Digestive and Gastrointestinal Conditions (opens new window)

ABOUT THE CONDITION

What is Colorectal Cancer

Colorectal Cancer is a type of cancer that affects the colon (large intestine) or rectum. It usually begins as small growths of cells called polyps that develop on the inner lining of the colon, which is the last part of the digestive system that breaks down food.

Polyps are either non-cancerous or pre-cancerous clumps of cells that are often small and produce few symptoms other than slow bleeding. There are two main types of polyps:

Hyperplastic are benign polyps that have no potential to develop into cancer

Adenomatous are pre-cancerous polyps which means they have the potential to turn into cancer

Colorectal Cancer can develop from a variety of sources, but the most common is through these pre-cancerous ‘adenomatous’ polyps.¹

How common are colorectal polyps?

The prevalence of colorectal polyps increases with age and, while most polyps won’t develop into colon cancer, 75% of all Colorectal Cancer cases develop from adenomatous polyps.¹

That’s why a screening colonoscopy is so important. During a colonoscopy procedure, the doctor can identify and remove the precancerous polyps to reduce the risk of Colorectal Cancer developing.^2,3

Worldwide

Colorectal Cancer is the 3rd most common type of cancer⁴

When Colorectal Cancer is detected early, the five-year relative survival rate is around 71%.⁵ Routine screenings at regular intervals are the best tool you have to protect yourself.

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Symptoms of Colorectal Cancer

There are often no symptoms of Colorectal Cancer during its early stages. When symptoms do occur, they will vary according to the location and size of the cancer.

Symptoms may include⁴:

Prolonged changes in your bowel habits, including diarrhoea or constipation
Changes in size or shape of bowel movements (i.e., narrow, pencil thin stools)
Persistent abdominal pain or distention
Rectal bleeding, blood or mucus in your stool
Unexplained weight loss or change in appetite

Causes of Colorectal Cancer

Age increases the risk of colorectal cancer, significantly after the age of 50. Although bowel cancer is less common among younger adults, rates are on the rise, with 1-in-10 bowel cancer cases now diagnosed in Australians under age 50.⁴
Inflammatory Bowel Disease: Crohn’s disease and Ulcerative Colitis are chronic inflammatory conditions that are known to increase the risk of Colorectal Cancer.^6-8
Obesity and an increased waist circumference in adulthood alone is associated with a 53% increased risk of Colorectal Cancer.⁹
Poor lifestyle and diet, alcohol consumption, smoking, and a lack of physical activity contribute to risk of Colorectal Cancer.^7-10
Family history of Colorectal Cancer in first degree relatives is associated with a higher risk. Around 30% of all bowel cancer cases diagnosed are due to a hereditary contribution, family history, or a combination of both. The other 70% of people have no family history of the disease and no hereditary contribution.⁴

Colorectal Cancer Diagnostic Options

There are a couple of ways for your doctor to diagnose colon polyps. These include colonoscopy and capsule endoscopy. Your doctor will discuss the most suitable diagnostic tests with you.

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References

Øines M, Helsingen LM, Bretthauer M, Emilsson L. Epidemiology and risk factors of colorectal polyps. Best Practice & Research Clinical Gastroenterology. 2017;31(4):419-424.
Niikura R, Hirata Y, Suzuki N, et al. Colonoscopy reduces colorectal cancer mortality: A multicenter, long-term, colonoscopy-based cohort study. PloS one. 2017;12(9).
Corley DA, Jenson CD. Marks AR Jr., et al. Adenoma detection rate and risk of colorectal cancer and death. N Engl J Med 2014; 370:1298-1306. DOl: 10.1056/NEJMoa1309086
Bowel Cancer Australia. Non-modifiable risk factors. Available at: https://www.bowelcanceraustralia.org/non-modifiable-risk-factors
Bowel cancer (Colorectal cancer) in Australia statistics. January 2024. Available at: https://www.canceraustralia.gov.au/cancer-types/bowel-cancer/statistics
Lopez A, Collet-Fenetrier B, Belle A, Peyrin-Biroulet L. Patients’ knowledge and fear of colorectal cancer risk in inflammatory bowel disease. Journal of digestive diseases. 2016;17(6):383-391.
Ahmed M. Colon Cancer: A Clinician’s Perspective in 2019. Gastroenterology research. 2020;13(1):1-10.
Johnson CM, Wei C, Ensor JE, et al. Meta-analyses of colorectal cancer risk factors. Cancer Causes Control. 2013;24(6):1207-22
Schaberg MN, Smith KS, Greene MW, Frugé AD. Characterizing Demographic and Geographical Differences in Health Beliefs and Dietary Habits Related to Colon Cancer Risk in US Adults. Frontiers in nutrition. 2020;7:568643: 1-8
Brenner H, Kloor M, Pox CP. Colorectal cancer. Lancet (London, England). 2014;383(9927):1490–1502.

Colorectal Cancer is a type of cancer that affects the colon (large intestine) or rectum. It usually begins as small growths of cells called polyps that develop on the inner lining of the colon, which is the last part of the digestive system that breaks down food.

How common are colorectal polyps?

Worldwide

Colorectal Cancer is the 3rd most common type of cancer⁴

Symptoms of Colorectal Cancer

Causes of Colorectal Cancer

Colorectal Cancer Diagnostic Options

Living with Colorectal Cancer

Diagnostic options

FAQ's

Colorectal Cancer is a type of cancer that affects the colon (large intestine) or rectum. It usually begins as small growths of cells called polyps that develop on the inner lining of the colon, which is the last part of the digestive system that breaks down food.

How common are colorectal polyps?

Worldwide

Colorectal Cancer is the 3rd most common type of cancer4

Symptoms of Colorectal Cancer

Causes of Colorectal Cancer

Colorectal Cancer Diagnostic Options

Living with Colorectal Cancer

Diagnostic options

FAQ's

Colorectal Cancer is the 3rd most common type of cancer⁴