Cancer Council Australia
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Bowel cancer

Bowel cancer, also called colorectal cancer, is the second most common cancer in both men and women in Australia1. Eighty per cent of cases have no known hereditary genetic associations. Bowel cancer is preceded by adenomas (polyps), which may become invasive cancer if undetected.

Incidence and mortality

In 2011, 15,151 new cases of bowel cancer were diagnosed in Australia. The risk of being diagnosed by age 85 is 1 in 10 for men and 1 in 15 for women.

In 2012, there were 3980 deaths caused by bowel cancer in Australia. This represents the second highest number of cancer deaths after lung cancer.


Screening, using a non-invasive test for blood in the faeces, is available through the National Bowel Cancer Screening Program to Australians who turn 50, 55, 60 or 65 years of age.

People turning 70 will be added in 2015. Abnormal tests are followed up with a colonoscopy.

Symptoms and diagnosis

Symptoms of colorectal cancer include:

  • change in bowel habit with diarrhoea, constipation or the feeling of incomplete emptying
  • thin bowel movements
  • blood in the motion or abdominal bloating or cramping.

More general symptoms are:

  • tiredness
  • weight loss
  • unexplained anaemia.

Diagnosis is by a colonoscopy.


Staging is determined by how far the cancer has penetrated through the bowel wall. Stage I is superficial, stage II is deeper and stage III is when the cancer has gone through the thickness of the wall or out into the tissues or lymph nodes beside the bowel. Stage 4 means the cancer has spread to other organs, commonly the liver.

A CT scan can be used to detect spread to the liver or lungs. A blood test to check if CEA (carcinoembryonic antigen) is elevated can be used to monitor the progress of the disease.


Risk factors include age, inherited genetic risk, inflammatory bowel disease, obesity and smoking.


The risk of bowel cancer can be reduced by not smoking, a healthy diet with plenty of fresh fruit and vegetables, and maintaining a healthy body weight.


Stage I and II disease can be treated with surgery alone to remove the bowel and surrounding lymph nodes. Stage III disease requires surgery and additional chemotherapy to try to prevent recurrence. Widespread disease is treated with chemotherapy. More recently targeted therapies are being trialled in addition to chemotherapy.


An individual's prognosis depends on the type and stage of cancer, as well as their age and general health at the time of diagnosis. With stage I bowel cancer, an estimated 93% of patients will still be alive at five years. This falls to 82% with stage II, 59% with stage III and 8% for widespread disease. Across all cases, the five year survival rate for Australians diagnosed with bowel cancer is 66%.

For more information, contact Cancer Council 13 11 20 (cost of a local call).

1) Excluding non-melanoma skin cancer, which is the most commonly diagnosed cancer according to general practice and hospitals data, however there is no reporting of cases to cancer registries.


For more information

Related information


  • Australian Institute of Health and Welfare 2012. Cancer survival and prevalence in Australia: period estimates from 1982 to 2010. Cancer Series no. 69. Cat. no. CAN 65. Canberra: AIHW.
  • Australian Institute of Health and Welfare 2015. ACIM (Australian Cancer Incidence and Mortality) Books. Canberra: AIHW.
  • Australian Institute of Health and Welfare & Australasian Association of Cancer Registries 2012. Cancer in Australia: an overview, 2012. Cancer series no. 74. Cat. no. CAN 70. Canberra: AIHW.
  • Australian Institute of Health and Welfare 2012. National Bowel Cancer Screening Program monitoring report: phase 2, July 2008-June 2011. Cancer series no. 65. CAN 61. Canberra: AIHW.

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This page was last updated on: Friday, June 5, 2015