We previously demonstrated that the non-O blood type is associated with a higher risk of aggressive prostate cancer (PCa) than the O blood type. However, the influence of the ABO blood phenotype on the exact risk stratification parameters, especially prostate-specific antigen (PSA), remains unknown. We retrospectively evaluated 426 patients with PCa underwent radical prostatectomy in our centers. We divided them into three groups based on PSA levels: PSA1 (<
10 ng/ml), PSA2 (10-20 ng/ml), and PSA3 (>
20 ng/ml), and compared the clinicopathological characteristics among the groups. The association of clinicopathological parameters with PSA was determined using logistic regression analyses. The percentages of patients with advanced pathological stage T (pT) and grade, lymph node (pN) involvement, A + AB type, perineural invasion (PNI), vessel carcinoma embolus (VCE), and positive surgical margin rate were significantly higher in the PSA3 group than in the PSA1 group (all p <
0.05). Univariate logistic regression analyses revealed that type A + AB, grade, pT, pN, PNI, and VCE were positively correlated with PSA levels when comparing PSA3 with PSA1. Multivariate analysis showed that the association between blood type A + AB and PSA levels remained significant (OR 1.810, 95% CI 1.061-3.086, for PSA2 vs. PSA1
OR 2.682, 95% CI 1.550-4.641, for PSA3 vs. PSA1) after adjusting for confounding factors. The A + AB blood type was independently associated with PSA levels in PCa patients, indicating that the A-allele might participate in PSA synthesis and PSA screening may be more efficient for A-allele carriers.