Sequential induction chemotherapy plus intensity-modulated radiotherapy versus concurrent chemoradiotherapy in locoregionally advanced nasopharyngeal carcinoma: the three-year report of a phase II, single center, randomized, non-inferiority trial.

To compare the efficacy and safety of induction chemotherapy (IC) followed by intensity-modulated radiotherapy (IMRT) alone versus concurrent CCRT in locoregionally advanced nasopharyngeal carcinoma (LA-NPC). Patients with newly diagnosed stage III to IVB nasopharyngeal carcinoma (NPC) were randomized to receive IC plus IMRT (IC+RT arm), or concurrent chemotherapy plus IMRT (CCRT arm), using a random number table. Both treatment arms received the same chemotherapy regimen. The primary endpoint was progression-free survival (PFS). Secondary end points included overall survival (OS), locoregional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS), treatment response, and acute treatment toxicities. From June 2013 to September 2018, a total of 204 patients histologically diagnosed with LA-NPC were enrolled in the study, with 102 patients randomly assigned to each arm. After a median follow-up duration of 45 months (range 4 to 84 months), the 3-year PFS, OS, LRRFS and DMFS were 72.2%, 87.8%, 92.3%, and 82.7% in the IC+RT arm, compared with 82.6%, 92.8%, 94.7%, and 88.2% in the CCRT arm. No statistical difference for PFS, OS, LRRFS, DMFS, or treatment response was observed between the two arms (p > 0.05). The incidences of leukopenia (p = 0.008) and anemia (p = 0.015) were significantly higher in patients in the CCRT arm than those in the IC+RT arm. Compared to CCRT, IC plus IMRT alone provided similarly favorable treatment outcomes in terms of PFS, OS, LRRFS, and DMFS for patients with LA-NPC, but resulted in fewer incidences of leukopenia and anemia.