ABO blood type and risk of hepatocellular carcinoma: a meta-analysis

Background: ABO blood type is an invariant factor. There is a link between ABO blood type and some malignancies, such as gastric, pancreatic, and skin cancer. The role of ABO blood type in the pathogenesis of hepatocellular carcinoma (HCC) remains controversial. We performed a meta-analysis to explore the relationship between ABO blood type and risk of HCC.Methods: Literature search was conducted among the PubMed, EMBASE, and Cochrane Library databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.Results: Seven papers were included. They included 92,847 healthy subjects, 5,463 patients with hepatitis, 294 cirrhotic patients, and 3,322 HCC patients. The proportion of blood type O was significantly lower in HCC patients than healthy subjects (OR=0.76, 95%CI=0.66-0.87, P<0.0001) without any significant heterogeneity (P=0.55, I-2=0%). The proportions of blood types A, B, and AB were not significantly different between HCC patients and healthy subjects. The proportion of ABO blood type was not significantly different between patients with HCC and those with hepatitis or cirrhosis.Conclusion: HCC patients might have a lower proportion of blood type O than healthy subjects. Among the patients with chronic liver diseases, ABO blood type might not be associated with the risk of HCC.