Tu1444 Characteristics of Colorectal Muscularis Propria Carcinoma Derived From Depressed- Type Early Lesions

Abstracts

Endoscopic Mucosal Resection Margin and Depth Assessment Scale (EMR-MDA Scale) Nomenclature e p n B B0 B1 E E0 E1 MDA Scale 0 MDA Scale 1 MDA Scale 2

En Bloc resection Piecemeal resection Number of pieces taken during piecemeal resection Base of the resection No neoplastic tissue at resection base-clean base Neoplastic tissue at the resection base Edge of the resection No neoplastic tissue at resection edge; round mucosal pit pattern observed Neoplastic tissue at resection edge EMR MDA Scale eB0E0 (Enbloc resection without residual tissue) p n (ⱕ3)B0E0 (Piecemeal resection, nⱕ3, without residual tissue) p n (3) or B1 or E1 (Piecemeal resection, n3 or residual tissue at base or edge)

Tu1444 Characteristics of Colorectal Muscularis Propria Carcinoma Derived From Depressed- Type Early Lesions Tomokazu Hisayuki*1, Shin-Ei Kudo1, Shigeharu Hamatani2, Hideyuki Miyachi1, Katsuro Ichimasa1, Hiromasa Oikawa1, Yuichi Mori1, Masashi Misawa1, Toyoki Kudo1, Kenta Kodama1, Yoshiki Wada1, Takemasa Hayashi1, Kunihiko Wakamura1, Eiji Hidaka1, Fuyuhiko Yamamura1, Shogo Ohkoshi1, Fumio Ishida1, Jun-Ichi Tanaka1 1 Digestive Disease Center, Showa University Northern Yokohama Hospital, Yokohama, Japan; 2Department of Pathology, Showa University Northern Yokohama Hospital, Yokohama, Japan Backgrounds: The general recognition is that “adenoma-carcinoma sequence” has been considered as the mainstream theory of the development of colorectal cancer. Recently, an increasing number of depressed-type early colorectal cancers are being reported not only in the East but also in the West. Depressedtype early cancers are considered to emerge directly from normal mucosa without going through adenomas and become invasive even when carcinomas as early as they are around 10mm in diameter. Aims: The aim is to clarify the characteristics of colorectal muscularis propria carcinoma derived from depressed-type early lesions. Method: A total of 16200 neoplasms were resected endoscopically or surgically at our unit from April 2001 to April 2009. Of these 195 muscularis propria carcinomas were included. There were 50 lesions(25.6%) with nodal metastasis and 2 lesions(1.0%) with distant metastasis. The lesions were classified into 4 categories based on the endoscopic view: (A) Depressed type (with the periphery consisted of normal mucosa), (B) Laterally spreading type, (C) Protruded type, and (D) Ulcerative type (with the periphery consisted of neoplastic tissue). Category A lesions are the cases which can be estimated to have developed from depressed-type early cancers. We analyzed those lesions in terms of tumor size, lymphatic involvement, venous involvement, nodal metastasis and distant metastasis. Results: The 195 muscularis propria carcinomas were classified as (A) 74 lesions(38.0%), (B) 26 lesions(13.3%), (C) 24 lesions(12.3%), and (D) 71 lesions(36.4%). The average tumor size for each category was (A) 22.79.5mm, (B) 51.222.6mm, (C) 29.98.7mm, and (D) 36.311.3mm. The numbers of positive findings for lymphatic involvement,

www.giejournal.org

venous involvement, nodal metastasis and distant metastasis for each category were: (A) 50(67.6%), 54(73.0%), 18(24.3%), 0(0%), (B) 14(53.8%), 12(46.2%), 8(30.8%), 0(0%), (C) 14(58.3%), 8(33.3%), 6(25.0%), 0(0%), (D) 35(49.3%), 41(57.7%), 16(22.5%), 2(2.8%). Category A showed significantly higher rate of lymphatic and venous involvement (P0.01, P0.05 respectively). As for the other factors, there were no significant differences. Conclusion: Compared to the other forms, depressed-type colorectal muscularis propria carcinoma showed higher rate of lymphatic and venous invasion and its malignant nature has been highlighted.

