First-generation epidermal growth factor receptor inhibitors in non-small cell lung cancer: clinical impact of the epidermal growth factor receptor fluorescence in situ hybridization assay

Epidermal growth factor receptor (EGFR) inhibitors have been proven to improve survival in advanced non-small cell lung cancer patients, even after failure of previous chemotherapy. However, how to identify the patients, who will benefit from this treatment, is still not known. Clinical and demographic factors, i.e., females, never-smokers, patients with Asian ethnicity, or histology of adenocarcinoma, seem all to be favorable factors for clinical outcome, but not sufficient for patient selection. Increased EGFR gene copy number detected by fluorescence in situ hybridization has consistently been shown in several retrospective studies to be a good predictive "marker," especially for EGFR tyrosine kinase inhibitors. Nevertheless, most of the data obtained so far are retrospective, and prospective validation is ongoing. The current review summarizes the clinical data based on the first generation EGFR inhibitors and discusses future strategies for exploring the role of EGFR fluorescence in situ hybridization as a selection marker for EGFR inhibitor therapy in non-small cell lung cancer.

Biomarkers of response to epidermal growth factor receptor inhibitors in Non-Small-Cell Lung Cancer Working Group: standardization for use in the clinical trial setting

The body of literature on the correlations between molecular assessments and patient outcomes after treatment with epidermal growth factor receptor (EGFR) inhibitors continues to grow. It will be important in the future to determine how to most effectively integrate molecular assays that assess the likelihood of therapeutic benefit into clinical practice. Although EGFR-targeted therapies such as erlotinib have been approved for use without molecular testing, immunohistochemistry, fluorescence in situ hybridization, and mutational analyses of the EGFR gene have all been proposed as candidates to help predict response or survival benefit from EGFR-targeted therapy in patients with non-small-cell lung cancer (NSCLC). Further prospective validation from ongoing randomized studies will be needed to fully determine which assays are best to help predict patient outcome. In addition, it will be critical for these assays to undergo standardization before widespread clinical use. The Molecular Assays in NSCLC Working Group, under the sponsorship of Genentech Inc, Roche Pharmaceuticals, and OSI Pharmaceuticals, Inc, was convened to evaluate the available molecular assays for use in the clinical trial setting and provide recommendations for application and interpretation of these tests for future clinical trials. Recommendations of the Molecular Assays in NSCLC Working Group for the use of EGFR molecular assays are presented and include guidelines for tissue storage, handling, and processing. Recommendations for the standardization of molecular assays are also discussed.