Simple SummaryThe aim of the present study is to determine the prognostic impact of ABO blood types on the survival of a Japanese population of patients with HCC who underwent surgical resection. We retrospectively analyzed 480 patients with HCC who had R0 resection between 2010 and 2020. Outcomes for type A (n= 173) and non-type A (n= 173) groups after surgery were compared using 1-to-1 propensity score matching to control for variables. Recurrence-free survival (RFS; hazard ratio [HR] 0.75, 95% confidence interval [Cl] 0.58–0.98,p= 0.038) and overall survival (OS; HR: 0.67, 95% Cl: 0.48–0.95,p= 0.023) for patients with blood type A were both significantly decreased relative to non-type A patients. Cox proportional hazard analysis demonstrated that patients with HCC who have blood type A had a worse prognosis than those with non-type A blood. ABO blood type may have a prognostic impact for patients with HCC after hepatectomy.AbstractBackground/Purpose: The effect of the ABO blood group on the survival of patients with hepatocellular carcinoma (HCC) is unclear. The aim of the present study is to determine the prognostic impact of ABO blood types on the survival of a Japanese population of patients with HCC who underwent surgical resection. Methods: Patients with HCC (n= 480) who underwent an R0 resection between 2010 and 2020 were retrospectively analyzed. Survival outcomes were investigated according to ABO blood type (A, B, O, or AB). Outcomes for type A (n= 173) and non-type A (n= 173) groups after surgery were compared using 1-to-1 propensity score matching to control for variables. Results: In the study cohort, 173 (36.0%), 133 (27.7%), 131 (27.3%), and 43 (9.0%) of participants had Type A, O, B, and AB, respectively. Type A and non-type A patients were successfully matched based on liver function and tumor characteristics. Recurrence-free survival (RFS; hazard ratio [HR] 0.75, 95% confidence interval [Cl] 0.58–0.98,p= 0.038) and overall survival (OS; HR: 0.67, 95% Cl: 0.48–0.95,p= 0.023) for patients with blood type A were both significantly decreased relative to non-type A patients. Cox proportional hazard analysis demonstrated that patients with HCC who have blood type A had a worse prognosis than those with non-type A blood. Conclusion: ABO blood type may have a prognostic impact on patients with HCC after hepatectomy. Blood type A is an independent unfavorable prognostic factor for recurrence-free and overall survival (RFS and OS) after hepatectomy.