PhD defence Arthur Kooyker

In 2020, colorectal cancer was diagnosed in approximately 1.9 million persons worldwide and caused 900,000 deaths. Screening is proven to effectively reduce colorectal cancer- related mortality by detection in an early stage and removing pre-cursors of colorectal cancer (adenomas). Therefore, a population-based colorectal cancer screening programme was implemented in 2014 in the Netherlands, biennially inviting inhabitants between 55 to 75 for a stool-based screening test, called the faecal immunochemical test (FIT). Participants with positive FIT are referred for endoscopic examination of the colon (colonoscopy).

The benefits of screening ought to outweigh the harms. This thesis aims to evaluate the benefits (yield of screening) and harms (colonoscopy complications) of FIT-based colorectal cancer screening to provide further insights in how these aspects relate to each other and how a disbalance between them can be corrected.