Association Between p21 Ser31Arg Polymorphism and Gastrointestinal Tract Tumor Risk: A Meta-analysis

Human p21 gene is characterized by a polymorphism at codon 31 leading to a Serine-to- Arginine (S/R), two different alleles of p21 Ser31Arg (rs 1801270) polymorphism have been shown to differ significantly in their transcriptional efficiency. More and more investigations are now being carried out to examine a possible link between the p21 Ser31Arg polymorphism and cancer. However, the results were inconclusive. Therefore, we carried out a systematic review and meta-analysis to examine whether this polymorphism is associated with gastrointestinal tract tumor in Asian. Seven studies (n = 2690), comprising 967 cases and 1723 controls in Asian population, were included in our study. The meta-analysis showed significant association between Ser-allele or Ser/Ser genotype and the susceptibility to gastrointestinal tract tumor in overall studies (Ser-allele vs. Arg-allele: OR = 1.17, 95% CI: 1.04-1.31; Ser/Ser vs. Arg/Arg: OR = 1.38, 95% CI: 1.09-1.75; Ser/Ser vs. Arg/Ser: OR = 1.27, 95% CI: 1.05-1.53; Ser/Ser vs. Arg/Ser + Arg/Arg: OR = 1.29, 95% CI: 1.07-1.54). Despite the limitations, the results of the present meta-analysis suggested that, in the p21 Ser31Arg polymorphism, Ser-allele and Ser/Ser genotype might be risk factors for gastrointestinal tract tumor in Asian populations.