Liquid Biopsy as a Tool to Evaluate Resistance to First and Third (AZD9291) (EGFR) (TKIs) in (EGFR) Mutant NSCLC

Based on the possibilities that both plasma and circulating tumor cells (CTCs) (the "liquid biopsy") may offer, we consider that it could be feasible to longitudinally monitor the genetic evolution and the biologic characteristics of CTCs, by using Circulating tumor DNA (ctDNA) and CTCs as a source of biologic material. This approach could provide information regarding the genetic/molecular changes associated with primary and acquired resistance to AZD9291 and, thus, to facilitate to more appropriately adapt the tailored treatment in this particular group of NSCLC patients. It has been recently reported that the detection of resistant clones, based on the tumor-associated genetic aberrations in the blood, can identify treatment resistance up to 10 months earlier than the radiological methods providing, thus, the potential for an early switch to a non cross-resistant therapy in order to improve patients' outcome.