But pain and bleeding can also be a symptom of anal cancer—a much less common condition but one that people may worry about more. Before you jump to the conclusion that a bump on your butt is anal cancer, get a reality check from Joel Palefsky, MD, and J. Michael Berry-Lawhorn, MD, who are both anal dysplasia specialists. Anal cancer is caused by the sexually transmitted infection human papillomavirus HPV. An estimated 79 million Americans are infected.
The anus is the end of the large intestine , below the rectum , through which stool solid waste leaves the body. The anus is formed partly from the outer skin layers of the body and partly from the intestine. Two ring-like muscles, called sphincter muscles, open and close the anal opening and let stool pass out of the body. Enlarge Anatomy of the lower digestive system, showing the colon and other organs. The skin around the outside of the anus is called the perianal area. Tumors in this area are skin tumors, not anal cancer. Risk factors include the following:.
HPV-Associated Anal Cancer Rates by Race and Ethnicity
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 estimated that about 4, new cases of HPV-associated anal cancers external icon are diagnosed in women and about 2, are diagnosed in men each year in the United States. More black men get HPV-associated anal cancer than men of other races. Cancer registries do not collect data on the presence or absence of HPV in cancer tissue at the time of diagnosis. Anal cancers described include anal and rectal squamous cell carcinomas. The Data Visualizations tool makes it easy for anyone to explore and use the latest official federal government cancer data from United States Cancer Statistics.