Risk stratification after recurrence of human papillomavirus (HPV)-related and non-HPV-related oropharyngeal cancer: A secondary analysis of NRG Oncology RTOG 0129 and 0522

Background No risk-stratification strategies exist for patients with recurrent oropharyngeal cancer (OPC). Methods Retrospective analysis using data from prospective NRG Oncology clinical trials RTOG 0129 and 0522. Eligibility criteria included known p16 status and smoking history, and locoregional/distant recurrence. Overall survival (OS) was measured from date of recurrence. Recursive partitioning analysis was performed to produce mutually exclusive risk groups. Results Hundred and fifty-four patients were included with median follow-up after recurrence of 3.9 years (range 0.04-9.0). The most important factors influencing survival were p16 status and type of recurrence, followed by surgical salvage and smoking history (<= 20 vs. >20 pack-years). Three significantly different risk groups were identified. Patients in the low-, intermediate-, and high-risk groups had 2-year OS after recurrence of 81.1% (95%CI 68.5-93.7), 50.2% (95%CI 36.0-64.5), and 20.8% (95%CI 10.5-31.1), respectively. Conclusion Patient and tumor characteristics may be used to stratify patients into risk groups at the time of OPC recurrence.