Validating the role of ABO blood type in risk of perioperative venous thromboembolism after radical cystectomy.

Purpose: To validate the relationship between ABO blood type and risk of VTE post-RC in a large retrospective database.
Methods: Patients with urothelial bladder cancer (UBC) who underwent RC (intent-to-cure) for whom ABO blood type was available between 2003 and 2015 were identified from our IRB-approved database. VTE was defined as deep vein thrombosis (DVT) or pulmonary embolism (PE) within 90 days of surgery. VTE prophylaxis consisted of immediate postoperative Coumadin (2003-2009), unfractionated heparin (UFH) during hospitalization (2009-2015), and UFH during hospitalization plus 4 weeks of enoxaparin after discharge (2013-2015). Univariable and multivariable analyses of the association of ABO blood type with postoperative, symptomatic VTE and oncologic outcomes were performed.
Results: Of 1341 patients, 595 (44.4%) were ABO type O and 746 (55.6%) were non-O (A, B and AB). 90 patients were diagnosed with VTE within 90 days of surgery (6.7%) (43% DVT-only, 57% PE ± DVT). On multivariable analysis non-O blood type was associated with a nearly twofold increased risk of VTE (OR = 1.94, 95% CI 1.215-3.098, p = 0.004). No difference in recurrence-free survival or overall survival was seen between ABO groups.
Conclusion: Non-O blood type is an independent, non-modifiable risk factor for postoperative VTE after RC. More comprehensive counseling and thromboprophylaxis should be considered in this high-risk group.