Reliability of chromogenic in situ hybridization for epidermal growth factor receptor gene copy number detection in non-small-cell lung carcinomas: a comparison with fluorescence in situ hybridization study.
Fluorescence in situ hybridization (FISH) has been known to be the most representative and standardized test for assessing gene amplification. However, FISH requires a fluorescence microscope, the signals are labile and rapidly fade over time. Recently, chromogenic in situ hybridization (CISH) has emerged as a potential alternative to FISH. The aim of this study is to test the reliability of CISH technique for the detection of epidermal growth factor receptor (EGFR) gene amplification in non-small-cell lung carcinomas (NSCLC), to compare CISH results with FISH. A total of 277 formalin-fixed and paraffin embedded NSCLC tissue samples were retrieved from the surgical pathology archives at Seoul National University Bundang Hospital. CISH and FISH examinations were performed to test EGFR gene amplification status. There was high concordance in the assessment of EGFR gene copy number between CISH and FISH tests (Kappa coefficient=0.83). Excellent concordance was shown between two observers on the interpretation of the CISH results (Kappa coefficient=0.90). In conclusion, CISH result is highly reproducible, accurate and practical method to determine EGFR gene amplification in NSCLC. In addition, CISH allows a concurrent analysis of histological features of the tumors and gene copy numbers.
Yoo
Seol Bong
SB
Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea.
Lee
Hyun Ju
HJ
Park
Jung Ok
JO
Choe
Gheeyoung
G
Chung
Doo Hyun
DH
Seo
Jeong-Wook
JW
Chung
Jin-Haeng
JH
D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics*; D002863:Chromogenic Compounds / Q000737:chemistry*; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D005557:Formaldehyde / Q000737:chemistry; D005784:Gene Amplification; D018628:Gene Dosage; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods*; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016612:Paraffin Embedding; D015203:Reproducibility of Results; D016707:Tissue Fixation
D002863:Chromogenic Compounds; D005557:Formaldehyde; D066246:ErbB Receptors