From gaps to compliance: a 12-year retrospective cohort study of trends in mismatch repair protein testing and Lynch syndrome identification in colorectal cancer in Central Switzerland

Remarkable progress in colorectal cancer diagnostics across Central Switzerland could be demonstrated, leading to a near-complete compliance with guidelines for mismatch repair proteins and molecular testing by 2022. This high adherence to guidelines provides a solid foundation for better personalised surveillance and treatment, ultimately improving the quality of care for colorectal cancer patients in the region. However, during the early years of the study some gaps existed, particularly in testing practices for rectal cancers and incomplete molecular follow-up, potentially missing some patients with a microsatellite instability, who could have benefited from different therapies, and Lynch syndrome patients, who together with their families could have benefited from tighter surveillance.