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616 The Indication for Additional Surgical Colectomy With Lymph Node Dissection After Endoscopic Treatment in T1 Colorectal Carcinomas
Abstracts
moplastic reaction (DR) on the superficial layer, degree of SM invasion, and state of muscularis mucosae (MM grade). MM grade was evaluated into two conditions using the desmin immunostaining: MM grade 1 (complete or almost maintenance of the muscular fiber) and MM grade 2 (fragmentation or disappearance of the muscular fiber). Finally, based on significant factors, we stratified these SM cancers into 3 groups at ultralow, low and high risk of nodal metastasis. Results: The existence of vessel permeation, tumor budding, POR/MUC component or MM grade 2 was a significant risk factor for nodal metastasis, while DR on the superficial layer and degree of SM invasion were not significant. In contrast with MM grade 2, no lesions corresponding to MM grade 1 had lymph node metastases. Among T1 carcinomas with MM grade 2, lesions without vessel permeation, tumor budding or POR/MUC component showed low incidence (2/163: 1.2%) of nodal metastases, while 50 (14.4%) of 347 lesions with at least one factor had lymph node involvement. Conclusion: The indication for additional surgical colectomy after endoscopic resection has been more clarified and simplified: MM grade 1 was suggested to be an antirisk factor for nodal metastasis (Ultralow-risk group). T1 carcinomas with MM grade 2 and without vessel permeation, tumor budding or POR/MUC component may need further monitoring (Low-risk group). For T1 carcinomas with MM grade 2 and with at least one factor, additional surgical colectomy with lymph node dissection should be recommended (High-risk group).
683 Molecular Features of Colorectal Polyps Presenting Kudo’s Type II Mucosal Crypt Pattern Kensuke Shinmura*1, Kazuo Konishi1, Yutaro Kubota1, Yuichiro Yano1, Atsushi Katagiri1, Takashi Muramoto1, Toshihiro Kihara1, Masayuki Tojo1, Kenichi Konda1, Teppei Tagawa1, Fumito Yanagisawa1, Kentaro Iijima1, Toshiko Yamochi2, Masafumi Takimoto2, Hitoshi Yoshida1 1 Division of Gastroenterology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan; 2Department of Pathology Clinico-diagnostic Pathology, Showa University School of Medicine, Tokyo, Japan
616 The Indication for Additional Surgical Colectomy With Lymph Node Dissection After Endoscopic Treatment in T1 Colorectal Carcinomas Hideyuki Miyachi*1, Shin-Ei Kudo1, Shigeharu Hamatani2,1, Katsuro Ichimasa1, Tomokazu Hisayuki1, Yuta Kouyama1, Hiromasa Oikawa1, Shingo Matsudaira1, Yuichi Mori1, Masashi Misawa1, Toyoki Kudo1, Shunpei Mukai1, Kenta Kodama1, Kunihiko Wakamura1, Takemasa Hayashi1, Eiji Hidaka1, Shogo Ohkoshi1, Haruhiro Inoue1, Fumio Ishida1 1 Digestive Disease Center, Showa Univercity Northern Yokohama Hospital, Yokohama, Japan; 2Department of Pathology, Showa University Northern Yokohama Hospital, Yokohama, Japan Background: Recent advances in EMR or ESD technology has enabled easier and safer endoscopic treatment. A lot of T1 colorectal carcinomas are resected endoscopically with negative margins. Therefore, additional surgical colectomy with lymph node dissection should be considered according to the pathological analysis. Although it is critical to determine the criteria for curative endoscopic resection, there is only a few data pursuing a large number of samplings in terms of the indication for additional surgical colectomy. Aims: The aim is to clarify pathological risk factors for lymph node metastasis of T1 colorectal