OBJECTIVETo examine the association between long-term oral low-dose aspirin and overall survival in colorectal cancer patients after diagnosis.

METHODSThe literature databases, such as PubMed, Embase, Cochrane Library, Web of Science, CBM, CNKI, and Wanfang database, were extensively searched to retrieve the comparative studies about the association between low-dose aspirin use after colorectal cancer diagnosis and overall survival published before June 2014. The state 12.0 version software was used for meta-analysis. The quality of these studies was assessed using the Newcastle-Ottawa scale.

RESULTSThere were eight studies meeting the inclusion criteria for meta-analysis. The total sample size of these studies included 28 103 cases and the score of all the studies was more than 6 points. Meta-analysis of the data using I(2) test showed significant heterogeneity (I(2)=78.2%, P<0.01), therefore, a random effect model was performed. Aspirin use after diagnosis was associated with longer overall survival (HR=0.732, 95% CI:0.613-0.875, P<0.01). There were seven studies with the same design or tumor stage in I-IIII period respectively for sensitivity analysis. The results of studies showed that the sensitivity was low and accurate (HR=0.687, 95% CI: 0.557-0.849, P<0.01; HR=0.682, 95% CI: 0.539-0.864, P<0.01).

CONCLUSIONMeta-analysis shows that long-term oral low-dose aspirin after diagnosis of colorectal cancer is identified as a significant prognostic factor.