Induction Chemotherapy Plus Imrt-Based Concurrent Chemoradiotherapy Versus Induction Chemotherapy Plus Imrt Alone In Locoregionally Advanced Nasopharyngeal Carcinoma: A Retrospective Cohort Study

In the era of intensity modulated radiation therapy (IMRT), the value of concurrent chemotherapy after induction chemotherapy in the treatment of locoregionally advanced nasopharyngeal carcinoma is not yet clear. Between January 2008 and December 2014, a total of 156 locoregionally advanced NPC patients who received induction chemotherapy TPF (docetaxel, cisplatin, 5-fluorouracil) plus IMRT with or without triweekly cisplatin were included in the study population. Overall survival (OS), progression-free survival (PFS), locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were evaluated by the Kaplan-Meier method and a log-rank test. Cox proportional hazard regression analysis was applied to identify the independent prognostic factors. Treatment toxicities were clarified and compared between two groups. A total of 77 patients received induction chemotherapy plus IMRT-based concurrent chemoradiotherapy (IC+CCRT) while 79 patients underwent induction chemotherapy plus IMRT alone (IC+RT). There were no differences between two groups in clinicopathological characteristics including age, gender, T stage, N stage. With a median follow-up of 40 months, no differences were observed between the IC+CCRT group and the IC+RT group in 3-year OS (92.3% vs. 94.9%, p=0.083), PFS (81.8% vs. 77.4%, p=0.262), LRFS (88.0% vs. 88.5%, p=0.230), and DMFS (86.8% vs. 80.3%, p=0.970). Multivariate analysis showed that treatment group (IC+CCRT vs. IC+RT) was not an independent prognostic factor for 3-year OS (HR, 2.656; 95% CI, 0.674-10.468; p=0.163), PFS (HR, 1.382; 95% CI, 0.693-2.757; p=0.359), LRFS (HR, 2.173; 95% CI, 0.757-6.234; p=0.149), DMFS (HR, 0.914; 95% CI, 0.394-2.120; p= 0.833). The addition of concurrent chemotherapy was not associated with increased rates of treatment associated toxicities. The addition of concurrent chemotherapy to IMRT after induction chemotherapy TPF did not significantly improve survival in locoregionally advanced nasopharyngeal carcinoma.