Systemic immune inflammation index combined with Epstein-Barr virus DNA for predicting the prognosis of nasopharyngeal carcinoma: A retrospective study

Background: Cancer has consistently been the leading cause of death worldwide, with head and neck cancer (HNC) being one of the top ten causes of cancer-related death. Nasopharyngeal carcinoma (NPC), in particular, is a cancer that is unique to East Asia. Numerous studies have shown that the Epstein-Barr virus (EBV) DNA load and the systemic immune inflammation (SII) index can serve as prognostic indicators for NPC patients. However, no studies have compared different predictive models of inflammatory factors. This study combines the SII and the EBV virus load in patients with stage I to IV NPC and compares different inflammatory factor models to determine the best predictive model.

Materials and methods: We reviewed 240 patients with stage I to IV NPC who were diagnosed between January 2016 and July 2023. We collected data from adult patients who were diagnosed with NPC and included those who completed the definitive staging workup and treatment in this analysis. We tested various inflammatory markers and the EBV DNA load via Cox regression for survival analysis.

Results: We found that the EBV viral load, the SII, and the SIRI are related to the severity of nasopharyngeal cancer. In the univariate Cox regression analysis, clinical stage, EBV virus load (HR: 2.15, 95 % CI: 1.19-3.90), NLR (2.37, 1.29-4.34), PLR (2.7, 1.06-6.87), SIRI (2.02, 1.11-3.68), and SII (2.45, 1.251-4.89) were prognostic factors for overall survival. In the multivariate analysis, after adjusting for sex, age and clinical stage, a higher EBV virus load and SII were associated with a worse prognosis (HR: 4.71, 1.95-11.41).

Conclusion: The combination of the EBV viral load and the SII was a better predictor of NPC prognosis.