Concurrent T790M and L858R mutations in treatment-naïve metastatic non-small-cell lung cancer: A therapeutic challenge – Current treatment strategies and promising therapies of the future in a nutshell

De novo (pretreatment) epidermal growth factor receptor T790M mutation in non-small-cell lung cancer (NSCLC) is rare when detected by standard genotyping methods. We present a case of concurrent de novo T790M and L858R mutations detected by direct sequencing in treatment-naïve metastatic NSCLC. This case is worthy of mention as the presence of this mutation has a bearing on the choice of treatment. This article aims to evaluate the clinical outcome for metastatic NSCLC with de novo T790M mutation and formulate an optimum treatment plan in this clinical scenario. The novel targeted therapy agents have also been reviewed