Pancreatic cancer incidence and outcome in relation to ABO blood groups among Han Chinese patients: a case-control study.

The aim of the current study was to determine the association between ABO blood group and the risk and progression of pancreatic ductal adenocarcinoma (PDAC) in the Han Chinese ethnic group. During the period of 2000-2009, 1,431 patients with PDAC and 1,449 age- and sex-matched controls were recruited in two university-affiliated hospitals. An unconditional multivariable logistic regression analysis was used to estimate adjusted odds ratios (ORs). The relationship between patient ABO blood group and clinicopathologic features was also analyzed. Compared with subjects having blood group O, a modestly higher risk was observed among cases with blood group A or AB with adjusted ORs (95% confidence interval) of 1.368 (1.127-1.661) and 1.391 (1.053-1.838), respectively. The TNM stages of tumors in patients with non-O blood groups (A, B or AB) were more highly advanced than in patients with blood group O (p < 0.001). Among patients who underwent a potentially curative operation, the median survival time of patients with blood group O was significantly longer than that of patients with non-O blood groups (16.0 months vs. 11.0 months, p = 0.001, log-rank test). This study shows evidence of an association between blood group type and risk for development and progression of PDAC. These findings merit further confirmation in a large population-based prospective study in patients of the Han Chinese ethnic group.