Bowel cancer is a common malignancy that involves the bowel wall. It starts with changes within the cells of the lining, and with time may grow and progress through the wall and then reach other organs.
The underlying cause is not known. There may be a genetic (inherited) component, and also the effects of carcinogens exposed to the bowel lining, such as different food types, and lifestyle.
Some factors that will increase your risk of developing colorectal cancer are:
- A close relative with bowel cancer (parents, children or siblings)
- Bowel polyps (abnormal growth of cells on the bowel wall that form a mushroom-like lump)
- Inflammatory bowel diseases such as Ulcerative Colitis and Crohn’s Disease
- Genetic conditions where there are multiple polyps (e.g. Familial Adenomatous Polyposis – FAP)
- Recent change in bowel habit, such as new onset of diarrhoea or constipation
- Anal bleeding
- Persisting abdominal pain
If you have some of the above symptoms or risk factors you may require investigations to determine if you have cancer. This may include a colonoscopy.
Other tests may be done if cancer is diagnosed, to help determine the stage of your cancer (ie if it is early or more advanced), and to plan your treatment. These may include CT, MRI and or endoanal ultrasound (for rectal cancer), blood tests.
The aim of treatment is cure. Usually this involves an operation to remove the section of the bowel that contains the cancer.
If the cancer is in the rectum, sometimes radiotherapy with or without chemotherapy may be given first, followed by an operation. If the cancer has spread to other organs chemotherapy may be required.
If the cancer has spread extensively and in unable to be cured with these modalities, therapy aims to palliate symptoms.