Oral HPV incidence and risk factors for acquisition

Abstract

Background: We evaluated incidence of oral HPV infection, which precedes HPV-related oropharynx cancer.

Methods: In this prospective multicenter cohort of participants with HIV and demographically similar participants without HIV, oral rinse and gargle samples were collected every 6-12 months and tested for 35 HPV types (anyHPV), 13 of which were oncogenic (oncHPV). Kaplan Meier and Cox regression were used for incidence curves and clustered risk factor hazard ratios. Logistic regression was used to determine relative odds of same infection at next visit.

Results: The 1587 participants had a median follow-up of 3.67 years, 422 had 708 incident type-specific oral HPV detected. The most common oncHPV was HPV16 [incidence rate = 7.8 per 1000 person-years (95 %CI 5.8-10.6)]. At 5 years, the cumulative incidence of anyHPV, oncHPV and HPV16 was 34.9 % (95 %CI = 31.9 %, 38.3 %), 17.1% (95 %CI = 14.8 %, 19.8 %) and 4.0 % (95 %CI = 2.9, 5.6 %), respectively. Risk of incident oral HPV infection was independently associated with a higher number of oral sex partners, current smoking, younger age, prevalent oral anyHPV, living with HIV and lower CD4 counts. Prevalent oncHPV at baseline had greater odds of being re-detected at subsequent visits than an incident oncHPV detected for the first-time at a later visit. Detection of oral HPV type at one visit was associated with highly elevated odds of detecting that same type-specific infection at the next visit (OR > 100).

Conclusion: Cumulative incidence of oral HPV is increased among PLWH and with prevalent oral HPV, represents a mix of new and intermittently detected infections, and is higher among those with repeated detection of oral HPV.

Keywords: HPV; Incidence; Latency; Latent HPV; Natural history; Oral; Oropharyngeal cancer; Risk factors.