Association between ABO blood types and sporadic pancreatic neuroendocrine tumors in the Chinese Han population

BACKGROUND Although the relationship between non-O blood types and the risk of exocrine pancreatic cancer has been demonstrated, the association between ABO blood types and sporadic pancreatic neuroendocrine tumor (PNET) has not been reported thus far. METHODS This hospital-based, case-control study included 387 patients with PNET and 542 age- and sex-matched controls. Unconditional multivariable logistic regression analysis was performed to estimate the adjusted odds ratios (AORs) and 95% confidence intervals (CIs). The relationship between ABO blood types and clinicopathologic features was also analyzed. RESULTS After adjusting for age, sex, smoking status, alcohol drinking, and first-degree family history of any cancer, the AORs (95% CI) of functional PNET were 0.87 (0.59-1.28) for blood type A, 0.86 (0.58-1.28) for blood type B, and 0.71 (0.39-1.26) for blood type AB compared with subjects with blood type O. A similar ABO blood-type distribution was observed among cases with non-functional PNETs compared with controls. On comparing blood type B with non-B blood type, cases with non-functional PNETs had marginally higher rates of lymph node invasion (P = 0.047), distant metastasis (P = 0.044), and advanced European Neuroendocrine Tumor Society Stage (P = 0.040). CONCLUSIONS There is no association between the ABO blood group and the development of functional and non-functional PNETs. The ABO blood types are not associated with the clinicopathologic features in patients with functional and non-functional PNETs.