title: Epidermal growth factor receptor test performed on liquid-based cytology lung samples: experience of an academic referral center.
abstract: OBJECTIVE
  In this study we reviewed our practice of lung cancer epidermal growth factor receptor (EGFR) mutational testing in an academic centralized laboratory setting, where direct smears and liquid-based cytology (LBC) slides represent the most frequent cytological specimens received. The aim was to assess the differences, if any, between these sample types in terms of DNA yield, adequacy rates and overall EGFR testing performance.
  
  
  METHODS
  A total of 362 cases were retrieved - received from January 2012 to January 2014 for EGFR testing - including 204 LBC specimens and 158 smears. Exon 19 deletions and the L858R point mutation in exon 21, detected by fragment assay and TaqMan assay, respectively, were confirmed by direct sequencing or by high-resolution melting.
  
  
  RESULTS
  Although the direct smears showed a higher DNA yield (60.94 vs. 23.07 ng/µl) and were more frequently cell-rich (54%) than the LBC slides (31.4%), the differences in adequacy (direct smears: 97.4%; LBCs: 94.1%) and in mutant rate (direct smears: 10.3%; LBCs: 14.0%) between the two sample types did not reach statistical significance.
  
  
  CONCLUSIONS
  Not only direct smears but also LBC slides represent an effective preparation and storage medium for cytological material to be used for EGFR molecular testing.
authors.affiliation: Pathology Section, Department of Public Health, University of Naples Federico II, Naples, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bellevicine
authors.forename: Umberto
authors.initials: U
authors.lastname: Malapelle
authors.forename: Elena
authors.initials: E
authors.lastname: Vigliar
authors.forename: Caterina
authors.initials: C
authors.lastname: de Luca
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Troncone
mesh_terms: D003581:Cytodiagnosis / Q000379:methods*; D004252:DNA Mutational Analysis / Q000379:methods*; D004273:DNA, Neoplasm / Q000235:genetics* / Q000302:isolation & purification; D066246:ErbB Receptors / Q000235:genetics*; D005091:Exons; D006785:Hospitals, University; D006801:Humans; D007558:Italy; D008168:Lung / Q000201:enzymology*; D017354:Point Mutation; D011237:Predictive Value of Tests; D012017:Referral and Consultation; D015203:Reproducibility of Results; D017384:Sequence Deletion; D013048:Specimen Handling / Q000379:methods*
chemical_list: D004273:DNA, Neoplasm; C512478:EGFR protein, human; D066246:ErbB Receptors