The ABO Blood Group Impacts the Survival of Patients Undergoing Pancreatoduodenectomy for Biliary Tract Cancer

Abstract

Background/Aim: Although ABO blood group has been reported to be associated with the outcome of patients with pancreatic cancer, little is known about its impact on patients with biliary tract cancer (BTC). We evaluated the prognostic relevance of ABO blood group in patients who had undergone resection of BTC. Patients and Methods: A total of 154 patients with BTC undergoing pancreatoduodenectomy were retrospectively reviewed. Associations between ABO blood group and patient survival were evaluated by univariate and multivariate analysis. Results: The 5-year overall survival rate was higher in group O patients (n=46) than in other blood group patients (n=108) (65.8% vs. 47%, p=0.005). Multivariate analysis revealed that a non-O blood group was an independent risk factor for poor survival (p=0.021). Conclusion: ABO blood group is associated with the prognosis of patients with resected BTC; group O patients have a better outcome. The ABO blood group antigens are the most important alloantigens among the human blood group systems, being expressed not only on red blood cell membranes but also on the surfaces of several other cell types and tissues (1-3). The association between ABO blood group and cancer has been studied by a number of investigators since the mid-1900s (4-7); and several plausible mechanisms have been proposed to explain this association, including inflammation, immune response, intercellular adhesion, and cellular membrane signaling (3, 8-10). In fact, the influence of ABO blood group has been reported in various types of malignancy, including cancers of the gastrointestinal tract, urinary tract, respiratory tract, and breast (3, 6). In the pancreato-biliary field, a lower incidence of pancreatic cancer in blood group O individuals was revealed in a two-stage genome-wide association study (GWAS) (11). Some studies have also suggested that blood group O confers a more favorable prognosis than non-O blood groups in patients with pancreatic cancer (12, 13). With regard to biliary tract cancer (BTC), it remains unclear if ABO blood group impacts the clinical outcome. Because BTC is a relatively rare malignancy (14-16), the relationship between blood groups and outcome might be difficult to assess because of the small number of cases. Therefore, the aim of this study was to investigate the associations between the ABO blood groups and outcomes of patients with BTC who had undergone pancreatoduodenectomy (PD), and whether blood group O is associated with a favorable prognosis.