Comparing Outcomes for Patients with Human Papillomavirus (HPV) Type 16 versus Other High-Risk HPV Types in Oropharyngeal Squamous Cell Carcinoma

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is related to improved treatment outcomes. What remains unclear is whether all HPV DNA genotypes carry similar prognostic relevance. We aimed to evaluate disease control and survival outcomes by HPV DNA genotype. Patients with primary OPSCC without distant metastases treated with curative intent were retrospectively identified from an IRB-approved institutional database. Patients that underwent HPV DNA polymerase chain reaction (PCR) testing with available genotype were included and dichotomized by the presence of HPV type 16 (HPV-16) or other high-risk HPV genotype (HPV-non16). Overall survival (OS), disease-free survival (DFS), locoregional control (LRC) and distant control (DC) were determined using the Kaplan-Meier method and compared using the log-rank test. In our cohort of 193 patients treated from 2012 to 2018 with HPV DNA PCR, 10% were detected as HPV-non16 high-risk types. Patients with HPV-16 were significantly younger than those with HPV-non16, but no other baseline factors were associated with HPV-non16. With a median follow-up of 42.9 months, there were no significant differences in outcomes between the HPV-16 and HPV-non16 groups for 3-year OS (87.7% v. 73.6%), DFS (82.9% v. 68.7%), LRC (92.8% v. 88.5%) or DC (91% v. 89.2%). There is no statistically significant difference in outcomes between OPSCC with HPV-16 and HPV-non16 high-risk genotypes in our cohort, though trends of overall worse survival and disease-free survival in HPV-non 16 OPSCC were seen. Further studies with larger cohorts of patients with HPV-non 16-associated OPSCC are required to make definitive conclusions regarding the prognostic and clinical significance of HPV type.