P072 Low Detection Rate of EGFR Driver and T790M Mutation in Plasma by Cobas v2 After Acquired Resistance to Afatinib

Cell free DNA (cfDNA) genotyping in plasma by cobas EGFR Mutation Test v2 (cobas test) is the first liquid biopsy approved as companion diagnostic systemtest to identify patients with EGFR T790M (T790M) mutation after first-generation EGFR-TKIs (G: gefitinib and erlotinib: E) and second-generation EGFR-TKIs (afatinib) failure. However, it remains unclear whether cobas testin plasma is sufficient method for detecting T790M mutation after afatinib...