Screening has helped lower the rates of new colorectal cancer diagnoses in Canadians over the age of 50. The opposite is happening for cohorts too young to qualify for screening.Melissa Tait/The Globe and Mail
Canada should lower the starting age for colorectal-cancer screening to 45 from 50 because rates of the disease are rising among younger patients, according to a prominent cancer advocacy group.
Colorectal Cancer Canada will unveil a campaign Tuesday calling on provinces and territories to promote and provide stool tests to people beginning five years earlier than is the practice today, after similar advice from the United States and Australia.
“We know we can save lives and we can save money,” said Barry Stein, the president of Colorectal Cancer Canada. “That’s the reason why I couldn’t sleep at night, and we had to launch this campaign.”
The advocacy organization’s pitch comes just days after Ottawa released an expert report recommending Canada modernize the way it crafts screening guidelines, and as rates of several types of cancer increase among millennials and members of Generation X.
Although colorectal cancer is the second-leading cause of cancer death in Canadian men and third-leading in women, rates of new diagnoses have been falling among people over 50 because of screening.
The opposite is happening for cohorts too young to qualify. Between 2001 and 2021, rates of new colorectal-cancer diagnoses rose by 3.7 per cent for Canadians 35 to 39, 2.6 per cent for those 40 to 44, and 1 per cent for those 45 to 49.
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Nearly every province and territory – save for Nunavut and Quebec – has an organized colorectal screening program that offers a mail-in stool test, usually the fecal immunochemical test (FIT), every second year to people ages 50 to 74 at average risk of developing colorectal cancer.
If the FIT results suggest a problem, patients are referred for a colonoscopy, a diagnostic exam that can spot precancerous polyps, prompting doctors to remove them and prevent cancer.
Critics who oppose lowering the starting age for FIT tests often point to resource constraints in Canada’s public-health system. At-home stool tests are relatively inexpensive, but they increase demand for colonoscopies, which require more equipment, trained staff and public funds.
Sharlene Gill, a medical oncologist specializing in gastrointestinal cancer and a professor at the University of British Columbia, acknowledged that expanding colonoscopy capacity in Canada is likely to be a challenge. But she said there is a strong case that lowering the starting age will save lives and money.
Dr. Gill was a co-author on a 2023 modelling study that predicted starting screening at 45 instead of 50 would result in 12,188 fewer cases of colorectal cancer and 5,261 fewer deaths in Canada over 40 years. Starting younger would cost the medical system $298-million more than the status quo over the same time horizon, but produce $719-million in savings on treatment.
“Every time I see a patient who’s younger, it kind of awakens this desire to say, ‘Look, we do need to address this shift,’” Dr. Gill said. “I think it’s very widely recognized now that patients who are younger are at risk for colorectal cancer.”
On Friday, Ottawa published a long-awaited independent report recommending that the Public Health Agency of Canada overhaul the Canadian Task Force on Preventive Health Care, a panel of experts that produces guidelines for family doctors.
The task force came under fire from breast-cancer advocacy groups and some doctors for declining to lower the starting age for screening mammograms to 40 from 50 as its U.S. counterpart did in 2023.
The same Canadian task force last weighed in on colorectal-cancer screening in 2016, five years before the U.S. Preventive Services Task Force adopted a recommendation that screening start at 45. Australia followed suit last year. Most of Canada’s other peer countries still advise starting at 50.