Introduction

Recent guideline from the European Society of Gastrointestinal Endoscopy (ESGE) recommends the use of risk-profiles to determine surveillance colonoscopy after polypectomy.¹ These risk-profiles are potentially a better predictor for the development of colorectal cancer (CRC) incidence after polypectomy. CRC screening programs use advanced neoplasia as primary outcome parameter.² It might be more recognizable for doctors and policy makers to use the same outcome parameter. However, by changing the outcome parameter from advanced neoplasia to high-/low-risk profiles in a FIT-based CRC screening program, the definition of what is considered a relevant lesions will change. Using risk-profiles as outcome parameter may impact both colonoscopy surveillance capacity and the positive predictive value (PPV) of finding a relevant lesions after a positive FIT.

Aims & Methods

Study aim: assessing the impact of applying the ESGE risk-profiles as outcome parameter of a FIT based CRC screening program on colonoscopy surveillance and PPV after a positive FIT.
Methods: We retrospectively analyzed all persons who had a positive FIT (≥ 47µg Hb/g feces) followed by a colonoscopy in the Dutch CRC screening program from 2019-2022. Colonoscopy and pathology reports were used to define the surveillance interval based on the old and new guideline.
The old guideline used a scoring table in which, adenoma count, location, villous type (≥ 75%) or the presence of an adenoma or serrated polyp ≥ 10mm were used to determine a 3 or 5 year surveillance interval.² The new guideline defined a high-risk profile as either a high-risk adenoma or high-risk serrated polyp or ≥ 5 adenomas. A high-risk adenoma is an adenoma ≥ 10mm or with high-grade dysplasia. A high-risk serrated polyp is a serrated polyp ≥ 10mm or with any dysplasia.³ All persons with a high-risk profile receive surveillance in 3 years.
The old definition of the PPV was advanced neoplasia. Advanced neoplasia is defined as CRC or advanced adenoma (adenoma ≥ 10mm or high-grade dysplasia or ≥ 25% villous type).³ The new definition of the PPV was CRC, high-risk adenoma or high-risk serrated polyps. A chi-squared test was used to determine significant differences between the old and new definition.

Results

218,109 persons with a positive FIT underwent a colonoscopy between 2019-2022. Based on the old surveillance guideline, 51.2% of the persons would require colonoscopy surveillance. When applying high-risk profiles only 32.3% persons required surveillance. However, the number of persons referred for a 3-year surveillance interval was now doubled (Table 1). This is a result of 723 persons who first qualified for 10-year return to screening, and 34,451 persons who previously had a 5-year interval. In contrast, only 32 persons who initially had a 3-year interval will be advised to return to screening in 10 years, when risk-profiles are applied. The corresponding PPV for CRC, high-risk adenoma or high-risk serrated polyps was 34.4%, showing an increase of 1.7% (p < 0.05) compared to PPV based on advanced neoplasia.

Conclusion

This study shows that when the new ESGE surveillance guideline risk-profiles are applied as outcome parameter in FIT CRC screening, a total reduction of 18.9% of surveillance colonoscopies can be achieved although the number of persons in the 3-year surveillance interval will be doubled. A minor change in PPV can be expected.

References

1. Hassan C, Antonelli G, Dumonceau JM, Regula J, Bretthauer M, Chaussade S, et al. Post-polypectomy colonoscopy surveillance: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2020. Vol. 52, Endoscopy. Georg Thieme Verlag; 2020. p. 687–700.
2. Nederlandse Vereniging van maag-darm-leverartsen (NVMDL) Nederlandse coloscopie surveillance richtlijn 2013 [Internet] cited April 2024, https://www.mdl.nl/files/richlijnen/Richtlijn_Coloscopie_Surveillance_definitief_2013.pdf
3. Federatie Medisch Specialisten (FMS) richtlijn colorectal carcinoom [Internet] cited April 2024, available from https://richtlijnendatabase.nl/richtlijn/coloscopie_surveillance/startpagina.html