Adjuvant Chemotherapy Following Combined Induction Chemotherapy and Concurrent Chemoradiotherapy Improves Survival in N2-3-positive Nasopharyngeal Carcinoma Patients
Abstract Objective: This study aimed to explore the clinical value of adjuvant chemotherapy (ACT) in locoregionally advanced nasopharyngeal carcinoma (LANC) following concurrent chemoradiotherapy (CCRT) and induction chemotherapy (ICT).Methods: We included 839 newly diagnosed LANC patients in the study. ICT plus CCRT (ICT+CCRT group) was administered to 443 patients and 396 patients who received ACT after receiving ICT plus CCRT (ICT+CCRT+ACT group). Univariate and multivariate Cox regression analyses were carried out in this study. Furthermore, to balance the study and control groups, propensity score matching (PSM) was applied.Results: 373 pairs of LANC patients were obtained after the PSM analysis. We found that ACT following ICT+CCRT had no significant effect on improving the survival of LANC patients. By further exploring the ICT+CCRT+ACT regimen, we excluded N0-1-positive patients and performed PSM in the ICT+CCRT and ICT+CCRT+ACT groups again. Each group consisted of 237 patients. Kaplan-Meier analysis revealed that there was a difference between the ICT+CCRT and ICT+CCRT+ACT groups in terms of the 5-year overall survival (OS) (78.9% vs. 85.0%, P = 0.034), disease-free survival (DFS) (73.4% vs. 81.7%, P = 0.029), and distant metastasis-free survival (DMFS) (84.9% vs. 76.0%, P = 0.019). In addition, the ICT+CCRT+ACT group had a higher incidence of grade 3-4 acute leukocytopenia/neutropenia.Conclusion: Compared with ICT+CCRT, ACT following ICT plus CCRT can reduce distant metastasis of N2-3-positive LANC and improve the OS and DFS of these patients, thus demonstrating higher clinical feasibility.