Concurrent chemoradiotherapy with or without neoadjuvant chemotherapy in pediatric patients with stage III-IVa nasopharyngeal carcinoma: a real-world propensity score-matched cohort study.

Abstract

To compare neoadjuvant chemotherapy (NAC) plus concurrent chemoradiotherapy (CCRT) to CCRT alone in children and adolescents (age ≤ 18years) with locoregionally advanced nasopharyngeal carcinoma (CA-LANPC, stage III-IVA). 195 CA-LANPC patients who were treated through CCRT with or without NAC between 2008 and 2018 were enrolled in this study. A matched cohort composed of CCRT patients and NAC-CCRT patients was generated by propensity score matching (PSM) at a 1:2 ratio. Survival outcomes and toxicities were compared between the CCRT group and NAC-CCRT group. Of the 195 patients, 158 (81%) received NAC plus CCRT, and 37 (19%) received CCRT alone. The NAC-CCRT group had higher EBV DNA levels (≥ 4000 copy/mL), more advanced TNM stage (stage IV disease), and lower incidence of a high radiation dose (> 6600cGy) than the CCRT group. To avoid bias in treatment selection within retrospectively analysis, 34 patients from the CCRT group were matched with 68 patients from the NAC-CCRT group. In the matched cohort, the 5-year DMFS rate was 94.0% in the NAC-CCRT group versus 82.4% in the CCRT group, with marginal statistical significance (HR = 0.31; 95%CI 0.09-1.10; P = 0.055). During treatment, the accumulate incidence of severe acute toxicities (65.8% vs 45.9%; P = 0.037) in the NAC-CCRT group was higher than the CCRT group. However, the CCRT group had significantly higher accumulate incidence of severe late toxicities (30.3% vs 16.8%; P = 0.041) than the NAC-CCRT group. Addition of NAC to CCRT tended to improve long-term DMFS in CA-LANPC patients with acceptable toxicity. However, relative randomized clinical trial is still needed in the future.