Recurrence Rate After Endoscopic Resection of , Laterally Spreading Tumor Granular Type (LST-G) of the Colon and Rectum: Endoscopic Mucosal Resection vs. Endoscopic Submucosal Dissection

Recurrence Rate After Endoscopic Resection of , Laterally Spreading Tumor Granular Type (LST-G) of the Colon and Rectum: Endoscopic Mucosal Resection (EMR) vs. Endoscopic Submucosal Dissection (ESD): A Multicenter Randomized Controlled Trial ( ESD vs EMR )

Colorectal cancer is one of the leading causes of cancer-related mortality worldwide. Early-stage non-polypoid neoplastic lesions, particularly Laterally Spreading Tumors - Granular Type (LST-G) larger than 20mm, require effective endoscopic removal to prevent malignant progression. The two primary techniques for resecting these lesions are Endoscopic Mucosal Resection (EMR) and Endoscopic Submucosal Dissection (ESD).

EMR is a widely used, minimally invasive technique that involves resecting the lesion with a diathermic snare after submucosal injection. While effective and safe, EMR often necessitates piecemeal resection, increasing the risk of local recurrence. In contrast, ESD, developed in Asia, allows for en bloc resection regardless of lesion size, ensuring more accurate histopathological assessment and lower recurrence rates. However, ESD requires greater technical expertise, has longer procedural times, and carries a higher risk of complications.

In Western clinical practice, EMR remains the standard treatment, whereas ESD is selectively performed in high-expertise centers. Given the lack of randomized controlled trials comparing EMR and ESD in Western populations, this study aims to provide robust clinical evidence to guide treatment decisions.

The primary objective of this study is to compare the recurrence/residual adenomatous tissue rate at 6 and 12 months between EMR and ESD in patients with LST-G lesions of the colon and rectum

Inclusion Criteria:

• Age ≥ 18 years.
• Diagnosis of Laterally Spreading Tumor - Granular Type (LST-G) ≥ 20 mm in the colon or rectum with an indication for endoscopic resection.
• Life expectancy > 10 years.
• Ability to understand and sign the informed consent form, demonstrating comprehension of the study and willingness to participate.

Exclusion Criteria:

• Diagnosis of Laterally Spreading Tumor - Non-Granular Type (LST-NG).
• Presence of depressed areas within the lesion.
• Lesions located on a scar or anastomosis site.
• Lesions classified as Kudo Vi or Vn pattern.
• History of chronic inflammatory bowel disease (e.g., ulcerative colitis, Crohn's disease).
• Diagnosis of hereditary polyposis syndromes (e.g., familial adenomatous polyposis, Lynch syndrome).