In patients with isolated HGD confined to a single colonic segment, how does the risk of progression to CRC after endoscopic mucosal resection compare with that after segmental colectomy

What is known

- HGD can carry a >40% risk of harboring underlying invasive malignancy, and traditionally warranted surgical resection, though discrete HGD may be endoscopically removed. ¹ - Guidelines recommend endoscopic resection for well-circumscribed dysplasia without surrounding invisible dysplasia, with surveillance colonoscopy if R0 resection is achieved. ² - After segmental/subtotal colectomy the retained colon/rectum remains at risk of subsequent neoplastic progression via field cancerization, justifying ongoing surveillance. ³ - Occult CRC at colectomy remains elevated in high-grade polypoid and invisible dysplasia, but occult cancer occurred in the same segment as the dysplasia. ⁴

What is unknown / caveats

- SCENIC allows individualized surveillance vs colectomy for HGD, whereas ECCO/ASGE call invisible HGD an indication for surgery ¹ - No direct EMR-vs-segmental-colectomy comparison of CRC progression for single-segment HGD in the excerpts - Much segmental-resection data is from Crohn's colitis, not UC ^5,6 - No evidence-based surveillance intervals for the retained colon after partial resection ³ - The excerpts do not quantify or compare post-EMR versus post-segmental-colectomy CRC progression specifically for isolated single-segment HGD.

## References

1. Ansell J, Grass F, Merchea A. Surgical Management of Dysplasia and Cancer in Inflammatory Bowel Disease. Surg Clin North Am. 2019;99(6):1111-1121. PMID: 31676051.

2. [No authors listed]. Endoscopic resection is feasible for high-grade dysplasia in patients with ulcerative colitis. Scand J Gastroenterol. 2023;58:101-106. PMID: 36200368.

3. Shah SC, Itzkowitz SH. Colorectal Cancer in Inflammatory Bowel Disease: Mechanisms and Management. Gastroenterology. 2022;162(3):715-730.e3. PMID: 34757143.

4. [No authors listed]. The Contemporary Probability of Occult Colorectal Cancer in Patients With Colitis-Related Dysplasia Undergoing Colectomy. Am J Gastroenterol. 2023;118:1453-1456. PMID: 37040554.

5. Macleod A, Kavalukas SL, Scheurlen KM, Galandiuk S. State-of-the-art surgery for Crohn's disease: Part II-colonic Crohn's disease and associated neoplasms. Langenbecks Arch Surg. 2022;407(7):2595-2605. PMID: 35729401.

6. Maser Elana A, Sachar David B, Kruse D, Harpaz N, Ullman T, Bauer Joel J. High rates of metachronous colon cancer or dysplasia after segmental resection or subtotal colectomy in Crohn's colitis. Inflamm Bowel Dis. 2013;19(9):1827-32. PMID: 23669402.

For educational use only, not a substitute for clinical judgement or medical advice. Consult qualified clinicians for diagnosis and treatment decisions. This tool may contain errors; use the flag button below to report inaccurate or harmful content.

---

_Draft, generated by the IBDology RAG and not yet clinician-reviewed. Answers are grounded in the retrieved literature listed above; a high faithfulness score means the answer matches its sources, not that the sources are correct._