Missed Adjuvant Therapy in Human Papillomavirus Positive Oropharyngeal Squamous Cell Carcinoma

Objective: Investigate missed adjuvant therapy and associated disparities in overall survival (OS) for human papillomavirus-associated (HPV+) oropharyngeal squamous cell carcinoma (OPSCC). Methods: The 2010–2017 National Cancer Database was queried for patients with surgically resected HPV+ OPSCC. Indications for adjuvant radiotherapy (aRT) included pT3-4 classification, pN2-3 classification, lymphovascular invasion, pathologic extranodal extension (pENE), and/or positive surgical margins (PSM). Indication(s) for adjuvant chemoradiotherapy (aCRT) included pENE and/or PSM. Multivariable logistic and Cox regression models were implemented. Results: Of 5297 patients satisfying inclusion criteria, 4288 had indication(s) for aRT; 775 did not receive any adjuvant therapy and were considered as missing aRT. A total of 2234 patients had indication(s) for aCRT. Of these, 1383 (61.9%) received aCRT, 555 (24.8%) patients received aRT alone and were considered as having missed aCRT, and 296 (13.2%) did not receive any adjuvant therapy. Missed aRT and missed aCRT were each associated with age, treatment facility type, pN classification, and surgical margin status (p < 0.015). Among patients with indication(s) for aRT alone, OS of those receiving no adjuvant therapy, aRT alone, and aCRT was 90.0%, 94.8%, and 93.4%, respectively (p = 0.080). Among patients with indication(s) for aCRT, those receiving aRT alone and aCRT had similar OS (89.0% vs. 86.6%, p = 0.357) which was superior to receiving no adjuvant therapy (74.9%, p < 0.001). These patterns in OS persisted on multivariable Cox regression. Conclusion: Among patients with HPV+ OPSCC and indication(s) for aRT, missed aRT was not associated with worse OS. For patients with indication(s) for aCRT, aRT alone was associated with similar OS as aCRT. Level of Evidence: 3 Laryngoscope, 135:729–740, 2025.