Human papillomavirus and overall survival after progression of oropharyngeal squamous cell carcinoma

Risk of cancer progression is reduced for patients with human papillomavirus (HPV) -positive oropharynx cancer (OPC) relative to HPV-negative OPC, but it is unknown whether risk of death after progression is similarly reduced. Patients with stage III-IV OPC enrolled onto Radiation Therapy Oncology Group trials 0129 or RTOG 0522 who had known tumor p16 status plus local, regional, and/or distant progression after receiving platinum-based chemoradiotherapy were eligible for a retrospective analysis of the association between tumor p16 status and overall survival (OS) after disease progression. Rates were estimated by Kaplan-Meier method and compared by log-rank; hazard ratios (HRs) were estimated by Cox models. Tests and models were stratified by treatment protocol. A total of 181 patients with p16-positive (n = 105) or p16-negative (n = 76) OPC were included in the analysis. Patterns of failure and median time to progression (8.2 v 7.3 months; P = .67) were similar for patients with p16-positive and p16-negative tumors. After a median follow-up period of 4.0 years after disease progression, patients with p16-positive OPC had significantly improved survival rates compared with p16-negative patients (2-year OS, 54.6% v 27.6%; median, 2.6 v 0.8 years; P < .001). p16-positive tumor status (HR, 0.48; 95% CI, 0.31 to 0.74) and receipt of salvage surgery (HR, 0.48; 95% CI; 0.27 to 0.84) reduced risk of death after disease progression whereas distant versus locoregional progression (HR, 1.99; 95% CI, 1.28 to 3.09) increased risk, after adjustment for tumor stage and cigarette pack-years at enrollment. Tumor HPV status is a strong and independent predictor of OS after disease progression and should be a stratification factor for clinical trials for patients with recurrent or metastatic OPC.