Colorectal cancer screening in Flanders

Ondertitel:towards an optimal performance

Colorectal cancer (CRC) has a large impact on our European society through an estimated 500,000 new colorectal cancer cases and 442,000 deaths which occurred in 2018 and accounted for about 1 in 10 cancer cases and deaths. For Belgium (2018), CRC was estimated to occur in 9,346 persons and mortality in 3,224 persons. To slow the growing trend of precursor lesions, CRC incidence and mortality, preventative interventions are an excellent approach, considering that most CRCs develop from precursor lesions over the course of several years without symptoms. The CRC screening approach (secondary prevention) is part of the solution due to the long latent period (time between first neoplasia and symptoms) which enables early detection of CRC. Based on prominent randomised controlled trials (RCTs) and EU guidelines, screening for CRC by the faecal occult blood test (FIT) followed-up by a colonoscopy increased over the past 20 years in the European Union, where Flanders (Belgian region) started with CRC screening in October 2013. Because this start up happened rather recently, naturally, there is lacking scientific knowledge regarding CRC screening in the Flemish population. This PhD focused on the performance of the Flemish population-based CRC screening programme. Specifically, we investigated whether the FIT results, screening participation, age group to be included and the number of interval cancers were representable for the whole Flemish screening-eligible population. This resulted in fairly clear outcomes, some examples; the odds for detecting CRC in men aged 74, with a FIT result of ≥1000 ng/ml, was higher by a factor of 58.43 than that for women aged 56, with a FIT result of 75 ng/ml. However, nothing was communicated about these differences in the result letter, which has since been partially amended. Another example that we discovered, was that every other nationality (currently and at birth, except Dutch) compared to the Belgian nationality participated significantly less in the CRC screening programme. Likewise, people with a relatively low income participated significantly less.

Jaar van publicatie:2020

Trefwoorden:Doctoral thesis

Toegankelijkheid:Closed