title: Biological behavior of the intramucosal Helicobacter pylori-negative undifferentiated-type early gastric cancer: comparison with Helicobacter pylori-positive early gastric cancer.
abstract: BACKGROUND
  The differences in the growth morphology, proliferative ability, and background mucosa of the cancer between Helicobacter pylori (HP)-positive (HP+) gastric cancer (GC) and HP-negative (HP-) GC are still unclear. To clarify the differences, we compared the characteristics of the two types of cancer.
  
  
  METHODS
  Of the 91 patients with undifferentiated-type early GC who underwent endoscopic treatment at our hospital between August 2005 and April 2011, 23 HP- GC patients (all of whom had signet ring cell carcinoma measuring 20 mm or less in diameter) and 46 HP+ GC patients with signet ring cell carcinoma measuring 20 mm or less in diameter (out of a total of 68 HP+ GC patients) were enrolled in this study. Endoscopic atrophy and background mucosa were classified according to the updated Sydney system. The proliferative capacity of the cancer was assessed by examining the MIB-1 labeling index.
  
  
  RESULTS
  With regard to the growth in the mucosal layer, the proportion of patients with cancer confined to the proliferative zone was significantly higher in the HP- GC group. Moderate or severer atrophy, intestinal metaplasia, mononuclear cell infiltration, and neutrophil infiltration according to the updated Sydney system were significantly commoner in the HP+ GC patients. Also, the MIB-1 labeling index was significantly higher in the HP+ GC group.
  
  
  CONCLUSIONS
  HP+ GC appeared to show a higher proliferative capacity, more extensive spread, and more rapid progression, and inflammation associated with HP infection was suggested to be involved in the proliferation of this type of GC.
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan. yusuke.horiuchi@jfcr.or.jp.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Horiuchi
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Fujisaki
authors.affiliation: Department of Pathology, Cancer Institute Hospital, Tokyo, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Miyamoto
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Hideomi
authors.initials: H
authors.lastname: Tomida
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Taniguchi
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Morishige
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Omae
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Ishiyama
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yoshio
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Hirasawa
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Yorimasa
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Tsuchida
authors.affiliation: Department of Gastroenterology, Cancer Institute Hospital, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Igarashi
authors.affiliation: Department of Gastrointestinal Surgery, Cancer Institute Hospital, Tokyo, Japan.
authors.forename: Toshifusa
authors.initials: T
authors.lastname: Nakajima
authors.affiliation: Department of Gastroenterology, Showa University Fujigaoka Hospital, Yokohama, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D000368:Aged; D018279:Carcinoma, Signet Ring Cell / Q000382:microbiology* / Q000473:pathology*; D016099:Endoscopy, Gastrointestinal; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D005757:Gastritis, Atrophic / Q000150:complications / Q000382:microbiology; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000382:microbiology* / Q000473:pathology*
keywords: Endoscopic gastrointestinal surgery; Gastric cancer; Helicobacter pylori; Undifferentiated-type carcinoma