Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 7, 2016; 22(45): 10015-10023
Published online Dec 7, 2016. doi: 10.3748/wjg.v22.i45.10015
Clinical implications of doubling time of gastrointestinal submucosal tumors
Shuko Koizumi, Mitsuhiro Kida, Hiroshi Yamauchi, Kosuke Okuwaki, Tomohisa Iwai, Shiro Miyazawa, Miyoko Takezawa, Hiroshi Imaizumi, Wasaburo Koizumi
Shuko Koizumi, Mitsuhiro Kida, Hiroshi Yamauchi, Kosuke Okuwaki, Tomohisa Iwai, Shiro Miyazawa, Miyoko Takezawa, Hiroshi Imaizumi, Wasaburo Koizumi, Department of Gastroenterology, Kitasato University School of Medicine, Sagamihara, Kanagawa 252-0375, Japan
Author contributions: Koizumi S designed and performed the research and wrote the paper; Kida M designed the research and supervised the report and contributed to the analysis; Yamauchi H, Okuwaki K, Iwai T, Miyazawa S, Takezawa M and Imaizumi H provided clinical advice; Koizumi W supervised the report.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Kitasato University School of Medicine.
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent. For full disclosure, the details of the study are published on the home page of Kitasato University School of Medicine.
Conflict-of-interest statement: We have no financial relationships to disclose.
Data sharing statement: No additional data are available.
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: Mitsuhiro Kida, MD, PhD, Department of Gastroenterology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0375, Japan. m-kida@kitasato-u.ac.jp
Telephone: +81-42-7788111 Fax: +81-42-7788390
Received: August 22, 2016
Peer-review started: August 24, 2016
First decision: October 20, 2016
Revised: November 1, 2016
Accepted: November 14, 2016
Article in press: November 16, 2016
Published online: December 7, 2016
Abstract
AIM

To evaluate the efficacy of doubling time (DT) of gastrointestinal submucosal tumors (GIST).

METHODS

From April 1987 through November 2012, a total of 323 patients were given a final histopathological diagnosis of GISTs on surgical resection or endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in Kitasato University East Hospital or Kitasato University Hospital. We studied 53 of these patients (34 with resected tumors and 19 with unresected tumors) whose tumors could be measured on EUS on at least two successive occasions. The histopathological diagnosis was GIST in 34 patients, leiomyoma in 5, schwannoma in 3, ectopic pancreas in 1, hamartoma in 1, cyst in 1, Brunner’s adenoma in 1, and spindle-cell tumor in 7. We retrospectively calculated the DT of GISTs on the basis of the time course of EUS findings to estimate the growth rate of such tumors.

RESULTS

The DT was 17.2 mo for GIST, as compared with 231.2 mo for leiomyoma, 104.7 mo for schwannoma, 274.9 mo for ectopic pancreas, 61.2 mo for hamartoma, 49.0 mo for cyst, and 134.7 mo for Brunner’s adenoma. The GISTs were divided into risk classes on the basis of tumor diameters and mitotic figures (Fletcher’s classification). The classification was extremely low risk or low risk in 28 patients, intermediate risk in 3, and high risk in 3. DT of GIST according to risk was 24.0 mo for extremely low-risk plus low-risk GIST, 17.1 mo for intermediate-risk GIST, and 3.9 mo for high-risk GIST. DT of GIST was significantly shorter than that of leiomyoma plus schwannoma (P < 0.05), and DT of high-risk GIST was significantly shorter than that of extremely low-risk plus low-risk GIST (P < 0.05).

CONCLUSION

For GIST, a higher risk grade was associated with a significantly shorter DT. Small SMTs should initially be followed up within 6 mo after detection.

Keywords: Gastrointestinal submucosal tumor, Doubling time, Submucosal tumor, Initial observational duration, Endoscopic ultrasonography, Endoscopic ultrasonography-guided fine needle aspiration, Fletcher’s classification

Core tip: The doubling time (DT) differed according to the type of submucosal tumors (SMTs), and gastrointestinal submucosal tumors (GISTs) were confirmed to have a significantly shorter doubling time than the other types of tumors. DT was 17.2 mo for GIST, as compared with 231.2 for leiomyoma, 104.7 for schwannoma. DT of GIST was significantly shorter than that of leiomyoma plus schwannoma (P < 0.05), and DT of high-risk GIST (3.9 mo) was significantly shorter than that of extremely low-risk plus low-risk GIST (24.0 mo) (P < 0.05). Even small SMTs less than 2 cm in diameter should initially be followed up within at least 6 mo after detection.