Targeted treatment of mutated EGFR-expressing non-small-cell lung cancer: focus on erlotinib with companion diagnostics

Abstract

Niki Karachaliou,1 Rafael Rosell21Translational Research Unit, Dr Rosell Oncology Institute, Quirón Dexeus University Hospital, 2Cancer Biology and Precision Medicine Program, Catalan Institute of Oncology, Hospital Germans Trias i Pujol, Barcelona, SpainAbstract: Deeper understanding of the pathobiology of non-small-cell lung cancer (NSCLC) has led to the development of small molecules that target genetic mutations known to play critical roles in the progression to metastatic disease. The discovery of epidermal growth factor receptor (EGFR) mutations in 15%–20% of lung adenocarcinomas and the associated response to EGFR tyrosine kinase inhibitors have provided a successful avenue of attack in late-stage adenocarcinomas. Use of the EGFR tyrosine kinase inhibitors gefitinib, erlotinib, and afatinib is limited to patients who have adenocarcinomas with known activating EGFR mutations. However, the EGFR mutation testing landscape is varied and includes many screening and targeted methods, each with its own benefits and limitations. These tests can simplify the drug discovery process, make clinical trials more efficient and informative, and individualize cancer therapy. In practice, the choice of method should be determined by the nature of the sample to be tested, the testing laboratory's expertise and access to equipment, and whether the detection of only known activating EGFR mutations, or of all possible mutations, is required. Development of companion diagnostic tests for this identification is advancing; nevertheless, the use of such tests merits greater attention.Keywords: lung adenocarcinoma, EGFR mutations, companion diagnostics