Bowel cancer, which is also known as colorectal cancer or colon cancer, is any cancer that affects the large bowel (colon) and back passage (rectum). Before starting to spread to affect other parts of the body, it usually grows very slowly and can take up to 10 years before spreading. This process of spreading is called metastasis.
Most bowel cancers start as benign innocent growths, known as polyps, on the bowel wall. Most polyps do not produce symptoms and are not pre-cancerous. They look like small spots or balls on stalks and are quite common as we grow older. There is one type of malignant polyp, called an adenoma, which can become cancerous. Should these cancer cells not be detected, they multiply to form a tumour in the bowel that causes pain, bleeding and other symptoms. This tumour can grow into the wall of the bowel or back passage if untreated and once cancer cells enter the wall, they can travel into the bloodstream or lymph nodes; where they can travel to other parts of the body. The most common places to where bowel cancer cells spread are the liver and the lungs.
Anal cancer is a rare form of bowel cancer. It is very strongly linked to the HPV virus that also causes cervical cancer in women, and much less commonly to melanomas, which is a form of skin cancer. If diagnosed at an early stage, both these forms of cancer can be treated very successfully.
The earlier bowel cancer is caught, the easier it is to treat.
The primary source for some of the content of this article, which was written some years ago, was Cancer Research UK. To read their latest detailed research findings, we strongly recommend that you access their web site page, just click on the link below:
then click on the particular type of cancer that concerns you.