Factors associated with the decreasing rate of oropharyngeal cancer in young adults in the United States.
Authors: Chan John K , Rohatgi Atharva , Caesar Michelle Ann , Johnson Caitlin Ruth , Mann Amandeep Kaur , Chan Ava , Kapp Daniel Stuart , Liao Cheng-I 
Published: June 2022

10534 Background: To evaluate trends of HPV-associated oropharyngeal cancers and HPV infections in the United States. Methods: Data was extracted from the United States Cancer Statistics Public Use Database (USCS) between 2001 and 2017 and the National Health and Nutrition Examination Survey (NHANES) between 2011 to 2016. Data on oropharyngeal squamous cell carcinoma (OSCC) was obtained from the USCS database. HPV vaccination and screening (oral washings) data were obtained from NHANES. Based on CDC guidelines, HPV strains were further subdivided into high-risk strains (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68). Results: Based on USCS, oropharyngeal cancer incidence rates have increased in males by 1.64% every year (p < 0.001) while remaining stable in females over the last 17 years. Oropharyngeal cancers have increased for all age groups over the age of 55, with the largest increase seen in those between the ages of 65-69 years old (p < 0.001). However, individuals between the ages of 30-34 had the largest decrease in oropharyngeal cancers over the same time period (p = 0.016). Based on race, Whites had the highest incidence rates at 5.12/100,000 followed by 2.99 in Blacks, 2.32 in Hispanics, and 1.11 in Asians. By geographical region, the incidence was found to be the highest in the Midwest with 4.68/100,000 and the lowest in the West at 3.78. Our intersectional analysis showed that White males in the South aged 65-69 had the highest incidence of oropharyngeal cancers at 40.57/100,000 and this same group aged 60-64 had the highest annual increase at 4.65% (p < 0.001). Using the NHANES database, we showed that those with greater than 4 lifetime sexual partners have a 3-fold higher risk of high risk HPV infection compared to those with 4 or under (7.1% vs 1.9%, p < 0.0001). 8.8% of current smokers are infected with high risk oral HPV compared to only 3.9% of non smokers (p < 0.001). The incidence of any HPV infection for those <39 years old was 5.9% in 2011 and 4.7% in 2016 (p = 0.4723). In contrast, the incidence in those > 39 years old was 6.6% in 2011 and 6.4% in 2016 (p = 0.99). On multivariate analysis, males have a 4-fold higher risk of high risk HPV infections compared to females (4.45, 95% CI: 2.94 - 6.74, p < 0.0001). Those with five or more sexual partners have 7-fold higher rate of high risk oral HPV infections compared to those without any sexual partners (7.15, 95% CI: 1.94 - 26.3, p = 0.0039). Furthermore, current smokers (1.81, 95% CI: 1.17 - 2.77, p = 0.0081) and three to four drinks per day (1.63, 95% CI: 1.05 - 2.55, p = 0.0312) have an increased risk of high risk oral HPV infections. Conclusions: Over the last 18 years, oropharyngeal cancers are increasing in individuals over the age of 55, particularly White males residing in the South. Individuals with greater than 4 lifetime sexual partners, current smokers, and those who consume three to four drinks per day have increased HPV infectivity rates.