4.

Management strategy after polypectomy

Pathological staging	Stratification	Class I recommendation	Class II recommendation	Class III recommendation
a, Patients who fulfilled all the following criteria (7): Specimen was completely excised, with a negative resection margin and good histological characteristics (includes Grade 1 or 2 differentiation and absence of vascular and lymphatic invasion). b, Patients who fulfilled one of the following criteria (8): Fragmented specimen, indeterminate or positive resection margin [tumor cells are present within 1 mm from the resection margin or tumor cells can be seen at the electroresection margin (7-9)] or histological characteristics with poor prognosis (Grades 3/4 differentiation and lymphovascular invasion). c, The patient should be informed that the probability of poor outcomes will significantly increase with sessile malignant polyps, including disease recurrence, mortality, and blood dissemination, which is highly associated with positive resection margin after endoscopic resection (10).
High-grade intraepithelial neoplasia	NA	Observation	—	—
pT1N0M0 Pedunculated polyp with invasive cancer	Good prognosisa	Observation	—	—
pT1N0M0 Sessile polyp with invasive cancer	—	Observationc	Coloctomy with enbloc removal of regional lymph nodes	—
pT1N0M0 Pedunculated or sessile polyp with invasive cancer	Poor prognosisb	Coloctomy with enbloc removal of regional lymph nodes		Observation