Are we ready to introduce T790M plasma analysis in the follow up of patients with NSCLC under treatment with EGFR-TKI?

In the last few years, cell free circulating DNA (cfDNA) analysis has advanced from research to clinical laboratory in the case of non-small cells lung cancer (NSCLC), where patients harboring EGFR activating mutations can benefit from treatments with EGFR inhibitors (EGFT-TKIs). Treatment with an EGFR-TKI has been recently approved for patients with activating mutations of EGFR detected in cfDNA when tumor sample is not available for analysis (1). As cfDNA comes from dead cells whose DNA spills out into circulation, tumor cfDNA can provide eventually more information of tumor heterogeneity NSCLC than tissue biopsy.