New guidelines published online by Cancer Care Ontario indicate that the province is reducing the age for colorectal cancer screening from 50 to 45. This change comes in response to a notable increase in diagnoses among younger individuals. The updated recommendation, detailed in an Ontario Health document, will take effect on July 1.
Rising Incidence in Younger Populations
Prince Edward Island became the first Canadian province to lower its screening age to 45 in March. Colorectal Cancer Canada and the Canadian Cancer Society have urged all provinces and territories to adopt this change, citing evidence that people under 50 are now two to 2.5 times more likely to be diagnosed with colorectal cancer than in previous generations. The United States and Australia have also implemented similar screening age reductions.
Evidence-Based Decision
The Ontario government document, intended for primary care providers, states that the decision is based on expert panel guidance, evidence of increasing early-onset colorectal cancer in the province, and modeling that shows earlier screening reduces both incidence and mortality. The Ministry of Health emphasized that this change will help detect and treat cancer earlier, building on the province's 2024 move to lower breast cancer screening from 50 to 40.
Screening Process and Implementation
A routine colorectal screening involves a fecal immunochemical test (FIT), where individuals swab stool at home and send it to a lab. Those with normal results are advised to repeat the test every two years. If blood is detected, a colonoscopy is arranged. The government will send screening invitation letters in a phased manner, but doctors can order FIT for anyone aged 45 to 49 starting July 1.
Updated Guidelines for High-Risk Groups
The recommended age for colonoscopies has also been lowered for individuals with an immediate relative diagnosed with colorectal cancer before age 60. This group will now begin screening at 40, or 10 years earlier than the age of their youngest relative's diagnosis, with a five-year screening interval. For those with one relative diagnosed at age 60 or older, screening will now use FIT every two years starting at 45 instead of a colonoscopy, based on evidence that their risk is similar to the general population.
The government anticipates a modest increase in abnormal test results and higher demand for colorectal cancer surgeries and pathology services, but expects these volumes to stabilize over time as pre-cancers are detected and removed.
Reactions and Logistics
Barry Stein, president and CEO of Colorectal Cancer Canada, called Ontario's decision a huge step forward and urged other provinces to follow. FIT kit drop-off locations are also changing; patients can leave completed kits at any Rexall location or mail them to In-Common Laboratories.
