ABO Blood Group, Epstein-Barr virus Infection and Prognosis of Patients with Non-metastatic Nasopharyngeal Carcinoma

Background: A prior study showed blood type A/AB to be associated with an increased risk of nasopharyngeal carcinoma (NPC) compared to subjects with blood type O. However, the relationship between ABO blood groups and prognosis of NPC patients is still questionable. In addition, whether Epstein-Barr virus (EBV) infection is associated with prognosis of NPC patients with different ABO blood groups is unclear. Materials and Methods: We conducted univariate and multivariable Cox regression analyses based on a consecutive cohort of 1,601 patients to investigate the above issues. Results: There was no significant difference in overall survival (OS) between different ABO blood groups (p=0.629), neither between A vs. non-A blood groups (p=0.895) nor AB vs. non-AB blood group (p=0.309) in univariate analyses and after adjusting for other factors. Interaction tests revealed that high immunoglobulin A against Epstein-Barr virus viral capsid antigen (VcA-IgA) level was associated with a favorable prognosis in male patients with UICC stage II disease who had an A blood type (p=0.008), compared with those with non-A blood type. In addition, male patients with an A blood group with a high blood lymphocyte level showeda tendency towards better survival in UICC stage III (p=0.096). Conclusions: ABO blood group status is not associated with the prognosis of patients with NPC. Additionally, blood group A male NPC patients with high VcA-IgA level or high blood lymphocyte counts might be correlated with a favorable prognosis in UICC stage II or III, respectively.