Anal cancer is the term for abnormal cell growth in the anal area or the anal canal. The anal canal connects the anus the opening to the rectum. This passage is about inches long. It is the part of the body that excretes solid waste bowel movements, feces.
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. Some noncancerous forms of anal cancer can also turn cancerous over time.
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.
Most anal cancers seem to be linked to infection with the human papillomavirus HPV. While HPV infection seems to be important in the development of anal cancer, the vast majority of people with HPV infections do not get anal cancer. A great deal of research is now being done to learn how HPV might cause anal cancer.