Abstract A59: Prospective analysis of the association between use of statins or other lipid-lowering agents and colorectal cancer risk

Abstract

Abstract Background: Experimental and epidemiologic data suggest that 3-hydroxy-3-methylglutaryl coenzyme A inhibitors (statins) have antitumor activity against colorectal cancer (CRC). We utilized data from the population-based Women's Health Initiative (WHI) cohort to assess whether statins are associated with a decreased risk of CRC. Methods: The study population included 159,219 postmenopausal women ages 50-79 at baseline, in which 2,000 cases of CRC were identified over an average of 10.7 (2.9) years of follow-up. All cases of CRC were confirmed by review of medical records and pathology reports. Participants were asked to bring all current medications to their screening interviews and clinic staff entered information on statin use and other lipid lowering medications into the WHI database. Self- and interviewer-administered questionnaires were used to collect information on other CRC risk factors. Cox proportional hazards regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). Analyses investigated the association of any statin use, type of statin, statin potency, and duration of use with CRC. Statistical tests were two-sided. Results: Statins were used by 12,030 (7.6%) women in the cohort. The annualized rate of CRC was 0.13% among statin users and 0.12% among nonusers. The multivariable adjusted HR for statin users compared with nonusers was 0.99 (95% CI=0.83 to 1.20, p=0.95). There was no trend in risk of CRC by duration of statin use, with HR = 0.91 (95% CI=0.66 to 1.27) for < 1 years of use, HR = 1.28 (95% CI=0.97 to 1.68) for 1- < 3 years of use, and HR =0.79 (95% CI=0.56 to 1.11) for > 3 years of use. There was no relationship between type of statin use, statin potency (low, medium and high), or use of other lipid-lowering medications and CRC risk. In addition there was no relationship between statin use and tumor location (proximal, distal and rectal), or clinical features (tumor stage, grade or histology). Conclusions: Statin use was not associated with a decrease in CRC risk in the WHI cohort. Citation Information: Cancer Prev Res 2010;3(12 Suppl):A59.