carcinomas and to establish the indication for additional surgical colectomy with nodal dissection after endoscopic treatment. Methods: A total of 20072 colorectal neoplasms excluding advanced cancers have been resected endoscopically or surgically at our unit from April 2001 to May 2013. Of these, 853 T1 carcinomas were included. Initial or additional surgical colectomy with nodal dissection was performed in 563 cases, and of which lymph node metastasis was found in 52 cases (9.2%). We analyzed the pathological risk factors for nodal metastasis as follows: vessel permeation, tumor budding, poorly-differentiated/mucinous carcinoma (POR/MUC) component, des-
AB162 GASTROINTESTINAL ENDOSCOPY Volume 79, No. 5S : 2014
Background & Aims: Hyperplastic polyp (HP), sessile serrated adenoma/polyps (SSA/P) and traditional serrated adenoma (TSA) are thought to be precursor lesions of serrated pathway. However, hyperplastic mucosal crypt patterns (so-called Kudo’s type II) are frequently observed in these lesions under chromoendoscopy. We hypothesized that there are biological or molecular differences among the serrated polyps (SPs) with hyperplastic crypt pattern and that these features are associated with their different pathways of progression to colon cancer. To test this hypothesis, we evaluated the molecular features of SPs with hyperplastic crypt pattern. Methods: We examined the clinicopathological and molecular features of 114 SPs with hyperplastic [stellar or papillary pits] crypt pattern that were resected endoscopically at Showa University Hospital from February 2009 to August 2012. We investigated the frequency of mutations of KRAS and BRAF, and CpG island methylator phenotype (CIMP), including the methylation of two or more CIMP-related genes (MINT1, MINT2, MINT31, p16, and MLH1). HPs were classified into microvesicular HP (MVHP), goblet cell-rich HP (GCHP), and mucin-poor HP (MPHP) variants on the basis of WHO classification. Results: A total of 114 SPs with hyperplastic pattern comprised 68 serrated neoplasms (SNs) (5 dysplastic SPs [4 SSA/P with cytological dysplasia and 1 TSA] and 63 SSA/Ps), 36 MVHPs and 10 GCHPs. Dysplastic SPs and SSA/Ps were frequently located in the proximal colon, compared to others (SSA/Ps vs. MVHPs or GCHPs, P ! 0.001). We found no significant difference in the frequency of BRAF mutation among SPs except GCHP (60% for dysplastic SPs, 44% for SSA/Ps, 47% for MVHPs and 0% for GCHPs). Furthermore, the frequency of CIMP was higher in dysplastic SPs or SSA/Ps than MVHPs or GCHPs (60% for dysplastic SPs, 56% for SSA/Ps, 32% for MVHPs and 10% for GCHPs) (SSA/Ps vs. GCHP, P Z 0.0068). When we classified SNs and MVHPs into proximal and distal lesions, the frequency of CIMP was significantly higher in the proximal than the distal SNs (64% vs. 11%, P Z 0.0032). Although the frequency of CIMP was higher in the proximal than the distal MVHPs, this difference was not statistically significant (50% vs. 23%). Finally, multivariate analysis showed that proximal location, BRAF and KRAS mutations were significantly associated with an increased risk of CIMP. Conclusions: We observed distinct molecular features between proximal and distal SPs with hyperplastic crypt pattern. Proximal SPs with hyperplastic pattern may develop from MVHPs through SSA/Ps to colon cancers. In the present time, therefore, endoscopists should aggressively remove proximal lesions when colorectal polyps with type-II pit pattern are detected by chromoendoscopy or electronic chromoendoscopy (e.g., narrow-band imaging).
