Association of ABO Blood Groups and Risk of Gastric Cancer

Objective: This study sought to investigate the relationship between ABO blood groups and the risk of gastric cancer as well as clinical pathological parameters and prognosis. Methods: Gastric cancer patient data were collected from January 1995 to January 2012 at Jilin Cancer Hospital, and the blood group information of the blood donors at Jilin City Blood Center was recorded. The relationships between ABO blood group and both clinicopathological parameters and the risk of gastric cancer were analyzed retrospectively. The impact of ABO blood type on the 5-year survival rate of patients with gastric cancer was evaluated through outpatient and telephone interviews. Results: (1) Compared with the healthy population, the frequency distribution of gastric cancer patients with the A blood group was significantly increased (chi(2) = 4.708, P = 0.000), whereas the frequency distribution of gastric cancer patients with the AB blood group was significantly decreased (chi(2) = 9.630, P = 0.002). However, there was no significant difference in the distributions of the B blood group and O blood group (P > 0.05). (2) The risk of gastric cancer in people with the A blood group was higher, whereas the risk of gastric cancer in people with the AB blood group was lower. There was no significant difference in the risk of gastric cancer between type B and type O patients (P > 0.05). (3) The ABO blood group was not related to pathological factors, including the size of the gastric tumor or the T stage or N stage of the disease (P > 0.05). (4) Univariate analysis results showed that the degree of differentiation, tumor size, T stage, lymph node metastasis, and type O blood were factors affecting the 5-year survival rate of gastric cancer patients (P < 0.05). Multivariate analysis results showed that tumor size, T stage, lymph node metastasis, and O blood group were independent prognostic factors. The 5-year survival rate for gastric cancer was significantly better in patients with type O blood (hazard ratio = 0.97, 95% confidence interval = 1.67-3.92). Conclusion: (1) The risk of gastric cancer was higher in patients with the A blood group and lower in those with the AB blood group. (2) The ABO blood group showed no significant effect on the clinicopathological parameters of gastric cancer. (3) The O blood group may be a prognostic factor for gastric cancer patients.