Comparison of induction chemotherapy combined with concurrent chemoradiotherapy versus concurrent chemoradiotherapy alone in Lymph-Node-Stage III nasopharyngeal carcinoma based on propensity score-matching

Abstract

Purpose: To explore the role of induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CCRT) versus CCRT alone in patients diagnosed with N3 nasopharyngeal carcinoma (NPC).

Patients and methods: A total of 787 patients with newly diagnosed N3 NPC treated with IC + CCRT or CCRT alone were included. Progression-free survival (PFS) was the primary endpoint. We balanced variables using propensity score matching (PSM). Kaplan-Meier curves with log-rank tests were applied to evaluate the survival condition of each group. Independent prognostic factors were identified using the Cox regression analysis.

Results: PSM assigned 228 patients to IC + CCRT and CCRT alone groups. Survival analysis for the matched data set showed that IC + CCRT achieved better survival outcomes compared with CCRT alone, and significant difference was observed in 5-year PFS [74.8% (95%CI 69.2 ∼ 80.9%) vs 65.4% (95%CI 59.4 ∼ 72.0%), P = 0.008], 5-year OS [(77.4%(95%CI 71.9 ∼ 83.3%) vs66.3%(95%CI 60.3 ∼ 72.9%), P = 0.005)] and 5-year distant metastasis-free survival (DMFS)[(81.8%(95%CI 76.7 ∼ 87.2%) vs72.4%(95%CI 66.7 ∼ 78.7%), P = 0.007)] between the two treatment groups. In multivariate analysis, IC + CCRT remained an independent protective factor for PFS (adjusted HR, 0.603; 95% CI, 0.433-0.841; P = 0.003), OS (adjusted HR, 0.568; 95% CI, 0.406-0.793; P < 0.001), and DMFS (adjusted HR, 0.541; 95% CI, 0.364-0.805; P = 0.002).

Conclusion: More chemotherapy should be considered in patients with N3 NPC because of its ability to improve survival time. This could be from the use of IC or adjuvant metronomic chemotherapy.

Keywords: Concurrent chemoradiotherapy; Induction chemotherapy; Nasopharyngeal carcinoma; Prognosis; Propensity score-matched analysis.