What is anal cancer?
Anal cancer is abnormal growth of the cells that make up the anus, which is the last part of the large bowel. Most anal cancers start in the cells that line the surface of the anus. It is usually diagnosed through a physical examination or a proctoscopy. This is when a thin tube is inserted into a person’s anus, allowing their doctor to inspect it and take a tissue sample. This sample is called a biopsy and it is tested for signs of cancer.