Background Studies investigating the association between p21 genetic polymorphism Ser31Arg and cervical cancer (CC) risk report conflicting results. The aim of this study was to quantitatively summarize the evidence for p21 polymorphism and CC risk.

Methods Two investigators independently searched the MEDLINE, Embase, CNKI, and Chinese Biomedicine databases. Summary odds ratios (ORs) and 95% confidence intervals (CIs) for p21 polymorphism and CC were calculated in a fixed effects model (the Mantel-Haenszel method) and a random effects model (the DerSimonian and Laird method) when appropriate. The pooled ORs were performed for codominant model (Arg/Arg vs Ser/Ser and Arg/Ser vs Ser/Ser), dominant model (Arg/Arg + Arg/Ser vs Ser/Ser), and recessive model (Arg/Arg vs Arg/Ser + Ser/Ser). Subgroup analyses were performed by country, matched controls, and Hardy-Weinberg equilibrium in the controls and study sample size.

Results This meta-analysis included 10 case-control studies from an Asian population, which included 1415 CC cases and 1947 controls. Overall, the variant genotypes (Arg/Arg and Arg/Ser) of Ser31Arg were not associated with CC risk, when compared with the wild-type homozygote Ser/Ser (Arg/Arg vs Ser/Ser: OR, 1.30; 95% CI, 0.81-2.08; Arg/Ser vs Ser/Ser: OR, 1.06; 95% CI, 0.72-1.55). Similarly, no associations were found in the dominant and recessive models (dominant model: OR, 1.05; 95% CI, 0.73-1.51; recessive model: OR, 1.28; 95% CI, 0.86-1.90). Stratified analyses also detected no significant association in any subgroup, except among those studies from "other" country and those studies with controls deviated from Hardy-Weinberg equilibrium.

Conclusion No association was found between the p21 polymorphism Arg31Ser and risk of CC among Asians. In the future, additional studies based on white and African American patients should be performed to re-evaluate the association.