ABO blood groups and cancer of the pancreas.

Few investigations discussing an association between ABO blood groups and pancreatic cancer exist. We have selected a series of 224 patients with histologically-confirmed pancreatic cancer, and their ABO blood groups distribution was compared with two control groups: 7086 patients with various diseases (Group 1) and 7320 voluntary blood donors (Group 2). There was an increased number of pancreatic cancer among the patients with blood group B (relative risk 1.5 vs Group 1 p = 0.021; 1.7 vs Group 2 p = 0.0025) and a decreased number in patients with blood group O, when compared with the two control groups.