Long-term effectiveness of faecal immunochemical test screening for proximal and distal colorectal cancers

• Published in: Gut Vol. 70; no. 12; p. 2321
• Main Authors: Chiu, Han-Mo, Jen, Grace Hsiao-Hsuan, Wang, Ying-Wei, Fann, Jean Ching-Yuan, Hsu, Chen-Yang, Jeng, Ya-Chung, Yen, Amy Ming-Fang, Chiu, Sherry Yueh-Hsia, Chen, Sam Li-Sheng, Hsu, Wen-Feng, Lee, Yi-Chia, Wu, Ming-Shiang, Wu, Chien-Yuan, Jou, Yann-Yuh, Chen, Tony Hsiu-Hsi
• Format: Journal Article
• Language: English
• Published: England 01-12-2021
• Subjects: Aged; Bayes Theorem; Colorectal Neoplasms - diagnosis; Colorectal Neoplasms - epidemiology; Colorectal Neoplasms - pathology; Early Detection of Cancer; Feces - chemistry; Female; Humans; Incidence; Male; Mass Screening - methods; Middle Aged; Neoplasm Staging; Prospective Studies; Taiwan - epidemiology; Taiwan; cancer prevention; cancer epidemiology; colorectal cancer screening
• ISSN: 1468-3288
• DOI: 10.1136/gutjnl-2020-322545

To measure the effects of faecal immunochemical test (FIT) for colorectal cancer (CRC) screening on overall and site-specific long-term effectiveness of population-based organised service screening.
A prospective cohort study of Taiwanese nationwide biennial FIT screening was performed. A total of 5 417 699 eligible subjects were invited to attend screening from 2004 through 2009 and were followed up until 2014. We estimated the adjusted relative rates (aRRs) on the effectiveness of reducing advanced-stage CRC (stage II+) and CRC death by Bayesian Poisson regression models with the full adjustment for a cascade of self-selection factors (including the screening rate and the colonoscopy rate) and the completeness of colonoscopy together with demographic features.
FIT screening (exposed vs unexposed) reduced the incidence of advanced-stage CRC (48.4 vs 75.7 per 100 000) and mortality (20.3 vs 41.3 per 100 000). Statistically significant reductions of both incidence of advanced-stage CRCs (aRR=0.66, 95% CI 0.63 to 0.70) and deaths from CRC (aRR=0.60, 95% CI 0.57 to 0.64) were noted. FIT screening was more effective in reducing distal advanced-stage CRCs (aRR=0.61, 95% CI 0.58 to 0.64) and CRC mortality (aRR=0.56, 95% CI 0.53 to 0.69) than proximal advanced CRCs (aRR=0.84, 95% CI 0.77 to 0.92) and CRC mortality (aRR=0.72, 95% CI 0.66 to 0.80).
A large-scale population-based biennial FIT screening demonstrates 34% significant reduction of advanced-stage CRCs and 40% reduction of death from CRC with larger long-term effectiveness in the distal colon than the proximal colon. Our findings provide a strong and consistent evidence-based policy for supporting a sustainable population-based FIT organised service screening worldwide. The disparity of site-specific long-term effectiveness also provides an insight into the remedy for lower effectiveness of FIT screening in the proximal colon.