Purpose: We aimed to select optimal candidates benefiting from the addition of induction chemotherapy (IC) to concurrent chemoradiotherapy (CCRT) in advanced N-stage nasopharyngeal carcinoma (NPC).
Patients and Methods: A total of 624 NPC patients with N2-3 stage received CCRT with or without IC were retrospectively reviewed. We constructed a nomogram for predicting overall survival (OS) based on the result of the multivariate analysis in the training cohort (n = 468) and then tested it on the validation cohort (n = 156). Harrell’s concordance indices (C-index) and time-independent receiver operating characteristic (tdROC) analysis were applied to evaluate the discriminatory ability of the nomogram and compare it with TNM staging. IC plus CCRT was compared with CCRT in the whole cohort and two risk groups based on the nomogram with balanced baseline characteristics. In addition, acute toxicities were compared between different treatment groups.
Results: The nomogram showed good prognostic accuracy with a C-index of 0.716 (95% CI 0.669– 0.763) in the validation cohort. The 5-year OS of low and high-risk groups stratified by the nomogram were significantly different. IC+CCRT was significantly associated with superior OS as compared with CCRT (75.4 vs 52.6%, p = 0.009) in the high-risk group. However, no significant difference between IC plus CCRT and CCRT was observed (p = 0.843) in the low-risk group. IC plus CCRT was associated with more grade 1– 4 acute toxicities.
Conclusion: Our study can help clinicians select NPC patients with advanced N stage who benefit from IC.
Keywords: nasopharyngeal carcinoma, advanced N-stage, induction chemotherapy, survival, nomogram