Efficacy of international web-based educational intervention in the detection of high-risk flat and depressed colorectal lesions higher (CATCH project) with a video: Randomized trial

Abstract

Objectives: Three subcategories of high-risk flat and depressed lesions (FDLs), laterally spreading tumors non-granular type (LST-NG), depressed lesions, and large sessile serrated lesions (SSLs), are highly attributable to post-colonoscopy colorectal cancer (CRC). Efficient and organized educational programs on detecting high-risk FDLs are lacking. We aimed to explore whether a web-based educational intervention with training on FIND clues (fold deformation, intensive stool/mucus attachment, no vessel visibility, and demarcated reddish area) may improve the ability to detect high-risk FDLs.

Methods: This was an international web-based randomized control trial that enrolled non-expert endoscopists in 13 Asian countries. The participants were randomized into either education or non-education group. All participants took the pre-test and post-test to read 60 endoscopic images (40 high-risk FDLs, five polypoid, 15 no lesions) and answered whether there was a lesion. Only the education group received a self-education program (video and training questions and answers) between the tests. The primary outcome was a detection rate of high-risk FDLs.

Results: In total, 284 participants were randomized. After excluding non-responders, the final data analyses were based on 139 participants in the education group and 130 in the non-education group. The detection rate of high-risk FDLs in the education group significantly improved by 14.7% (66.6-81.3%) compared with -0.8% (70.8-70.0%) in the non-education group. Similarly, the detection rate of LST-NG, depressed lesions, and large SSLs significantly increased only in the education group by 12.7%, 12.0%, and 21.6%, respectively.

Conclusion: Short self-education focusing on detecting high-risk FDLs was effective for Asian non-expert endoscopists. (UMIN000042348).

Keywords: colonoscopy; detection; education; flat and depressed lesions; randomized trial.

Figure 1

The FIND clues. (a) Fold deformation (white arrows). Laterally spreading tumors non‐granular type (LST‐NG) on the fold forms this change. (b) Chromoendoscopy clearly demonstrates the LST‐NG 35 mm in size. (c) Intensive stool/mucus attachment. The mass of stools is accumulated. (d) After removing the stool and mucus, the sessile serrated lesion, 10 mm in size, is visualized by chromoendoscopy. (e) No vessel visibility (white arrows). A flat lesion masks the visibility of the vessels in the background mucosa. (f) Chromoendoscopy reveals LST‐NG 30 mm in size. (g) Demarcated reddish area. A small marginally reddish area (o‐ring sign) is recognized. (h) Depressed lesion 5 mm in size can be seen by chromoendoscopy.

Figure 2

Baseline characteristics of colorectal lesions in the test images. LST‐NG, laterally spreading tumor non‐granular type; SD, standard deviation; SSL, sessile serrated lesion.

Figure 3

Study flowchart.

Figure 4

Extremely large laterally spreading tumors non‐granular type (LST‐NGs) missed in the test. (a) A large LST‐NG (50 mm) on the fold was missed by 39% (105/269) of the participants. (b) Chromoendoscopy reveals the whole shape of LST‐NG on the fold. Histopathology was high‐grade adenoma. (c) A large LST‐NG (55 mm) on the fold was missed by 17% (45/269) of the participants. (d) Chromoendoscopy makes the margin of the LST‐NG clear. Histopathology was deep submucosal invasive cancer (T1b).