HPV: What New Places Does It Live, What New Diseases Does It Cause?

Much of the information about the oncogenicity of human papillomavirus genotypes is predicated on cervical cancer epidemiology studies. Hence, the classification of high, intermediate and low risk types is based on cervical disease.  The natural history of HPV infections in the cervix has taken forty years of longitudinal follow up to understand the transmission, acquisition and clearance rate of specific HPV types, and the differential progression rates to cervical cancer. When we explore HPV infection at different anatomy sites, we have done so using the classification systems defined for cervical cancer.  This becomes apparent when we discuss penile cancers in which 40% are associated with the five most common cervical oncogenic types: HPV 16, 18, 31, 33, and 45, but 10% are associated with HPV types considered low/no risk for cervical cancer.  The behavioral risk and preventive factors for cervical cancer are now established; but those risk and preventive factors for other HPV associated cancers have yet to be studied and cannot be assumed to be equivalent to cervical cancer.  Complicating the study of exposure, transmission and future vulnerability are the non-comparable serologic assays for specific HPV types which may be gender specific.  The detection of antibody is as much a function of the assay as it is of viral exposure, making interpretations of seroepidemiology work for all HPV associated diseases uncertain.