Colorectal Cancer

Colorectal cancer is a significant health concern in Ontario representing the second leading cause of cancer death in men, and the third leading cause of cancer death in women as well as the third most common cancer diagnosed.

Approximately 93 per cent of the men and women who are diagnosed with colorectal cancer are over the age of 50.

A person with colorectal cancer has a 90 percent chance of being cured if the cancer is caught early enough through regular screening.

What is Colorectal Cancer?

Colorectal cancer is cancer of the colon or rectum. The colon is also called the large intestine or large bowel and is a hollow tube five to six feet long that is coiled within the abdomen and makes up the last part of the digestive system. The rectum makes up the last six inches of the colon.

Graphic used with permission of the Canadian Cancer Society.

colorectal_illustration.jpg Most colorectal cancers start in the cells that line the inside of the colon or the rectum. When these normal cells begin to grow abnormally a small precancerous growth can form called a 'polyp'. A polyp is a non-cancerous growth that sticks out from the inner lining of the colon or rectum. If these polyps are removed in their early stages, colorectal cancer can be prevented. But if left unchecked, some polyps can slowly become cancers.

Colorectal cancer usually grows slowly and in a predictable way and can take up to ten years or more to develop to an advanced stage. Colorectal cancer is curable when found at an early stage. That's why it's very important to be screened regularly for colorectal cancer.

What are the Risk Factors?

There is no single cause of colorectal cancer, but some factors may increase the risk of developing it:

  • Age - particularly after 50 years
  • Having polyps (small growths on the inner wall of the colon and rectum)
  • Family history of colorectal cancer 
  • Inflammatory bowel disease (ulcerative colitis or Crohn's disease)
  • Diet high in red meat or processed meat 
  • Alcohol consumption
  • Smoking
  • Physical inactivity
  • Obesity
  • Ethnic background

Some people develop colorectal cancer without any of these risk factors.

What is Colorectal Cancer Screening?

ColonCancerCheck is a province-wide, population-based cancer screening program that is a partnership between the Ministry of Health and Long-Term Care and Cancer Care Ontario.

ColonCancerCheck provides funding to screen all Ontarians aged 50 and over for colorectal cancer. For those at average risk for colorectal cancer, a simple at home test - the Fecal Occult Blood Test (FOBT) - is recommended. For those at increased risk because of a family history of one or more first-degree relatives (parent, sibling or child) with a diagnosis of colorectal cancer, colonoscopy is advised.

By undergoing regular screening you may be able to prevent cancer by detecting and removing precancerous polyps. A person with colorectal cancer has an increased chance of survival if the cancer is caught early enough through screening.

Colorectal cancer screening can be the difference between life and death.

ColonCancerCheck FOBT kits are available through primary care providers.

Individuals without a primary care provider can obtain a kit from a pharmacist or by calling Telehealth Ontario 1-866-828-9213.

What is a Fecal Occult Blood Test?

The Fecal Occult Blood Test (FOBT) is a simple test that you do yourself in the privacy of your own home. The FOBT checks for blood in the stool that's not visible to the naked eye. Finding blood in your stool doesn't always mean that you have cancer. There can be other causes such as polyps (non-cancerous tissue growth that can turn into cancer), ulcers or even hemorrhoids.

To complete the FOBT:

  1. Fill out your information on the special stool collection card. 
  2. Smear three samples of your stool from three separate bowel movements onto the card. 
  3. Seal the collection card in the envelope provided.
  4. Either drop the envelope off at a medical laboratory or if your test came with a postage-paid envelope, you can put in it the mail.

Please review this instruction pamphlet (available in 28 different languages) for more information.

Or watch either of these videos for simple instructions on how to complete the FOBT test.

There may be certain foods or drugs that you should avoid before doing the test. It's important to check the instructions included in the test kit and follow the instructions your doctor gave you.

It's natural to be uncomfortable about handling stool, but remember that this simple test can help save your life.

A test that comes back negative means that blood was not found in the stool. A positive result means that blood was found in the stool. Having blood in your stool doesn't always mean that you have cancer. If the stool test shows blood in your stool, follow-up testing with a colonoscopy is recommended to find where the bleeding is coming from and why.

What is a Colonoscopy?

A colonoscopy lets your doctor look at the inside of the entire colon. A long flexible tube with a camera on the end, called a colonoscope, is inserted through the rectum and into the colon to examine the lining. If your doctor sees something abnormal, tissue samples (called a biopsy) may be taken. If polyps are seen, they can be removed during this test before they become cancerous.

How Often Should I Be Screened?

ColonCancerCheck recommends:

  • All average risk adults 50 years and older with no symptoms should be screened by using the Fecal Occult Blood Test (FOBT) every two years
  • Those with a positive FOBT should be screened with a follow-up colonoscopy. A positive FOBT does not necessarily mean you have cancer. Approximately 5% of people with a positive FOBT are found to have cancer during a follow-up colonoscopy.
  • Individuals at increased risk - i.e., those with a first degree family member (parent, child or sibling) who have had colorectal cancer - should be screened with a colonoscopy at the age of 50 years, or ten years earlier than the relative's age at diagnosis, whichever occurs first.

Colorectal Cancer Resources 

Cancer Care Ontario
Cancer Care Ontario - Colorectal Cancer Screening

Canadian Cancer Society
Canadian Cancer Society - Cancer Information

Ministry of Health and Long Term Care
Ministry of Health and Long Term Care - Cancer Screening and Prevention

Public Health Agency of Canada
Public Health Agency of Canada - Colorectal Cancer Information