On the 10th of January 2017, Marjolein Greuter will defend her Thesis titled ‘Colorectal cancer screening; benefit, burden and opportunities’. In this Thesis, she describes the Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) model and its use to predict the long-term impact of the recently implemented Dutch colorectal cancer (CRC) screening program. She assesses possible threats to the program and explores opportunities for optimization.
A unique feature of the ASCCA model is that it includes two pathways, i.e. the adenoma-carcinoma pathway and the serrated pathway, via which colorectal lesions can develop into cancer. The model is calibrated against a Dutch colonoscopy trial in previously unscreened individuals and data on CRC incidence and mortality from the Dutch Cancer Registry. Read more about the ASCCA model.
- Thirty years of biennial stool-based screening in individuals aged 55-75 years (Dutch screening program) is predicted to considerably reduce CRC burden ( 47% reduction in CRC mortality compared to no screening).
- To achieve this reduction, substantial colonoscopy resources are required; >100,000 colonoscopies per year in a fully implemented screening program.
- Screening fatigue can considerable reduce the effectiveness of a screening program. Screening benefit would be decreased by roughly 30% if individuals stop attending screening after 3 negative stool tests.
- Screening with CT colonography or MR colonography is not a cost-effective alternative for stool-based testing.
- Colonoscopy surveillance adds only marginally to the effectiveness of stool-based screening. It decreases the CRC burden slightly, but requires many colonoscopies and is not cost-effective compared to screening without surveillance.
Read the Thesis here.