title: Cytokeratin 19, carcinoembryonic antigen, and epithelial cell adhesion molecule detect lung cancer lymph node metastasis in endobronchial ultrasound-guided transbronchial aspiration samples.
abstract: BACKGROUND
  Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) holds promise for accurate examination of mediastinal lymph nodes in NSCLC patients. However, it is not always possible to achieve a definitive diagnosis or subtype all cases. We aimed to evaluate the role of EBUS-TBNA combined with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and flow cytometry (FCM) to assess tumor-associated antigens and immune responses to identify metastases and pathological patterns in lymph node aspirates.
  
  
  METHODS
  EBUS-TBNA samples from patients with NSCLC (n = 33) and nonmalignant diseases (n = 17) were prospectively collected. Cytokeratin 19 (CK-19), carcinoembryonic antigen (CEA), epithelial cell adhesion molecule (EPCAM), sialyl-Lewis(x), CD44, and the immune compartment were analyzed using qRT-PCR and FCM.
  
  
  RESULTS
  In the NSCLC patients, the epithelial cell compartment was significantly increased (30.8% vs. 12% CD45⁻ CK-19⁺ cells) and showed brighter CK-19 staining than controls (P = .039) using FCM. Carcinoembryonic antigen was exclusively expressed by the NSCLC epithelial compartment (35% of the cases) and absent in controls. The NSCLC immune compartment showed an increased monocyte population (P = .04), and decreased lymphocyte subpopulations, anticipating a disruption in the distribution of myeloid and lymphoid immune cells. Quantitative reverse transcription polymerase chain reaction showed that CK-19, CEA, and EPCAM transcripts were significantly higher in NSCLC. A positive correlation between the primary tumor lesion size and EPCAM (ρ = 0.476; P = .005), CK-19 (ρ = 0.594; P = .001), and CEA (ρ = 0.394; P = .023) was also found.
  
  
  CONCLUSIONS
  The identification of CK-19, CEA, and EPCAM in EBUS-TBNA samples using FCM and qRT-PCR is feasible and might further aid in the detection of NSCLC lymph node metastasis.
authors.affiliation: Chronic Diseases Research Center (CEDOC), Departamento de Imunologia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal; Interventional Pulmonology Unit, Centro Hospitalar Lisboa Norte, Hospital Pulido Valente, Lisbon, Portugal; Interventional Pulmonology Unit, Hospital Beatriz Angelo, Loures, Portugal. Electronic address: antonio.bugalho@gmail.com.
authors.forename: Antonio
authors.initials: A
authors.lastname: Bugalho
authors.forename: Catarina
authors.initials: C
authors.lastname: Martins
authors.forename: Sara S
authors.initials: SS
authors.lastname: Dias
authors.forename: Gloria
authors.initials: G
authors.lastname: Nunes
authors.forename: Zelia
authors.initials: Z
authors.lastname: Silva
authors.forename: Manuela
authors.initials: M
authors.lastname: Correia
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Marques Gomes
authors.forename: Paula A
authors.initials: PA
authors.lastname: Videira
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D044963:Biopsy, Fine-Needle; D001980:Bronchi / Q000000981:diagnostic imaging; D002272:Carcinoembryonic Antigen / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis*; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002469:Cell Separation; D019160:Endosonography / Q000379:methods*; D000071858:Epithelial Cell Adhesion Molecule; D004847:Epithelial Cells / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D053539:Keratin-19 / Q000378:metabolism; D008175:Lung Neoplasms / Q000175:diagnosis*; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology; D011446:Prospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D015815:Cell Adhesion Molecules; D000071858:Epithelial Cell Adhesion Molecule; D053539:Keratin-19
keywords: Endobronchial ultrasound; Fine needle aspiration; Flow cytometry; Non–small-cell lung cancer; Tumor markers