Introduction. The human papillomavirus (HPV) vaccine was approved for use in the US in 2006 to prevent HPV–related cancer. We assessed whether HPV vaccination has affected the incidence of HPV–related cancers among adolescent and young adult males and females in the US.

Methods. We analyzed data from the United States Cancer Statistics (USCS) 2001–2018 database on US males and females 15–44 years old. We included primary cancer cases of HPV-related cancers, including oropharyngeal squamous cell carcinoma, anal and rectal squamous cell carcinoma, vulvar squamous cell carcinoma, vaginal squamous cell carcinoma, penile squamous cell carcinoma, and cervical carcinoma. We compared the 4–year average annual incidence of HPV-related cancers during the 4 years before HPV vaccine introduction (2003–2006) and the latest 4 years in the vaccine era (2015–2018). Annual incidence rates were calculated as the number of cases per 1,000,000 persons and were age-adjusted to the 2000 US standard population.

Results. The 4–year average annual incidence rates for HPV-related cancers decreased in 2015–2018 compared to 2003–2006 among females 15–19 years old (0.4 vs. 1.3 per 1,000,000, rate ratio 0.31, 95% CI 0.17–0.54), 20–24 years old (7.1 vs. 14.5 per 1,000,000, rate ratio 0.49, 95% CI 0.43–0.57), 25–29 years old (50.2 vs. 58.0 per 1,000,000, rate ratio 0.87, 95% CI 0.82–0.92) and 30-34 years old (116.2 vs. 122.6 per 1,000,000, rate ratio 0.95, 95% CI 0.91–0.99). In addition, the incidence decreased in 2015–2018 compared to 2003–2006 among males 35–39 years old (17.8 vs. 22.5 per 1,000,000, rate ratio 0.79, 95% CI 0.72–0.87) and those 40-44 years old (50.7 vs. 61.5 per 1,000,000, rate ratio 0.82, 95% CI 0.78–0.87).

Conclusions. Incidence rates for HPV-related cancers decreased in the vaccine era compared to the pre-vaccine era among both males and females in certain age groups, suggesting possible early effects of HPV vaccination in the US.