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©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
Reevaluation of the expanded indications in undifferentiated early gastric cancer for endoscopic submucosal dissection
Jiyoung Yoon, Seung-Yeon Yoo, Young Soo Park, Kee Don Choi, Beom Su Kim, Moon-Won Yoo, In Seob Lee, Jeong Hwan Yook, Ga Hee Kim, Hee Kyong Na, Ji Yong Ahn, Jeong Hoon Lee, Kee Wook Jung, Do Hoon Kim, Ho June Song, Gin Hyug Lee, Hwoon-Yong Jung
Jiyoung Yoon, Kee Don Choi, Ga Hee Kim, Hee Kyong Na, Ji Yong Ahn, Jeong Hoon Lee, Kee Wook Jung, Do Hoon Kim, Ho June Song, Gin Hyug Lee, Hwoon-Yong Jung, -Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, South Korea
Seung-Yeon Yoo, Young Soo Park, Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, South Korea
Beom Su Kim, Moon-Won Yoo, In Seob Lee, Jeong Hwan Yook, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, South Korea
Author contributions: Yoon J and Yoo SY equally contributed to this article; Yoon JY and Yoo SY collected and analyzed data, and drafted the manuscript; Kim BS, Yoo MW, Lee IS, Yook JH, Kim GH, Na HK, Ahn JY, Lee JH, Jung KW, Kim DH, Song HJ, Lee GH and Jung HY were involved in study patient enrollment, data collection, and data analysis; Choi KD and Park YS were involved in study design, supervision, and critical revision of the study; Choi KD and Park YS equally contributed as co-corresponding authors; all authors read and approved the final version of the manuscript.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board of Asan Medical Center.
Informed consent statement: The requirement for informed consent was waived by the Institutional Review Board considering the retrospective design of the study.
Conflict-of-interest statement: All authors have no conflict of interest related to the study.
Data sharing statement: Data used in this study are available from the corresponding author upon reasonable request.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Kee Don Choi, MD, PhD, Doctor, Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, South Korea. keedon@amc.seoul.kr
Received: December 2, 2021
Peer-review started: December 2, 2021
First decision: January 23, 2022
Revised: February 5, 2022
Accepted: March 16, 2022
Article in press: March 16, 2022
Published online: April 21, 2022
Processing time: 134 Days and 3.7 Hours
BACKGROUND
Although the criteria for the indication of endoscopic submucosal dissection (ESD) for undifferentiated early gastric cancer (UD-EGC) have been recently proposed, accumulating reports on the non-negligible rate of lymph node metastasis (LNM) after indicated ESD raise questions on the reliability of the current criteria.
AIM
To investigate the prevalence and risk factors of LNM in UD-EGC cases meeting the expanded indication for ESD.
METHODS
We retrospectively reviewed 4780 UD-EGC cases that underwent surgical resection between January 2008 and February 2019 at Asan Medical Center, a tertiary university hospital in Korea. To identify the risk factors of LNM of UD-EGC meeting the expanded criteria for ESD, we performed a case-control study by matching the cases with LNM to those without at a ratio of 1:4. We reviewed the clinical, endoscopic, and histologic features of the cases to identify features with a significant difference according to the presence of LNM. Univariate and multivariate logistic regression analyses were performed to estimate the odds ratios (ORs).
RESULTS
Of the 4780 UD-EGC cases, 1240 (25.9%) were identified to meet the expanded indication for ESD. Of the 1240 cases, 14 (1.1%) cases had LNM. Among the various clinical, endoscopic, and histopathological features that were evaluated, mixed histology (tumors consisting of 10%-90% of signet ring cells) had a marginally significant association (P = 0.059) with the risk of LNM. Moreover, diffuse blurring of the muscularis mucosae (MM) underneath the tumorous epithelium, a previously unrecognized histologic feature, had a significant association with the absence of LNM (P = 0.028). Multivariate logistic regression analysis showed that the blurring of MM was the only explanatory variable significantly associated with a reduced risk of LNM (OR: 0.12, 95%CI: 0.02-0.95; P = 0.045).
CONCLUSION
The risk of LNM is higher than expected when using the current expanded indication for UD-EGC. Histological evaluation could provide useful clues for reducing the risk of LNM.
Core Tip: This was a retrospective study investigating the prevalence and risk factors of lymph node metastasis (LNM) in cases with undifferentiated early gastric cancer meeting the expanded indication for endoscopic submucosal dissection (ESD). We found that the incidence rate of LNM was 1.1% (14/1240), which was higher than expected for indicated ESD. A subsequent case-control study revealed that two histological features-histologic purity of tumors and blurring of the muscularis mucosae underneath the tumorous epithelium-are promising factors for predicting the risk of LNM. Combining these histologic features could improve the current expanded indication criteria for ESD.
