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Tu1428 Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection for Colorectal Laterally Spreading Tumors
Abstracts
compared to only 25%(2/8) of multifocal group. In the 261 LST-NG lesions, the rate of adenocarcinoma and rate of SM invasion were 77%(201/261) and 27%(70/ 261), respectively. The rate of SM invasion for lesions measures 20⬃29mm, 30⬃39mm, 40⬃49mm and ⬎50mm was 28%(40/141), 28%(20/72), 14%(5/36) and 42%(5/12), respectively. The location of deepest SM penetration were under elevation in the lesion, depressed area and multifocal for 4%(3/70), 31%(22/70) and 64%(45/70), respectively. In these SM invasive lesions, 73%(16/22) of depressed area group had SM deep invasion, compared to only 11%(5/45) of multifocal group. Because VI-invasive pit pattern indicates SM deep invasion, we re-evaluated pit pattern of the SM invasive lesions (Matsuda Am J Gastroenterol 2008). However, most of the SM lesions did not demonstrate VI-invasive pit pattern. Finally, 5%(2/39) of SM invasive LST-G lesions and 6%(4/70) of SM invasive LST-NG lesions could not be estimated the SM deep invasion correctly by both conventional or high magnification colonoscopy. Conclusions: There is a strong indication for performing ESD in the LST-NG in order to accurately define the extent of invasion. It may be possible to perform EMR rather than ESD for the LST-G nodular mixed type when the nodule is ⬍2cm in size.
especially LST-NG over 20mm in diameter showed the very high rate of submucosal invasion (25.6%). The en bloc resection rate over 20mm in diameter of LSTs was 29.4% (178/605) in the EMR group and 97.5% (274/281) in the ESD group. Residual tumor/recurrence was observed in 118 (9.0%) of the EMR group, but there was no case with recurrence in the ESD group. With regards to complications over 20mm in diameter, there was no significant difference in the rates of post-treatment bleeding (2.8%vs.1.9%) and perforation (1.5%vs.2.2%) between EMR/EPMR and ESD, In summary, LST-NG over 20mm in diameter should be removed en bloc with ESD technique because of its higher potential for submucosal invasion. In contrast, LST-G and small LST-NG are usually associated with low rate of submucosal invasion, and acceptable for EMR/EPMR based on correct diagnoses. Conclusion: It is important to classify LSTs into LSTNG and LST-G in diagnosis. ESD is feasible treatment for LST-NG especially more than 20 mm which is hard to be resected by EMR technique.
Tu1429 The Relationship Between Lateral Resection Margin and Local Recurrence After Endoscopic Resection of Colorectal Polyps Makomo Makazu*1, Taku Sakamoto1, Eriko so1, Yosuke Otake1, Takeshi Nakajima1, Takahisa Matsuda1, Ryoji Kushima2, Yutaka Saito1 1 Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan; 2 Pathology Division, National Cancer Center Hospital, Tokyo, Japan
Tu1428 Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection for Colorectal Laterally Spreading Tumors Kosuke Sudo*, Shin-Ei Kudo, Takemasa Hayashi, Yasuharu Maeda, Tomoyuki Ishigaki, Yusuke Yagawa, Makoto Kutsukawa, Naoya Toyoshima, Masashi Misawa, Yuichi Mori, Kenta Kodama, Tomokazu Hisayuki, Kunihiko Wakamura, Yoshiki Wada, Hideyuki Miyachi Showa University Northern Yokohama Hospital, Digestive Disease Center, Yokohama, Japan Backgrounds and aims: Laterally spreading tumors (LSTs) are usually benign in spite of their large diameter and therefore, good indication for endoscopic treatment. On the other hand, Endoscopic submucosal dissection (ESD) enables en bloc resection for colorectal neoplasms regardless of their localization or diameter, and has been developed more popular as a treatment in Japan. However, the ESD procedures are difficult and associated with more risk of complications compared to conventional endoscopic mucosal resection or endoscopic piecemeal mucosal resection (EMR/EPMR). The aim of this study is to evaluate the outcomes of treatment for LSTs, and to clarify indications for EMR/EPMR and ESD. Methods: We retrospectively assessed all patients who underwent endoscopicaly or surgically treatment from April 2001 to June 2012. 