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©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
Histopathological validation of magnifying endoscopy for diagnosis of mixed-histological-type early gastric cancer
Yuichiro Ozeki, Kingo Hirasawa, Ryosuke Kobayashi, Chiko Sato, Yoko Tateishi, Atsushi Sawada, Ryosuke Ikeda, Masafumi Nishio, Takehide Fukuchi, Makomo Makazu, Masataka Taguri, Shin Maeda
Yuichiro Ozeki, Kingo Hirasawa, Ryosuke Kobayashi, Chiko Sato, Atsushi Sawada, Ryosuke Ikeda, Masafumi Nishio, Takehide Fukuchi, Makomo Makazu, Division of Endoscopy, Yokohama City University Medical Center, Yokohama 232-0024, Japan
Yoko Tateishi, Department of Pathology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
Masataka Taguri, Department of Data Science, Yokohama City University School of Data Science, Yokohama 236-0004, Japan
Shin Maeda, Department of Gastroenterology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
Author contributions: Ozeki Y and Hirasawa K equally contributed to conception, design, and writing this article; Ozeki Y, Hirasawa K, Kobayashi R, Sato C, and Tateishi Y reviewed all the histopathological slides and endoscopic images studied in this article; Ozeki Y, Hirasawa K, Kobayashi R, Sato C, Sawada A, Ikeda R, Nishio M, Fukuchi T, and Makazu M performed endoscopic treatment for patients studied in this article; Taguri M provided statistical assistance required in this study; Hirasawa K and Maeda S supervised the draft of this article; Each co-author read and approved of the final version of this article.
Institutional review board statement: The study protocol was reviewed and approved by the Ethics Committee of Yokohama City University Medical Center Hospital (Approval number: D1602024).
Informed consent statement: Patients were not required to provide informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Data sharing statement: No additional data are available.
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: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Kingo Hirasawa, MD, PhD, Associate Professor, Division of Endoscopy, Yokohama City University Medical Center, 4-57 Urafune, Minami-ku, Yokohama 232-0024, Japan. kingo-h@urahp.yokohama-cu.ac.jp
Received: May 18, 2020
Peer-review started: May 18, 2020
First decision: July 29, 2020
Revised: August 7, 2020
Accepted: September 8, 2020
Article in press: September 8, 2020
Published online: September 28, 2020
ARTICLE HIGHLIGHTS
Research background
Endoscopic resection has become a mainstay therapy for early gastric cancers (EGCs). EGCs with very low risk of lymph node metastasis are indications for endoscopic resection. The risk of lymph node metastasis markedly differs according to the histological types.
Research motivation
Although the undifferentiated-type (UDT) component adversely affects the clinical course of EGCs, whether the UDT component within histological-mixed-type (MT) EGCs can be recognized preoperatively is not known. This is particularly important because accurate pretreatment diagnosis of the UDT component can help make the right treatment decision for EGC.
Research objectives
We investigated the feasibility of the preoperative diagnosis of the UDT component within MT EGCs.
Research methods
This is a retrospective study using clinical data and samples from patients with EGCs treated by endoscopic submucosal dissection. Through histopathological examination, we investigated each lesion’s UDT component: (1) Whole mucosal layer occupation; (2) Exposure to the mucosal surface; and (3) Existence of a clear border between the differentiated-type and UDT components. We examined endoscopic images using magnifying endoscopy with narrow-band imaging to identify whether the endoscopic UDT component finding was recognizable within the area where it was present in the histopathological examination. The preoperative biopsy results and comparative relationships between endoscopic and histopathological findings were also examined.
Research results
Whole mucosal layer occupation of the UDT component and exposure of the UDT component to the mucosal surface were observed in 67.3% and 79.6% of samples, respectively. However, the preoperative endoscopic images showed that only 24.5% of MT EGCs revealed the UDT component within the area where it was present histopathologically. Histopathological UDT predominance was the single significant factor associated with the presence of the endoscopic UDT component finding (61.5% vs 11.1%, P = 0.0009). Combined results of the pretreatment biopsy and magnifying endoscopy with narrow-band imaging showed the preoperative presence of the UDT component in 40% of MT EGCs.
Research conclusions
Accurate pretreatment diagnosis of the UDT component was hardly achieved even when pretreatment biopsy and diagnostic endoscopy were combined. However, the possibility of UDT predominance should be suspected when a lesion shows an endoscopic finding of the undifferentiated-type component.
Research perspectives
Currently, endoscopic resection plays a significant role in both the diagnosis and treatment of MT EGCs. Future studies should seek novel UDT findings to distinguish MT EGCs from pure differentiated-type EGCs.
