Optimizing the colorectal cancer screening programme using faecal immunochemical test (FIT) in Flanders, Belgium from the "interval cancer" perspective

Tran TN, Peeters M, Hoeck S, Van Hal G, Janssens S, De Schutter H
Publicatiedatum
Naam tijdschrift
British journal of cancer
Background: Interval cancer (IC) is a critical issue in colorectal cancer (CRC) screening. We identified factors associated with ICs after faecal immunochemical test (FIT) screening and explored the impact of lowering FIT cut-off or shortening screening interval on FIT-ICs in Flanders.

Methods: FIT participants diagnosed with a CRC during 2013-2018 were included. Factors associated with FIT-ICs were identified using logistic regression. Distributions of FIT results among FIT-ICs were examined.

Results: In total, 10,122 screen-detected CRCs and 1534 FIT-ICs were included (FIT-IC proportion of 13%). FIT-ICs occurred more frequently in women (OR 1.58 [95% CI 1.41-1.76]) and ages 70-74 (OR 1.35 [1.14-1.59]). FIT-ICs were more often right-sided (OR 3.53 [2.98-4.20]), advanced stage (stage IV: OR 7.15 [5.76-8.88]), and high grade (poorly/undifferentiated: OR 2.57 [2.08-3.18]). The majority (83-92%) of FIT-ICs would still be missed if FIT cut-off was lowered from 15 to 10 µg Hb/g or screening interval was shortened from 2 to 1 year.

Conclusions: FIT-ICs were more common in women, older age, right-sided location, advanced stage and high grade. In Flanders, lowering FIT cut-off (to 10 µg Hb/g) or shortening screening interval (to 1 year) would have a minimal impact on FIT-ICs.