Screening and therapy of anal intraepithelial neoplasia (AIN) and anal carcinoma in patients with HIV-infection

Abstract

Anal intraepithelial neoplasia (AIN) is a potential precursor of invasive anal carcinoma. Introduction of highly active antiretroviral therapy (HAART) in the treatment of HIV infection substantially reduced the incidence of some diseases associated with opportunistic viral infections. However, the incidence of AIN is reported to increase and HAART seems to have only little impact on the regression or progression of AIN. Paradoxically, improvement of survival in the HAART era results in an increased risk of anal cancer. The incidence of anal carcinoma amongst homosexual men is substantially higher compared to the normal population (35/100.000). This incidence is similar to the incidence of cervical cancer before screening for CIN with cervical cytology. Recent data suggest that the incidence of AIN and anal cancer is even higher among HIV-infected individuals. Both cancer entities share biologic similarities, including the association with human papillomavirus infection (HPV). Screening for CIN with cervical cytology and early treatment has resulted in a significant decline in the incidence of cervical carcinoma. Like cervical cancer, anal carcinoma may be preventable through identification and treatment of its precursors. Future efforts should focus on a screening protocol, training of clinicians in the diagnosis and treatment of AIN and anal carcinoma, and novel approaches to treatment of these lesions. This screening protocol could help to reduce anal cancer in HIV-infection as well as save limited resources in health care system.