Epidermoid carcinoma of the anal canal.

Anal cancers are rare tumors with only an expected 4000 new diagnoses in 2005. The majority of these are epidermoid or squamous cell cancers. Despite the rarity of this disease, great advances have been made in its understanding and treatment. The human papillomavirus (HPV), immunosuppression for solid organ transplantation, the human immunodeficiency virus (HIV), and sexual practices are changing the demographics of the disease from elderly women to young men who have sex with men and young women infected with HPV and HIV. The treatment of these malignancies was radically changed with Dr. Nigro's description in 1974 of the use of a nonoperative treatment strategy. Today, radiochemotherapy represents first-line therapy and the role of surgery has been largely relegated to that of salvage therapy for treatment failures of nonoperative management.