Daily aspirin reduced the incidence of recurrent colorectal adenomas compared to placebo (17% vs 27%; RR 0.65, 95% CI 0.46-0.91; P=0.004) in patients with previous colorectal cancer.
RCT (n=635)
Double-blind
Randomized
Does aspirin 325 mg per day reduce the incidence of colorectal adenomas in patients with previous colorectal cancer?
Daily aspirin 325 mg significantly reduces the incidence of recurrent colorectal adenomas in patients with a history of colorectal cancer.
Effect estimate: RR 0.65 (95% CI 0.46-0.91)
Absolute Event Rate: 17% vs 27%
p-value: p=0.004
BACKGROUND: Experimental studies in animals and observational studies in humans suggest that regular aspirin use may decrease the risk of colorectal adenomas, the precursors to most colorectal cancers. METHODS: We conducted a randomized, double-blind trial to determine the effect of aspirin on the incidence of colorectal adenomas. We randomly assigned 635 patients with previous colorectal cancer to receive either 325 mg of aspirin per day or placebo. We determined the proportion of patients with adenomas, the number of recurrent adenomas, and the time to the development of adenoma between randomization and subsequent colonoscopic examinations. Relative risks were adjusted for age, sex, cancer stage, the number of colonoscopic examinations, and the time to a first colonoscopy. The study was terminated early by an independent data and safety monitoring board when statistically significant results were reported during a planned interim analysis. RESULTS: A total of 517 randomized patients had at least one colonoscopic examination a median of 12.8 months after randomization. One or more adenomas were found in 17 percent of patients in the aspirin group and 27 percent of patients in the placebo group (P=0.004). The mean (+/-SD) number of adenomas was lower in the aspirin group than the placebo group (0.30+/-0.87 vs. 0.49+/-0.99, P=0.003 by the Wilcoxon test). The adjusted relative risk of any recurrent adenoma in the aspirin group, as compared with the placebo group, was 0.65 (95 percent confidence interval, 0.46 to 0.91). The time to the detection of a first adenoma was longer in the aspirin group than in the placebo group (hazard ratio for the detection of a new polyp, 0.64; 95 percent confidence interval, 0.43 to 0.94; P=0.022). CONCLUSIONS: Daily use of aspirin is associated with a significant reduction in the incidence of colorectal adenomas in patients with previous colorectal cancer.
Sandler et al. (Wed,) conducted a rct in Previous colorectal cancer (n=635). Aspirin vs. Placebo was evaluated on Proportion of patients with adenomas (RR 0.65, 95% CI 0.46-0.91, p=0.004). Daily aspirin reduced the incidence of recurrent colorectal adenomas compared to placebo (17% vs 27%; RR 0.65, 95% CI 0.46-0.91; P=0.004) in patients with previous colorectal cancer.