title: Targeted treatment of mutatedEGFR-expressing non-small-cell lung cancer: focus on erlotinib with companion diagnostics.
abstract: 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 activatingEGFRmutations. However, theEGFRmutation 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 activatingEGFRmutations, 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.
authors.affiliation: Translational Research Unit, Dr Rosell Oncology Institute, Quirón Dexeus University Hospital.
authors.forename: Niki
authors.initials: N
authors.lastname: Karachaliou
authors.affiliation: Cancer Biology and Precision Medicine Program, Catalan Institute of Oncology, Hospital Germans Trias i Pujol, Barcelona, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Rosell
keywords: EGFR mutations; companion diagnostics; lung adenocarcinoma