Gastric MALT lymphomas are divided into three groups based on responsiveness to Helicobacter Pylori eradication and detection of API2-MALT1 fusion.
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.
Inagaki
Hiroshi
H
Department of Pathology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. hinagaki@med.nagoya-cu.ac.jp
Nakamura
Tsuneya
T
Li
Chunmei
C
Sugiyama
Toshiro
T
Asaka
Masahiro
M
Kodaira
Jyunichi
J
Iwano
Masahiro
M
Chiba
Tsutomu
T
Okazaki
Kazuichi
K
Kato
Atsunaga
A
Ueda
Ryuzo
R
Eimoto
Tadaaki
T
Okamoto
Shiro
S
Sasaki
Naomi
N
Uemura
Naomi
N
Akamatsu
Taiji
T
Miyabayashi
Hideharu
H
Kawamura
Yoko
Y
Goto
Hidemi
H
Niwa
Yasumasa
Y
Yokoi
Takio
T
Seto
Masao
M
Nakamura
Shigeo
S
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
D048868:Adaptor Proteins, Signal Transducing; D000900:Anti-Bacterial Agents; D000074018:B-Cell CLL-Lymphoma 10 Protein; C118591:BCL10 protein, human; D015514:Oncogene Proteins, Fusion