Fecal immunochemical test (FIT) screening was found to result in a 34% reduction in advanced-stage colorectal cancer (CRC) and a 40% reduction in death from CRC after 10 years of follow-up, researchers reported in Gut.
In the prospective cohort study, 5,417,699 individuals (aged 50-69 years) who were eligible for CRC screening during the inaugural 5 years (2004-2009) of the Taiwan Colorectal Cancer Screening Program were continuously offered a subsequent screen on a biennial basis and were followed up until the end of 2014. Participants who had at least 1 FIT screening from 2004 to 2014 were the exposed group (N = 3,067,853; 44.8% men), and the remaining cohort formed the unexposed group (N = 2,349,846; 50.4% men).
The researchers found that FIT screening (exposed vs unexposed) reduced the incidence of advanced-stage CRC (48.4 vs 75.7 per 100 000, respectively) and mortality (20.3 vs 41.3 per 100,000, respectively). In addition, they observed statistically significant reductions in the incidence of advanced-stage CRC (adjusted relative rate [aRR] = 0.66; 95% CI, 0.63-0.70) and deaths from CRC (aRR = 0.60; 95% CI, 0.57-0.64).
In addition, FIT screening was found to be more effective in reducing distal advanced-stage CRC (aRR = 0.61; 95% CI, 0.58-0.64) and CRC mortality (aRR = 0.56; 95% CI, 0.53-0.69) than proximal advanced CRC (aRR = 0.84; 95% CI, 0.77-0.92) and CRC mortality (aRR = 0.72; 95% CI, 0.66-0.80).
“The results not only demonstrate the overall statistically significant reduction of incidence of advanced-stage CRC (34%) and mortality for CRC (40%), given 10 years of follow-up, but also show larger effectiveness in the distal colon than in the proximal colon (39% vs 16% for advanced-stage CRC and 44% vs 28% for CRC mortality), although the findings on both locations were still statistically significant,” stated the study authors.
Study limitations included an unsatisfactory diagnostic examination rate, according to the investigators, and they did not evaluate the overall incidence rate because the follow-up time was too short.
“Our current results on long-term effectiveness, together with the findings from previous studies, may provide a strong and consistent evidence-based policy for supporting a sustainable population-based FIT organized service screening worldwide, which is very meaningful for attaining the Sustainable Development Goal 3 of global health,” the researchers commented.
Chiu H-M, Jen GH-H, Wang Y-W, et al. Long-term effectiveness of faecal immunochemical test screening for proximal and distal colorectal cancers. Gut. Published online January 25, 2021. doi:10.1136/ gutjnl-2020-322545