title: Predicting gefitinib responsiveness in lung cancer by fluorescence in situ hybridization/chromogenic in situ hybridization analysis of EGFR and HER2 in biopsy and cytology specimens.
abstract: In non-small cell lung cancer (NSCLC), epidermal growth factor receptor (EGFR) mutational analysis is an excellent predictor of responsiveness to treatment with tyrosine kinase inhibitors, such as gefitinib. In up to 80% of NSCLCs, cytologic samples or endoscopic biopsies are the only specimens available for molecular analysis, but PCR amplification of DNA from small fixed and paraffin-embedded samples may create artifactual mutations. Fluorescence in situ hybridization (FISH) of EGFR and HER2 has been proposed as an alternative method of analysis. This project aimed to determine the optimal scoring method for FISH or chromogenic in situ hybridization (CISH) assays when analyzing small NSCLC samples to predict response. FISH or CISH analysis of EGFR and HER2 genes was done on 42 small samples derived from NSCLC patients treated with gefitinib. EGFR mutational analysis was done after quantity and quality controls of DNA. In seven of seven cases, a balanced increase in EGFR gene and chromosome 7 number was found to correlate with the presence of specific EGFR mutations. In addition, seven of seven cases with balanced EGFR/HER2 polysomy and two of three cases with balanced EGFR/HER2 trisomy responded to gefitinib (75% of responders). Instead, the EGFR mutations predicted only 7 of 12 (58%) of gefitinib-responsive patients. When only endoscopic biopsies or cytologic specimens are available, we propose using FISH/CISH for EGFR and HER2 as the test of choice for selecting patients for treatment with gefitinib and to consider as negative predictive factor the absence of EGFR/HER2 gene gain.
authors.affiliation: Department of Biomedical Sciences and Human Oncology, University of Turin, Turin, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Daniele
authors.forename: Luigia
authors.initials: L
authors.lastname: Macrì
authors.forename: Marina
authors.initials: M
authors.lastname: Schena
authors.forename: Diego
authors.initials: D
authors.lastname: Dongiovanni
authors.forename: Lisa
authors.initials: L
authors.lastname: Bonello
authors.forename: Enrico
authors.initials: E
authors.lastname: Armando
authors.forename: Libero
authors.initials: L
authors.lastname: Ciuffreda
authors.forename: Oscar
authors.initials: O
authors.lastname: Bertetto
authors.forename: Gianni
authors.initials: G
authors.lastname: Bussolati
authors.forename: Anna
authors.initials: A
authors.lastname: Sapino
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001483:Base Sequence; D001706:Biopsy; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000235:genetics*; D005091:Exons / Q000235:genetics; D005260:Female; D000077156:Gefitinib; D018628:Gene Dosage; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011799:Quinazolines / Q000627:therapeutic use*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics*
chemical_list: D000970:Antineoplastic Agents; D066246:ErbB Receptors; D000077156:Gefitinib; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases