Using Population-based Cancer Registry Data to Assess the Burden of Human Papillomavirus-associated Cancers in the United States: Overview of Methods

Increased attention to human papillomavirus (HPV)-associated cancers in light of the recent release of an HPV vaccine, as well as increased availability of cancer registry data that now include reporting from a large proportion of the US population, prompted the current assessment of HPV-associated cancers. This article describes methods used to assess the burden of HPV-associated cervical, vulvar, vaginal, penile, anal, and oral cavity/oropharyngeal cancers in the United States during 1998 through 2003 using cancer registry data, and it provides a brief overview of the epidemiology of these cancers. Persistent infection with the human papillomavirus (HPV) is considered to be a cause of nearly all cervical cancer.1 It is believed that HPV also is associated with approximately 90% of anal cancers; 40% of penile, vaginal, and vulvar cancers; 25% of oral cavity cancers; and 35% of oropharyngeal cancers.2,3 A quadrivalent HPV vaccine that protects against HPV type 6 (HPV-6), HPV-11, HPV-16, and HPV-18 has been approved for use in the United States for females ages 9 years to 26 years, and a bivalent vaccine that protects against HPV-16 and HPV-18 currently is under review by the US Food and Drug Administration. It has been demonstrated that the HPV vaccine reduces the incidence of cervical, vaginal, and vulvar precancers, offering hope for the reduction in incidence of these diseases and the corresponding invasive cancers among women.4,5 Current studies are assessing the efficacy of the vaccine on HPV-associated disease in men.6 Close surveillance of these cancers will be necessary to ensure that high-risk populations are being reached by vaccination programs. Increased attention to HPV-associated cancers in light of the recent release of the vaccine, as well as increased availability of cancer registry data, prompted the current Supplement of Cancer titled ‘‘Assessing the Burden of HPV-Associated Cancers in the United States’’ (ABHACUS). The major purposes of this Supplement are to assess the current burden of anogenital and oropharyngeal cancers associated with HPV within the United States and to provide a baseline for monitoring future trends in HPV-associated cancers. This article describes methods used to assess the burden of HPV-associated cancers in the United States—methods that are common to several articles in the Supplement. This article describes the data sources, case definitions, variables, and analytic methods of descriptive epidemiologic articles that are included in this Supplement, and it provides an overall picture of the burden of HPV-associated cancers