Abstract
Objective The long-term effect of the ABO blood type on the clinical course of patients with pancreatic cancer (PC) is inconclusive. This study aimed to determine whether or not the ABO blood type influences the long-term outcomes of PC in Japanese patients. Methods The medical records of Japanese patients with PC were reviewed. Data, including the age, sex, and outcomes, from the Ehime Pancreato-Cholangiology Study Group were analyzed. Results The mean age of the 406 patients was 71.0±10.5 years, and 220 (54.2%) were men. A total of 44.6%, 20.7%, 22.4%, and 12.3% had blood type A, B, O, and AB, respectively. The median survival time (MST) of patients with A alleles was shorter than that of patients with non-A alleles (p=0.048), especially among those who underwent resection (p=0.031). In contrast, no marked difference in the MST was noted among those who underwent chemotherapy and palliative care. Finally, a multivariate analysis confirmed A alleles as an independent factor associated with the long-term outcome of PC (p<0.05 in 2 different models). Conclusion The ABO blood type influenced the long-term outcomes of Japanese patients with PC, presumably due to its impact on disease onset and tumor behavior.