2R of Thymidylate Synthase 5’-untranslated Enhanced Region Contributes to Gastric Cancer Risk: a Meta-analysis

Background: Studies investigating the association between 2R/3R polymorphisms in the thymidylate synthase5’-untranslated enhanced region (TYMS 5’-UTR) and gastric cancer risk have generated conflicting results.Thus, a meta-analysis was performed to summarize the data on any association.
Methods: Pubmed, Embase,and CNKI databases were searched for all available studies. The strength of association between TYMS 5’-UTR2R/3R polymorphism and gastric cancer risk was estimated by odds ratios (ORs) with 95% confidence intervals(CIs).
Results: Six individual case-control studies with a total of 1, 472 cases and 1, 895 controls were included intothis meta-analysis. Analyses of total six relevant studies showed that there was no obvious association betweenthe TYMS 5’-UTR 2R/3R polymorphism and gastric cancer risk. Subgroup analyses based on ethnicity showed2R of TYMS 5’-UTR 2R/3R contributes to gastric cancer risk in the Asian population (OR Homozygote model = 1.71,95%CI 1.19-2.46, P = 0.004; OR Recessive genetic model = 1.70, 95%CI 1.18-2.43, P = 0.004). However, the association inCaucasian populations was uncertain due to the limited studies.
Conclusions: Our meta-analysis suggests that2R of TYMS 5’-UTR 2R/3R contributes to gastric cancer risk in the Asian population, while this association inCaucasians populations needs further study.