684 A Randomised Controlled Trial Comparing the Modified Sano’s Versus the Nice Classifications Using Narrow Band Imaging With Near Focus Magnification in Differentiating Colorectal Polyps Rajvinder Singh*1,2, Amanda Ovenden2, Andrew Ruszkiewicz3 1 Gastroenterology, Lyell McEwin Hospital, Adelaide, SA, Australia; 2 Department of Medicine, University of Adelaide, Adelaide, SA, Australia; 3Research Laboratory, SA Pathology, Adelaide, SA, Australia Introduction: Advances in endoscopic imaging with real time diagnosis of colorectal polyps may lead to substantial time and cost savings and could potentially reduce
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moplastic reaction (DR) on the superficial layer, degree of SM invasion, and state of muscularis mucosae (MM grade). MM grade was evaluated into two conditions using the desmin immunostaining: MM grade 1 (complete or almost maintenance of the muscular fiber) and MM grade 2 (fragmentation or disappearance of the muscular fiber). Finally, based on significant factors, we stratified these SM cancers into 3 groups at ultralow, low and high risk of nodal metastasis. Results: The existence of vessel permeation, tumor budding, POR/MUC component or MM grade 2 was a significant risk factor for nodal metastasis, while DR on the superficial layer and degree of SM invasion were not significant. In contrast with MM grade 2, no lesions corresponding to MM grade 1 had lymph node metastases. Among T1 carcinomas with MM grade 2, lesions without vessel permeation, tumor budding or POR/MUC component showed low incidence (2/163: 1.2%) of nodal metastases, while 50 (14.4%) of 347 lesions with at least one factor had lymph node involvement. Conclusion: The indication for additional surgical colectomy after endoscopic resection has been more clarified and simplified: MM grade 1 was suggested to be an antirisk factor for nodal metastasis (Ultralow-risk group). T1 carcinomas with MM grade 2 and without vessel permeation, tumor budding or POR/MUC component may need further monitoring (Low-risk group). For T1 carcinomas with MM grade 2 and with at least one factor, additional surgical colectomy with lymph node dissection should be recommended (High-risk group).
683 Molecular Features of Colorectal Polyps Presenting Kudo’s Type II Mucosal Crypt Pattern Kensuke Shinmura*1, Kazuo Konishi1, Yutaro Kubota1, Yuichiro Yano1, Atsushi Katagiri1, Takashi Muramoto1, Toshihiro Kihara1, Masayuki Tojo1, Kenichi Konda1, Teppei Tagawa1, Fumito Yanagisawa1, Kentaro Iijima1, Toshiko Yamochi2, Masafumi Takimoto2, Hitoshi Yoshida1 1 Division of Gastroenterology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan; 2Department of Pathology Clinico-diagnostic Pathology, Showa University School of Medicine, Tokyo, Japan
616 The Indication for Additional Surgical Colectomy With Lymph Node Dissection After Endoscopic Treatment in T1 Colorectal Carcinomas Hideyuki Miyachi*1, Shin-Ei Kudo1, Shigeharu Hamatani2,1, Katsuro Ichimasa1, Tomokazu Hisayuki1, Yuta Kouyama1, Hiromasa Oikawa1, Shingo Matsudaira1, Yuichi Mori1, Masashi Misawa1, Toyoki Kudo1, Shunpei Mukai1, Kenta Kodama1, Kunihiko Wakamura1, Takemasa Hayashi1, Eiji Hidaka1, Shogo Ohkoshi1, Haruhiro Inoue1, Fumio Ishida1 1 Digestive Disease Center, Showa Univercity Northern Yokohama Hospital, Yokohama, Japan; 2Department of Pathology, Showa University Northern Yokohama Hospital, Yokohama, Japan Background: Recent advances in EMR or ESD technology has enabled easier and safer endoscopic treatment. A lot of T1 colorectal carcinomas are resected endoscopically with negative margins. Therefore, additional surgical colectomy with lymph node dissection should be considered according to the pathological analysis. Although it is critical to determine the criteria for curative endoscopic resection, there is only a few data pursuing a large number of samplings in terms of the indication for additional surgical colectomy. Aims: The aim is to clarify pathological risk factors for lymph node metastasis of T1 colorectal carcinomas and to establish the indication for additional surgical colectomy with nodal dissection after endoscopic treatment. Methods: A total of 20072 colorectal neoplasms excluding advanced cancers have been resected endoscopically or surgically at our unit from April 2001 to May 2013. Of these, 853 T1 carcinomas were included. Initial or additional surgical colectomy with nodal dissection was performed in 563 cases, and of which lymph node metastasis was found in 52 cases (9.2%). We analyzed the pathological risk factors for nodal metastasis as follows: vessel permeation, tumor budding, poorly-differentiated/mucinous carcinoma (POR/MUC) component, des-
