Anal cancer is cancer that starts in the cells of the anus. Different types of tumors can form in the anus. Some of these tumors are not cancer. These tumors can include:
Understanding the anus
The anus is the last part of the digestive or gastrointestinal tract. It’s at the end of the rectum. It's where stool comes out of the body. It consists of a muscular ring (sphincter) that opens during a bowel movement to allow stool (feces) to pass through. It’s also made of flat cells that form the lining of the inside of the anus. Most anal cancers start in these flat lining cells, which are also called squamous cells. The lower part of the anus, where it meets the skin, is called the anal margin.
Talk with your healthcare provider
If you have questions about anal cancer, talk with your healthcare provider. He or she can help you understand more about this cancer.