Five COX-2 gene polymorphisms and risk of breast cancer: an updated meta-analysis based on 19 case-control studies

The correlationship between COX-2 gene polymorphisms and breast cancer has been wildly studied, but the results remain controversial. Hence, the present meta-analysis aimed to investigate the association between COX-2 SNPs (rs5275, rs20417, rs689466, rs5277, rs2206593) and risk of breast cancer. Data were collected from PubMed, Embase and China National Knowledge Infrastructure. Summary odds ratio (OR) with 95 % confidence interval (CI) was applied to assess the relationship. Heterogeneity test, sensitivity analysis and publication bias test were also performed. There were 17 articles that contained 19 studies in this research. Fourteen case-control studies with 15,007 breast cancer cases and 20,005 controls were concerning rs5275 polymorphism, and 8 case-control studies with 10,216 cases and 12,839 controls were about rs20417 polymorphism. Other three polymorphisms (rs689466, rs2206593, rs5277) were studied in 5, 3 and 3 studies, respectively. COX-2-rs20417 CC genotype was significantly associated with increased risk of breast cancer when comparing to G allele [ORs were 1.231 (1.050-1.444) for CC vs. GG, P = 0.01, 1.223 (1.045-1.432) for CC vs. G carrier, P = 0.01]. Furthermore, the results of the subgroup analysis by ethnicity suggested that C allele significantly contributed to the risk of breast cancer for Asians [1.459 (1.182-1.802) for GC vs. GG, 1.472 (1.201-1.805) for C carrier vs. GG]. However, no association was found for rs5275, rs689466, rs5277 and rs2206593 in all comparison modes. This meta-analysis indicated that the COX-2 rs20417 polymorphism contributed to genetic susceptibility of breast cancer. In contrast, COX-2 rs5275, rs689466, rs2206593 and rs5277 polymorphisms might be not associated with the risk of breast cancer.