ABSTRACT
Objective To assess the effect of aspirin for the chemoprevention of colorectal adenomas by meta analysis of the published literature.Methods Cochrane strategy in combination with manual search was used to identify previously published randomized controlled trials by searching PubMed,EMBase,Cochrane Library,China Journal Full-text Database(CNKI),Chinese Scientific Journal Full-text Database (CSJD) and Chinese Biomedical Literature Database (CBM).Results Six randomized controlled trials involving a total of 2 858 patients were studied.Of the six trials,two trials were performed in China,four trials were in the Europe and the United States.Some sufficient evidence were found to support that aspirin could prevent of colorectal adenomas compared with placebo group ( P =0.003,RR =0.66,95％ CI:0.50-0.86).No adaquate evidence supported the role of aspirin in the prevention of development of colorectal cancer ( P =0.29,RR =0.65,95％ CI:0.30-1.44).High-dose aspirin ( P =0.10,RR =0.85,95％ CI:0.71-1.30 ) and low-dose aspirin could prevent colorectal adenomas compared with placebo group( P =0.02,RR =0.57,95％ CI:0.36-0.90),and a dose-dependent associtation was found.The risk of stroke was higher in any dose of aspirin compared with placebo group ( P =0.04),and the risks of adverse events had no significant differences in all groups.Conclusion Aspirin might prevent the development of colorectal adenomas in individuals,but could not prevent the colorectal cancer.