Comparative study of epidermal growth factor receptor mutation analysis on cytology smears and surgical pathology specimens from primary and metastatic lung carcinomas.
BACKGROUND
The detection of epidermal growth factor receptor (EGFR) mutations on small biopsy or fine-needle aspiration samples is required to guide therapy in nonsmall cell lung cancer (NSCLC). In this study, the authors compared results from EGFR mutation testing on both cytologic smears and surgical specimens and also compared the performance of platforms using 2 different technologies (pyrosequencing and real-time polymerase chain reaction) for both specimen types.


METHODS
Specimens from 114 patients were divided into 2 subsets. The first subset had 60 paired cytology smears and surgical specimens, including 37 paired specimens from the same site and 23 paired specimens from different sites. The second subset consisted of nonpaired cytology smears and formalin-fixed, paraffin-embedded (FFPE) tissues (including 8 cell blocks), which were compared on the pyrosequencing and real-time polymerase chain reaction platforms. Laser-capture microscopy was used to enrich tumor in the FFPE specimens before DNA extraction.


RESULTS
All cytology smears that were used in the study were adequate for analysis on both platforms. Comparison between smears and concurrent FFPE tissues from the same anatomic site had a concordance rate of 97%. The concordance rate between the pyrosequencing platform and the real-time polymerase chain reaction platform was 84% and 85% for FFPE tissues and cytology smears, respectively.


CONCLUSIONS
The current results indicated that direct extraction and analysis of EGFR mutations from cytology smears can be performed successfully on both a pyrosequencing platform and a real-time polymerase chain reaction platform with results comparable to those achieved in matched surgical specimens. In fine-needle aspiration/endobronchial ultrasound samples with limited tissue, cytology smears can be important for molecular analysis. Cancer (Cancer Cytopathol) 2013;121:361-369. © 2012 American Cancer Society.
Department of Pathology, Scott & White Memorial Hospital and Texas A&M University Health Science Center, Temple, Texas 76504, USA.
Renu
R
Khode
Douglas A
DA
Larsen
Brianne C
BC
Culbreath
Shane
S
Parrish
Kimberly L
KL
Walker
Lubna
L
Sayage-Rabie
Robert S
RS
Beissner
Arundhati
A
Rao
D000230:Adenocarcinoma / Q000235:genetics / Q000556:secondary* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003581:Cytodiagnosis; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis* / Q000235:genetics; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D016612:Paraffin Embedding; D010340:Pathology, Surgical; D060888:Real-Time Polymerase Chain Reaction
D004273:DNA, Neoplasm; C512478:EGFR protein, human; D066246:ErbB Receptors
PyroMark Q24; Rotor-Gene Q; cytology surgical correlation; epidermal growth factor receptor