title: API2-MALT1 fusion gene in colorectal lymphoma.
abstract: The API2-MALT1 fusion gene was originally identified from a t(11;18)(q21;q21) translocation, a specific chromosomal abnormality that is found in mucosa-associated lymphoid tissue (MALT) lymphoma. Gastric MALT lymphomas positive for the API2-MALT1 fusion gene do not respond to Helicobacter pylori-eradication therapy, but otherwise, the incidence and clinicopathological behavior of colorectal MALT lymphoma with this genetic abnormality are unclear. We examined the API2-MALT1 fusion by multiplex RT-PCR method in 47 cases of MALT lymphoma and 13 cases of diffuse large B-cell lymphoma and evaluated the relevance of API2-MALT1 positivity to the clinical and pathological features. The mean ages of MALT lymphoma and diffuse large B-cell lymphoma patients were 65 (range, 37-87 y) and 58 (range, 14-85 y) years, respectively. API2-MALT1 fusion genes were detected in seven cases (15%) of MALT lymphoma and one case (8%) of diffuse large B-cell lymphoma. In MALT lymphomas, the tumor size in API2-MALT1-positive cases was 62 +/- 39 mm (mean +/- SD), statistically larger than that in API2-MALT1-negative cases (25 +/- 19 mm; P <.01). The API2-MALT1-positive cases demonstrated more advanced clinical stages and a male predominance, compared with API2-MALT1-negative cases. Thus, API2-MALT1-positive tumors should be cared for as a more aggressive subgroup and be followed for a longer time.
authors.affiliation: Department of Pathology, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan.
authors.forename: Sumie Takase
authors.initials: ST
authors.lastname: Sakugawa
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yoshino
authors.forename: Shigeo
authors.initials: S
authors.lastname: Nakamura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inagaki
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Sadahira
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Nakamine
authors.forename: Mitsukuni
authors.initials: M
authors.lastname: Okabe
authors.forename: Koichi
authors.initials: K
authors.lastname: Ichimura
authors.forename: Mitsune
authors.initials: M
authors.lastname: Tanimoto
authors.forename: Tadaatsu
authors.initials: T
authors.lastname: Akagi
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000074018:B-Cell CLL-Lymphoma 10 Protein; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016393:Lymphoma, B-Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018442:Lymphoma, B-Cell, Marginal Zone / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis; D009367:Neoplasm Staging; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C415943:API2-MALT1 fusion protein, human; D048868:Adaptor Proteins, Signal Transducing; D000074018:B-Cell CLL-Lymphoma 10 Protein; C118591:BCL10 protein, human; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; D012334:RNA, Neoplasm