Anal Cancer What is Anal Cancer? The anus is the opening at the end of the rectum (the end part of the large intestine) through which body waste passes. Cancer of the anus (anal cancer) is very rare, and is the result of abnormal cell growth in the anus. Cancer of the outer part of the anus is more likely to occur in men, while cancer of the inner part of the rectum occurs more often in women. Risk Factors of Anal Cancer While we do not currently know the exact cause of anal cancer, we do know that there are certain risk factors linked to this disease. These risk factors include: Virus. Having HPV (human papillomavirus) increases the chances of developing one type of anal cancer. The virus spreads through sexual contact. Smoking. The carcinogens contained in tobacco smoke are linked to a higher risk of developing cancer. Weakened immune systems. People with weakened immune systems, such as transplant patients or people with various types of chronic illnesses, are at a higher risk for developing anal cancer. Age. Most people with anal cancer are over 50 years old. Common Symptoms of Anal Cancer Following are some common symptoms of anal cancer: Bleeding from the rectum (even trace amounts) Pain or pressure in the area around the anus Itching or discharge from the anus A lump near the anus These symptoms may be caused by cancer or by other, less serious conditions. If you are experiencing any of these symptoms, see your doctor. Diagnosing Anal Cancer Anal cancer can be detected and diagnosed through a rectal examination. The doctor may use a biopsy to examine tissue under a microscope to confirm the diagnosis. Further tests will be done to determine the stage of the cancer.