Polymorphisms Of Thymidylate Synthase Gene 5’-Untranslated Region Tandem Repeat Sequences And Risk Of Gastric Cancer:A Meta-Analysis

Objective:To explore the association between polymorphisms of thymidylate synthase gene 5’-untranslated region tandem repeat sequences and risk of gastric cancer. Methods:SinoMed, wanfang data, Pubmed, Cochrane library were searched for published case—control studies investigating the association between polymorphisms of thymidylate synthase gene 5’-untranslated region tandem repeat sequences and risk of gastric cancer From the database set up until January 2015. Studis were choosed According to the Inclusion criteria and then Extractied data and evaluate the quality. Publication bias was assessed by funnel chart and egger. Stata 12.0 software was using for meta analysis. Result:A total of 4 case—control studies involving 839 patients and 826 controls were analyzed in the study. Meta analysis showed that polymorphism of TS 5’-UTR tandem repeats gene and gastric cancer risk have no significant statistical significance:2R/2Rvs2R/3R:OR and 95%CI:0.891(0.362,2.191); 2R/2Rvs3R/3R:OR and 95%C:0.995(0.492,2.011);2R/3Rvs3R/3R:OR and 95%CI:0.963(0.772,1.202);2R vs 3R:OR and 95%CI:0.912(0.696,1.196). But in the subgroup analysis, the east Asian group shows that 2R/2R vs 2R/3R and 2R/2R vs 3R/3R have statistical significance:2R/2R vs 2R/3R: OR and 95%CI:1.913(1.060,3.452); 2R/2R vs 3R/3R:OR and 95%CI: 1.811 (1.024,3.202). The Mediterranean Sea group shows that 2R/2R vs 2R/3R,2R/2R vs 3R/3R and 2R vs 3R have statistical significance:2R/2R vs 2R/3R:OR and 95%CI:0.466 (0.260,0.838); 2R/2R vs 3R/3R:OR and 95%CI:0.552(0.324,0.939); 2R vs 3R:OR and 95%CI: 0.704(0.531,0.933). Conclusion:Association between polymorphisms of thymidylate synthase gene 5’-untranslated region tandem repeat sequences and risk of gastric cancer is based on the classification of regional or ethnic: 2R/2R genetype Have a higher risk of gastric cancer than 2R/3R、3R/3R genetypes in east Asia; However in the Mediterranean Sea,2R/2R genetype Have a lower risk of gastric cancer than 2R/3R、3R/3R genetypes and 2R gene is a factor keeping people Away from gastric cancer.