title: Napsin A/p40 antibody cocktail for subtyping non-small cell lung carcinoma on cytology and small biopsy specimens.
abstract: BACKGROUND
  Subtyping non-small cell lung carcinomas (NSCLC) into adenocarcinoma (ACA) or squamous cell carcinoma (SQCC) is important for treatment and specimen triage for molecular studies. To preserve tissue for molecular studies in cytology/small biopsy specimens, a 2-antibody cocktail for NSCLC subtyping was developed.
  
  
  METHODS
  Markers for lung ACA (thyroid transcription factor 1 and napsin A) and SQCC (cytokeratin 5/6 and p40) were evaluated on tissue microarrays (TMAs) with 143 ACA and 98 SQCC specimens. The napsin A/p40 combination was selected for NSCLC subtyping and validated on the TMA as well as on a cohort of cell block/small biopsy specimens from 80 poorly differentiated NSCLCs.
  
  
  RESULTS
  Using TMA analysis, the napsin A-positive (+)/p40± immunophenotype identified ACA with 94% sensitivity and 100% specificity, whereas the napsin A (negative)-/p40+ immunophenotype identified SQCC with 100% sensitivity and specificity. On the validation cohort of 80 cell block and small biopsy specimens, the napsin A/p40 cocktail accurately subtyped 63 of 70 NSCLC (90%) as ACA or SQCC using the subsequent surgical resection as reference histology. Of the remaining 17 cases, 15 were classified as NSCLC-not otherwise specified based on a napsin A-/p40- immunophenotype; their corresponding resections were diagnosed as ACA (7 cases), large cell carcinoma (7 cases), or pleomorphic carcinoma (1 case). Two additional large cell carcinoma cases showed a napsin A-/p40+ or napsin A+/p40+ profile in the preoperative cell block/small biopsy sample.
  
  
  CONCLUSIONS
  A napsin A/p40 cocktail can accurately subtype NSCLC into ACA and SQCC in most cell block/small biopsy specimens of poorly differentiated NSCLC. In the minority of cases in which the napsin A/p40 immunophenotype is indeterminate, additional stains may be necessary for precise classification. Cancer Cytopathol 2016;124:472-84. © 2016 American Cancer Society.
authors.affiliation: Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts.
authors.forename: Michiya
authors.initials: M
authors.lastname: Nishino
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Mai P
authors.initials: MP
authors.lastname: Hoang
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Patricia
authors.initials: P
authors.lastname: Della Pelle
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Vicente
authors.initials: V
authors.lastname: Morales-Oyarvide
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Tiffany G
authors.initials: TG
authors.lastname: Huynh
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Eugene J
authors.initials: EJ
authors.lastname: Mark
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Mari
authors.initials: M
authors.lastname: Mino-Kenudson
mesh_terms: D000230:Adenocarcinoma / Q000145:classification / Q000473:pathology / Q000601:surgery; D016282:Aspartic Acid Endopeptidases / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001706:Biopsy; D002289:Carcinoma, Non-Small-Cell Lung / Q000145:classification / Q000473:pathology* / Q000601:surgery; D002294:Carcinoma, Squamous Cell / Q000145:classification / Q000473:pathology / Q000601:surgery; D003581:Cytodiagnosis / Q000379:methods*; D006801:Humans; D016056:Immunodominant Epitopes / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000145:classification / Q000473:pathology / Q000601:surgery; D010446:Peptide Fragments / Q000378:metabolism*; D046888:Tissue Array Analysis; D014157:Transcription Factors / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D016056:Immunodominant Epitopes; C495942:P40, iodinated C-terminal peptide, human; D010446:Peptide Fragments; C115051:TP63 protein, human; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D016282:Aspartic Acid Endopeptidases; C498549:NAPSA protein, human
keywords: adenocarcinoma; cytology; napsin A; non-small cell lung cancer; p40 (ΔNp63); small biopsy; squamous cell carcinoma