Reduced-Dose Dabrafenib-Trametinib for BRAF V600E-Mutant Lung Adenocarcinoma in a Very Elderly Patient With ECOG PS 2.

BRAF V600E mutations occur in approximately 1%-2% of non-small cell lung cancers (NSCLCs). Dabrafenib plus trametinib has demonstrated clinical efficacy in BRAF V600E-mutant NSCLC, although pyrexia frequently leads to treatment interruption. We report an 86-year-old woman with lung adenocarcinoma harbouring a BRAF V600E mutation and an ECOG performance status (PS) of 2. She had undergone partial lung resection (Stage IA2) 4 years earlier and later developed pleural dissemination and liver metastases. Although she initially declined systemic therapy because of concerns about treatment-related adverse events, she subsequently experienced progressive malignant pleural effusion requiring repeated thoracentesis followed by chest tube drainage and pleurodesis, accompanied by worsening dyspnea, pleuritic chest pain and appetite loss. She then requested therapy for symptom relief and disease control. Reduced-dose dabrafenib and trametinib were initiated with prophylactic naproxen to mitigate the risk of pyrexia. Within 2 weeks, her chest pain and appetite improved, and ECOG PS recovered to 1. Treatment has been continued for over 6 months with sustained disease stability. This case suggests that an upfront dose-attenuation strategy combined with proactive toxicity management, including pyrexia prophylaxis, may represent a practical approach to maintain treatment continuity and clinical benefit in selected very elderly or frail patients.