A Nomogram to Predict Survival and Determine Necessity of Induction Chemotherapy for Patients With Stage T3-4N1 Nasopharyngeal Carcinoma

Background: The value of induction chemotherapy (IC) is still controversial for stage T3-4N1 nasopharyngeal carcinoma (NPC) patients receiving concurrent chemoradiotherapy (CCRT). Therefore, we established a nomogram to predict clinical outcome and explore the therapeutic efficiency of IC. MethodsOverall, 699 stage T3-4N1 NPC patients treated with CCRT with or without IC between January 2010 and December 2018 were examined. Overall survival (OS) was regarded the main endpoint. A nomogram was developed including prognostic variables selected by multivariate analysis. The Harrell Concordance Index (C-index), calibration curves, and time-dependent receiver operator characteristic (td-ROC) curves were performed to assess the predictive ability of the nomogram. All patients were divided into high- and low-risk groups based on the optimal cutoff of risk score to investigate the role of IC. Resultshe nomogram yielded C-index of C-index of 0.725 (95% CI: 0.672–0.778) in the training and 0.647 (95% CI: 0.580–0.742) in the validation cohort. Calibration curves for 3- and 5-year OS rate suggested a good association between the nomogram predicted and actual observed probabilities. Td-ROC analysis demonstrated good discriminatory ability. In the high-risk group, no statistically significant difference was observed between patients receiving IC + CCRT and those with CCRT alone. However, in the low-risk group, the applying of IC was associated with worse locoregional recurrence-free survival (LRRFS) and distant metastasis-free survival (DMFS). Conclusionse established and validated a nomogram for LA-NPC patients with N1 disease to predict OS and determine necessity of IC, which has satisfactory prognosis predicting ability and clinical practicability. The use of IC for stage T3-4N1 NPC patients should be considered carefully.