16746 colorectal adenomas and early cancers were treated, and among them 1812 lesions were so-called LSTs. There are two subtypes of LSTs; non granular type (LST-NG) and granular-type (LST-G). We analyzed features of LST-NG and LST-G, and investigated the rate of en bloc resection, residual tumor/recurrence and complications between EMR/EPMR and ESD in LSTs. Results: The lesions which were treated by EMR/EPMR technique were 1312 in number and those treated by ESD technique were 413. The rate of submucosal invasion was significantly higher in LST-NG than in LST-G (17.0% vs 8.4%: p⬍0.01), and
www.giejournal.org
Background & Aims: En bloc and R0 resections are the gold standard outcome measures for endoscopic resection (ER) of colorectal polyps and are used as surrogate markers for predicting local recurrence. It is often not possible to evaluate the lateral resection margin (LM) because of thermal artifacts, close proximity of neoplastic mucosa to the resection margin and piecemeal resection. It would seem unreasonable to deal with LM status equally from the viewpoint of risk of recurrence. The aim of the study is to evaluate the status of LM and the risk of local recurrence after ER of colorectal polyps. Methods: We retrospectively reviewed the clinicopathological findings and prognosis of colorectal intramucosal neoplastic lesions treated by polypectomy, endoscopic mucosal resection and endoscopic submucosal dissection at our institution between January 2009 and October 2011. Lesions less than 10 mm, patients who failed to attend for colonoscopic surveillance at ⱖ 6 months, pathological features of non-curative resection, familial adenomatous polyposis and hereditary non-polyposis colorectal cancer were excluded. Results: The total number of lesions (n⫽569) were classified into clear lateral resection margin (LM0), positive lateral resection margin (LM1) and indefinite lateral resection margin (LMX). The median observation period from resection was 13 months (range: 6-43 months). None of 251 LM0 lesions, 18/294 (6.1%) of LMX lesions and 1/24 (4.2%) of LM1 lesions recurred locally. The median period for recurrence from ER was 6 months (range: 1-24 months). In the en-bloc resection group (n⫽481), the local recurrence was lower in LMx lesions (4/211, 1.9%) compared with LM1 lesions (1/21, 4.8%), but this was not statistically significant. In the piecemeal resection group (n⫽88), the LMX lesions recurred frequently (14/83, 16.7%). None of the LM1 lesions recurred (0/5). The frequency of local recurrence of piecemeal LMX lesions was significantly higher than en-bloc LMX lesions (p⬍0.01). All 19 local recurrences underwent further ER. Three out of 19 (one en-bloc LMX lesion and two piecemeal LMX lesions) recurred after second ER. Two out of the three persistent lesions were cured with a third ER, but one lesion that was originally characterized as piecemeal LMX lesion represented an invasive cancer and was treated with surgery. Conclusion: Piecemeal resection of colorectal polyps results in significantly higher recurrence rates than en-bloc resections, and therefore an en-bloc resection offers a greater likelihood of a cure. Similarly, lesions with indefinite resection margins removed en-bloc demonstrate very low recurrence rates and such lesions could be managed as for the LM0 resected lesions. The status of resection, lateral resection margin and recurrence
LM0 (n⫽251) LMX (n⫽294) LM1 (n⫽24) Total (n⫽569)
En bloc resection (nⴝ481)
Piecemeal resection (nⴝ88)
rec 0/non-rec 249 rec 4/non-rec 207 rec 1 /non-rec 20 rec 5/non-rec 476
rec 0/non-rec 2 rec 14/non-rec 69 rec 0 /non-rec 3 rec 14/non-rec 74
LM0, clear lateral resection margin; LMX, indefinite lateral resection margin; LM1, positive lateral resection margin; rec, recurrence; non-rec, non-recurrence
