[Anal cancer].

Abstract

A nal cancer is a disease in which malignant (cancer) cells form in the tissues of the anus. The anus is located at the end of the large intestine, below the rectum, through which solid waste leaves the body. The anus is formed partly from the outer skin layers and partly from the intestine. The anal canal, the part of the anus between the rectum and the anal opening, is about 11⁄2 inches long. Anal carcinoma (cancer) is unique and can be distinguished from all other gastrointestinal tumors. It is mainly a local-regional cancer, with a metastatic potential (possibility of spreading to other body tissues) in only 15% of patients. The April 23/30, 2008, issue of JAMA includes an article evaluating current therapies for the treatment of anal carcinoma.