Fig. 2

Biological responses to NAC and their correlations with radiological responses. A Comparison of pretreatment cfEBV DNA levels across N categories. B Kaplan-Meier survival plot of DMFS in patients with pretreatment cfEBV DNA ≥ 2000 copies/mL versus <2000 copies/mL. C Scatter plot showing circulating cfEBV DNA levels before treatment initiation, at NAC completion (post-NAC), and at CRT completion (post-CRT). D Changes in cfEBV DNA from baseline in patients with increased cfEBV DNA levels post-NAC (n = 33). E Kaplan-Meier survival plot of DMFS in patients with cBR post-NAC versus decreased/increased cfEBV DNA in patients with non-cBR. F RECIST groupings (columns) and cfEBV DNA biological responses (rows) of 821 patients with matched treatment-naïve and post-NAC surveillance data. G Kaplan-Meier survival plot of DFS in patients with cBR versus non-cBR post-NAC. H Kaplan-Meier survival plot of DFS in patients achieving cBR at the end of CRT stratified by biological responses to NAC. Abbreviations: cBR, complete biological response; cfEBV DNA, cell-free Epstein-Barr virus DNA; CI, confidence interval; CR, complete response; CRT, chemoradiotherapy; DFS, disease-free survival; DMFS, distant metastasis-free survival; HR, hazard ratio; IC, induction chemotherapy; N, node; NAC, neoadjuvant chemotherapy; non-cBR, non-complete biological response; PD, progression disease; PR, partial responses; PreEBV, pretreatment cfEBV DNA; SD, stable disease