Cancer anus

Cancer of the anus is a type of cancer that develops in the tissues of the anus, which is the opening at the end of the digestive tract. It is a rare form of cancer, accounting for 1-2% of all gastrointestinal cancers. Anal cancer usually begins as precancerous changes in the cells of the anus. These changes can be detected early and treated before they become cancerous. Anal cancer is classified as either squamous cell carcinoma or adenocarcinoma. Squamous cell carcinoma begins in the thin, flat cells that line the anal canal, while adenocarcinoma develops in the cells that make up the glands of the anus. Risk factors for anal cancer include smoking, a weakened immune system, human papillomavirus (HPV) infection, and a history of other anogenital cancers. Symptoms of anal cancer include rectal bleeding, anal pain, itching, and a lump or mass in the anal area. Diagnosis of anal cancer is made through physical examination, anoscopy (visual examination of the anus using a lighted instrument), biopsy (removal of a small tissue sample for laboratory testing), imaging studies, and laboratory tests.