Trends in Human Papillomavirus-Related Oropharyngeal Squamous Cell Carcinoma Incidence, Vermont 1999-2013

This study examines trends in age-adjusted incidence rates of human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) in comparison to oral cavity proper squamous cell carcinoma (OSCC) in the population of Vermont from 1999 to 2013. Data on cases of oral and pharynx cancers diagnosed in Vermont between 1999 and 2013 were obtained from the Vermont cancer registry. The age-adjusted incidence rates and annual percentage change of HPV-related OPSCC and OSCC were calculated using Joinpoint trend analysis. Four hundred and thirty-one cases of HPV-related OPSCC were diagnosed from 1999 to 2013. Males constituted 83% (P < 0.0001) of the cases and the 6th decade of life marked the highest incidence. The overall age-adjusted incidence rates for HPV-related OPSCC significantly increased (from 2.39 to 3.86 per 100,000, P < 0.0001). In males, it significantly increased (from 3.62 to 6.93 per 100,000, P < 0.0001), while in females it remained stable (from 1.18 to 1.02 per 100,000, P = 0.28) during 1999-2013. The average rate of HPV-related OPSCC significantly increased by 4.4% annually (P = 0.004). In males the average rate significantly increased by 5.3% annually (P = 0.001) and in females the rate increased by 0.37% annually (P = 0.87). In contrast, age-adjusted overall incidence rates for OSCC significantly decreased (from 3.99 to 3.35 per 100,000, P = 0.018). The overall rate of OSCC decreased by 0.96% annually (P = 0.37) and the highest incidence of cases was in the 7th decade of life. In conclusion, there was an increasing trend of HPV-related OPSCC, specifically in males, and there appears to be a decreasing trend of OSCC in Vermont.