Colorectal Cancer

Ontario has among the highest rates of colorectal cancer in the world. Colorectal cancer is the second leading cause of cancer in Ontario for men and women combined. The risk of getting colorectal cancer increases with age, with over 90% of new cases diagnosed in people 50 years of age and over. It can take up to 10 years or more to develop to an advanced stage. That’s why it’s important for both men and women to know the symptoms of colorectal cancer, how to reduce the risk of getting cancer and when to go for screening.

Who is eligible for screening?

There are different screening recommendations depending on whether a person has an average or increased risk of colorectal cancer.

Who has an average risk?

  • People ages 50 to 74 with no first-degree relative who has been diagnosed with colorectal cancer
  • No personal history of pre-cancerous colorectal polyps requiring surveillance or inflammatory bowel disease (i.e., Crohn’s disease or ulcerative colitis)

Who has an increased risk?

  • People with a family history of colorectal cancer that includes one or more first-degree relatives who have been diagnosed with colorectal cancer, but do not meet the criteria for colorectal cancer hereditary syndromes


  1. "Screening Guidelines - Colon Cancer", Cancer Care Ontario, accessed April 20, 2017 from

How is screening performed?

Screening is done using fecal occult blood tests, flexible sigmoidoscopy and colonoscopies.

What is a Fecal Occult Blood Test (FOBT)?

A screening test that can be done at home that checks for the presence of small amounts of blood in the stool (poop) that may be caused by colorectal cancer.

  1. ColonCancerCheck FOBT kits are available from family physicians and nurse practitioners. Those without a family physician or nurse practitioner can get a kit by contacting Telehealth Ontario at 1-866-828-9213.
  2. The test can be done at home, and only takes a few minutes a day on three separate days to complete.
  3. Once the samples are collected, they are sent to a lab for testing (using the postage-paid envelope provided in the kit or by returning the kit to specimen collection centres).
  4. At the lab, a technician uses special equipment to test the stool samples for blood.
  5. If blood is found, the test result is abnormal and follow-up is needed. Although most people who have blood in their stool do not have colorectal cancer, a colonoscopy is required follow-up for all abnormal tests to find out if there is a cancer.
  6. If no blood is found in the stool, the test result is normal. People with a normal test should re-screen using the FOBT every two years.

What is a Flexible sigmoidoscopy?

Flexible sigmoidoscopy is a procedure to examine the lining of the rectum and sigmoid colon (lower third of the colon) that can be used for colorectal cancer screening. It allows for the detection, biopsy and removal of small polyps (pre-cancerous lesions). Flexible sigmoidoscopy does not require sedation and the preparation is simple.

What is a Colonoscopy?

A colonoscopy is an exam done by a doctor to look at the lining of the rectum and colon using a long, flexible tube with a tiny camera on the end. During the colonoscopy, the doctor can also take biopsies or remove abnormal growths. The colonoscopy may need to be repeated every five or 10 years depending on the person being screened and the outcome of their colonoscopy.

Recommendations for people with average risk

  • Fecal occult blood test (FOBT) every two years for asymptomatic people ages 50 to 74 without a family history of colorectal cancer
  • Abnormal FOBT results should be followed up with a colonoscopy within eight weeks.
  • People ages 50 to 74 without a family history of colorectal cancer who choose to be screened with flexible sigmoidoscopy should be screened every 10 years.

Recommendations for people with increased risk

  • Screened with colonoscopy if they have a family history of colorectal cancer that includes one or more first-degree relatives with the disease. Screening should be begin at 50 years of age, or 10 years earlier than the age their relative was diagnosed, whichever occurs first


  1. "Screening Guidelines - Colon Cancer", Cancer Care Ontario, accessed April 20, 2017 from
  2. "Fecal Occult Blood Test," Cancer Care Ontario, accessed April 20, 2017 from
  3. "Registered Nurse Flexible Sigmoidoscopy," Cancer Care Ontario, accessed April 20, 2017 from
  4. "Colonoscopy", Cancer Care Ontario, accessed April 20, 2017 from

How is screening encouraged?

Cancer Care Ontario sends invitation letters to men and women between the ages of 50 and 74 who have never previously been screened or are due for screening to invite them to visit their healthcare provider to discuss colorectal cancer screening.

Invitation letters are not sent to individuals who

  1. have had recent colorectal cancer screening activity (fecal occult blood test or flexible sigmoidoscopy)
  2. have had a colonoscopy within the past 10 years
  3. have received other colorectal screening letters within the last two years
  4. have been previously diagnosed with colorectal cancer
  5. have withdrawn from receiving screening letters
  6. do not have a valid mailing address registered with us
Learn more about colorectal cancer screening letters

How many people get screened?

The visualizations on this page begin by looking at screening rates throughout Ontario. This serves to give an idea of the absolute and relative numbers of people who are overdue for screening, and where they are concentrated.

The later visualizations add context to this data by displaying the incidence and mortality rates of colorectal cancer, as well as risk factors divided by regions of Ontario.

Colorectal Cancer Screening Rates

This visualization shows screening rates divided by region of Ontario. The hexbinplot displays regions of Ontario as equally-sized hexagons, where darker colours indicate higher number of people overdue for screening. The stacked bar chart shows the same data, where the grey values are people who have been screened, coloured bars are overdue for screening, and the total length of the bar shows the number of people eligible for screening. Hover over the bars to display more information.

Incidence and Mortality Rates for colorectal Cancer

These graphs display incidence and mortality rates. The hexbinplots show rates from 2010-12 combined, divided by region and age groups. The line graphs indicate changes in rate over a three-year period, divided by age groups.

Demographic information

These graphs show socio-demographic variables and chronic disease risk factors for regions in Ontario. The hexbinplots show the percentage of the population in each region with each risk factor. The heatmaps show the same data as a table, including multiple years when available. To sort the heatmap, click on the rows and columns.


  • Region refers to either Ontario or one of the Local Health Integration Networks (LHINs) in Ontario. The Ontario statistics excluded cancer cases of unknown residence. Therefore, provincial statistics may not match the true counts and rates published elsewhere.
  • Age refers to the age at diagnosis for the cancer.
  • Year refers to the calendar year in which a cancer was diagnosed.