The Effects of Different Induction Chemotherapy Cycles and Adjuvant Chemotherapy on the Survival Outcomes of Patients With Locally Advanced Nasopharyngeal Carcinoma

ObjectiveThis study investigated whether differences in the induction chemotherapy (IC) cycle number and adjuvant chemotherapy (AC) affect survival outcomes in patients with locally advanced nasopharyngeal carcinoma (LA-NPC). MethodsThe survival outcomes of 386 consecutive LA-NPC patients treated between January 2015 and March 2018 were retrospectively analyzed. Univariate and multivariate analyses were used to compare treatment groups defined by IC< 3 or >= 3 IC cycles followed by radiotherapy with or without AC (i.e., IC<3+AC, IC<3+non-AC, IC >= 3+AC, and IC >= 3+non-AC groups). ResultsThe median follow-up time was 53 months (range: 2-74 months) and the median number of IC cycles was 2 (range: 1-6 cycles). The 3-year overall survival (OS) rate was significantly higher in patients with IC >= 3 cycles compared to IC<3 cycles (95.7% vs. 90.3%, P=0.020). Multivariate analysis indicated that the IC cycle number is an independent factor for OS (hazard ratio=0.326, P=0.007). Furthermore, patients in the IC<3+AC group had a better OS rate than those in the IC<3+non-AC group (91.6% vs. 79.1%, P=0.030), indicating that AC positively affected OS in patients with IC<3. However, no significant difference in the OS rate was found between IC >= 3+non-AC and IC >= 3+AC groups (92.1% vs. 94.6%, P =0.550). ConclusionThe IC cycle number appears to be an independent prognostic factor for higher OS in LA-NPC patients who received >= 3 cycles. Sequential AC after IC plus radiotherapy may improve OS in patients with IC<3 cycles.