Volume 77, No. 5S : 2013
GASTROINTESTINAL ENDOSCOPY
AB537
compared to only 25%(2/8) of multifocal group. In the 261 LST-NG lesions, the rate of adenocarcinoma and rate of SM invasion were 77%(201/261) and 27%(70/ 261), respectively. The rate of SM invasion for lesions measures 20⬃29mm, 30⬃39mm, 40⬃49mm and ⬎50mm was 28%(40/141), 28%(20/72), 14%(5/36) and 42%(5/12), respectively. The location of deepest SM penetration were under elevation in the lesion, depressed area and multifocal for 4%(3/70), 31%(22/70) and 64%(45/70), respectively. In these SM invasive lesions, 73%(16/22) of depressed area group had SM deep invasion, compared to only 11%(5/45) of multifocal group. Because VI-invasive pit pattern indicates SM deep invasion, we re-evaluated pit pattern of the SM invasive lesions (Matsuda Am J Gastroenterol 2008). However, most of the SM lesions did not demonstrate VI-invasive pit pattern. Finally, 5%(2/39) of SM invasive LST-G lesions and 6%(4/70) of SM invasive LST-NG lesions could not be estimated the SM deep invasion correctly by both conventional or high magnification colonoscopy. Conclusions: There is a strong indication for performing ESD in the LST-NG in order to accurately define the extent of invasion. It may be possible to perform EMR rather than ESD for the LST-G nodular mixed type when the nodule is ⬍2cm in size.
especially LST-NG over 20mm in diameter showed the very high rate of submucosal invasion (25.6%). The en bloc resection rate over 20mm in diameter of LSTs was 29.4% (178/605) in the EMR group and 97.5% (274/281) in the ESD group. Residual tumor/recurrence was observed in 118 (9.0%) of the EMR group, but there was no case with recurrence in the ESD group. With regards to complications over 20mm in diameter, there was no significant difference in the rates of post-treatment bleeding (2.8%vs.1.9%) and perforation (1.5%vs.2.2%) between EMR/EPMR and ESD, In summary, LST-NG over 20mm in diameter should be removed en bloc with ESD technique because of its higher potential for submucosal invasion. In contrast, LST-G and small LST-NG are usually associated with low rate of submucosal invasion, and acceptable for EMR/EPMR based on correct diagnoses. Conclusion: It is important to classify LSTs into LSTNG and LST-G in diagnosis. ESD is feasible treatment for LST-NG especially more than 20 mm which is hard to be resected by EMR technique.
Tu1429 The Relationship Between Lateral Resection Margin and Local Recurrence After Endoscopic Resection of Colorectal Polyps Makomo Makazu*1, Taku Sakamoto1, Eriko so1, Yosuke Otake1, Takeshi Nakajima1, Takahisa Matsuda1, Ryoji Kushima2, Yutaka Saito1 1 Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan; 2 Pathology Division, National Cancer Center Hospital, Tokyo, Japan
Tu1428 Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection for Colorectal Laterally Spreading Tumors Kosuke Sudo*, Shin-Ei Kudo, Takemasa Hayashi, Yasuharu Maeda, Tomoyuki Ishigaki, Yusuke Yagawa, Makoto Kutsukawa, Naoya Toyoshima, Masashi Misawa, Yuichi Mori, Kenta Kodama, Tomokazu Hisayuki, Kunihiko Wakamura, Yoshiki Wada, Hideyuki Miyachi Showa University Northern Yokohama Hospital, Digestive Disease Center, Yokohama, Japan Backgrounds and aims: Laterally spreading tumors (LSTs) are usually benign in spite of their large diameter and therefore, good indication for endoscopic treatment. On the other hand, Endoscopic submucosal dissection (ESD) enables en bloc resection for colorectal neoplasms regardless of their localization or diameter, and has been developed more popular as a treatment in Japan. However, the ESD procedures are difficult and associated with more risk of complications compared to conventional endoscopic mucosal resection or endoscopic piecemeal mucosal resection (EMR/EPMR). The aim of this study is to evaluate the outcomes of treatment for LSTs, and to clarify indications for EMR/EPMR and ESD. Methods: We retrospectively assessed all patients who underwent endoscopicaly or surgically treatment from April 2001 to June 2012. 