Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 21, 2015; 21(47): 13302-13308
Published online Dec 21, 2015. doi: 10.3748/wjg.v21.i47.13302
Clinical impact of atypical endoscopic features in rectal neuroendocrine tumors
Jong Hee Hyun, Seong Dae Lee, Eui Gon Youk, Jae Bum Lee, Enu-Jung Lee, Hee Jin Chang, Dae Kyung Sohn
Jong Hee Hyun, Hee Jin Chang, Dae Kyung Sohn, Center for Colorectal Cancer, National Cancer Center, Gyeonggi-do 10408, South Korea
Seong Dae Lee, Eui Gon Youk, Jae Bum Lee, Enu-Jung Lee, Department of Surgery, Daehang Hospital, Seoul 06699, South Korea
Author contributions: Sohn DK conceived the study, participated in study design and patient accrual, and provided final approval for publication of the manuscript; Hyun JH contributed to data collection, performed statistical analyses and drafted the manuscript; Chang HJ contributed to the design and coordination of the study and critical revision of the manuscript; Lee SD, Youk EG, Lee JB and Lee EJ contributed to patient accrual; all authors read and approved the final manuscript.
Supported by National Cancer Center Grant, No. NCC-1510150-1.
Institutional review board statement: The study was reviewed and approved by the National Cancer Center Institutional Review Board (NCC-2014-0104).
Conflict-of-interest statement: The authors declare that they have no competing interests.
Data sharing statement: Statistical analysis and dataset are available from the corresponding author at gsgsbal@ncc.re.kr.
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: Dae Kyung Sohn, MD, Center for Colorectal Cancer, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do 10408, South Korea. gsgabal@ncc.re.kr
Telephone: +82-31-9201636 Fax: +82-31-9201289
Received: August 4, 2015
Peer-review started: August 5, 2015
First decision: September 9, 2015
Revised: September 20, 2015
Accepted: November 13, 2015
Article in press: November 13, 2015
Published online: December 21, 2015
Processing time: 132 Days and 23.7 Hours
Abstract

AIM: To validate the association between atypical endoscopic features and lymph node metastasis (LNM).

METHODS: A total of 247 patients with rectal neuroendocrine tumors (NETs) were analyzed. Endoscopic images were reviewed independently by two endoscopists, each of whom classified tumors by sized and endoscopic features, such as shape, color, and surface change (kappa coefficient 0.76 for inter-observer agreement). All of patients underwent computed tomography scans of abdomen and pelvis for evaluation of LNM. Univariate and multivariate analyses were performed to identify the factors associated with LNM. Additionally, the association between endoscopic atypical features and immunohistochemical staining of tumors was analyzed.

RESULTS: Of 247 patients, 156 (63.2%) were male and 15 (6.1%) were showed positive for LNM. On univariate analysis, tumor size (P < 0.001), shape (P < 0.001), color (P < 0.001) and surface changes (P < 0.001) were significantly associated with LNM. On multivariate analysis, tumor size (OR = 11.53, 95%CI: 2.51-52.93, P = 0.002) and atypical surface (OR = 27.44, 95%CI: 5.96-126.34, P < 0.001) changes were independent risk factors for LNM. The likelihood of atypical endoscopic features increased as tumor size increased. Atypical endoscopic features were associated with LNM in rectal NETs < 10 mm (P = 0.005) and 10-19 mm (P = 0.041) in diameter. Immunohistochemical staining showed that the rate of atypical endoscopic features was higher in non L-cell tumors.

CONCLUSION: Atypical endoscopic features as well as tumor size are predictive factors of LNM in patients with rectal NETs.

Keywords: Rectal neuroendocrine tumor; Colonoscopy; Lymph node metastasis

Core tip: We were studied about association between endoscopic atypical features in rectal neuroendocrine tumor and metastasis in 2008. Thus, our study was designed to validate the association between atypical endoscopic features and lymph node metastasis (LNM). Our study showed that the atypical endoscopic features, such as size > 10 mm, surface changes, were risk factors for LNM. Additionally, rectal neuroendocrine tumors which showed atypical endoscopic features were associated with non L-cell tumors. When we examined rectal neuroendocrine tumor using colonoscopy, atypical endoscopic features help to predict the treatment plan.