RESUMEN
Objective To definite the correlation between allergic diseases with the occurrence risk and prognosis of colorec tal cancer by meta analysis.Methods The databases of PubMed,MEDLINE,EMBASE,Web of Science,CNKI and Wanfang data were retrieved by computer.The time limit was from January 1988 to October 2015.The literatures were screened and the data were extracted according to the inclusion and exclusion criteria.The meta analysis was performed by using STATA12.0 software.Results A total of 16 articles(ll cohort studies,5 case-control studies)were included in this study.The meta analysis showed that the risk of colorectal cancer occurrence in the patients with allergic diseases was significantly lower than that of the control group(OR=0.88,95％CI:0.80-0.98,P＜0.05;the stratified analysis found that the risk of colorectal cancer occurrence in the patients with hay fever(OR=0.93,95％CI..0.87-0.99,P＜0.05)and patients with allergic dermatitis(OR=0.73,95％CI:0.56-0.95,P＜ 0.05) were lower than that of the control group.Compared with the control group,the death risk of colorectal cancer in the patients with allergic diseases was significantly lower than that of the control group(OR=0.73,95 ％ CI:0.85-0.97,P＜0.05).Conclusion The patients with allergic diseases may reduce the occurrence risk and death risk of colorectal cancer through enhancing the recognition ability of immune system and destroying tumor cells.