Tumor Volume Reduction Rate to Induction Chemotherapy Is a Prognostic Factor for Locally Advanced Head and Neck Squamous Cell Carcinoma: a Retrospective Cohort Study

BackgroundAim of this study was to evaluate the prognostic of tumor volume reduction rate (TVRR) status post induction chemotherapy (IC) in LA-HNSCC.MethodsPatients with newly diagnosed LA-HNSCC from year 2007 to 2016 at a single center were included in this retrospective study. All patients had received IC as TPF (taxotere, platinum, fluorouracil) followed by daily definitive intensity-modulated radiotherapy (IMRT) for 70 Gy in 35 fractions concurrent with or without cisplatin-based chemotherapy. Tumor volume reduction rate of the primary tumor (TVRR-T) and lymph node (TVRR-N) was measured and calculated by contrast-enhanced CT images at diagnosis, and one month after final IC cycle, and analyzed though a univariate and multivariate Cox regression model.ResultsNinety patients of the primary cancer sites at hypopharynx (31/90, 34.4%), oropharynx (29/90, 32.2%), oral cavity (19/90, 21.1%) and larynx (11/90, 12.2%) were included in this study, with a median follow-up time interval of 3.9 years. In univariate Cox regression analysis, the TVRR-T as the only variable showed a significant difference for disease-free survival (DFS) (hazard ratio [HR] 0.77, 95% confidence interval (CI) 0.63 to 0.96; P = 0.02), aside from cancer site, RECIST, age and IC dose. In multivariate Cox regression analysis, The TVRR-T was also an independently significant prognostic factor for DFS (HR 0.77, 95% CI 0.62 to 0.97; P = 0.02). At a cutoff value using TVRR-T of 50% in Kaplan-Meier survival analysis, the DFS was significant higher with TVRR-T ≥ 50% group (log-rank test, p = 0.024), and also a trend of improved OS. (log-rank test, p = 0.069).ConclusionsTVRR-T was related to improved DFS and trend of improved OS. Other factors including patient’s age at diagnosis, the primary cancer site, and RECIST, were not significantly related to DFS.