Locoregional Recurrence in p16-Positive Oropharyngeal Squamous Cell Carcinoma After TORS.

Objective: To analyze the patterns, risk factors, and salvage outcomes for locoregional recurrences (LRR) after treatment with transoral robotic surgery (TORS) for HPV-associated oropharyngeal squamous cell carcinoma (HPV+ OPSCC).

Study Design: Retrospective analysis of HPV+ OPSCC patients completing primary TORS, neck dissection, and NCCN-guideline-compliant adjuvant therapy at a single institution from 2007 to 2017.

Methods: Features associated with LRR, detailed patterns of LRR, and outcomes of salvage therapy were analyzed. Disease-free survival (DFS) and overall survival (OS) were calculated for subgroups of patients receiving distinct adjuvant treatments.

Results: Of 541 patients who completed guideline-indicated therapy, the estimated 5-year LRR rate was 4.5%. There were no identifiable clinical or pathologic features associated with LRR. Compared to patients not receiving adjuvant therapy, those who received indicated adjuvant radiation alone had a lower risk of LRR (HR 0.28, 95% CI [0.09-0.83], P = .023), but there was no difference in DFS (P = .21) and OS (P = .86) between adjuvant therapy groups. The 5-year OS for patients who developed LRR was 67.1% vs. 93.9% for those without LRR (P < .001). Patients who initially received adjuvant chemoradiation and those suffering local, in-field, and/or retropharyngeal node recurrences had decreased disease control after salvage therapy.

Conclusion: LRR rates are low for HPV+ OPSCCs completing TORS and guideline-compliant adjuvant therapy. Patients without indication for adjuvant therapy more often suffer LRR, but these recurrences are generally controllable by salvage therapy. Improved understanding of the patterns of recurrence most amenable to salvage therapy may guide treatment decisions, counseling, and adjuvant therapy de-escalation trials.

Level Of Evidence: 3 Laryngoscope, 131:E2865-E2873, 2021.