Circulating Epstein-Barr virus DNA level post induction chemotherapy contributes to prognostication in advanced-stage nasopharyngeal carcinoma

Background: To investigate the value of post-induction chemotherapy (IC) cell-free Epstein-Barr virus DNA (cfEBV DNApostIC) for prognostication in locally advanced nasopharyngeal carcinoma (LA-NPC). Methods: A total of 910 histologically proven LA-NPC undergoing radical IC + concurrent chemo-radiotherapy (CCRT) or targeted radiotherapy (CTRT) or both (CTCRT) were involved. The concentration of cfEBV DNA was measured by quantitative polymerase chain reaction pre-IC (cfEBV DNApreIC) and at IC completion. CfEBV DNApostIC was classified as undetectable (0 copy/ml) and detectable (>0 copy/ml). Recursive partitioning analysis (RPA) with respect to the overall survival (OS) was applied to construct a risk stratification system incorporating cfEBV DNApostIC and critical risk factors. Results: We observed that 660 (72.5%) and 250 (27.5%) patients had cfEBV DNApostIC undetectable and detectable respectively. CfEBV DNApostIC positive was associated with a significant inferior 5-year OS (76.2% versus 85.9%), metastasis-free survival (DMFS, 71.7% versus 86.4%) and disease-free survival (DFS, 57.7% versus 80.1%) than cfEBV DNApostIC negative (P < 0.001 for all). Additionally, cfEBV DNApostIC was independently significant for OS (hazard ratio [HR] 1.90, 95% CI 1.40-2.59), DMFS (1.99, 1.45-2.71) and DFS (2.38, 1.86-3.06) in multivariate analyses (P < 0.001 for all). RPA modelling yielded three distinct risk groups:

Automated summary

This study investigated the value of post-induction chemotherapy (IC) cell-free Epstein-Barr virus DNA (cfEBV DNApostIC) for prognostication in locally advanced nasopharyngeal carcinoma (LA-NPC). The results showed that cfEBV DNApostIC positivity was associated with significantly inferior overall survival, metastasis-free survival, and disease-free survival. Furthermore, cfEBV DNApostIC was independently significant for overall survival, metastasis-free survival, and disease-free survival in multivariate analyses.