Retrospective Analysis of Induction Chemotherapy plus Concurrent Chemoradiotherapy under Intensity-Modulated Radiotherapy Mode for Locally Advanced Nasopharyngeal Carcinoma.

Introduction: Nasopharyngeal carcinoma (NPC) originates from the mucous epithelium of the nasopharynx. Although induction chemotherapy plus concurrent chemoradiotherapy is the major therapeutic protocol used for locally advanced NPC without metastasis, more research studies are needed to evaluate the curative effects. We aim to identify the therapeutic effects and prognosis after induction chemotherapy plus concurrent chemoradiotherapy in the treatment of locally advanced NPC under the intensity-modulated radiotherapy mode.

Methods: The patients (N = 544) with locally advanced NPC (III and Iva, UICC 8th) after intensity-modulated radiotherapy with induction chemotherapy and concurrent chemoradiotherapy were included in this study. We analyzed the characteristics of patients including gender, age, smoking status, tumor node staging system, clinical stage, pathological type, the therapy protocol of induction chemotherapy and concurrent chemoradiotherapy, and chemotherapy prescription.

Results: We have found the 5-year survival rates of overall survival (OS), progression-free survival (PFS), locoregional relapse-free survival (LRRFS), and distant metastasis-free survival (DMFS) were 85.21%, 78.51%, 90.71%, and 85.21% in follow-up, and these data indicated that our therapeutic procedure provided beneficial effects on survival rates. Subsequently, the chemotherapy drug based on docetaxel (DOC) provided a more beneficial effect on survival rate compared with taxol (TXT) (all estimated HR >1; p = 0.005, 0.004, and <0.001 of OS, PFS, and DMFS), but there was no significant difference between chemotherapy drugs based on cisplatin (DDP) and nedaplatin (NDP) in treating NPC patients (p = 0.390, 0.549, 0.364, and 0.645 of OS, PFS, LRRFS, and DMFS). The therapeutic effects of induction chemotherapy revealed no difference between TPF and TP (T: DOC or TXT, P: DDP or NDP, and F: 5-fluorouracil) (p = 0.541, 0.897, 0.498, and 0.765 of OS, PFS, LRRFS, and DMFS). In addition, there was also no significant change between concurrent chemotherapy with TP dual drugs or a single platinum drug (being excluded in the multivariate model using forward [Wald] procedure). Moreover, the survival rate showed no difference between platinum accumulation dose of more or less than 150 mg/m2 for concurrent chemotherapy (being excluded in the multivariate model using forward [Wald] procedure).

Conclusion: Our results indicate that induction chemotherapy plus concurrent chemoradiotherapy under intensity-modulated radiotherapy which is the standard therapeutic method for locally advanced NPC provides beneficial therapeutic effects, and it is worthy of further study.