Risk factors for locoregional relapse after transoral robotic surgery for human papillomavirus-related oropharyngeal squamous cell carcinoma

Background: Factors predicting locoregional relapse after surgery for oropharyngeal squamous cell carcinoma (SCC) were identified in the pre-human papillomavirus (HPV) era. We examined whether traditional indications for adjuvant radiotherapy (RT) or adjuvant chemoradiotherapy (CRT) still correlate with locoregional relapse in HPV-positive patients after transoral robotic surgery (TORS). Methods: Retrospective review of oropharyngeal SCC cases identified patients with HPV-positive tumors who did not receive adjuvant therapy after TORS despite intermediate or high-risk features. Results: Median follow-up was 26.7 months (range, 4.9-73.1 months). Five of 25 eligible patients (20%) relapsed at a median 4.8 months (range, 3.2-7.8 months). Two of 18 (11%) intermediate and 3 of 7 (43%) high-risk patients relapsed. Kaplan-Meier 2-year locoregional relapse-free survival estimates for intermediate and high-risk patients were 88% and 57% (p=.078), respectively. Conclusion: Traditional indications for adjuvant RT or CRT were associated with high risk of locoregional relapse in HPV-positive patients treated with TORS alone.