title: Molecular testing guidelines for lung adenocarcinoma: Utility of cell blocks and concordance between fine-needle aspiration cytology and histology samples.
abstract: BACKGROUND
  Lung cancer is a leading cause of mortality, and patients often present at a late stage. More recently, advances in screening, diagnosing, and treating lung cancer have been made. For instance, greater numbers of minimally invasive procedures are being performed, and identification of lung adenocarcinoma driver mutations has led to the implementation of targeted therapies. Advances in molecular techniques enable use of scant tissue, including cytology specimens. In addition, per recently published consensus guidelines, cytology-derived cell blocks (CBs) are preferred over direct smears. Yet, limited comparison of molecular testing of fine-needle aspiration (FNA) CBs and corresponding histology specimens has been performed. This study aimed to establish concordance of epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma (KRAS) virus homolog testing between FNA CBs and histology samples from the same patients.
  
  
  METHODS
  Patients for whom molecular testing for EGFR or KRAS was performed on both FNA CBs and histology samples containing lung adenocarcinoma were identified retrospectively. Following microdissection, when necessary, concordance of EGFR and KRAS molecular testing results between FNA CBs and histology samples was evaluated.
  
  
  RESULTS
  EGFR and/or KRAS testing was performed on samples obtained from 26 patients. Concordant results were obtained for all EGFR (22/22) and KRAS (17/17) mutation analyses performed.
  
  
  CONCLUSIONS
  Identification of mutations in lung adenocarcinomas affects clinical decision-making, and it is important that results from small samples be accurate. This study demonstrates that molecular testing on cytology CBs is as sensitive and specific as that on histology.
authors.affiliation: Address: Department of Pathology and Cell Biology, Departments of Medicine, Columbia University Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA.
authors.forename: Jonas J
authors.initials: JJ
authors.lastname: Heymann
authors.affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, Columbia University Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA.
authors.forename: William A
authors.initials: WA
authors.lastname: Bulman
authors.affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, Columbia University Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA.
authors.forename: Roger A
authors.initials: RA
authors.lastname: Maxfield
authors.affiliation: Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, The Mount Sinai Medical Center, New York, NY 10029, USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Powell
authors.affiliation: Division of Hematology/Oncology, Columbia University Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA.
authors.forename: Balazs
authors.initials: B
authors.lastname: Halmos
authors.affiliation: Department of Surgery, Division of General Thoracic Surgery, Columbia University Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Sonett
authors.affiliation: Department of Pathology, Northwestern Memorial Hospital, Chicago IL 60611, USA.
authors.forename: Nike T
authors.initials: NT
authors.lastname: Beaubier
authors.affiliation: Address: Department of Pathology and Cell Biology, Departments of Medicine, Columbia University Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Crapanzano
authors.affiliation: Address: Department of Pathology and Cell Biology, Departments of Medicine, Columbia University Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA.
authors.forename: Mahesh M
authors.initials: MM
authors.lastname: Mansukhani
authors.affiliation: Address: Department of Pathology and Cell Biology, Departments of Medicine, Columbia University Medical Center, New York-Presbyterian Hospital, New York, NY 10032, USA.
authors.forename: Anjali
authors.initials: A
authors.lastname: Saqi
keywords: Cell blocks; Kirsten rat sarcoma; cytopathology; endobronchial ultrasound-guided; epidermal growth factor receptor; fine needle aspiration; lung adenocarcinoma; molecular testing