title: Helicobacter pylori and Molecular Markers as Prognostic Indicators for Gastric Cancer in Korea.
abstract: BACKGROUND
  The prognosis of H. pylori infection-negative gastric cancer (HPIN-GC) has been rarely investigated. Applying a strict definition of H. pylori status, the prognosis and molecular prognostic markers in HPIN-GC were evaluated.
  
  
  METHODS
  A combination of multiple methods was carried out to strictly evaluate H. pylori infection in gastric cancer (GC) patients between June 2003 and October 2012 at Seoul National University Bundang Hospital. H. pylori infection was defined as negative if histology, a rapid urease test, culturing, serology and history of H. pylori eradication were all negative. Patients with severe gastric atrophy by the serum pepsinogen test or histology were assumed to have had a previous H. pylori infection. Epstein-Barr virus (EBV) in situ hybridization, PCR-based microsatellite instability (MSI) testing, and p53 immunohistochemistry were performed.
  
  
  RESULTS
  Compared to 509 H. pylori infection-positive gastric cancer (HPIN-PC) patients, 24 HPIN-GC patients showed a significantly higher frequency of cardia location (P=0.013), and the depth of invasion in HPIN-GC was more advanced, although there was no statistical significance (pT3-pT4, 37.5% for HPIN-GC vs. 28.5% for HPIP-GC, P=0.341). In multivariate analysis, depth of invasion and lymph node metastasis were identified as the most important prognostic factors for relapse-free survival and overall survival (P<0.001). However, the status of H. pylori infection was not an independent prognostic factor for relapse-free survival and overall survival. The positivity of EBV in both groups was low, and the survivals according to MSI and p53 status in HPIN-GC patients were not significantly different.
  
  
  CONCLUSIONS
  The status of H. pylori infection was not a prognostic factor for survival in GC patients when applying the strict definition of H. pylori infection. The prognostic implication of MSI and p53 on survival in HPIN-GC patients was not clear.
authors.affiliation: Departments of Internal Medicine, Seoul National University Bundang Hospital, Seongnam.
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sung Wook
authors.initials: SW
authors.lastname: Hwang
authors.affiliation: Departments of Internal Medicine, Seoul National University Bundang Hospital, Seongnam ; Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Nayoung
authors.initials: N
authors.lastname: Kim
authors.affiliation: Departments of Internal Medicine, Seoul National University Bundang Hospital, Seongnam.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Yoon
authors.affiliation: Departments of Internal Medicine, Seoul National University Bundang Hospital, Seongnam.
authors.forename: Cheol Min
authors.initials: CM
authors.lastname: Shin
authors.affiliation: Departments of Internal Medicine, Seoul National University Bundang Hospital, Seongnam.
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Park
authors.affiliation: Departments of Internal Medicine, Seoul National University Bundang Hospital, Seongnam ; Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Surgery, Seoul National University Bundang Hospital, Seongnam.
authors.forename: Do Joong
authors.initials: DJ
authors.lastname: Park
authors.affiliation: Surgery, Seoul National University Bundang Hospital, Seongnam.
authors.forename: Hyung Ho
authors.initials: HH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Joo Sung
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyun Chae
authors.initials: HC
authors.lastname: Jung
authors.affiliation: Pathology, Seoul National University Bundang Hospital, Seongnam.
authors.forename: Hye Seung
authors.initials: HS
authors.lastname: Lee
keywords: Gastric cancer; Helicobacter pylori; Microsatellite instability; Prognosis; p53