title: Characteristics of Helicobacter pylori-positive and Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma and their influence on clinical outcome.
abstract: BACKGROUND
  To compare clinicopathologic and molecular characteristics of low-grade gastric mucosa-associated lymphoid tissue lymphoma depending on Helicobacter pylori positivity and to find out a predictive factor for unresponsiveness to Helicobacter pylori eradication therapy in Korea.
  
  
  METHODS
  A total of 53 Helicobacter pylori-positive and 13 negative mucosa-associated lymphoid tissue lymphoma patients were enrolled, and tissues from 21 patients were investigated to examine the presence of t(11;18)(q21;q21) with fluorescence in situ hybridization. Clinicopathologic features such as the endoscopic appearance, dominant site of lesion, depth of invasion, clinical stage, and the existence of MALT1 gene rearrangement were compared between these two groups. Fifty-six patients who underwent H. pylori eradication therapy were divided into responder and nonresponder groups. The two groups were analyzed to calculate odds ratios for resistance to the eradication.
  
  
  RESULTS
  Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma patients averaged a more advanced clinical stage than H. pylori-positive (p = .023) patients. The frequency of t(11;18)/API2-MALT1 did not differ between H. pylori-positive (45.5%) and H. pylori-negative cases (55.6%). Thirty-eight of 51 (74.5%) H. pylori-positive patients achieved complete regression after the eradication, while 2 of 5 (40%) H. pylori-negative patients obtained regression. Presence of lesions in both distal and proximal parts of stomach (p = .041) and bearing of t(11;18)(q21;q21) (p = .007) were predictors for nonresponsiveness for H. pylori eradication.
  
  
  CONCLUSIONS
  Helicobacter pylori eradication could be performed as a primary therapy regardless of H. pylori status, and assessing t(11;18)/API2-MALT1 would be considered after failure to remission by H. pylori eradication.
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yoon Jin
authors.initials: YJ
authors.lastname: Choi
authors.forename: Nayoung
authors.initials: N
authors.lastname: Kim
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Paik
authors.forename: Jung Mogg
authors.initials: JM
authors.lastname: Kim
authors.forename: Sang Hyub
authors.initials: SH
authors.lastname: Lee
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Park
authors.forename: Jin-Hyeok
authors.initials: JH
authors.lastname: Hwang
authors.forename: Jin-Wook
authors.initials: JW
authors.lastname: Kim
authors.forename: Sook-Hyang
authors.initials: SH
authors.lastname: Jeong
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Lee
authors.forename: Hyun Chae
authors.initials: HC
authors.lastname: Jung
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D020169:Caspases / Q000235:genetics; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D015321:Gene Rearrangement; D016481:Helicobacter Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D018442:Lymphoma, B-Cell, Marginal Zone / Q000188:drug therapy / Q000235:genetics / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein; D009363:Neoplasm Proteins / Q000235:genetics; D011379:Prognosis; D056910:Republic of Korea; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000382:microbiology / Q000473:pathology; D014178:Translocation, Genetic; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D009363:Neoplasm Proteins; D020169:Caspases; C400109:MALT1 protein, human; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein