Learn more about Bowel cancer
A bowel cancer arises from an uncontrolled local overgrowth of cells in the lining of the bowel. Bowel cancers first arise from polyps, which continued, abnormal growth and proliferation of cells within the polyp. As a bowel cancer enlarges, it can then develop the ability to grow into and through the bowel wall, spread to lymph nodes, or spread beyond the bowel to liver, lung or the abdominal cavity.
Bowel cancer may not cause any symptoms, especially in the early stages. It may present with anaemia (low blood count), weight loss, fatigue, abdominal pain, altered bowel habits or rectal mucous or bleeding. Even large polyps or bowel cancers may not cause symptoms – thus the importance not only of checking your stools, but also participating in the Bowel Cancer Screening program and/or attending for colonoscopy.
The first step of treating bowel cancer is gathering more information. A colonoscopy is performed to take a biopsy, define the site of the cancer within the bowel, and to make sure there is no more than one. A CT scan then looks for signs of spread outside the bowel, particularly in the liver or lung. In rectal cancer, an MRI is also performed to look at the rectum and surrounding structures in more detail.
An operation usually entails the removal of the affected segment of bowel, with healthy tissue margins on either side. The operation also removes the relevant packet of lymph nodes that drains the bowel, and any sign of cancer in the lymph nodes can affect your ongoing treatment. Generally speaking, a stoma or bag, is usually avoidable but may be required in some rectal cancers or as a temporary safety valve after particular operations.
Chemotherapy and/or radiotherapy is decided on a case by case basis. Generally, for colon cancers, chemotherapy is indicated if there are positive lymph nodes. The treatment of rectal cancer is more complex and is usually discussed in a multi-disciplinary team meeting.