Anal cancer occurs in the anus, which is at the end of the gastrointestinal tract. It is different from and less common than colorectal cancer, which is cancer of the colon or rectum. Anal cancer is rare, but the number of new cases is rising. Of these, 5, will affect females, and 2, will affect males.
Muscles anal sphincters that surround the anal canal relax to allow waste to leave your body. Anal cancer is an uncommon type of cancer that occurs in the anal canal. The anal canal is a short tube at the end of your rectum through which stool leaves your body. Most people with anal cancer are treated with a combination of chemotherapy and radiation. Though combining anal cancer treatments increases the chance of a cure, the combined treatments also increase the risk of side effects.
Researchers continue to investigate the causes of anal cancer. Known risk factors that have been identified include chronic infection with high-risk types of human papillomavirus HPV , gender and age. HPV, a collection of more than viruses spread primarily by contact during vaginal, oral or anal sexual activity, is responsible for the majority of anal cancers. HPV may be asymptomatic for years, and persistent HPV infections may cause cell changes that, left untreated, may become cancer.
When cancer cells form into benign or malignant tumors in the tissues of the anus, anal cancer has occurred. The anus is the opening at the bottom of your intestines where stool exits the body. Anal cancer is rare, but when it occurs, it may spread to other parts of the body.