Subgroup analysis based on geographic region showed that low expression of p16 was associated with RFS in patients with bladder cancer both in Asia (HR = 1.44, 95% CI = 1.15~1.81, and P = 0.002) and in Europe (HR = 1.90, 95% CI = 1.13~3.19, and P < 0.001). This evidence concerns the gene CDKN2A and urinary bladder carcinoma.