Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 28, 2015; 21(48): 13500-13506
Published online Dec 28, 2015. doi: 10.3748/wjg.v21.i48.13500
Histological evaluation for chemotherapeutic responses of metastatic lymph nodes in gastric cancer
Osamu Kinoshita, Daisuke Ichikawa, Yusuke Ichijo, Shuhei Komatsu, Kazuma Okamoto, Mitsuo Kishimoto, Akio Yanagisawa, Eigo Otsuji
Osamu Kinoshita, Daisuke Ichikawa, Shuhei Komatsu, Kazuma Okamoto, Eigo Otsuji, Department of Surgery, Division of Digestive Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
Osamu Kinoshita, Department of Surgery, Maizuru Medical center, Maizuru 625-8502, Japan
Yusuke Ichijo, Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
Mitsuo Kishimoto, Akio Yanagisawa, Department of Surgical Pathology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
Author contributions: Kinoshita O and Ichikawa D contributed equally to this work; Kinoshita O participated in the design of the study, performed the statistical analysis and drafted the manuscript; Ichikawa D participated in the design of the study and helped to draft the manuscript; Komatsu S, Okamoto K and Otsuji E supplied the case materials; Kishimoto M and Yanagisawa A performed the histological evaluation and assisted in the design of the study; Ichijo Y performed the evaluation of clinical response for metastatic lymph nodes; all authors have read and approved the manuscript.
Institutional review board statement: This study was approved by the Institutional Review Board of the Kyoto Prefectural University of Medicine.
Informed consent statement: Written consents were obtained from all study participants, or their legal guardian, in their first medical examination.
Conflict-of-interest statement: We received no funding and grant support concerning this study.
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: Daisuke Ichikawa, MD, PhD, Lecturer, Department of Surgery, Division of Digestive Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan. ichikawa@koto.kpu-m.ac.jp
Telephone: +81-75-2515527 Fax: +81-75-2515522
Received: August 3, 2015
Peer-review started: August 4, 2015
First decision: September 9, 2015
Revised: September 22, 2015
Accepted: October 17, 2015
Article in press: October 20, 2015
Published online: December 28, 2015
Abstract

AIM: To investigate the effect of preoperative chemotherapy (pre-CTx) for metastatic lymph nodes (MLNs) of gastric cancer (GC).

METHODS: A retrospective cohort of patients with advanced GC, who underwent pre-CTx followed by gastrectomy, was reviewed. The histological tumor regression grade (TRG), which considered the percentage of residual cancer in the visible tumor bed, was applied to primary tumors and individual MLNs: G1a (complete response), G1b (< 10%), G2 (10%-50%) and G3 (> 50%). The clinical response to pre-CTx was retrospectively evaluated using only MLNs information, and we compared the histological and clinical evaluations of MLNs.

RESULTS: Twenty-eight patients were enrolled. A total of 438 MLNs were retrieved, and 22 (5%), 48 (11%), 63 (14%) and 305 (70%) LNs were assigned as G1a, G1b, G2 and G3, respectively. Stratification of the residual MLNs based on the TRGs was as follows: 28 G1b MLNs (9%), 48 G2 MLNs (15%), and 253 G3 MLNs (76%) in the D1 region; 20 (23%), 15 (17%), and 52 (60%) in the D2 region, respectively. However, no significant correlation was found between TRGs in MLNs and clinical response in the subgroup for which evaluation of clinical response was available.

CONCLUSION: Pre-CTx does not provide any outstanding histological benefit for MLNs, and an appropriate D2 lymphadenectomy should routinely be performed to offer the chance of curative resection.

Keywords: Preoperative chemotherapy, Gastric cancer, Metastatic lymph node, Histological regression grade, Lymphadenectomy

Core tip: Preoperative chemotherapy for gastric cancer does not provide any outstanding histological regression for regional metastatic lymph nodes, and residual metastatic lymph nodes were located irrespective of D1 and D2 region. In addition, no significant correlation was found between the clinical response of metastatic lymph nodes based on RECIST classification and histological response grading. Consequently, an appropriate D2 lymphadenectomy should routinely be performed in order to offer the chance of curative resection of advanced gastric cancer treated with preoperative chemotherapy.