RT Journal Article SR Electronic T1 Long-term clinical outcome of gastric MALT lymphoma after eradication of Helicobacter pylori: a multicentre cohort follow-up study of 420 patients in Japan JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 507 OP 513 DO 10.1136/gutjnl-2011-300495 VO 61 IS 4 A1 Shotaro Nakamura A1 Toshiro Sugiyama A1 Takayuki Matsumoto A1 Katsunori Iijima A1 Shouko Ono A1 Masahiro Tajika A1 Akira Tari A1 Yasuhiko Kitadai A1 Hiroshi Matsumoto A1 Tadanobu Nagaya A1 Toshiro Kamoshida A1 Norihiko Watanabe A1 Toshimi Chiba A1 Hideki Origasa A1 Masahiro Asaka A1 for the JAPAN GAST Study Group YR 2012 UL http://gut.bmj.com/content/61/4/507.abstract AB 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.