Risk-Adapted Starting Ages of Colorectal Cancer Screening for People With Diabetes or Metabolic Syndrome.

Background: Individuals with diabetes and metabolic syndrome have an increased risk of colorectal cancer (CRC), suggesting earlier screening than the average-risk population may be warranted.

Aims: To derive risk-adapted starting ages of CRC screening for people with diabetes or metabolic syndrome.

Methods: We determined 5-year cumulative risks of CRC at individual ages between 30 and 50 across Europe (overall and individually for Germany, France, the UK and Italy) and North America (the United States and Canada) based on the GLOBOCAN 2022 database. Using risk estimates from meta-analyses (2020-2023), we derived the ages at which individuals with diabetes or metabolic syndrome reach the same CRC risk as the average-risk population at age 50 (aCR) or 45 (aCR).

Results: Individuals with diabetes were estimated to reach aCR at age 47 (95% confidence interval, 45-49) in Europe and 46 (42-49) in North America. For metabolic syndrome, the corresponding ages were 47 (47-48) in Europe and 46 (46-47) in North America. Disparities across countries were minimal, with deviations of up to no more than one year. For screening programmes starting at age 45, corresponding risk-adapted starting ages for people with diabetes or metabolic syndrome were estimated to be 42 (41-44) and 43 (42-43) for Europe and 41 (38-44) and 41 (41-42) for North America, respectively.

Conclusions: People with diabetes or metabolic syndrome reach risk levels comparable to the average risk population three to four years earlier. Our results offer empirical guidance for defining risk-adapted starting ages of CRC screening for these high-risk groups.