Management of large polyps in a colorectal cancer screening programme with faecal immunochemical test: a population- and community-based observational study

Objective: To analyse presentation, management and outcomes of large (≥ 20 mm) polyps (LPs) detected in a colorectal cancer (CRC) screening programme using a faecal immunochemical test (FIT) and to compare them with those of a previous guaiac-based faecal occult blood test (gFOBT) programme. Design: Retrospective population-based study of all LPs detected in patients aged 50-74 years between 2015 and 2019 during FIT-positive colonoscopies within the screening programme organised in Alsace (France). Results: Overall, 1256 LPs (8.5% malignant and 51.8% non-pedunculated) were detected by 102 community gastroenterologists in 1164 patients (one in 12 colonoscopies). Endoscopic resection rate was 82.7% for benign LPs (70.2% non-pedunculated, 95.2% pedunculated, p<0.001), varying from 0 to 100% depending on the endoscopist. The sensitivity of optical diagnosis of malignancy was 54% for non-pedunculated and 27% for pedunculated T1 CRCs. Endoscopic resection was curative for 4.3% of non-pedunculated and 37.8% pedunculated T1 CRCs. One surgery was avoided for 57 endoscopic submucosal dissections. Management practices did not vary significantly between the gFOBT and FIT periods. Conclusion: Compared with current recommendations, there is tremendous room for improvement of community endoscopy practices for the diagnosis and management of LPs. Endoscopic resection is curative in 15.9% of T1 CRCs only. The benefit of endoscopic submucosal dissection is marginal in community practice.