The death of James Van Der Beek has renewed conversation about colorectal cancer.Jordan Strauss/The Associated Press
The recent death of Dawson’s Creek actor James Van Der Beek has renewed conversation about colorectal cancer, which has been on the rise among Canadians younger than 50. Mr. Van Der Beek was 48.
The Globe and Mail spoke with Sami Chadi, a colorectal surgeon at Toronto’s University Health Network, about the disease on Friday.
Here, he explains what Canadians need to know about early detection, screening and risk factors.
What is colorectal cancer?
Colorectal cancer is a broad term that indicates a tumour or a malignancy in the colon or rectum, which is the end of the gastrointestinal tract.
The colon and rectum are responsible for absorbing water out of the stool and solidifying the stool to make sure that you have a complete bowel movement.
What are some of the most significant signs and symptoms of colorectal cancer?
One of the signs is bleeding. Sometimes that bleeding is overt. We can see it.
I’ve had patients present where I was asked to do a colonoscopy because they’re slightly anemic. Or the bleeding can be based off a stool test for microscopic blood that we can’t see with the naked eye.
Some patients might experience a thinning of their bowel movements. They might even experience a change in the frequency or in their habitual process of having bowel movements.
When and how should Canadians be screened for colorectal cancer?
A stool-based test can look for any evidence of bleeding or blood within the stools. It’s not perfect, but it’s better than our version that we used to have a few years back. This is one of the options that Canadians at average risk have for screening.
The second would be a colonoscopy. It’s a procedure by which a camera exists at the end of a tube. The tube is probably the size of an individual’s digit finger.
The tube itself is advanced with the camera at its end through the entire rectum and colon, with the patient under sedation, to look for any evidence of cancerous or precancerous processes.
Polyps are basically an abnormal growth of cells on the inner lining of the colon or rectum that has precancerous changes within it that can continue to mutate to eventually form a cancerous process.
There is the option of what we call a virtual colonoscopy, which is a CT scan-based approach to performing a colonoscopy.
What are the greatest risk factors?
There’s a number of risk factors that we like to stratify into genetic and environmental.
Environmental risk factors for colorectal cancer are oftentimes related to risk factors that exist for a lot of different health conditions: high alcohol intake, smoking, high-fat and low-fibre diets and a sedentary lifestyle.
We do have information about some genetic factors that predispose one to colorectal cancer. One of the most common is Lynch syndrome, whereby a patient would have a deficiency in a protein that increases the risk of a malignancy in the colon or rectum, among other malignancies in their body.
Genetic conditions only account for 10 to 15 per cent of cases. The vast majority of patients are at risk based off standard environmental factors.
Why is the incidence of younger people with colorectal cancer increasing rapidly in Canada and other developed countries?
It’s great question. And to be honest, we don’t have the answer. There is a substantial amount of research going on around the globe trying to investigate this phenomenon.
There was a good population study in the Lancet Oncology back a year ago in January, 2025. They compared the risks between countries such as the U.S., Canada, England, Australia to countries around the world.
Countries that were lowest in risk were those like Uganda and countries in sub-Saharan Africa, where potentially higher fibre diets and less sedentary lifestyle and some of the regular risk factors are less prominent.
What would be your advice to Canadians who want to take pro-active steps to mind their colon health?
I believe the majority of us need to be supplementing our diets with fibre. Tt doesn’t matter which one you’re taking, as long as you’re taking something that brings up your dietary intake of soluble fibres to at least 25 to 30 grams a day.
This interview has been edited and condensed.