The advent of genomic based precision medicine led to the implementation of biomarker testing in metastatic non-small cell lung cancer (NSCLC) patients. Next generation sequencing (NGS) has been recently implemented to routine diagnostic requirements in lung oncology. Areas covered: Two cases of patients with metastatic NSCLC for whom NGS analysis performed on both tumor and liquid biopsy has not improved the clinical course of their disease are reported. These cases illustrate the difficulty of the so-called 'personalized or precision' medicine in clinical routine practice for metastatic NSCLC. Expert commentary: Discovery and detection of critical cancer-gene alterations better indicates targeted therapies that must be administered to improve the care of NSCLC patients in the personalized medicine era. There has been much interest in the literature and the scientific community for NGS tailored therapies approach for patients. However, there may be a gap between this theoretical stratified medicine and clinical practice. The advantages and drawbacks of NGS on tumor tissue and cell-free DNA for metastatic NSCLC are discussed.
Keywords: ALK; EGFR; Non-small cell lung cancer; circulating free DNA; limitations; next generation sequencing.