Individualized induction chemotherapy by pre-treatment plasma Epstein-Barr viral DNA in advanced nasopharyngeal carcinoma

Background The role of pretreatment Epstein-Barr virus DNA (pre-DNA) for individualized induction chemotherapy (IC) in locoregionally advanced nasopharyngeal carcinoma (LA-NPC) still remains unknown. We aimed to address this clinical issue. Methods In total, data on 6218 patient with newly diagnosed LA-NPC receiving concurrent chemoradiotherapy (CCRT) with or without IC were retrospectively reviewed. Receiver operating characteristics (ROC) curve was adopted to calculate the cut-off value of pre-DNA based on disease-free survival (DFS). Propensity score matching (PSM) method was adopted to balance prognostic factors and match patients. Survival outcomes between IC + CCRT and CCRT groups were compared. Results Among the original cohort, no survival difference between IC + CCRT and CCRT groups was found. The cut-off value of pre-DNA was 4650 copies/ml (area under curve [AUC], 0.620; sensitivity, 0.6224; specificity, 0.5673). For patients with Pre-DNA ≤ 4650 copies/ml, the IC + CCRT and CCRT groups also achieved comparable survival outcomes (P > 0.05 for all rates). However, IC + CCRT was associated with significantly improved 3-year DFS (78.6% vs. 74.8%, P = 0.03), overall survival (OS; 91.4% vs. 87.5%, P = 0.002) and distant metastasis-free survival (DMFS; 86.0% vs. 82.2%, P = 0.036) for patient with pre-DNA > 4650 copies/ml. Multivariate analysis also confirm that IC + CCRT was an independent prognostic factor for DFS (HR, 0.817; 95% CI, 0.683–0.977; P = 0.027), OS (HR, 0.675; 95% CI, 0.537–0.848; P = 0.001) and DMFS (HR, 0.782; 95% CI, 0.626–0.976; P = 0.03). Conclusions Pre-DNA may be a feasible and powerful consideration for individualized IC apart from other baseline clinical characteristics in LA-NPC. Electronic supplementary material The online version of this article (10.1186/s12885-018-5177-9) contains supplementary material, which is available to authorized users.