Search CDDW 2007 Abstracts
Return to Table of Contents
187 THE USE OF ASPIRIN TO PREVENT COLORECTAL CANCER: A SYSTEMATIC REVIEW A Rostom1, C Dubé1, G Lewin2, A Tsertsvadze2, N Barrowman2, C Code2, M Sampson2, D Moher2 BACKGROUND: Aspirin for colorectal cancer (CRC) prevention is controversial.
1Department of Medicine, University of Calgary, Calgary, Alberta; 2Chalmers Research Group, Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario
OBJECTIVE: To examine the benefits and harms of aspirin chemoprevention.
METHODS: Medline 1966-April 2005, Embase 1980-April 2005, CENTRAL, Cochrane Collaboration's registry of clinical trials, Cochrane Database of Systematic Reviews DARE, HealthStar, NHS-EED, HTA databases of Cochrane Library, and TRIP database. Two independent reviewers conducted multilevel screening to identify randomized controlled trials (RCTs), case-control and cohort studies of ASA chemoprophylaxis. Systematic reviews for the harms and cost-effectiveness analyses were sought. Data was abstracted and checked and quality assessed in duplicate.
RESULTS: Regular use of ASA effectively reduced the incidence of CRA in RCTs (RR=0.82; 95% CI: 0.7-0.95), case-control (RR=0.87; 95% CI: 0.77-0.98) and cohort studies (RR=0.72; 95% CI: 0.61-0.85). Regular use of ASA was associated with relative risk reductions of 15% to 40% for CRC incidence. The combined relative risk of CRC incidence for cohort studies was 0.78 (95% CI: 0.63-0.97), while two large RCTs failed to show a benefit of ASA. One cohort study showed approximately 40% reduction in CRC mortality with ASA when used for more than 15 years. However, a large RCT in women failed to show a CRC mortality benefit of 100 mg ASA every second day.
CONCLUSIONS: ASA appears to be effective at reducing the incidence of CRAs and CRC. Inconsistencies between the RCT and observational data suggest that ASA must be used in high doses for greater than 10 years for a chemo-preventative effect.
THE USE OF ASPIRIN TO PREVENT COLORECTAL CANCER: A SYSTEMATIC REVIEW
A Rostom1, C Dubé1, G Lewin2, A Tsertsvadze2, N Barrowman2, C Code2, M Sampson2, D Moher2
BACKGROUND: Aspirin for colorectal cancer (CRC) prevention is controversial.