Evaluation of EGFR protein expression by immunohistochemistry using H-score and the magnification rule: Re-analysis of the SATURN study

Autor: Peter Middel, Barbara Klughammer, Julien Mazieres, Alice Frosch, Gaelle Klingelschmitt, Ilze Bara, Federico Cappuzzo, Wolfram Brugger
Rok vydání: 2013
Předmět:
Male
Oncology
Cancer Research
Pathology
Lung Neoplasms
Gene Expression
0302 clinical medicine
Non-small cell lung cancer
Biomarkers
Epidermal growth factor receptor
Erlotinib
Immunohistochemistry
Maintenance
Risk Factors
Carcinoma
Non-Small-Cell Lung
Antineoplastic Combined Chemotherapy Protocols
Aged
80 and over
0303 health sciences
education.field_of_study
Cetuximab
biology
Hazard ratio
Middle Aged
ErbB Receptors
030220 oncology & carcinogenesis
Female
medicine.drug
Adult
Pulmonary and Respiratory Medicine
medicine.medical_specialty
Population
Placebo
03 medical and health sciences
Internal medicine
medicine
Humans
education
Protein Kinase Inhibitors
Aged
Neoplasm Staging
030304 developmental biology
business.industry
Confidence interval
biology.protein
Receptor
Epidermal Growth Factor
business
Zdroj: Lung Cancer. 82:231-237
ISSN: 0169-5002
Popis: INTRODUCTION: The phase III SATURN study demonstrated that first-line maintenance erlotinib extended progression-free survival (PFS) and overall survival (OS) versus placebo in patients with advanced non-small cell lung cancer (NSCLC). Analysis of epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC) found no significant interaction between EGFR IHC status and PFS (p = 0.63) or OS (p = 0.52). The FLEX study of first-line cetuximab plus chemotherapy demonstrated that EGFR IHC expression was predictive of improved OS with cetuximab when assessed by H-score with a magnification rule. This novel method was used to reassess samples from SATURN. METHODS: The H-score method assigned a score of 0-300 to each patient, based on the percentage of cells stained at different intensities viewed at various magnifications. The discriminatory threshold was set at 200, per the FLEX study, and existing samples were re-read and classed as low (H-score < 200) or high (≥200) EGFR expression. PFS and OS were re-analyzed based on these new classifications. RESULTS: In the overall and EGFR wild-type populations, erlotinib provided a consistent survival benefit versus placebo. Hazard ratios (HRs) in the overall population were similar between EGFR IHC-positive and -negative patients for median PFS (HR 0.68 [95% confidence interval (CI) 0.53-0.86] and 0.76 [95% CI 0.62-0.93], respectively) and OS (HR 0.80 [95% CI 0.62-1.05] and 0.80 [95% CI 0.64-1.01] for IHC-positive and IHC-negative, respectively). In the EGFR wild-type population, HRs were again similar between EGFR IHC-positive and -negative subpopulations for PFS (HR 0.69 [95% CI 0.51-0.95] and 0.84 [95% CI 0.63-1.12], respectively) and OS (HR 0.78 [95% CI 0.55-1.10] and 0.76 [95% CI 0.55-1.05], respectively). CONCLUSIONS: These data suggest that EGFR IHC does not have value as a marker to predict erlotinib benefit in the first-line maintenance setting for advanced NSCLC. peerReviewed
Databáze: OpenAIRE
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