BACKGROUND: Through search the possible randomized control trials, we make a 
renewed meta-analysis in order to assess the impact of aspirin in preventing the 
recurrence of colorectal adenoma.
MATERIALS AND METHODS: The Medicine/PubMed, Embase, Cochrane Central Register of 
Controlled Trials (CENTRAL), Chinese biomedical literature service system 
(SinoMed) databases were searched for the related randomized controlled trials 
until to the April 2016. Three different authors respectively evaluated the 
quality of studies and extracted data, and we used the STATA software to 
analyze, investigate heterogeneity between the data, using the fixed-effects 
model to calculate and merge data.
RESULTS: 7 papers were included the renewed meta- analysis, among these studies, 
two pairs were identified as representing the same study population, with the 
only difference being the duration of follow-up. Thus there were only five 
papers included our meta-analysis, and one Chinese paper were also included the 
work. Results were categorized by the length of follow-up, different kinds of 
people, varied dose of oral aspirin. The relative of adenoma in patients taking 
aspirin vs placebo were 0.73 (95% CI 0.55-0.98, P=0.039) with 1 year follow up; 
0.84 (95% CI 0.72-0.98, P=0.484) with greater than 1 year follow up; for the 
advanced adenoma, the RR 0.68 (95% CI 0.49-0.94, P=0.582),for one year; RR=0.75 
(95% CI 0.52-1.07, P=0.552) for greater one year. Furthermore the white 
population could divided into two subgroups according to the different length of 
follow-up time. When the length of follow-up time less than 3-year, The RR of 
two subgroups respective were RR=0.86 (95% CI 0.76-0.98, P=0.332), I2=0%, 
RR=0.68 (95% CI 0.47-0.98, P=0.552), I2=64.6%, But with the extension of 
follow-up time greater than 2-year, with the white, oral aspirin without 
considering dose had no efficacy on preventing the recurrence of any adenoma, 
the RR was 0.86 (95% CI 0.71-1.05, P=0.302), I2=16.4%.
CONCLUSIONS: This meta-analysis indicated that oral aspirin is associated with a 
remarkable decrease in the recurrence of any adenoma and advanced adenomas in 
patients follow-up for 1 year without concerning the dose of aspirin, but with 
the extension of follow-up time for greater than 1 year, oral aspirin can be 
effective on preventing the recurrence of any adenoma, but for the advanced 
adenoma, the result indicated that oral aspirin had no efficacy, According to 
the inclusion of ethnic groups, we also divided relevant papers into two 
subgroups as the yellow and white group. Then the follow-up time was less than 3 
years, oral aspirin without considering the dose, had an significant efficacy on 
preventing the recurrence of any adenoma. But with the follow-up greater than 2 
years, oral aspirin had no effect in the white.