Does three cycles of neoadjuvant chemotherapy prior to concurrent chemoradiotherapy provide benefits for all childhood patients with locoregionally advanced nasopharyngeal carcinoma?

Adding neoadjuvant chemotherapy (NAC) to concurrent chemoradiotherapy (CCRT) is the main strategy in treatment of children and adolescents with locoregionally advanced nasopharyngeal carcinoma (CA-LANPC). Yet, an optimal number of NAC cycles remains unknown. We aimed to optimize the NAC cycle and potentially contribute to clinical decision making for the individual treatment of CA-LANPC. Utilizing an NPC-specific database through an acknowledged big-data information system at our center, we identified 143 CA-LANPC treated with NAC followed by CCRT between September 2007 through April 2018. Recursive partitioning analysis (RPA) was performed to categorize the patients and predict disease-free survival (DFS). The clinical benefits of NAC cycles (two cycles vs three cycles) were assessed in each risk group. Independent factors derived from multivariable analysis to predict DFS were T stage (T1–3 vs T4) and plasma Epstein-Barr virus (EBV) DNA (< 4000 vs ≥ 4000 copies/mL) for risk stratification. Consequently, 87 (61%) participants were classified as low-risk group (T1–3 with low or high EBV DNA, and T4 with low EBV DNA) and the other 56 patients (39%) were classified as a high-risk group (T4 with high EBV DNA) through RPA, and corresponding 5-year DFS rates of 91.9% and 71.2%, respectively (p = 0.001). Among the high-risk group, patients receiving three cycles of NAC had statistically significant improvement in 5-year DFS over those who received two cycles of NAC (86.7% vs 59.1%; p = 0.020), while the survival benefit of three cycles NAC for low-risk groups were not observed (94.7% vs 89.7%; p = 0.652). We found three cycles of NAC with CCRT was a positive prognostic indicator for improved DFS for the high-risk group among CA-LANPC. However, whether low-risk patients could benefit from three cycles NAC needs further study.