Establishing and applying nomograms based on the 8th edition of the UICC/AJCC staging system to select patients with nasopharyngeal carcinoma who benefit from induction chemotherapy plus concurrent chemoradiotherapy

Abstract

ObjectivesThe subgroups of patients with nasopharyngeal carcinoma (NPC) who benefit from induction chemotherapy plus concurrent chemoradiotherapy (IC+CCRT) remain unclear. Materials and methodsWe established prognostic nomograms for overall survival (OS) and disease-free survival (DFS), and validated the nomograms in 1230 patients with NPC and subgroup of 923 patients with locoregionally advanced NPC (LANPC). Three well-matched risk groups (i.e., low, intermediate and high risk) were created via recursive partitioning and 1-to-1 propensity score matching; IC+CCRT was compared with CCRT in each risk group. ResultsHistological type, T category, N category, plasma Epstein-Barr virus deoxyribonucleic acid (and the same factors plus age and neutrophil-lymphocyte ratio) were included in the nomograms for DFS (and OS). Both nomograms had higher c-indexes than the 7th edition staging system in both NPC/LANPC (all P-values≤0.010). The nomogram for OS also had a higher c-index in LANPC than the 8th edition staging system (P-value=0.052). OS was significantly different between all three risk groups in the individualized risk stratification (all P-values<0.001), while the 7th and 8th edition staging systems failed to clearly separate OS for stage II and III disease (P-value=0.415 and 0.347, respectively). IC+CCRT improved OS in intermediate and high risk patients with LANPC compared to CCRT alone (P-value<0.001 and P-value=0.002, respectively). ConclusionThese prognostic nomograms could accurately guide treatment of individual patients with NPC. IC+CCRT could improve OS for patients with LANPC at intermediate to high risk.