Overview

Colon cancer forms in the lining of the colon.  Rectal cancer forms in the lining of the rectum, the last several cm of the large intestine terminating in the anus. Either of these cancers is could colorectal cancer (bowel cancer).

Australia has one of the highest rate of bowel cancer in the world, around 1 in 23 Australians will develop bowel cancer during their lifetime. Bowel cancer develops in the wall or lining of the colon when cells grow too quickly forming a clump known as a polyp or adenoma.  Most are benign (non- cancerous) however over several years some can progress to cancer (malignancy) and if untreated the cancer can spread to other areas of the body (metastatic malignancy).

If caught early, up to 90 per cent of bowel cancers can be successfully treated. 

Risk Factors

• Age over 50
• Polyps, growths inside the colon and rectum that can become cancerous
• High fat diet
• Family or personal history of colon cancer or polyps
• Ulcerative colitis or Crohn’s disease

Warning Signs and Symptoms

Many cases of bowel cancer have no symptoms or warning signs until the cancer has advanced hence screening can be a strong tool in the prevention of bowel cancer. 

• Lower abdominal pain or tenderness in the lower abdomen
• Bleeding through the bowel or rectum
• Change in bowel action such as new onset constipation or diarrhoea
• Narrower than normal stools
• Unexplained anaemia
• Unexplained weight loss
• Abdominal bloating and fullness or cramps

Colon Polyps

A colonic polyp is a growth of extra tissue in the lining of the rectum or colon, whilst some can be cancerous most are not.  Almost all colon cancer does begin as a polyp, therefore by removing polyps early the chances of it growing into colon cancer are eliminated.  Polyps generally do not cause symptoms and can be removed quite safely during a colonoscopy in most cases. 

Treatment and Procedures

Three primary treatment options for colon cancer are:

• Surgery
• Chemotherapy
• Radiation

Treat options for colon cancer depend on the stage of the cancer, whether the cancer has recurred and the patients’ general health. 

The surgical option, a partial colectomy is the main treatment and includes removing the affected portion of the colon.  How much of the colon is removed and whether it is done in conjunction with other treatments will depend on the location of the cancer, how deep it has penetrated the wall of the bowel and if it has spread to lymph nodes or other parts of the body.

Preventing Colon Cancer

Getting screened is the first step in preventing colon cancer.  Several screening options are available including colonoscopy.  Regular colonoscopy should begin at age 50 for people with average risk of developing colon cancer.  If you have a strong family history of polyps or colon cancer, many physicians may recommend getting your first colonoscopy at age 40 or even earlier depending on your history. 

Why Bowel Screening Works?

Bowel cancer screening saves lives!  It is the best way of detecting bowel cancer early because it often develops without symptoms.  Early diagnosis improves treatment options and chances of survival.  Evidence reveals, regular screening can reduce deaths from bowel cancer by 15 to 25 per cent and prevent 300 to 500 deaths per year in Australia.