Extra-capsular nodal extension after surgical resection for HPV-positive oropharyngeal Cancer: Adjuvant radiation versus chemoradiation.

PURPOSE: The prognostic significance of extra-capsular nodal extension (ECE) after surgical resection for human papillomavirus (HPV)-positive oropharyngeal cancer is controversial, and the optimal choice of adjuvant therapy is uncertain in this setting.

METHODS AND MATERIALS: A review of institutional databases identified a total of 63 patients with pathological evidence of ECE in at least 1 cervical lymph node after transoral robotic surgery and neck dissection for HPV-positive squamous cell carcinoma of the oropharynx. Clinical outcomes were compared based on whether patients received adjuvant radiation (20 patients) or chemoradiation (43 patients). The Kaplan Meier method was used to determine survival statistics with comparisons between groups conducted with the log-rank test.

RESULTS: With a median follow-up of 50 months (range, 6 to 110 months), the 3-year overall survival for the entire population was 87 %. No significant difference was observed between patients treated by adjuvant radiation and chemoradiation with respect to 3-year overall survival (86 % versus 87 %, p = 0.45), local-regional control (91 % vs. 90 %, p = 0.71), and progression-free survival (83 % vs. 85 %, p = 0.57). Exploratory subset analysis of competing variables failed to identify any group in which the addition of chemotherapy to radiation improved outcome.

CONCLUSIONS: While the presence of ECE after surgical resection has historically been considered an indication for the use of concurrent chemoradiation in the adjuvant setting, these data suggest that this paradigm should be re-evaluated in the setting of HPV-positive oropharyngeal cancer.