Non-O blood type is associated with an increased risk of venous thromboembolism after radical cystectomy

Objective To evaluate the association of blood type (non-O vs O) with venous thromboembolism (VTE) risk after radical cystectomy (RC) for bladder cancer. Methods From 1980 to 2005, we identified 2076 consecutive patients with RC for whom blood type was available in 2008 (96.7%). We evaluated the association of blood type with postoperative VTE using logistic regression, controlling for patient age, tumor, and nodal stage, Eastern Cooperative Oncology Group (ECOG) performance status, body-mass index (BMI), and number of lymph nodes removed at surgery. Results A total of 865 of 2076 patients (41.7%) had O blood type, 1143 (55.0%) were non-O, and 68 (3.3%) were missing. Median follow-up was 11.1 years, during which time VTE developed in 216 patients (10.4%). No significant differences were noted between those with O vs non-O blood type regarding patient age (median 69 years vs 69, P =.87), ECOG (P =.69), BMI (median 27.5 vs 28.1, P =.12), tumor stage (P =.97), pN+ status (15.6% vs 15.2%, P =.79), or number of nodes removed (median 9 vs 8, P =.43). On multivariate analysis, non-O blood type was associated with a nearly two-fold increased risk of VTE (odds ratio [OR] = 1.85, P =.007). Conclusion Non-O blood type was independently associated with an increased risk of VTE after RC. These patients should be counseled accordingly, and may benefit from increased perioperative prophylaxis.