Clinical Response of Advanced Lung Adenocarcinoma with Class III BRAF G466V Missense Mutation to Dabrafenib and Trametinib: A Case Report

BRAF is a pivotal driver gene in cancer development. Based on this, the combination of dabrafenib and trametinib was approved for treating NSCLC patients with BRAF mutations. However, the majority of BRAF mutations in lung cancer are non-V600E variants, particularly class III mutants, which currently lack targeted therapeutic options and result in unfavorable clinical outcomes. We present a case of advanced lung adenocarcinoma with a class III BRAF mutation. The patient experienced significant pleural and pericardial effusion, leading to chest tightness and an inability to lie flat. Severe pain and limited mobility from lumbar destruction seriously affected the patient's quality of life. Due to the patient's intolerance to chemotherapy, dabrafenib and trametinib combination therapy was chosen. After three months of targeted therapy, the patient's overall condition significantly improved, enabling self-care, and achieving partial response (PR) as an indicator of treatment efficacy. The combination therapy of dabrafenib and trametinib demonstrates remarkable clinical benefits for lung adenocarcinoma patients with the BRAF mutation. Targeted therapy should be considered for patients with BRAF class III mutations, especially those in poor general condition and may not tolerate chemotherapy.