Summary ORs (95% CI) categorized by ethnicity for the XRCC1 Arg399Gln polymorphism under different genetic models and cancer type1.

1all summary ORs were calculated using fixed-effects models. In the case of significant heterogeneity (indicated by *), ORs were calculated using random-effects models;2the results were excluded due to high heterogeneity;3total bladder cancer comparisons add up to 17 (which should be 20) because 1 Africans study, 1 Indians study, and 1 mixed population study did not be included. The reason is same with breast cancer, colorectal cancer, hepatocellular cancer and so on; the bold values indicate that the results are statistically significant; SZ, sample size