While rates of colorectal cancer have been decreasing in older adults, rates in people under the age of 50 are on the rise. The good news? When detected early through screening, nine out of 10 people with colorectal cancer can be successfully treated.
Colorectal cancer is the fourth most diagnosed cancer in Canada. In 2026, it is estimated that 25,300 Canadians will receive a diagnosis, representing 10 per cent of all new cancer cases.
While rates of colorectal cancer have been decreasing in older adults, rates in people under the age of 50 are on the rise. In the United States, colorectal cancer has surpassed breast cancer as the leading cause of cancer-related death among adults under 50, and similar trends are emerging in Canada, where it is projected to become the leading cause of cancer death in this age group by 2026. The good news? When detected early through screening, nine out of 10 people with colorectal cancer can be successfully treated.
First Nations communities across the province consistently shared concerns that their members were being diagnosed with colon cancer at ages far too young to qualify for provincial screening […]
In Ontario, publicly funded programs aim to help more people receive cancer screening in a timely manner. Yet some communities have historically faced barriers to screening services.
“We began to hear through qualitative research with First Nations communities that community members were presenting with cancers before the eligible screening age, faced difficulties accessing screening, and were more likely to be diagnosed with late-stage cancers,” says Jill Tinmouth, a scientist at ICES and Sunnybrook Research Institute and Provincial Medical Director, Cancer Control, Ontario Health.
These community concerns prompted ICES researchers to investigate whether existing screening programs were reaching people equitably and early enough. In collaboration with Indigenous partners and Ontario Health (OH) (formerly Cancer Care Ontario), the team sought to evaluate the effectiveness of Ontario’s organized cancer screening programs for First Nations people in the province.
The researchers examined the age and stage at colorectal cancer diagnosis for First Nations people in Ontario compared to other Ontarians using linked health administrative data at ICES. The study showed that First Nations people with colorectal cancer were younger and diagnosed at a later stage compared to other Ontarians.
In May 2026, the Ontario government announced that they were lowering the eligibility age from 50 to 45 for all individuals, and to 40 for those at increased risk. This change came in direct response to the growing evidence of rising colorectal cancer rates among those under age 50, and modelling that showed that earlier screening saves lives and is cost saving. The decision also reflects a growing commitment to ensuring cancer screening programs are responsive to the needs and realities of First Nations people.
“I am very happy to see Ontario lowering the colon cancer screening to 45,” says Alethea Kewayosh, former Director of the Indigenous Health Unit at Ontario Health. “During my tenure as Director, First Nations communities across the province consistently shared concerns that their members were being diagnosed with colon cancer at ages far too young to qualify for provincial screening. Now that I am retired and living back in my home community, I am seeing the realities of those stories firsthand.”
As Director, Kewayosh worked with ICES and Ontario Health researchers on the Catching Cancers Early project to show clear data that First Nations communities have long known. First Nations people are more likely to be diagnosed with colon cancer younger and at a later stage than other Ontarians. In fact, First Nations people aged 40-49 face a risk level nearly identical to those in the 50-59 age group.
“The First Nations people who have shared their stories were the catalyst for this research and I am happy we were able to give them a voice and move this research forward and substantiate what they have been saying for years,” says Kewayosh. “I know this change will be well received and will greatly improve health outcomes for First Nations people across the province.”
Building on these findings, the research team examined new cases, deaths, and survival trends in screening programs for breast, cervical, and colon cancers in First Nations people in Ontario compared to other Ontarians.
Overall, the results showed some encouraging progress: rates of new cases and deaths from these cancers have improved for First Nations people over time, particularly for cervical cancer. However, survival after a cancer diagnosis remains significantly lower than for other Ontario residents, even after accounting for factors such as how advanced the cancer was at diagnosis and other existing health conditions. Apart from breast cancer, First Nations people were still more likely to be diagnosed with these cancers and to die from them.
The study also found that the risk of colorectal cancer was higher among First Nations people—not only among those already eligible for screening, but also among adults aged 40 to 49. This finding further supports Ontario’s decision to lower the age for colorectal cancer screening.
Together, this research underscores the critical importance of earlier and more equitable cancer screening. By identifying that First Nations people are diagnosed younger and at later stages—and face persistently poorer survival outcomes—ICES provided clear, population-level evidence that current screening thresholds were not reaching those at highest risk.
[F]urther action is needed to strengthen prevention efforts, improve screening, and enhance care following a cancer diagnosis to improve outcomes for First Nations people in Ontario.
Ontario’s decision to lower the colorectal cancer screening age marks an important step toward addressing these gaps. Earlier access to screening means more cancers can be detected when they are most treatable, improving outcomes and saving lives.
However, the work is not finished. Persistent differences in survival highlight the need for continued efforts to ensure that screening programs are not only accessible, but culturally safe, timely, and effective for all communities. ICES research will continue to play a vital role in informing policies that advance equity in cancer care and improve health outcomes across Ontario.
“Lowering the colorectal cancer screening age is an important first step,” says Amanda Sheppard, senior scientist at Ontario Health’s Indigenous Health Unit. “However, our recent study indicates that further action is needed to strengthen prevention efforts, improve screening, and enhance care following a cancer diagnosis to improve outcomes for First Nations people in Ontario.”
The research team received permission to access the Indian Registry System (IRS) and Métis Citizenship Registry (MCR) data through established ICES First Nations and Métis data access processes. This included securing approvals from several key governing bodies, including the Chiefs of Ontario First Nations Data Governance Committee, the Métis Nation of Ontario, Grand Council Treaty #3 and the Kenora Chiefs Advisory.
