Plasma Epstein-Barr virus DNA for the prediction of treatment response and disease progression in non-keratinizing differentiated nasopharyngeal carcinoma

Abstract

Purpose

To explore the failure patterns, outcomes, and treatment response of differentiated non-keratinizing nasopharyngeal carcinoma (DNKC) and to further investigate the role of plasma Epstein-Barr virus (EBV)-DNA in follow-up monitoring, prognostic prediction, and assessment of treatment efficacy in DNKC.

Methods

We retrospectively collected data from patients diagnosed with DNKC from January 2015 to February 2022. The life-table method, Kaplan-Meier survival, and Cox proportional hazards analysis were used for statistical analyses.

Results

A total of 102 patients were included. Of the 77 patients with available EBV-DNA levels, 61 patients (79.2%) had EBV-DNA detectable before treatment. Twenty-seven patients (26.5%) experienced disease recurrence, and 88.9% (24/27) relapsed in the first three years. There were 20 patients who experienced disease recurrence and had pre-treatment EBV-DNA status records. At the time of disease progression, 4 patients initially had undetectable EBV-DNA remained undetectable. Among the 16 patients with initially detectable EBV-DNA, 15 (93.8%) had detectable EBV-DNA. Nodal stage and EBV-DNA levels before treatment were found to be independent prognostic factors for distant metastasis-free survival (DMFS) and disease-free survival (DFS). Those with residual EBV-DNA after induction chemotherapy had significantly inferior DMFS (P = 0.003), DFS (P = 0.006), and overall survival (OS) (P = 0.006) than those without residual EBV-DNA after IC. Those with residual EBV-DNA after radiotherapy had significantly inferior local recurrence-free survival (P = 0.003), DMFS (P < 0.001), DFS (P < 0.001), OS (P < 0.006) than those without residual EBV-DNA after radiotherapy.

Conclusion

Our study highlights the aggressive nature of DNKC, characterized by early recurrence. EBV-DNA levels may serve as a biomarker to monitor treatment response, prognostic prediction, and recurrence surveillance.