Colorectal cancer screening by means of fecal immunochemical tests requires successive screening rounds for an optimal preventive effect.
However, data on the influence of the length of the screening interval on participation and diagnostic yield are lacking.
Dr Aafke van Roon and colleagues from the Netherlands investigated repeated fecal immunochemical tests screening in a population-based trial comparing various repeat intervals.
The team examined 7501 Dutch individuals aged 50–74 years, which were randomly selected and invited for two 1-sample fecal immunochemical tests screening rounds with intervals of 1, 2 or 3 years.
In Group I, participation was 65% in the first screening round, and 63% in the second.
The corresponding percentages for Groups 2 and 3 were 61% vs 63%, and 62% vs 64%.
Triennial screening resulted in a higher participation rate in the second screening round compared with annual screening.
|In Group I, participation was 65% in the first screening round|
The research team reported that the overall positivity rate in the second screening round was significantly lower compared with the first round, and did not depend on interval length.
Similarly, the overall detection rate of advanced neoplasia was significantly lower in the second round compared with the first screening round and also did not depend on interval length.
The doctors assessed that the positive predictive value of the faecal immunochemical tests did not significantly change over time.
Dr van Roon's team concludes, "The total number of advanced neoplasia found at repeat faecal immunochemical tests screening is not influenced by the interval length within a range of 1–3 years."
"Furthermore, there is a stable and acceptably high participation in the second screening round."
"This implies that screening intervals can be tailored to local resources."