Feasibility of Intratumoral Washing Fluid for Detecting EGFR Mutations in Lung Cancer

Inclusion Criteria

• •Age ≥ 20 years
• •Obtained written informed consent
• •Patients diagnosed with NSCLC by histology or cytology and inoperable stage IV at the time of study enrollment
• •Patients with the following EGFR gene mutations: E19Del, L858R alone or concurrent rare EGFR gene mutations (T790M, G719X, exon 20 insertion, S768I)
• •Patients previously treated with EGFR-TKIs such as gefitinib, erlotinib, afatinib, dacomitinib as first line therapy
• •Patients who had shown clinical benefits (CR, PR, SD) from EGFR-TKIs and had been confirmed PD on those therapy according to RECIST v 1.1.
• •Patients who underwent liquid biopsy (plasma) for EGFR mutation at the time of PD on EGFR-TKIs
• •Patients who plan to undergo tissue biopsy for EGFR mutation at the time of PD on EGFR-TKIs