EGFR and non-small cell lung adenocarcinoma: Here, we report a case of acquired EGFR L858R/L718Q mutation with advanced NSCLC that resistant to osimertinib, which was successfully overcome using dacomitinib.<h4>Case presentation</h4>A 64-year-old non-smoker woman was diagnosed with stage IV non-small cell lung adenocarcinoma with EGFR L858R mutation and brain metastasis in November 2018.