Prevalence of residual neoplastic tissue after endoscopic resection of colonic neoplastic polyps: correlation with the surgical specimen

M Bun, MD, L Pereyra, MD, E Grzona, MD, A Canelas, MD, C Fisher, MD, M Laporte, MD, C Peczan, MD, D Cimmino, MD, N Rotholtz, MD

Colorectal Surgery and Endoscopy Divisions – Hospital Aleman de Buenos Aires. Argentina.

Prevalence of residual neoplastic tissue after endoscopic resection of colonic neoplastic polyps: correlation with the surgical specimen

BACKGROUND:Endoscopic resection of neoplastic colonic polyps may be curative depending on the depth of invasion and the presence of polypectomy margins free of disease. Information about the prevalence of residual neoplastic tissue (RNT)after polypectomy is scarce.

AIM: Determine the prevalence of RNT in surgical specimens from patients undergoing colectomy after endoscopic resection of malignant colon polyps, and evaluate the relationship between RNT status and the type of polypectomy, the resection margins and the depth of invasion

METHODS: Patients with colonic neoplastic polyps treated by laparoscopic colectomy in a university hospital in Buenos Aires between January 2003 and March 2011 were prospectively analyzed. Those with polyps containing in situ or invasive carcinoma in whom an endoscopic polypectomy with curative intention was performed before surgery were included. The polyp resection margins informed by the pathologist were classified into three groups: complete, incomplete and indeterminate. Primary outcome: proportion of patients with RNT in the surgical sample.

RESULTS: 155 patients undergoing colectomy for colonic polys, 46 with in situ or adecarcinoma and a previous attempt of curative endoscopic polypectomy were included 52% were men, average age was 63 (40-91). Polyp morphology: 0-Is (sessile) 64%, 0-Ip (pedunculated) 17% and 0-IIa (slightly elevated) 13%, average polyp size was 18 mm (3-35) 72% of the polyps contained in situ carcinoma and 26% invasive adenocarcinoma. RNT was found in the surgical specimens of 56% the patients. Prevalence following polypectomy with forceps (71%), EMR (55%), snare polypectomy 26%). RNT was found in 51%, 43% and 0% of incomplete, indeterminate and complete resections respectively.

SUMMARY AND CONCLUSIONS: A high prevalence of RNT was observed following forceps polypectomy, and when incomplete or indeterminate polypectomy resection margins were informed

Session: Podium Presentation

Program Number: S057