16746 colorectal adenomas and early cancers were treated, and among them 1812 lesions were so-called LSTs. There are two subtypes of LSTs; non granular type (LST-NG) and granular-type (LST-G). We analyzed features of LST-NG and LST-G, and investigated the rate of en bloc resection, residual tumor/recurrence and complications between EMR/EPMR and ESD in LSTs. Results: The lesions which were treated by EMR/EPMR technique were 1312 in number and those treated by ESD technique were 413. The rate of submucosal invasion was significantly higher in LST-NG than in LST-G (17.0% vs 8.4%: p⬍0.01), and
www.giejournal.org
Background & Aims: En bloc and R0 resections are the gold standard outcome measures for endoscopic resection (ER) of colorectal polyps and are used as surrogate markers for predicting local recurrence. It is often not possible to evaluate the lateral resection margin (LM) because of thermal artifacts, close proximity of neoplastic mucosa to the resection margin and piecemeal resection. It would seem unreasonable to deal with LM status equally from the viewpoint of risk of recurrence. The aim of the study is to evaluate the status of LM and the risk of local recurrence after ER of colorectal polyps. Methods: We retrospectively reviewed the clinicopathological findings and prognosis of colorectal intramucosal neoplastic lesions treated by polypectomy, endoscopic mucosal resection and endoscopic submucosal dissection at our institution between January 2009 and October 2011. Lesions less than 10 mm, patients who failed to attend for colonoscopic surveillance at ⱖ 6 months, pathological features of non-curative resection, familial adenomatous polyposis and hereditary non-polyposis colorectal cancer were excluded. Results: The total number of lesions (n⫽569) were classified into clear lateral resection margin (LM0), positive lateral resection margin (LM1) and indefinite lateral resection margin (LMX). The median observation period from resection was 13 months (range: 6-43 months). None of 251 LM0 lesions, 18/294 (6.1%) of LMX lesions and 1/24 (4.2%) of LM1 lesions recurred locally. The median period for recurrence from ER was 6 months (range: 1-24 months). In the en-bloc resection group (n⫽481), the local recurrence was lower in LMx lesions (4/211, 1.9%) compared with LM1 lesions (1/21, 4.8%), but this was not statistically significant. In the piecemeal resection group (n⫽88), the LMX lesions recurred frequently (14/83, 16.7%). None of the LM1 lesions recurred (0/5). The frequency of local recurrence of piecemeal LMX lesions was significantly higher than en-bloc LMX lesions (p⬍0.01). All 19 local recurrences underwent further ER. Three out of 19 (one en-bloc LMX lesion and two piecemeal LMX lesions) recurred after second ER. Two out of the three persistent lesions were cured with a third ER, but one lesion that was originally characterized as piecemeal LMX lesion represented an invasive cancer and was treated with surgery. Conclusion: Piecemeal resection of colorectal polyps results in significantly higher recurrence rates than en-bloc resections, and therefore an en-bloc resection offers a greater likelihood of a cure. Similarly, lesions with indefinite resection margins removed en-bloc demonstrate very low recurrence rates and such lesions could be managed as for the LM0 resected lesions. The status of resection, lateral resection margin and recurrence
LM0 (n⫽251) LMX (n⫽294) LM1 (n⫽24) Total (n⫽569)
En bloc resection (nⴝ481)
Piecemeal resection (nⴝ88)
rec 0/non-rec 249 rec 4/non-rec 207 rec 1 /non-rec 20 rec 5/non-rec 476
rec 0/non-rec 2 rec 14/non-rec 69 rec 0 /non-rec 3 rec 14/non-rec 74
LM0, clear lateral resection margin; LMX, indefinite lateral resection margin; LM1, positive lateral resection margin; rec, recurrence; non-rec, non-recurrence
Volume 77, No. 5S : 2013
GASTROINTESTINAL ENDOSCOPY
AB537