Anal cancer is a type of cancer that occurs in the anus. The anus is the part of the gastrointestinal tract, which is about 1-1/2 inches long and connects the rectum to the outside of the body. It also allows the solid waste to pass from the body. Anal cancer occurs when there is an uncontrollable growth of the cells, resulting in tumour formation.
A tumour can be cancerous or benign. A cancerous tumour is malignant and spreads to other parts of the body, while the benign tumour grows but does not spread. Anal cancer is uncommon and can be treated with a combination of treatments.