title: Long-term clinical outcome of gastric MALT lymphoma after eradication of Helicobacter pylori: a multicentre cohort follow-up study of 420 patients in Japan.
abstract: OBJECTIVE
  A multicentre cohort follow-up study of a large number of patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma was conducted to elucidate the long-term outcome of the disease after Helicobacter pylori eradication.
  
  
  METHODS
  420 patients with gastric low-grade MALT lymphoma who had undergone successful H pylori eradication and been followed up for at least 3 years were registered from 21 participating institutes. Responders to treatment were defined as patients whose post-treatment biopsies showed complete histological response (ChR) or probable minimal residual disease (pMRD). Treatment failure was defined as the status of progressive disease or lymphoma relapse after ChR/pMRD.
  
  
  RESULTS
  323 patients (77%) responded to H pylori eradication. A logistic regression analysis showed that absence of H pylori, submucosal invasion determined by endoscopic ultrasonography and t(11;18)/API2-MALT1 were independent predictors of resistance to H pylori eradication. During the follow-up periods ranging from 3.0 to 14.6 years (mean 6.5 years, median 6.04 years), the disease relapsed in 10 of 323 responders (3.1%) while progressive disease was found in 27 of 97 non-responders (27%). Thus, 37 of 420 patients (8.8%) were regarded as treatment failures. Of these 37 patients, transformation into diffuse large B cell lymphoma occurred in nine patients. Among the non-responders and relapsed patients, 17 patients were subjected to a 'watch and wait' strategy while 90 patients underwent second-line treatments including radiotherapy (n=49), chemotherapy (n=26), surgical resection (n=6), chemoradiotherapy (n=5), antibiotic treatment (n=2), rituximab monotherapy (n=1) or endoscopic resection (n=1). Probabilities of freedom from treatment failure, overall survival and event-free survival after 10 years were 90%, 95% and 86%, respectively. Cox multivariate analysis revealed endoscopic non-superficial type to be an independent prognostic factor for adverse freedom from treatment failure, overall survival and event-free survival.
  
  
  CONCLUSIONS
  The excellent long-term outcome of gastric MALT lymphoma after H pylori eradication was confirmed by this large-scale follow-up study.
authors: Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. shonaka@intmed2.med.kyushu-u.ac.jp
authors: Shotaro
authors: S
authors: Nakamura
authors: Toshiro
authors: T
authors: Sugiyama
authors: Takayuki
authors: T
authors: Matsumoto
authors: Katsunori
authors: K
authors: Iijima
authors: Shouko
authors: S
authors: Ono
authors: Masahiro
authors: M
authors: Tajika
authors: Akira
authors: A
authors: Tari
authors: Yasuhiko
authors: Y
authors: Kitadai
authors: Hiroshi
authors: H
authors: Matsumoto
authors: Tadanobu
authors: T
authors: Nagaya
authors: Toshiro
authors: T
authors: Kamoshida
authors: Norihiko
authors: N
authors: Watanabe
authors: Toshimi
authors: T
authors: Chiba
authors: Hideki
authors: H
authors: Origasa
authors: Masahiro
authors: M
authors: Asaka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001706:Biopsy; D018450:Disease Progression; D004359:Drug Therapy, Combination; D004812:Epidemiologic Methods; D005260:Female; D016481:Helicobacter Infections / Q000150:complications / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D007564:Japan; D018442:Lymphoma, B-Cell, Marginal Zone / Q000382:microbiology* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000473:pathology; D011379:Prognosis; D054328:Proton Pump Inhibitors / Q000627:therapeutic use; D012008:Recurrence; D013274:Stomach Neoplasms / Q000382:microbiology* / Q000473:pathology / Q000628:therapy; D017211:Treatment Failure; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D054328:Proton Pump Inhibitors