Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Aug 25, 2016; 8(16): 558-567
Published online Aug 25, 2016. doi: 10.4253/wjge.v8.i16.558
What types of early gastric cancer are indicated for endoscopic ultrasonography staging of invasion depth?
Jiro Watari, Shigemitsu Ueyama, Toshihiko Tomita, Hisatomo Ikehara, Kazutoshi Hori, Ken Hara, Takahisa Yamasaki, Takuya Okugawa, Takashi Kondo, Tomoaki Kono, Katsuyuki Tozawa, Tadayuki Oshima, Hirokazu Fukui, Hiroto Miwa
Jiro Watari, Shigemitsu Ueyama, Toshihiko Tomita, Hisatomo Ikehara, Ken Hara, Takahisa Yamasaki, Takuya Okugawa, Takashi Kondo, Tomoaki Kono, Katsuyuki Tozawa, Tadayuki Oshima, Hirokazu Fukui, Hiroto Miwa, Division of Gastroenterology, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
Kazutoshi Hori, Department of Inflammatory Bowel Disease, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
Author contributions: Watari J and Ueyama S designed and performed the research study; Tomita T, Ikehara H, Hori K, Hara K, Yamasaki T, Okugawa T, Kondo T, Kono T, Tozawa K, Oshima T and Fukui H helped to collect the data; Watari J performed statistical analysis and wrote the paper; Miwa H approved the final version of the manuscript.
Institutional review board statement: This study was approved by Institutional Review Board at Hyogo College of Medicine, Nishinomiya, Japan.
Informed consent statement: All patients in the study gave informed consent prior to endoscopy.
Conflict-of-interest statement: None.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at (watarij@hyo-med.ac.jp). Consent for data sharing was not obtained from the participants but the presented data are anonymized and risk of identification is low.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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/
Correspondence to: Dr. Jiro Watari, Division of Gastroenterology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan. watarij@hyo-med.ac.jp
Telephone: +81-798-456662 Fax: +81-798-456661
Received: April 2, 2016
Peer-review started: April 6, 2016
First decision: May 17, 2016
Revised: June 7, 2016
Accepted: July 11, 2016
Article in press: July 13, 2016
Published online: August 25, 2016
Processing time: 142 Days and 17.1 Hours
Abstract
AIM

To clarify the diagnostic efficacy and limitations of endoscopic ultrasonography (EUS) and the characteristics of early gastric cancers (EGCs) that are indications for EUS-based assessment of cancer invasion depth.

METHODS

We retrospectively investigated the cases of 153 EGC patients who underwent conventional endoscopy (CE) and EUS (20 MHz) before treatment.

RESULTS

We found that 13.7% were “inconclusive” cases with low-quality EUS images, including all nine of the cases with protruded (0-I)-type EGCs. There was no significant difference in the diagnostic accuracy between CE and EUS. Two significant independent risk factors for misdiagnosis by EUS were identified-ulcer scarring [UL(+); odds ratio (OR) = 4.49, P = 0.003] and non-indication criteria for endoscopic resection (ER) (OR = 3.02, P = 0.03). In the subgroup analysis, 23.1% of the differentiated-type cancers exhibiting SM massive invasion (SM2) invasion (submucosal invasion ≥ 500 μm) by CE were correctly diagnosed by EUS, and 23.1% of the undifferentiated-type EGCs meeting the expanded-indication criteria for ER were correctly diagnosed by EUS.

CONCLUSION

There is no need to perform EUS for UL(+) EGCs or 0-I-type EGCs, but EUS may enhance the pretreatment staging of differentiated-type EGCs with SM2 invasion without UL or undifferentiated-type EGCs revealed by CE as meeting the expanded-indication criteria for ER.

Keywords: Gastric cancer; Endoscopic ultrasonography; Invasion depth diagnosis; Conventional endoscopy; Endoscopic submucosal dissection

Core tip: With the increasingly expanded indications of endoscopic resection for early gastric cancer (EGC), the accurate diagnosis of the invasion depth has become more important in the pretreatment strategy. Although there have been many investigations comparing the efficacy of endoscopic ultrasonography (EUS) and conventional endoscopy (CE) for invasion depth diagnosis of EGCs, much controversy remains. Our results revealed that there is no need to perform EUS for EGCs that are protruded type or those that have an ulcer scar, but EUS may have an add-on effect in the pretreatment staging of differentiated-type EGCs diagnosed as SM2 (submucosal invasion ≥ 500 μm) and undifferentiated-type EGCs diagnosed by CE as meeting the expanded-indication criteria for endoscopic resection.