Frequency of T790M Mutation on Circulating Tumor DNA in EGFR-mutated NSCLC Patients With acquired resistance to irreversible EGFR-TKI :a prospective observational study - Frequency of T790M Mutation on ctDNA in patients with acquired resistance to irreversible EGFR-TKI

iquid biopsy detected EGFR mutations in 63.6% of the patients at diagnosis. Patients with positive EGFR mutations at diagnosis had significantly shorter overall and progression-free survival than patients with negative EGFR mutations. Four of 18 patients (22.2%) who reached progressive disease were positive EGFR T790M mutations. Only two patients were positive for major EGFR mutations at intermediate levels.