Comparison of Survival Outcomes Between Larynx-Preserving Open Partial Pharyngectomy and Radiotherapy or Chemoradiotherapy in Patients with Hypopharyngeal Squamous Cell Carcinoma: A Single-Center Retrospective Analysis with Inverse Probability of Treatment Weighting Adjustments

Background There is a group of hypopharyngeal squamous cell carcinoma (HPSCC) patients for whom larynx-preserving open partial pharyngectomy (PP) and radiotherapy/chemoradiotherapy (RT/CRT) are indicated. We aimed to retrospectively evaluate the survival difference as there is no evidence directly comparing the two therapies.Methods This study evaluated HPSCC patients who were initially treated by PP or RT/CRT at our institution between January 2007 and October 2019. Overall survival (OS), disease-specific survival (DSS), laryngectomy-free survival (LFS), and local relapse-free survival (LRFS) were evaluated. The main analyses were performed with inverse probability of treatment weighting (IPTW) adjustments. Sensitivity analyses compared hazard ratios (HRs) obtained with three models: unadjusted, multivariate Cox regression, and propensity score-adjusted.Results Overall, 198 patients were enrolled; 63 and 135 underwent PP and RT/CRT, respectively. IPTW-adjusted 5-year OS, DSS, LFS, and LRFS rates in the PP and RT/CRT groups were 84.3% and 61.9% (p = 0.019), 84.9% and 75.8% (p = 0.168), 94.8% and 90.0% (p = 0.010), and 75.9% and 74.1% (p = 0.789), respectively. In the IPTW-adjusted regression analysis, PP was associated with a significant benefit regarding OS (HR 0.48, 95% confidence interval [CI] 0.26-0.90) and LFS (HR 0.17, 95% CI 0.04-0.77). The results obtained with the three models in the sensitivity analyses were qualitatively similar to those of the IPTW-adjusted models.Conclusion Despite the risk of bias related to unadjusted factors, our results suggest that PP is associated with significantly better OS and LFS compared with RT/CRT for HPSCC.