Colorectal Cancer
Colorectal cancer occurs when the cells that line the colon or rectum begin to change and grow differently than intended. In some cases, these cells will develop into benign (non-cancerous) polyps, which may develop into cancerous tumors over time.
Colorectal cancer most often occurs in people over the age of 50 and is one of the most common causes of cancer death in Canada. However, if caught early, it is usually treatable, which is why screening is so important.
Screening
Who should be screened for colorectal cancer?
Any person 50 years and older. Start talking to your healthcare provider before you reach 50 years of age to determine your risk factors and to see if you need earlier screening. If you have a family history of colorectal cancer you may be recommended to be screened earlier than 50 years of age.
How do they screen?
Colorectal cancer screening is usually done through a self-collected, at-home stool test (feces test), or a visual exam of part of your colon using a small fiberoptic camera called a sigmoidoscopy.
Self-collected test
Self-collected tests include the Fecal Immunochemical Test (FIT) or the Fecal Occult Blood Test (FOBT). To complete a self-collected test, you will be given a plastic container with a small stick and will be asked to collect a small amount of your stool (feces) in the privacy of your own home. The sample will be analysed in a lab for small amounts of blood in your stool that isn’t easily visible.
Sigmoidoscopy
A sigmoidoscopy is a day-procedure, usually done at a physician's office, where a small flexible fiberoptic camera is passed through the lower part of your rectum and colon. If polyps and abnormalities are seen, samples can be taken for further testing. Prior to this procedure you will be given instructions on how to prepare for it.
People at high risk of developing colorectal cancer may be recommended for other testing such as a colonoscopy (fiberoptic camera exam of the entire colon, not just the lower portion), to start screening at an earlier age, or for more frequent testing based on the individual’s risk factors. Speak to your healthcare provider if you think you may be at higher risk.
How often should I get screening?
How often you get screened depends on the test:
- After a negative (normal) FIT or FOBT: recommended screening every two years
- After a negative sigmoidoscopy or colonoscopy: recommended to be screened again in ten years
Results
Your primary healthcare provider will be given your results. If you have a positive test result (either from an at-home collection test or sigmoidoscopy), a colonoscopy will likely be recommended. Your healthcare provider will contact you to discuss these results and the next steps in your care.
How do I know if I am at high risk for colorectal cancer?
If you have a personal or family history of one or more of the below, you may be at increased risk of developing colorectal cancer:
- One or more first degree relative* diagnosed with colorectal cancer at any age
- Personal diagnosis of one of the following hereditary syndromes: Lynch syndrome, familial adenomatous polyposis, Peutz–Jeghers, MYH-associated polyposis or juvenile polyposis
- Personal diagnosis of inflammatory bowel disease (Chrohn’s disease or ulcerative colitis)
- Personal history of colorectal polyps
*First degree relative includes parent, sibling or child
What are the signs and symptoms of colorectal cancer?
Most colorectal cancers do not create symptoms until the tumor has grown large, starts to bleed, or spreads to other areas. It is very important to get colorectal cancer screening, since symptoms exhibit so late.
Signs and symptoms can include:
- Rectal bleeding (can be bright red or dark red)
- Abdominal pain, discomfort, bloating or cramps that won’t go away
- Pain or discomfort in the rectum
- Dark or black stools
- Changes in your stool pattern (such as constipation or diarrhea that persist)
- Feeling like your bowels aren’t empty after a bowel movement
- Changes in your stool appearance (looks narrower)
- Lump in your abdomen or rectum
- Nausea or vomiting
- Unusual weight loss, loss of appetite, or fatigue
For a more complete list of potential symptoms visit the Canadian Cancer Society
If you have any of these signs or symptoms, seek care immediately.
Reducing your risk of developing colorectal cancer
Some of the risk factors for developing colorectal cancer are outside of your control, like older age, genetics, or health conditions (see high-risk section). However, there are things you can do to reduce your overall risk of developing colorectal cancer. These include:
- Stop smoking – smoking can increase your risk of certain cancers, including colorectal cancer
- Maintain a healthy diet - eat meals that are high in vegetables, fruits and whole grains
- Get regular exercise – aim for 2.5 hours or more of moderate intensity exercise per week
- Avoid being sedentary – being sedentary can increase the risk of developing some cancers, including colorectal cancer
- Be wise with alcohol consumption – alcohol can increase the risk of cancer; if you drink alcohol visit Canada’s low-risk alcohol drinking guidelines for information on recommended low-risk limits
For more information on colorectal cancer and screening, visit:
Canadian Cancer Society - Get screened for colorectal cancer
For additional questions on cancer or cancer screening, please contact your local Care Delivery Unit to speak to your healthcare provider.
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