title: Expression of focal adhesion kinase in small-cell lung carcinoma.
abstract: BACKGROUND
  The focal adhesion kinase (FAK) is a non-receptor tyrosine kinase linked to tumor growth, invasion, and metastasis. FAK is overexpressed and associated with prognosis in many cancers, but its prognostic value in small-cell lung carcinoma (SCLC) is unknown and was the focus of this study.
  
  
  METHODS
  Total FAK expression was analyzed via immunohistochemistry in tissue microarrays consisting of formalin-fixed, paraffin-embedded SCLC specimens from 85 patients. FAK staining scores were tested for correlations with pathological characteristics and clinical outcomes. Phospho-paxillin was also tested in 35 of the 85 specimens to evaluate whether FAK expression was associated with downstream signaling.
  
  
  RESULTS
  Specific FAK expression was localized to the cytoplasm of 78/85 (92%) SCLCs. FAK expression was scored low in 11 (13%), moderate in 17 (20%), and high in 50 (59%) SCLCs. FAK staining scores treated as continuous variables did not correlate with SCLC disease stage, response to therapy, recurrence/progression-free survival, or overall survival. Moreover, total FAK expression did not correlate with phospho-paxillin Tyr(118) expression.
  
  
  CONCLUSIONS
  Total FAK is strongly expressed in a majority of SCLC tumors. However, the expression evaluated via immunohistochemistry is not a prognostic factor in patients with SCLC.
authors.affiliation: Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University, Nashville, Tennessee 37232-6838, USA.
authors.forename: Sebahat
authors.initials: S
authors.lastname: Ocak
authors.forename: Heidi
authors.initials: H
authors.lastname: Chen
authors.forename: Clay
authors.initials: C
authors.lastname: Callison
authors.forename: Adriana L
authors.initials: AL
authors.lastname: Gonzalez
authors.forename: Pierre P
authors.initials: PP
authors.lastname: Massion
mesh_terms: D000368:Aged; D005260:Female; D051417:Focal Adhesion Kinase 1 / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D051419:Paxillin / Q000378:metabolism; D010766:Phosphorylation; D055752:Small Cell Lung Carcinoma / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism* / Q000401:mortality; D016019:Survival Analysis
chemical_list: C496061:PXN protein, human; D051419:Paxillin; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human