Abstract 945P
Background
NPC is an Epstein-Barr virus (EBV)-associated disease. EBV plays a pivotal role in tumor initiation and progression. It is well known that immune-suppression contribute to the initiation and progression of NPC and the immune function is correlated with the prognosis of NPC patients. However, the association of EBV infection status with peripheral immune parameters and clinical outcome in patients with advanced NPC is still not fully clear.
Methods
Histopathologically-confirmed NPC at IV stage were screened in our hospital between January 2011 and November 2018. The plasma EBV DNA lode and the peripheral blood immune parameters were evaluated by real-time quantitative PCR and flow cytometry, respectively, at the diagnosis of IV stage. The relationships between EBV infection and immune phenotype and clinical outcome were analyzed.
Results
A total of 146 patients including 113 males and 33 females with age ranging from 21 to 78 years (median 50.07 years) were enrolled. Eighty-seven patients were EBV positive. EBV positive status was significantly associated liver metastasis (P = 0.040). The EBV DNA load of patients with liver metastasis was significantly higher than that of patients without liver metastasis (7125.0 vs 1335.0 copies/mL, P = 0.020). EBV infection was a significant risk factor for liver metastasis (OR: 2.325, 95%CI: 1.029-5.256, P = 0.043). No significant effect of HBsAg positive status on liver metastasis was found in patients with NPC. The EBV viral load of patients with lower NK cell count was significantly associated with lower EBV viral load (median: 614.0 vs. 2190.0 copies/mL, P = 0.024). EBV positive status was an independent worse prognostic factor affecting PFS (HR: 1.94; 95%CI: 1.24-3.03; P = 0.003) and OS (HR: 2.12; 95%CI: 1.17-3.86; P = 0.014) in advanced NPC.
Conclusions
EBV infection would increase the risk of liver metastasis and EBV infection is an independent unfavorable prognostic factor for PFS and OS patients with advanced NPC. EBV positive patients had more chance to have lower CD8% and higher NK%, while the EBV viral load of patients with lower NK cell count was significantly associated with lower EBV viral load.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.