Mark Omundsen - Colorectal & General Surgeon
This is cancer that begins in your colon or rectum. Often, it may start as a polyp which is a growth of abnormal tissue on the lining of the colon or rectum.
Most people will not have symptoms of colorectal cancer until the disease is at a fairly advanced stage. Then they may experience symptoms such as:
- change in bowel habit that lasts for more than a few days
- blood in the stool
- stomach pain.
Tests used to confirm a diagnosis of colorectal cancer include:
- stool blood test – a sample of stool is tested for traces of blood
- barium enema – a chalky white substance (barium) and air are pumped into the colon and x-rays are taken
- biopsy – a small piece of tissue is removed for examination under a microscope
Stool blood tests, sigmoidoscopy, colonoscopy and barium enemas are also used as screening tests to look for colorectal cancer in people without symptoms. If these tests find cancers at an early stage, the chances of successful treatment are much higher than when the cancers are further advanced. Screening tests can also involve the removal of polyps that may become cancerous in the future.
The choice of treatment depends on your overall health as well as how far advanced the cancer is. This is determined in a process known as ‘staging’ in which the tumour size, lymph node involvement and spread to other organs is assessed.
The three main forms of treatment for colorectal cancer are:
Surgery – the most common treatment. Surgery may involve ‘Open Surgery’ in which a large incision (cut) is made in your abdomen or ‘Laparoscopic Surgery’ in which several much smaller incisions are made. The section of the colon or rectum with the cancer is removed and the two ends are reconnected. In some cases, a temporary or permanent colostomy may be required to remove body wastes.
Chemotherapy – anticancer medicines, either taken by mouth (oral) or injected into a vein (intravenous), can destroy cancer cells and slow tumour growth. Chemotherapy is useful to treat cancers that have spread to other parts of the body and may also be used before or after surgery or in combination with radiation therapy.
Radiation Therapy – high energy x-rays are used to destroy cancer cells or shrink tumours. It is often used together with surgery, in some cases to shrink the tumour before surgery, or to destroy any cells that may be left behind after surgery.