Human papillomavirus prevalence in oropharyngeal cancer before vaccine introduction, United States

Abstract

We conducted a study to determine prevalence of HPV types in oropharyngeal cancers in the United States and establish a prevaccine baseline for monitoring the impact of vaccination. HPV DNA was extracted from tumor tissue samples from patients in whom cancer was diagnosed during 1995-2005. The samples were obtained from cancer registries and Residual Tissue Repository Program sites in the United States. HPV was detected and typed by using PCR reverse line blot assays. Among 557 invasive oropharyngeal squamous cell carcinomas, 72% were positive for HPV and 62% for vaccine types HPV16 or 18. Prevalence of HPV-16/18 was lower in women (53%) than in men (66%), and lower in non-Hispanic Black patients (31%) than in other racial/ethnic groups (68%-80%). Results indicate that vaccines could prevent most oropharyngeal cancers in the United States, but their effect may vary by demographic variables.

Keywords: HPV typing; United States; archived tissue; cancer; human papillomavirus; oropharyngeal; oropharynx; viruses.

Figure 1

Hierarchical designation of human papillomavirus (HPV) types to oropharyngeal squamous cell carcinomas. White sections of bars indicate attribution of the specific HPV type or group. Black sections of bars indicate cumulative prevalence of types in higher hierarchy. HPV-16 includes all cases positive for this type regardless of other results. HPV-18 includes all cases positive for HPV-18, but negative for HPV-16. Cases of 9-valent HPV with high-risk HPV types included in the candidate 9-valent HPV vaccine: HPV-31, -33, -45, -52, -58, but not HPV-16 or -18. High-risk: cases positive for any high-risk type not included in the previous categories: HPV-35, -39, -51, -66, -68. Low-risk: cases only positive for HPV types with low or no oncogenic potential.