title: FNA smears as a potential source of DNA for targeted next-generation sequencing of lung adenocarcinomas.
abstract: BACKGROUND
  Diff-Quik-stained fine-needle aspiration (FNA) smears and touch preparations from biopsies represent alternative specimens for molecular testing when cell block or biopsy material is insufficient. This study describes the use of these samples for targeted next-generation sequencing (NGS) of primary and metastatic lung adenocarcinoma and reports the DNA quality and success rates of FNA smears versus other specimens from 1 year of clinical use.
  
  
  METHODS
  A validation set of 10 slides from 9 patients with prior clinical epidermal growth factor receptor (EGFR) Sanger sequencing and KRAS pyrosequencing (5 KRAS-positive/EGFR-negative and 4 KRAS-negative/EGFR-negative) underwent DNA extraction, quality assessment, and targeted NGS. Subsequently, lung adenocarcinoma specimens submitted for NGS solid tumor mutation panel testing in 1 calendar year (60 biopsies, 57 resections, 33 FNA cell blocks, 12 FNA smears, and 10 body fluid cell blocks) were reviewed for specimen adequacy, sequencing success, and DNA quality.
  
  
  RESULTS
  All 10 validation samples met the DNA quality threshold (delta Ct threshold < 8; range, -2.2 to 4.9) and yielded 0.5 to 22 μg of DNA. The KRAS and EGFR mutation status from FNA smears according to NGS was concordant with previous clinical testing for all 10 samples. In the 1-year review, FNA smears were 100% successful, and this suggested a performance equivalent to or better than the performance of established specimen types, including FNA cell blocks. DNA quality according to ΔCt was significantly better with FNA smears versus biopsies, resections, and FNA cell blocks.
  
  
  CONCLUSIONS
  FNA smears of lung adenocarcinomas are high-quality alternative specimens for a targeted NGS panel with a high success rate in clinical practice. Cancer Cytopathol 2016;124:406-14. © 2016 American Cancer Society.
authors.affiliation: Pathology and Laboratory Medicine, Children's Hospital Colorado, Aurora, Colorado.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Treece
authors.affiliation: Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Montgomery
authors.affiliation: Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.|Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Nirali M
authors.initials: NM
authors.lastname: Patel
authors.affiliation: Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Civalier
authors.affiliation: Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Leslie G
authors.initials: LG
authors.lastname: Dodd
authors.affiliation: Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.|Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Margaret L
authors.initials: ML
authors.lastname: Gulley
authors.affiliation: Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Jessica K
authors.initials: JK
authors.lastname: Booker
authors.affiliation: Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.|Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Weck
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000556:secondary / Q000601:surgery; D014408:Biomarkers, Tumor / Q000235:genetics*; D044963:Biopsy, Fine-Needle; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000556:secondary / Q000601:surgery; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D008207:Lymphatic Metastasis; D009154:Mutation / Q000235:genetics*; D060787:Neoplasm Grading; D011379:Prognosis; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; C117307:KRAS protein, human; C512478:EGFR protein, human; D066246:ErbB Receptors; D016283:Proto-Oncogene Proteins p21(ras)
keywords: KRAS; epidermal growth factor receptor (EGFR); fine-needle aspiration; lung carcinoma; massive parallel sequencing