文摘
Anal carcinomas occur rarely in the general population. In certain risk groups, such as human immunodeficiency virus (HIV) positive men who have sexual contact with other men, the proportion is strongly increased. Anal canal carcinomas and cervical carcinomas are very similar from a biological point of view because in both high risk groups carcinomas are preceded by a persistent human papillomavirus (HPV) infection. The HPV infection is transmitted by sexual contact and infections are very common but in most cases successfully eliminated by the immune system. Persistence of an infection with HPV in high risk groups initiate malignant alterations due to deregulation of infected cells. The early oncoproteins E6 and E7 play an important role because they deactivate the tumor suppressor proteins pRB and p53 so that nothing stands in the way of unlimited growth of infected cells and leads to genomic instability. Anal cancer originates from precursors, anal intraepithelial neoplasms or high-grade lesions of squamous cells. These can be detected using anal swab examination or anoscopy and treated early. Primary prevention is by HPV inoculation.