Complications and oncological outcomes after salvage surgery for recurrent and residual hypopharyngeal squamous cell carcinoma: a retrospective cohort study.

[BACKGROUND] Salvage surgery for hypopharyngeal squamous cell carcinoma (HPSCC) after radiotherapy may result in several postoperative complications and the oncological outcome is unsatisfying. Therefore, identifying the risk factors for postoperative complications and oncological outcome after salvage surgery is important. This study aimed to determine which HPSCC patients might benefit from salvage surgery following previous radiotherapy.

[METHODS] We retrospectively analyzed 91 HPSCC patients who underwent salvage surgery due to locoregional recurrence/residual disease after radiotherapy. The pre- and intraoperative characteristics with complications and oncological outcomes were collected through medical records and telephone follow-up. Risk factors for complications were analyzed by binary logistic regression. The oncological outcomes were assessed by overall survival (OS) after salvage surgery. Kaplan-Meier curves and Cox proportional hazard regression analysis were used for univariate and multivariate survival analyses.

[RESULTS] Postoperative complications occurred in 40.7% of patients, with pharyngo-cutaneous fistula (PCF) occurring in 29.7% of patients. Salvage surgery for local disease was the only independent risk factor for postoperative complications and PCF [complications: odds ratio (OR) =5.298, 95% confidence interval (CI): 1.163-24.130, P=0.031; PCF: OR =4.543, 95% CI: 1.187-17.387, P=0.027). In the subgroup of patients with local disease, time of curative treatment initiation >90 days (OR =7.331, 95% CI: 1.278-42.054, P=0.025) and preoperative hemoglobin <118 g/L (OR =10.101, 95% CI: 1.026-99.492, P=0.045) were independent risk factors for postoperative complications, while free flap reconstruction was an independent protective factor for PCF (OR =0.099, 95% CI: 0.010-0.934, P=0.043). The median OS time was 17 months, with 5-year OS rates of 30%. Age at salvage surgery <50 years [hazard ratio (HR) =2.047, 95% CI: 1.217-3.443, P=0.007] and recurrence or retreatment clinical T stage 3-4 (rcT3-4) (HR =2.051, 95% CI: 1.219-3.450, P=0.007) were identified as risk factors for OS. The 5-year OS rates of patients without and with both risk factors were 43% and 10% (P=0.001).

[CONCLUSIONS] Salvage surgery for locoregional recurrence/residual disease after previous radiotherapy could improve survival in selected patients with HPSCC. Patients with local recurrence/residual disease had a higher complication rate. Efforts can be made to shorten the time of curative treatment initiation and treat anemia to reduce the risk of postoperative complications in this subgroup.