966P - Management and long-term clinical outcome of API2-MALT1 positive gastric MALT lymphoma

Date 28 September 2014
Event ESMO 2014
Session Poster Display session
Topics Lymphomas
Presenter Masahiro Tajika
Citation Annals of Oncology (2014) 25 (suppl_4): iv327-iv339. 10.1093/annonc/mdu339
Authors M. Tajika1, Y. Niwa1, T. Tanaka1, M. Ishihara1, N. Mizuno2, K. Hara2, S. Hijioka2, H. Imaoka2, T. Yogi2, H. Tsutsumi2, T. Fujiyoshi2, T. Sato2, T. Yoshida2, N. Okuno2, N. Hieda2, Y. Yatabe3, V. Bhatia4, K. Yamao2
  • 1Endoscopy, Aichi Cancer Center Hospital, 4648681 - Nagoya/JP
  • 2Gastoroenterology, Aichi Cancer Center Hospital, 4648681 - Nagoya/JP
  • 3Pathology And Molecular Diagnostics, Aichi Cancer Center, 46488681 - Nagoya/JP
  • 4Medical Hepatology, Institute of liver and Biliary Sciences, New Delhi/IN



It is believed that API2-MALT1 positive gastric MALT lymphoma exhibit a good prognosis because they do not exhibit multiple genomic abnormalities. However, there is no data on the long-term natural history and clinical outcome of API2-MALT1 positive gastric MALT lymphoma. The aim of this study was to clarify the management and long-term outcome of this lymphoma.


From November 1993 to December 2013, 155 consecutive patients with gastric MALT lymphoma were enrolled in this study. 137 of 155 patients were examined for API2-MALT1 chimeric transcript by means of RT-PCR and/or FISH. 134 of 155 patients received H. pylori eradication therapy. Second-line treatments were radiation therapy (RTx), chemotherapy (CTx), and total gastrectomy. All patients were followed up by endoscopy and abdominal CT regularly.


The number of API2-MALT1 positive patients was 36. The mean follow-up period of these patients was 69.3 months (range: 12-175 months). Thirteen patients were H. pylori positive. Seven patients had ≥ stage II-1 disease. Of the 36 patients, H. pylori eradication therapy was given to 25, RTx to 7, and CTx to 2 as 1st line treatment, while 2 patients selected watchful waiting strategy. Only one patient out of 25 responded to H. pylori eradication therapy alone. Of the 24 non-responders, 9 patients selected watchful waiting, and 15 received 2nd line treatment. The clinical outcome of these latter 15 patients was complete response (CR) or stable disease (SD) over a mean follow-up period of 74.7 months (12-175 months). The clinical outcomes of 11 patients treated without H. pylori eradication as 1st line strategy, were CR in 9 and SD in 2, over a mean follow up time of 57.5 months (18-106 months). No patient died from disease progression of MALT. However, 4 patients died of gastric carcinoma, DLBCL without API2-MALT1, myelodysplastic syndrome, and laryngeal cancer. The 12 patients with watchful waiting strategy had SD for 75.6 months of mean follow-up time (12-175 months).


The long-term prognosis of API2-MALT1 positive gastric MALT lymphoma was good, and second-line treatments usually resulted in CR. Although a ‘watchful waiting strategy’ may be acceptable, careful observation for development of 2nd malignancies and disease progression is essential during follow-up of API2-MALT1-positive MALT lymphoma.


All authors have declared no conflicts of interest.