The Efficacy of Low Postoperative Radiation Dose in Patients with Advanced Hypopharyngeal Cancer without High-Risk Factors.

Objective: To evaluate the feasibility and efficacy of low postoperative radiotherapy (PORT) dose in patients with advanced hypopharyngeal squamous cell carcinoma (HPSCC) and identify prognostic factors in this group. Patients and Methods: Between January 2013 and September 2015, 110 consecutive patients with HPSCC with no high-risk factors were treated postoperatively to 50 Gy (n=89), 56 Gy (n=12), and 60 Gy (n=9) in 2 Gy/fraction. Overall survival (OS), 3-year progression-free survival (PFS), 3-year loco-regional recurrence-free survival (LRFS), and treatment-related toxicities were analyzed. Results: Median follow-up time was 40 months (range=6-75 months). The 3-year local-regional control (LRC) and 3-year neck control rate were 86.3% and 91.8%, respectively. The 3-year OS, PFS, and LRFS were 69.9%, 65.5%, and 80.5%, respectively. In a univariate analysis, T stage showed a significant correlation with improved OS, PFS, and LRFS (P=0.008, P=0.039, P=0.034). On multivariate analysis, T stage showed a significant correlation with improved OS and PFS. N stage showed a significant correlation with improved PFS. However, interval surgery-radiotherapy, reconstructive methods, and RT dose cannot serve as a significant prognostic factor for survival outcome. Conclusion: This study suggests that treating no high-risk factors for locally advanced HPSCC with a dose of 50 Gy to the whole operative bed and elective lymph node levels cannot compromise disease control and survival.