Five-Year Experience of Nationwide Implementation of Colorectal Cancer Screening in Sweden.

BACKGROUND: Colorectal cancer (CRC) is a major health concern. In Sweden, a CRC screening program was implemented nationwide between 2019 and 2022. This study evaluated participation, colonoscopy adherence, and diagnostic outcomes for the program's first five years. METHODS: The target group of screening was all residents 60-74 years old. Data were retrieved from SveReKKS, the Swedish national quality register for CRC screening and colonoscopies. A positive FIT test was defined as ≥ 40 μg Hb/g for females, ≥ 80 μg Hb/g in feces for males. Participation, FIT positivity, colonoscopy adherence, quality indicators, and neoplasia detection rates were assessed. RESULTS: Among 884,866 invitees, the overall participation rate was 64.3%. Participation was higher in older age groups, among females, but lower in regions with low population density. FIT positivity was 2.7%, with no major variation by age or sex. Colonoscopy adherence among FIT-positive individuals was 82%, with lower adherence among men and regional variation. The detection rate for CRC was 6.6%, 29.9% for advanced adenomas and adenocarcinoma, and an overall adenoma detection rate of 49.7%. Quality metrics were high: 98% had adequate bowel preparation, caecal intubation rate was 96%, and the complication rates (bleeding and perforation) were low (0.5% early, 0.7% late). CONCLUSION: The first 5 years of the implementation of CRC screening in Sweden demonstrated high participation and excellent diagnostic performance, although colonoscopy adherence fell slightly below the guideline targets. These findings support the effectiveness of FIT-based screening and highlight areas for further improvement, including enhancing colonoscopy uptake among men and in low-density regions.