Effect of ABO blood type on mortality in patients with urothelial carcinoma of the bladder treated with radical cystectomy

Objective: ABO blood type is an inherited characteristic that has been associated with the prognosis of several malignancies, but there is little evidence in urothelial carcinoma of the bladder (UCB). The purpose of this study was to evaluate the effect of ABO blood type on mortality in patients with UCB treated with radical cystectomy (RC). Methods: Multi-institutional data from 7,906 patients with UCB treated with RC between 1979 and 2012 were retrospectively analyzed. The effect of ABO blood type on UCB-related mortality was evaluated with univariable and multivariable competing-risks regression models. Results: ABO blood type was O in 3,728 (47%), A in 2,748 (35%), B in 888 (11%), and AB in 532 (7%) patients. Blood type B was associated with a greater likelihood of lymphovascular invasion (P = 0.010) and positive soft tissue margins (P = 0.008). The median follow-up was 41 months. The 5-year cumulative UCB-related mortality rates for blood type O, A, B, and AB were 29.5%, 30.5%, 33.2%, and 25.8%, respectively. In univariable competing-risks regression, patients with blood type B had worse UCB-related mortality than those with blood type O (P = 0.026) and AB (P = 0.020). In multivariable analysis, however, blood type lost its statistical significance. Conclusions: Among patients treated with RC, ABO blood type is associated with a statistically significant but clinically insignificant difference in UCB-related mortality. This association was not present in multivariable analysis. Our data therefore suggest no relevant association of ABO blood type with UCB-related prognosis.