Personalized Medicine and Inhibition ofEGFRSignaling in Lung Cancer

The concept underlying much of cancer therapy is that patients with specific types and stages of cancer should be treated according to standardized, predetermined protocols.However, recent advances in drug development, pharmacogenomics, and the molecular characterization of tumors -including genomewide RNA expression, DNA copy-number and sequence analyses, and micro-RNA and proteomic profiling -have the potential to allow individualized selection of treatment as determined by the characteristics of the patient and the tumor.In principle, targeted therapies attack cancer-cell-specific attributes that are essential for growth or survival ("oncogene addiction") and avoid the potentially severe side effects of conventional cytotoxic treatments.Successful examples of targeted therapy include imatinib for the treatment of BCR-ABL-positive chronic myeloid leukemia and the reversible tyrosine kinase inhibitors, erlotinib and gefitinib, for blocking the gene that encodes epidermal growth factor receptor (EGFR) in subgroups of patients with non-small-cell lung cancer.