Retrospective Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. May 16, 2022; 14(5): 320-334
Published online May 16, 2022. doi: 10.4253/wjge.v14.i5.320
Why is endosonography insufficient for residual diagnosis after neoadjuvant therapy for esophageal cancer? Solutions using muscle layer evaluation
Shohei Yonemoto, Masaya Uesato, Akira Nakano, Kentaro Murakami, Takeshi Toyozumi, Tetsuro Maruyama, Hiroshi Suito, Tomohide Tamachi, Manami Kato, Shunsuke Kainuma, Keisuke Matsusaka, Hisahiro Matsubara
Shohei Yonemoto, Masaya Uesato, Akira Nakano, Kentaro Murakami, Takeshi Toyozumi, Tetsuro Maruyama, Hiroshi Suito, Tomohide Tamachi, Manami Kato, Shunsuke Kainuma, Keisuke Matsusaka, Hisahiro Matsubara, Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
Author contributions: Yonemoto S performed the research and wrote the paper; Uesato M came up with the study idea and supervised the study; Uesato M, Nakano A, Murakami K, Toyozumi T, Maruyama T, Suito H, Tamachi T, Kobayashi M and Kainuma S collected the data; Matsusaka K provided pathological advice; Matsubara H supervised the report.
Institutional review board statement: The study protocol was approved by Hospital of Chiba University Biomedical Research Ethics Committee, No. 3550.
Informed consent statement: Written informed consent was obtained before treatment for all patients.
Conflict-of-interest statement: All authors declare no conflicts-of-interest related to this article.
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:
Corresponding author: Masaya Uesato, MD, PhD, Assistant Professor, Doctor, Statistician, Surgeon, Frontier Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
Received: December 4, 2021
Peer-review started: December 4, 2021
First decision: January 8, 2022
Revised: February 11, 2022
Accepted: April 3, 2022
Article in press: April 3, 2022
Published online: May 16, 2022
Processing time: 162 Days and 23.8 Hours
Research background

The diagnosis of endoscopic ultrasound (EUS) for esophageal cancer after neoadjuvant therapy is controversial. In addition, it is unclear whether the echogenic lesions detected using EUS are indeed residual tumors and how they appear on ultrasound.

Research motivation

There are few studies that contrast echographic and pathologic images of esophageal cancer after neoadjuvant therapy. In our clinical experience, we have observed that the esophageal muscle layer can be clearly visualized using EUS in patients with a good response to neoadjuvant therapy.

Research objectives

To investigate the ultrasound imaging features of residual tumors and identify the limitations and potential of EUS.

Research methods

Twenty-three patients receiving esophagectomy after neoadjuvant therapy [15 patients after neoadjuvant chemotherapy (NAC) and 8 patients after chemoradiotherapy (CRT)] were studied. We diagnosed the T stage and compared ultrasound images with pathological findings using ultrasound for surgical specimens. Furthermore, the rate of reduction for the muscle layer defect was evaluated using EUS images obtained before and after neoadjuvant therapy.

Research results

The accuracy of T stage rate was 61%, which worsened after CRT (38%) than after NAC (73%). Moreover, pT0 could not be diagnosed in all cases. The detection rate of residual tumor for specimens using ultrasound retrospectively was 75%. Tumor borders were irregular and echogenicity was mixed type after CRT. There was a correlation between the pT stage and the rate of muscle layer defect reduction measured by EUS.

Research conclusions

Some tumors are undetectable on ultrasound when compared to pathological images. However, focusing on the esophageal muscle layer may improve the accuracy of T stage diagnosis of residual tumors.

Research perspectives

If EUS helps diagnose T stage of residual tumors in patients after neoadjuvant therapy by focusing on the muscle layer, the clinical treatment options can be expanded significantly.