Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 14, 2015; 21(2): 549-555
Published online Jan 14, 2015. doi: 10.3748/wjg.v21.i2.549
Histological mixed-type as an independent prognostic factor in stage I gastric carcinoma
Shuhei Komatsu, Daisuke Ichikawa, Mahito Miyamae, Hiroki Shimizu, Hirotaka Konishi, Atsushi Shiozaki, Hitoshi Fujiwara, Kazuma Okamoto, Mitsuo Kishimoto, Eigo Otsuji
Shuhei Komatsu, Daisuke Ichikawa, Mahito Miyamae, Hiroki Shimizu, Hirotaka Konishi, Atsushi Shiozaki, Hitoshi Fujiwara, Kazuma Okamoto, Mitsuo Kishimoto, Eigo Otsuji, Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
Mitsuo Kishimoto, Department of Surgical Pathology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
Author contributions: Komatsu S, Ichikawa D, Miyamae M, Shimizu H, Konishi H, Shiozaki A, Fujiwara H, Okamoto K, Kishimoto K and Otsuji E performed the research; Komatsu S, Miyamae M and Shimizu H analyzed the data; Komatsu S wrote the paper.
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: Shuhei Komatsu, MD, Assistant Professor, Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachihirokoji, Kamigyo-ku, Kyoto 602-8566, Japan. skomatsu@koto.kpu-m.ac.jp
Telephone: +81-75-2515527 Fax: +81-75-2515522
Received: April 23, 2014
Peer-review started: April 23, 2014
First decision: May 29, 2014
Revised: June 13, 2014
Accepted: July 30, 2014
Article in press: July 30, 2014
Published online: January 14, 2015
Abstract

AIM: To evaluate the clinicopathological features of mixed-type gastric cancer and their influence on prognosis of mixed-type stage I gastric cancer.

METHODS: We analyzed 446 patients who underwent curative gastrectomy for stage I gastric cancer between 1999 and 2009. The patients were divided into two groups: those with differentiated or undifferentiated cancer (non-mixed-type, n = 333) and those with a mixture of differentiated and undifferentiated cancers (mixed-type, n = 113).

RESULTS: The overall prevalence of mixed-type gastric cancer was 25.3% (113/446). Compared with patients with non-mixed-type gastric cancer, those with mixed-type gastric cancer tended to be older at onset (P = 0.1252) and have a higher incidence of lymph node metastasis (P = 0.1476). They also had significantly larger tumors (P < 0.0001), more aggressive lymphatic invasion (P = 0.0011), and deeper tumor invasion (P < 0.0001). In addition, they exhibited significantly worse overall survival rates than did patients with non-mixed-type gastric cancer (P = 0.0026). Furthermore, mixed-type gastric cancer was independently associated with a worse outcome in multivariate analysis [P = 0.0300, hazard ratio = 11.4 (1.265-102.7)].

CONCLUSION: Histological mixed-type of gastric cancer contributes to malignant outcomes and highlight its usefulness as a prognostic indicator in stage I gastric cancer.

Keywords: Mixed-type gastric cancer, Histological type, Prognosis, Early gastric cancer

Core tip: Little is known about the clinical outcome of the histological mixed-type gastric cancer, which consists of differentiated and undifferentiated components. We evaluated the clinicopathological features of this cancer and their influences on the prognosis of patients with mixed-type stage I gastric cancer.