Validation of published nomograms and accordingly individualized induction chemotherapy in nasopharyngeal carcinoma

Objectives: We have attempted to validate two published nomograms in nasopharyngeal carcinoma (NPC) and individualize induction chemotherapy (IC) accordingly. Materials and methods: From 2007 to 2011, 920 patients were included in the study. The validity of the nomograms was assessed by Harrell's concordance index (C-index), areas under the curve (AUC), and calibration curves. Disease-free survival (DFS) and overall survival (OS) by IC were evaluated in and out of risk stratified patients with and without propensity score matching analysis. Results: Compared with the 7th edition of the Union for International Cancer Control (UICC) staging system, Tang's nomogram better discriminated DFS (C-index 0.629 versus 0.569, P = 0.002; AUC 0.635 versus 0.576, P = 0.018), whereas Yang's nomogram had no advantage in predicting OS (C-index 0.648 versus 0.606, P = 0.184; AUC 0.643 versus 0.604, P = 0.157). Calibration curves indicated good agreement between predicted and observed DFS or OS probability. Without risk stratification, patients achieved no benefit from IC in DFS (P >= 0.101) or OS (P >= 0.370). However, among 580 high-risk patients stratified by Tang's nomogram, IC improved five-year DFS from 68.8 to 74.8% (P = 0.072), and OS from 82.6 to 87.9% (P = 0.065), and the improvement of DFS and OS increased to 9.3% (P = 0.019) and 7.3% (P = 0.036), respectively, in 426 propensity-matched patients. Conclusions: Tang's nomogram helps to stratify stage III-IVa-b NPC, and IC is beneficial to high-risk patients in clinical practice. (C) 2017 The Authors. Published by Elsevier Ltd.