Overview Most cases of anal cancer occur in people older than 50. The most common type of anal cancer is squamous cell carcinoma, which begins in the cells that line most of the anal canal. Understanding Your Diagnosis Bleeding from the rectum is the most common symptom of anal cancer. Treatment for anal cancer is quite effective, though, and most people who are treated will be cured. Deciding on Treatment Your treatment depends on the size and location of the tumor and the extent of the disease. Chemotherapy, radiation, and surgery are all treatment options.