Projected Association of Human Papillomavirus Vaccination With Oropharynx Cancer Incidence in the US, 2020-2045

IMPORTANCE Oropharynx cancer (OPC) incidence has increased for several decades in the US. It is unclear when and how this trend will be affected by current HPV vaccination trends. OBJECTIVE To assess the association of HPV vaccination with future OPC incidence in the US. DESIGN, SETTING, AND PARTICIPANTS This population-based age-period-cohort analysis obtained OPC incidence data from the Surveillance, Epidemiology, and End Results program from 69 562 patients 34 to 83 years of age diagnosed with OPC. The HPV vaccination data were obtained from the National Immunization Survey–Teen (60 124 participants) and National Health Interview Survey (16 904 participants). Data were collected from January 1, 1992, to December 31, 2017. Age-period-cohort forecasting models projected expected 2018 to 2045 OPC incidence under a counterfactual scenario of no HPV vaccination and current levels of HPV vaccination, stratifying by sex. Data analyses were completed by December 2020. EXPOSURES Age- and sex-specific cumulative prevalence of HPV vaccination in 2016 to 2017 projected forward. MAIN OUTCOMES AND MEASURES Projected OPC incidence and number of OPC cases expected to be prevented by HPV vaccination. RESULTS Under current HPV vaccination rates, between 2018 and 2045, OPC incidence is projected to decrease in younger individuals (36-45 years of age: from 1.4 to 0.8 per 100 000 population; 46-55 years of age: from 8.7 to 7.2 per 100 000 population) but continue to increase among older individuals (70-83 years of age: from 16.8 to 29.0 per 100 000 population). The association of HPV vaccination with overall OPC incidence through 2045 wil remain modest (no vaccination vs vaccination: 14.3 vs 13.8 per 100 000 population in 2045). By 2045 HPV vaccination is projected to reduce OPC incidence among individuals 36 to 45 years of age (men: 48.1%; women: 42.5%) and 46 to 55 years of age (men: 9.0%; women: 22.6%), but among those 56 years or older, rates are not meaningfully reduced. Between 2018 and 2045, a total of 6334 OPC cases will be prevented by HPV vaccination, of which 88.8% of such cases occur in younger age (≤55 years) groups. CONCLUSIONS AND RELEVANCE According to the projections of this population-based age-period-cohort study, current HPV vaccination rates will have a limited association with overall OPC incidence through 2045 because older individuals who have not yet been vaccinated remain at high risk for OPC. However, reductions in OPC incidence should occur among young and middle-aged adults, the group at lowest risk of diagnosis. These findings forecast a continued shift in the landscape of OPC to an older population.