The association between current human papillomavirus vaccination trends and incidence of oropharynx cancer will be modest over the next 25 years.
Current human papillomavirus (HPV) vaccination rates are anticipated to have a limited association with overall incidence of oropharynx cancer from 2020 through 2045, as older individuals who are not yet vaccinated against HPV remain at high-risk of developing oropharynx cancer, according to results from a population-based age-period-cohort study published in JAMA Oncology.
The incidence rates of oropharynx cancer are projected to decrease from 1.4 (95% CI, 1.3-1.6) to 0.8 (95% CI, 0.7-0.9) per 100,000 individuals aged 36 to 45 years and from 8.7 (95% CI, 8.4-9.1) to 7.2 (95% CI, 6.2-8.2) per 100,000 individuals aged 46 to 55 years but is expected to increase from 16.8 (95% CI, 16.3-17.3) to 29.0 (95% CI, 26.5- 31.4) per 100,000 individuals aged 70 to 83 years.
“These findings forecast a continued shift in the landscape of oropharynx cancer to an older population. The results of this study suggest that the association of current US HPV vaccination trends with oropharynx cancer will be modest during the next 25 years because the reduction in oropharynx cancer incidence associated with HPV vaccination among older adults, who have the highest incidence of disease, will take longer,” the investigators wrote.
Investigators obtained oropharynx cancer incidence data of 69,562 patients aged 34 to 83 years who had been diagnosed with the disease from the Surveillance, Epidemiology, and End Results (SEER) program. Data on HPV vaccination was gathered from the National Immunization Survey-Teen, which included 60,124 individuals, and from the National Health Interview Survey, which included 16,904 individuals; data spanned from January 1, 1992, to December 31, 2017.
Further results indicated that the cumulative rate of HPV vaccination for participants 36 years or older is expected to notable increase between 2018 and 2045. By 2045, investigators estimate that 72.2% (95% CI, 71.4%-72.9%) of individuals aged 36 to 45 years will have been vaccinated. Although the proportion is estimated to be lower, investigators anticipate that 36.6% (95% CI, 35.2%-37.9%) of individuals aged 46 to 55 years, 8.7% (95% CI, 8.1%- 9.3%) of individuals aged 56 to 69 years, and 0% (95% CI, 0%-0%) of individuals aged 70-83 years will have received an HPV vaccination.
For participants of the same age group, consistently higher levels of HPV vaccinations were observed in women compared with men, with the discrepancies between each group decreasing over time. Investigators estimated that 19.5% (95% CI, 18.1%-20.9%) of women and 3.3% (95% CI, 2.6%- 3.9%) of men will be vaccinated by 2025, although 75.2% (95% CI, 74.1%-76.3%) of women and 69.1% (95% CI, 68.0%-70.2%) of men will be vaccinated by 2045.
HPV vaccinations are estimated to reduce the incidence of oropharynx cancer by 48.1% in men and 42.5% in women between the ages of 36 to 45 years by 2045. For participants aged 46 to 55 years, the reduction is estimated to be 9.0% for men and 22.6% for women.
The study was limited by simplified realizations of vaccine benefits that were used to estimate of the association between vaccinations and oropharynx cancer incidence. Additionally, the number of vaccine doses was not taken into consideration in the estimate, with individuals who underwent the vaccination process being expected to have completed the entire series.
Zhang Y, Fakhry C, D'Souza G. Projected association of human papillomavirus vaccination with oropharynx cancer incidence in the US, 2020-2045. JAMA Oncol. Published online September 2, 2021. doi:10.1001/jamaoncol.2021.2907