Difference in Outcomes for Patients with HPV Type 16 Versus HPV Non-Type 16 Oropharyngeal Squamous Cell Carcinoma

Abstract

Listen

Translate article

Oropharyngeal squamous cell carcinoma (OPSCC) associated with human papillomavirus (HPV) is known to have better treatment outcomes. What remains unclear is whether all HPV DNA types carry similar prognostic relevance. We aimed to evaluate disease control and survival outcomes by HPV DNA type. Patients with primary, non-metastatic OPSCC treated with curative intent were reviewed from an IRB-approved institutional database. Patients that underwent HPV DNA PCR testing with available genotype were dichotomized by the presence of HPV type 16 (HPV-16) or other (HPV-non16). Locoregional control (LRC), overall survival (OS) and disease-free survival (DFS) were determined using the Kaplan-Meier method and compared using the log-rank test. Multivariable Cox proportional hazards models were generated for OS, DFS, LRC using predictors found to be significant (p<0.05) on univariate models. A total of 205 patients were included: 150 had HPV DNA PCR testing, 120 (80%) were positive, and 114 had a known HPV type. Ninety-nine of 114 (87%) were positive for HPV16 and fifteen (13%) were positive for HPV-non16. p16 immunohistochemistry was available in 35 patients and positive in 97% of HPV16 and 100% of HPV-non16 patients. There were no significant differences in age, ECOG performance status, oropharynx subsite, AJCC 7th/8th Edition stage, smoking or alcohol use between HPV-16 and HPV-non16 patients. 3-year OS, DFS, and LRC for HPV16 and HPV-non16 was 84% v. 69% (p=0.02), 80% v. 63% (p=0.04), and 82% v. 62% (p=0.01), respectively. Multivariable models including ECOG, smoking status, AJCC 8th Edition stage, and treatment found HPV16 associated with OS (aHR 0.31, 95% CI 0.10-0.95, p=0.04) and LRC (aHR 0.33, 95% CI 0.11-0.99, p=0.05). This study provides insight into the outcomes of HPV positive oropharyngeal squamous cell carcinoma stratified by HPV16 and HPV-non16 subtypes. These data suggest that patients with HPV-non16-associated OPSCC may have worse outcomes including decreased survival and locoregional control compared to patients who carry the HPV16 subtype.