statin use and nonsteroidal anti-inflammatory drug use.
Conclusions: Overall, use of statins did not appear to be associated with reduced risk of colorectal cancer. The reduced risk of stage IV cancer observed among statin users requires confirmation.