Rapid and dramatic responses to dabrafenib and trametinib in BRAF V600E-mutated lung adenocarcinoma.

V-raf murine sarcoma viral oncogene homologue B1 (BRAF) is a proto-oncogene that regulates cell proliferation and survival. BRAF V600E-mutated lung cancer has aggressive characteristics and is resistant to chemotherapies. Combination of BRAF-specific inhibitor dabrafenib and mitogen-activated protein kinase kinase (MEK) inhibitor trametinib is the standard treatment for BRAF V600E-mutated lung cancer. We report a case of BRAF V600E-mutated lung adenocarcinoma, which presented with respiratory distress due to deterioration of advanced cancer. The tumour responded rapidly and significantly to BRAF/MEK inhibitors, and the patient's symptoms improved within 2 weeks. BRAF/MEK inhibitors are effective treatment in BRAF-mutated lung cancer even under critical conditions.