The Benefit of Adjuvant Radiation in Surgically-Treated T1-2 N1 Oropharyngeal Squamous Cell Carcinoma

Abstract

Importance: The benefit of adjuvant radiation in surgically treated T1-2N1 oropharyngeal cancer without adverse pathologic features remains unclear. Objectives: To compare population-level survival outcomes in surgically-treated T1-2N1 oropharyngeal squamous cell carcinoma (OPSCC) with and without the use of adjuvant radiation. Study Design: Retrospective population-based study using the Surveillance, Epidemiology, and End Results (SEER) registry data from 1998–2011. Setting: Population-level study. Participants: Patients with T1-2N1 OPSCC treated with surgical resection and neck dissection with or without adjuvant radiation. Intervention(s) for Clinical Trials or Exposure(s) for observational studies: The use of postoperative adjuvant radiation. Main Outcome(s) and Measures: Overall and disease-specific survival. Results: Radiation was utilized in 74% of patients and was positively associated with extracapsular extension and well-differentiated histology. The use of radiation was associated with improved mean overall survival (124 v. 108 months, p=0.023) and a non-significant increase in mean disease-specific survival (138 v. 131 months, p=0.053). Conclusions and Relevance: The use of adjuvant radiation is associated with improved survival in surgically-treated T1-2N1 squamous cell carcinoma of the oropharynx with unknown HPV status. Level of Evidence: IV.