AB162 GASTROINTESTINAL ENDOSCOPY Volume 79, No. 5S : 2014
Background & Aims: Hyperplastic polyp (HP), sessile serrated adenoma/polyps (SSA/P) and traditional serrated adenoma (TSA) are thought to be precursor lesions of serrated pathway. However, hyperplastic mucosal crypt patterns (so-called Kudo’s type II) are frequently observed in these lesions under chromoendoscopy. We hypothesized that there are biological or molecular differences among the serrated polyps (SPs) with hyperplastic crypt pattern and that these features are associated with their different pathways of progression to colon cancer. To test this hypothesis, we evaluated the molecular features of SPs with hyperplastic crypt pattern. Methods: We examined the clinicopathological and molecular features of 114 SPs with hyperplastic [stellar or papillary pits] crypt pattern that were resected endoscopically at Showa University Hospital from February 2009 to August 2012. We investigated the frequency of mutations of KRAS and BRAF, and CpG island methylator phenotype (CIMP), including the methylation of two or more CIMP-related genes (MINT1, MINT2, MINT31, p16, and MLH1). HPs were classified into microvesicular HP (MVHP), goblet cell-rich HP (GCHP), and mucin-poor HP (MPHP) variants on the basis of WHO classification. Results: A total of 114 SPs with hyperplastic pattern comprised 68 serrated neoplasms (SNs) (5 dysplastic SPs [4 SSA/P with cytological dysplasia and 1 TSA] and 63 SSA/Ps), 36 MVHPs and 10 GCHPs. Dysplastic SPs and SSA/Ps were frequently located in the proximal colon, compared to others (SSA/Ps vs. MVHPs or GCHPs, P ! 0.001). We found no significant difference in the frequency of BRAF mutation among SPs except GCHP (60% for dysplastic SPs, 44% for SSA/Ps, 47% for MVHPs and 0% for GCHPs). Furthermore, the frequency of CIMP was higher in dysplastic SPs or SSA/Ps than MVHPs or GCHPs (60% for dysplastic SPs, 56% for SSA/Ps, 32% for MVHPs and 10% for GCHPs) (SSA/Ps vs. GCHP, P Z 0.0068). When we classified SNs and MVHPs into proximal and distal lesions, the frequency of CIMP was significantly higher in the proximal than the distal SNs (64% vs. 11%, P Z 0.0032). Although the frequency of CIMP was higher in the proximal than the distal MVHPs, this difference was not statistically significant (50% vs. 23%). Finally, multivariate analysis showed that proximal location, BRAF and KRAS mutations were significantly associated with an increased risk of CIMP. Conclusions: We observed distinct molecular features between proximal and distal SPs with hyperplastic crypt pattern. Proximal SPs with hyperplastic pattern may develop from MVHPs through SSA/Ps to colon cancers. In the present time, therefore, endoscopists should aggressively remove proximal lesions when colorectal polyps with type-II pit pattern are detected by chromoendoscopy or electronic chromoendoscopy (e.g., narrow-band imaging).
684 A Randomised Controlled Trial Comparing the Modified Sano’s Versus the Nice Classifications Using Narrow Band Imaging With Near Focus Magnification in Differentiating Colorectal Polyps Rajvinder Singh*1,2, Amanda Ovenden2, Andrew Ruszkiewicz3 1 Gastroenterology, Lyell McEwin Hospital, Adelaide, SA, Australia; 2 Department of Medicine, University of Adelaide, Adelaide, SA, Australia; 3Research Laboratory, SA Pathology, Adelaide, SA, Australia Introduction: Advances in endoscopic imaging with real time diagnosis of colorectal polyps may lead to substantial time and cost savings and could potentially reduce
www.giejournal.org