title: Gastric MALT lymphomas are divided into three groups based on responsiveness to Helicobacter Pylori eradication and detection of API2-MALT1 fusion.
abstract: Gastric MALT lymphoma shows unique features including regression by Helicobacter pylori eradication and API2-MALT1 fusion. We performed a molecular and clinicopathologic study for 115 cases. All eradication-responsive cases were devoid of API2-MALT1 fusion. All tumors positive for the fusion and all negative for H. pylori infection were nonresponsive to the eradication. Consequently, gastric MALT lymphomas were divided into three groups: Eradication-responsive and fusion-negative (group A, n = 72), eradication-nonresponsive and fusion-negative (group B, n = 22), and eradication-nonresponsive and fusion-positive (group C, n = 21). Group A tumors were characterized by low clinical stage and superficial gastric wall involvement, and group C tumors by low H. pylori infection rate, advanced clinical stage, and nuclear BCL10 expression. All group C tumors showed exclusively low-grade histology. Group B tumors, which have not been well recognized, frequently showed nodal involvement, deep gastric wall involvement, and advanced clinical stage, and sometimes an increased large cell component. A multivariate discriminant analysis revealed that responsiveness to the eradication could be predicted accurately by negative API2-MALT1 fusion, positive H. pylori infection, low clinical stage, and superficial gastric wall invasion, the former being the most important factor for the prediction. This 3-group categorization may be helpful for a comprehensive understanding of gastric MALT lymphoma.
authors.affiliation: Department of Pathology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. hinagaki@med.nagoya-cu.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inagaki
authors.forename: Tsuneya
authors.initials: T
authors.lastname: Nakamura
authors.forename: Chunmei
authors.initials: C
authors.lastname: Li
authors.forename: Toshiro
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Masahiro
authors.initials: M
authors.lastname: Asaka
authors.forename: Jyunichi
authors.initials: J
authors.lastname: Kodaira
authors.forename: Masahiro
authors.initials: M
authors.lastname: Iwano
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Chiba
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Okazaki
authors.forename: Atsunaga
authors.initials: A
authors.lastname: Kato
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Ueda
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Eimoto
authors.forename: Shiro
authors.initials: S
authors.lastname: Okamoto
authors.forename: Naomi
authors.initials: N
authors.lastname: Sasaki
authors.forename: Naomi
authors.initials: N
authors.lastname: Uemura
authors.forename: Taiji
authors.initials: T
authors.lastname: Akamatsu
authors.forename: Hideharu
authors.initials: H
authors.lastname: Miyabayashi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kawamura
authors.forename: Hidemi
authors.initials: H
authors.lastname: Goto
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Niwa
authors.forename: Takio
authors.initials: T
authors.lastname: Yokoi
authors.forename: Masao
authors.initials: M
authors.lastname: Seto
authors.forename: Shigeo
authors.initials: S
authors.lastname: Nakamura
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000074018:B-Cell CLL-Lymphoma 10 Protein; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D018442:Lymphoma, B-Cell, Marginal Zone / Q000145:classification* / Q000235:genetics / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000145:classification* / Q000235:genetics / Q000382:microbiology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000900:Anti-Bacterial Agents; D000074018:B-Cell CLL-Lymphoma 10 Protein; C118591:BCL10 protein, human; D015514:Oncogene Proteins, Fusion