title: Standardization of epidermal growth factor receptor (EGFR) measurement by quantitative immunofluorescence and impact on antibody-based mutation detection in non-small cell lung cancer.
abstract: Challenges in measurement of epidermal growth factor receptor (EGFR) protein expression have led to conflicting data on its prognostic value and discontinuation of its use for prediction of response. Herein is described a quantitative standardized assay for EGFR and its use in a series of retrospective cohorts of patients with non-small cell lung cancer (NSCLC). The AQUA technology of quantitative immunofluorescence was used in conjunction with Western blot analysis to calculate the absolute concentration of EGFR in two independent NSCLC cohorts (170 from Yale New Haven Hospital and 335 from Sotiria and Patras Hospitals in Greece). EGFR and mutated EGFR were measured using D38B1 antibody and two mutation-specific antibodies. All patients positive or borderline for mutation-specific antibody were genotyped. A threshold for reproducible detection of EGFR was defined as 0.85 ng/μg total protein. EGFR expression demonstrated no prognostic value in either cohort. The mutation rate was 1.79% in the Yale cohort, and 1.52% in the Sotiria/Patras cohort, with no antibody detection-based false-positive cases. No mutations were detected for EGFR concentrations <1.46 ng/μg total protein. In summary, accurate measurement of EGFR still shows no prognostic value in NSCLC. In these two population-based cohorts, the antibody-based EGFR mutation rate was lower than has been frequently reported.
authors: Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06520-8023, USA.
authors: Anastasios
authors: A
authors: Dimou
authors: Seema
authors: S
authors: Agarwal
authors: Valsamo
authors: V
authors: Anagnostou
authors: Hollis
authors: H
authors: Viray
authors: Stephen
authors: S
authors: Christensen
authors: Bonnie
authors: B
authors: Gould Rothberg
authors: Vassiliki
authors: V
authors: Zolota
authors: Konstantinos
authors: K
authors: Syrigos
authors: David L
authors: DL
authors: Rimm
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism* / Q000473:pathology; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005838:Genotype; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods; D008875:Middle Aged; D009154:Mutation; D011379:Prognosis
chemical_list: D066246:ErbB Receptors