Case Report: Early detection of multiple resistance mechanisms by ctDNA profiling in a patient with EGFR-mutant lung adenocarcinoma treated with osimertinib

Case Report: Early detection of multiple resistance mechanisms by ctDNA profiling in a patient with EGFR-mutant lung adenocarcinoma treated with osimertinib: A 48-year old female patient, symptomatic with shortness of breath and cough, was diagnosed with stage IV adenocarcinoma of the lung with pulmonary metastases in a miliary pattern in November 2014. Tumor molecular testing by polymerase-chain reaction (PCR) method revealed an EGFR exon 19 deletion; treatment with gefitinib was initiated with rapid symptomatic relief and radiological response (Figure 1, A1 and A2). In May 2015, the patient received stereotactic radiosurgery with 1x22Gy for a singular cerebellar metastasis but otherwise had controlled disease while continuing on gefitinib.