Timing II. appropriate time to determine the presence of EGFR mutation and sequence of treatment

The discovery of the epidermal growth factor receptor (EGFR) mutations in Non-Small Cell lung cancer opened a new understanding in lung tumor biology and has changed the way we approach the care of our patients. Currently, there is general consensus about the importance of having this piece of molecular information, so as to offer a targeted therapy with tyrosine kinase inhibitors against EGFR (EGFR-TKI) in those patients whose result is positive for EGFR mutations. Moreover, the cumulative clinical experience directs the clinic care towards the EGFR-TKI as upfront treatment in EGFR-mutant patients. In this chapter, we will review the evidence for using EGFR-TKI in first line. There is room for debate in the sequence of treatment when the EGFR positive result returns positive once the chemotherapy has been started; for which EGFR-TKI should be used or for other potential strategies in this setting.