Background

Human papillomavirus (HPV)-positive oropharyngeal cancer (HPV-OPC) is distinct from HPV-unassociated head and neck cancer. However, whether risk factors for HPV-positive oropharyngeal and nonoropharyngeal squamous cell cancer are the same is unclear.

Methods

Incident cases of HPV-positive head and neck cell cancer and matched non-cancer controls were enrolled in a multi-institutional, prospective study examining risk factors, biomarkers, and survival.

Results

HPV-nonOPC (n = 20) were more likely to be ever smokers than controls (n = 80, OR 3.49, 95%CI 1.11-10.9) and HPV-OPC (n = 185, OR 3.28, 95%CI 1.10-10.2). Compared with HPV-OPC, HPV-nonOPC were less likely to have had over 3 oral sexual partners (OR 0.29, 95%CI 0.06-0.9), more likely to have multimorbidity (OR 3.30, 95%CI 1.04-10.5), and less likely to have antibodies to HPV16 E6 (90% vs 28%, OR 0.05, 95%CI 0.02-0.2). HPV-nonOPC had worse 4-year OS (77% vs 96%, P = .001) and RFS (69% vs 94%, P < .001) than HPV-OPC.

Conclusions

HPV-positive nonoropharyngeal are distinct from HPV-positive oropharyngeal cancers.

Background

HPV-positive oropharynx squamous cell cancer (HPV-OPC) patients were initially described as younger, however incidence has increased among older age-groups. It is unknown why some patients present at a younger age and others at a later age.

Methods

Multi-institutional prospective study of HPV-OPC cases (n = 163) and matched controls (n = 345) with detailed behavioral survey, and serum tested for HPV antibodies by fluorescent bead-based technology. Age at diagnosis was used to stratify patients into younger (≤50 years), middle-age (51-65), and older (>65).

Results

By age, demographic characteristics were largely similar, but HPV biomarkers and sexual acts differed. Younger cases were more likely to be HPV16-positive than older cases (100% vs 77%, p = 0.009). Similarly, younger cases were more likely to be HPV16 E6 or E7 seropositive (100% vs 82%, p = 0.03). Younger cases had a higher number of oral sex partners per year, a marker of sexual intensity (sex-years, p = 0.003), but a similar number of lifetime oral sex partners (measure of cumulative sexual exposure), compared to older cases. While sex-years were higher for younger cases and controls, cases had significantly higher sex-years than matched controls in each age-group (p < 0.001). Younger patients were also more likely to perform oral sex at sexual debut, and were younger at sexual debut (each p < 0.03).

Conclusions

Younger, middle-age and older HPV-OPC have distinct biomarker and behavioral profiles. Younger HPV-OPC cases have higher intensity of sexual exposure than older cases and controls, which may in part explain earlier disease onset. The distribution of HPV16-positive tumors among HPV-OPC differs by age group.