Tu1445 Colonic Endoscopic Mucosal Resection: Is It Safe in the Octogenarian Population? Victoria Gomez*, Mihir K. Patel, Ernest P. Bouras, Massimo Raimondo, Michael B. Wallace, Timothy a. Woodward, Frank Lukens Gastroenterology, Mayo Clinic, Jacksonville, FL Background: With endoscopic mucosal resection (EMR), large, sessile lesions of the colon can be resected endoscopically rather than surgically. While the majority of patients that undergo EMR are over the age of 50, the octogenarian patient population in particular could significantly benefit from EMR, avoiding a surgery that carries more morbidity and even mortality. However, little is known about EMR outcomes in the very elderly patient population. Aim: To evaluate outcomes and safety of colon EMR in the octogenarian patient population. Methods: We performed a retrospective review of the electronic medical records for all patients greater than or equal to 80 years of age that underwent EMR of the colon for lesions greater than or equal to 2 centimeters (cm), from March 2000 to May 2012 at a single tertiary referral center. Demographic information, specifics of the mucosal lesions and outcomes were evaluated. Results: Between the given dates, 132 EMR procedures were performed on 99 patients greater than or equal to 80 years of age. Fifty-nine patients were male, average age was 84 years (Range: 80-93 years) and 94% were Caucasian (N
93). Seven patients were greater than or equal to 90 years of age. EMR procedures were more commonly performed in the right colon (N
95, 72%). Average polyp size was 3.3 cm (Range 2-12.5 cm). The most frequently diagnosed pathologies were adenomas (N
95, 72%), followed by hyperplastic lesions (N
16, 12%), adenocarcinoma (N
10, 7.6%) and serrated polyps (N
7, 5.3%). Ten procedure-related complications occurred (8%). Five of these consisted of either immediate or delayed post polypectomy bleeding that required hospitalization for observation with/without colonoscopy with hemostasis. Four perforations occurred, 3 of which were managed with endoscopic hemostatic clips placement and observation in the hospital, and 1 that required urgent partial cecectomy. One patient experienced significant chest pain, nausea and vomiting after procedure and required hospitalization for observation. No deaths occurred. Six patients ultimately required a colonic operation, including 1 for a procedure related perforation, 4 for adenocarcinoma of the colon and 1 for a recurrent adenoma that was difficult to treat endoscopically. Conclusion: Colonic EMR in the very elderly patient population offers minimally invasive treatment of neoplastic lesions. While complications do occur, overall, EMR can be performed safely and furthermore avoid the need for surgical intervention in most instances.

Tu1446 Rectal Location Confers Increased Risk of Colorectal Cancer in Specific Subgroups of Advanced Mucosal Neoplasia Bronte a. Holt*1, Stephen J. Williams1, Rajvinder Singh2, Luke F. Hourigan3,4, Simon a. Zanati5,6, Gregor J. Brown5,7, Michael J. Bourke1 1 Gastroenterology and Hepatology, Westmead Hospital, Sydney, NSW, Australia; 2Gastroenterology and Hepatology, Lyell McEwin Hospital, Adelaide, SA, Australia; 3Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, QLD, Australia; 4Gastroenterology and Hepatology, Greenslopes Private Hospital, Brisbane, QLD, Australia; 5 Gastroenterology and Hepatology, The Alfred Hospital, Melbourne, VIC, Australia; 6Gastroenterology and Hepatology, Western Hospital, Melbourne, VIC, Australia; 7Gastroenterology and Hepatology, Epworth Hospital, Melbourne, VIC, Australia Background: Large sessile polyps and laterally spreading tumours 20mm are advanced colonic mucosal neoplasms (AMN) with a small but significant risk of invasive cancer. Accurate endoscopic assessment informs the therapeutic strategy. En bloc resection is preferred for those at risk of early colorectal cancer (CRC), especially in distal locations where surgery is associated with increased short and long-term morbidity and mortality. Compared to flat (Paris 0-IIa/b) and granular (G) AMN, non granular (NG) AMN or those with a Paris 0-Is component (including IsIIa, and IsIIb subtypes) have an increased risk of submucosal invasion. Rectal location may confer additional risk but this is currently unknown. Patients And Methods: Data from a large, multicentre prospective cohort of EMR for colonic AMN ⱖ20mm was analysed (June 2008- May 2012,

Volume 77, No. 5S : 2013

GASTROINTESTINAL ENDOSCOPY

AB543