title: [Expression of anaplastic lymphoma kinase and its clinical significance in non-small cell lung cancer].
abstract: OBJECTIVE
  To investigate the frequency of anaplastic lymphoma kinase (ALK) expression in non-small cell lung cancer (NSCLC) patients and its correlation with the clinicopathologic features.
  
  
  METHODS
  ALK immunohistochemistry and ALK fluorescent in situ hybridization (FISH) were performed on formalin-fixed, paraffin-embedded tissue in 100 cases of NSCLCs between 2011 and 2013. Relevant clinicopathologic data were collected and correlated with ALK expression.
  
  
  RESULTS
  All patients with immunohistochemical score of 3 (n = 12) were FISH-positive and all patients with score of 0 (n = 78) were FISH-negative. Among patients with immunohistochemical scores of 1 and 2, 2/3 and 6/7 were FISH-positive, respectively. The sensitivity and specificity of ALK immunohistochemistry with intensity score of 1 or more were 100% and 98%, respectively. Invasive mucinous adenocarcinoma, solid or acinar growth pattern, presence of mucous cells (signet-ring cells or goblet cells), extracellular mucus and lack of significant nuclear pleomorphism characterized ALK-rearranged cancer.
  
  
  CONCLUSIONS
  ALK-rearranged cancers possess specific histological features. Immunohistochemistry can be used as a routine test for screening ALK-positive cases in advanced NSCLC, and FISH testing should be used to confirm ALK translocation for patients with tumors showing staining for ALK by immunohistochemistry. All of these can help physicians identify patients who may benefit from targeted therapy.
authors.affiliation: Department of Pathology, the 81th Hospital of PLA, Nanjing 210002, China.
authors.forename: Guimei
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Pathology, Cancer Hospital of Jiangsu Province, Nanjing 210009, China; E-mail: hou_ning@126.com.
authors.forename: Ning
authors.initials: N
authors.lastname: Hou
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Cao
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Yang
authors.forename: Shumei
authors.initials: S
authors.lastname: Pan
mesh_terms: D000077548:Anaplastic Lymphoma Kinase; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000201:enzymology*; D008297:Male; D016612:Paraffin Embedding; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D012680:Sensitivity and Specificity
chemical_list: C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases