Cancer of the Anal Canal

Anal cancer is a rare type of gastrointestinal malignancy. Over 80% of anal cancers are of squamous origin and arise from the squamous epithelium of the anal canal and perianal area. Recent evidence has demonstrated that the incidence of squamous cell carcinoma of anal cancer increases in immunocompromised patients. Approximately 10% are adenocarcinoma arising from the glandular mucosa of the upper anal canal or anal glands. Other malignancies of the anal canal, such as melanoma, sarcoma, and lymphoma, are exceedingly rare. Surgery has limited application in the treatment of squamous cell carcinoma of the anal canal. Radiation therapy plays a major role in the treatment of anal cancer, and concurrent chemoradiation therapy is the standard treatment for most cases of locally advanced disease.