Background and Aims
Epidemiologic studies on a potential chemopreventive effect of statin therapy have yielded conflicting results. We sought to clarify whether long-term statin therapy has a chemopreventive effect on the risk of colorectal cancer (CRC) in a large, population-representative cohort.
A nested case–control study was conducted among patients ≥50 years of age and with ≥5 years of CRC-free initial follow-up in the General Practice Research Database (GPRD; 1987–2002). Cases consisted of all patients with incident CRC. Up to 10 controls were matched with each case on practice site and both duration and calendar time of follow-up prior to the index date. The primary exposure of interest was ≥5 years of cumulative statin use.
We identified 4432 incident CRC cases and 44 292 controls. The adjusted odds ratio (OR) for ≥5 years of statin exposure was 1.1 (95% confidence interval (CI): 0.5–2.2). Chronic NSAID/aspirin use did not modify this primary association (test for interaction, p = 0.5). Compared to statin non-users, the adjusted OR for 10 years of statin exposure was 1.3 (95% CI: 0.6–2.7), and the adjusted OR associated with the highest quartile of cumulative statin dose was 1.2 (95% CI: 0.9–1.7). There was a non-statistically significant trend towards a possible reduction in CRC risk among users of high daily statin dose.
Long-term statin therapy at usual doses was not associated with a significantly reduced risk of CRC. A chemopreventive effect at high daily doses cannot be excluded. Copyright © 2008 John Wiley & Sons, Ltd.