Human papillomavirus, anal cancer, and screening considerations among HIV-infected individuals.

Invasive anal cancer has become an important cause of non AIDS-related cancer among HIV-infected individuals. Human papillomavirus is the main etiological agent. This review explains the pathophysiologic role of human papillomavirus in the development of invasive anal cancer, summarizes recent epidemiological trends of invasive anal cancer, and reviews the evidence to address common clinical questions posed when screening for anal cancer in HIV-infected patients. The effect of highly active antiretroviral therapy on human papillomavirus oncogenesis is still unclear, but given the increased clinical burden of invasive anal cancer among HIV-infected patients, many clinics have implemented screening programs for anal cancer and its precursors. Despite the availability of several modalities for treatment of precursors of anal cancer, evidence that current treatment modalities favorably alter the natural history of human papillomavirus oncogenesis in the anal and perianal regions is still inconclusive. However, there is sufficient evidence to state that the accuracy of anal cancer screening procedures (cytology and high-resolution anoscopy directed biopsy) is comparable to the accuracy of those used in screening for cervical cancer precursors. Studies that systematically assess the efficacy of these anal cancer screening programs in reducing the incidence of and morbidity and mortality from invasive anal cancer among HIV-infected patients are needed.