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.
Interventions for clinical trials or exposures for observational studies: The use of postoperative adjuvant radiation.
Main outcomes 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.
Keywords: N1; Oropharynx; TORS; base of tongue; lymph node; radiation; robotic; squamous cell carcinoma; surgery; survival; tonsil.