title: Absence of anaplastic lymphoma kinase translocations in signet ring cell carcinomas of the upper gastrointestinal tract.
abstract: BACKGROUND
  Anaplastic lymphoma kinase (ALK) fusion oncogenes are present in multiple cancer types. The inversion of echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) genes on chromosome 2 is present in a subset of patients with non-small-cell lung cancer (NSCLC). ALK-rearranged lung cancers demonstrate a significantly higher incidence of signet ring cell histology than do ALK-negative tumors. Based on the histologic similarities of ALK-rearranged NSCLC and signet ring cell carcinomas (SRCCs) of the gastrointestinal tract, we hypothesized that SRCC of the upper gastrointestinal (GI) tract may also harbor ALK translocations.
  
  
  METHODS
  Thirty-five formalin-fixed, paraffin-embedded (FFPE) diagnostic tissue specimens of SRCC or poorly differentiated adenocarcinoma with greater than 10% signet ring cell features originating from the upper GI tract were obtained and confirmed by a board-certified, GI pathologist. SRCC specimens were analyzed by fluorescence in situ hybridization (FISH) analysis, with an ALK (2p23) break-apart probe.
  
  
  RESULTS
  The FISH analysis revealed no evidence of ALK translocation. All 35 (100%) SRCC specimens showed intact ALK FISH signals.
  
  
  CONCLUSIONS
  These data indicate that, despite histologic similarities between SRCC of the upper GI tract and ALK-positive NSCLC, ALK translocations are unlikely to be a significant contributor to the molecular etiology of SRCC. Further genomic investigations are ongoing.
authors.affiliation: Department of Pathology.
authors.forename: Jill
authors.initials: J
authors.lastname: Miller
authors.affiliation: Department of Pathology.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Peng
authors.affiliation: Department of Pathology.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Wilcox
authors.affiliation: Department of Pathology.
authors.forename: Mark
authors.initials: M
authors.lastname: Evans
authors.affiliation: Division of Hematology Oncology The University of Vermont Cancer Center Burlington, VT.
authors.forename: Steven
authors.initials: S
authors.lastname: Ades
authors.affiliation: Division of Hematology Oncology The University of Vermont Cancer Center Burlington, VT.
authors.forename: Claire
authors.initials: C
authors.lastname: Verschraegen