Retrospective Cohort Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Oct 15, 2019; 11(10): 877-886
Published online Oct 15, 2019. doi: 10.4251/wjgo.v11.i10.877
Fat clearance and conventional fixation identified ypN0 rectal cancers following intermediate neoadjuvant radiotherapy have similar long-term outcomes
Nan Chen, Ting-Ting Sun, Zhong-Wu Li, Yun-Feng Yao, Lin Wang, Ai-Wen Wu
Nan Chen, Ting-Ting Sun, Yun-Feng Yao, Lin Wang, Ai-Wen Wu, Department of Gastrointestinal Surgery, Peking University Cancer Hospital, Beijing 100142, China
Zhong-Wu Li, Department of Pathology, Peking University Cancer Hospital, Beijing 100142, China
Author contributions: Chen N, Sun TT, and Li ZW contributed equally to this work; Wang L and Wu AW designed the research; Chen N, Sun TT, Li ZW, and Yao YF collected and analyzed the data; Chen N and Wang L drafted the manuscript.
Supported by National Natural Science Foundation of China, No. 81773214; Beijing Municipal Science and Technology Commission (Capital Characteristic Clinical Study), No. Z15110004015105; Beijing Health System High Level Talented Scholar of Medicine Fund (The 215 Project); Science Foundation of Peking University Cancer Hospital, No. 2017-13.
Institutional review board statement: This study was performed under the ethics approval of the Ethic Committee of Beijing Cancer Hospital.
Informed consent statement: All patients were informed and consented.
Conflict-of-interest statement: No competing interest is claimed from all authors.
STROBE statement: The manuscript was revised according to the STROBE.
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/
Corresponding author: Lin Wang, MD, Assistant Professor, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Center, Peking University Cancer Hospital and Institute, 52 Fucheng Road, Haidian District, Beijing 100142, China. wanglinmd@foxmail.com
Telephone: +86-10- 88196086 Fax: +86-10-88196086
Received: April 6, 2019
Peer-review started: April 8, 2019
First decision: June 3, 2019
Revised: July 23, 2019
Accepted: August 20, 2019
Article in press: August 21, 2019
Published online: October 15, 2019
Processing time: 194 Days and 19.2 Hours
ARTICLE HIGHLIGHTS
Research background

For accurate tumor staging, it is recommended to obtain at least 12 lymph nodes (LNs) by international guidelines (such as the National Comprehensive Cancer Network and European Society for Medical Oncology guidelines). However, the number of LN decreases after neoadjuvant chemoradiation, leading to the hypothesis that enhanced LN yield would bring survival benefit.

Research motivation

Different methods have been implemented, trying to increase LN harvest. In this study, we employed the fat-clearance technique for LN yielding. So far, this study provided convincing evidence with big numbers of cases and long-term follow-up.

Research objectives

This study aimed to evaluate the efficacy of fat-clearance technique in terms of LN retrieval and potential prognostic values.

Research methods

This study employed the fat-clearance technique, which was demonstrated to be effective with a high sensitivity.

Research results

The conclusion of this study confirms the fact that for patients without LN metastasis, higher yield of LN might be only a time-consuming procedure, rather than prognostic approach.

Research conclusions

In rectal cancer patients undergoing neoadvjuant chemoradiation without LN metastasis, the pursuit for more LN harvest is not beneficial. Fat-clearance technique might not be useful for pN0 patients. Decreased number of LN in rectal cancer patients with neoadjuvant chemoradiation might be of nature, with no necessity to increase retrieval in pN0 patients. In pN0 rectal cancer patients with neoadjuvant conformal radiotherapy (CRT), additional LN retrieval might be useless. The 12 LN rule might not be essential for accurate staging. The fat-clearance technique utilized in this paper is a new method. The increased number of LNs did not bring in longer survival and was not associated with survival benefit. The pursuit for higher number of LNs retrieved might be of no use, therefore, to prolong patients’ survival, new strategy of treatment might be useful.

Research perspectives

The 12 LN rule might not work in patients with neoadjuvant CRT. Lymph node positivity or positive LNs might be more important in terms of prognostic value. Methods for tracing the positive LN might be the best way for the research in the future.