COLORECTAL CANCER SCREENING

Colorectal cancer screening means looking for the presence of cancer or pre-cancer in someone who does not show any signs or symptoms of the disease.

Most colorectal cancers begin as polyps (growths) in the lining of the large intestine. Over time, these polyps grow in size and number, increasing the risk that the polyps will become cancerous. Identifying polyps and removing them early reduces the risk of developing colorectal cancer. Screening can also identify colorectal cancer at an earlier stage when it is most treatable and curable.

DID YOU KNOW?

Most colorectal cancer deaths could be avoided if everyone aged 50 years and older underwent regular screening tests.

It is a common misconception that colorectal cancer is a disease that primarily strikes men. Colorectal cancer affects men and women almost equally.

More than 90% of the time, colorectal cancer can be effectively treated when diagnosed at its earliest stage through colonoscopy.

Learn more about what is colorectal cancer.

By following colorectal cancer screening guidelines, most colorectal cancer deaths could be avoided.

It is a common misconception that colorectal cancer is a disease that primarily strikes men. Colorectal cancer affects men and women almost equally.

More than 90% of the time, colorectal cancer can be effectively treated when diagnosed in an early stage.

Learn more about colorectal cancer and diagnosis.

WHEN SHOULD I GET SCREENED FOR COLORECTAL CANCER?

The Canadian Cancer Society recommends that adults aged 50 – 74 years that are not at high-risk of colorectal cancer:

Have a stool test (FIT) every 2 years. In the case of a positive stool test, follow-up should be done with a flexible sigmoidoscopy or colonoscopy, or
Flexible sigmoidoscopy every 10 years

The following video from the Canadian Cancer Society explains how to perform the FIT test:

Overview of most common colorectal cancer screening tests:

Fecal Immunochemical Test (FIT or iFOBT): A test in which a stool sample is collected and returned to the doctor or lab to examine for small amounts of blood in the stool.
Flexible Sigmoidoscopy: A thin, flexible, lit tube with a small video camera located at its end is inserted through the anus in order to view the inside of the lower part of the colon and rectum (usually around the lower two feet) for polyps and cancer-related growths.
Colonoscopy: A thin, flexible, lit tube with a small video camera located at its end is inserted through the anus in order to view the inside of the entire colon and rectum for polyps and cancers.

Less common screening tests that may be available at select hospitals and clinics:

CT Colonography (Virtual Colonoscopy): A less invasive test using special x-ray equipment to produce pictures of the colon and rectum. A screening alternative for individuals at higher risk of complications with standard colonoscopy, such as elderly patients.

Mount Sinai Hospital Virtual Colonoscopy

Stool DNA Test or Fecal DNA Testing: Much like the FOBT and FIT, the stool DNA test screens a stool sample but instead of looking for blood, it looks for DNA that may signal the presence of cancer or polyps in the colon.

HOW DO I KNOW IF I AM AT HIGH-RISK FOR COLORECTAL CANCER?

You may be at a higher risk of developing colorectal cancer if you have:

Signs or symptoms of colorectal cancer
A personal history of colorectal cancer or polyps
A family history of colorectal cancer in a parent, sibling, or child (first-degree relative)
An inflammatory bowel disease such as Crohn’s disease or ulcerative colitis
An inherited cancer syndrome such as Lynch syndrome or familial adenomatous polyposis (FAP)

If you are at a higher risk of developing colorectal cancer, it is recommended that you participate in more frequent screening and begin at an earlier age. Be sure to discuss your personal risk factors with your doctor to develop an appropriate screening plan.

For more information, see colorectal cancer risk factors