Activating BRAF G469A Missense Mutation in a Pediatric Patient With High-Grade Glioma

Efficacy of trametinib in a metastatic urothelial carcinoma patient with a BRAF mutation

Introduction

BRAF mutations in bladder cancer are rare. MEK inhibitors have excellent clinical benefits in the treatment of melanoma.

Case presentation

A 60-year-old male was diagnosed with muscle-invasive bladder cancer and underwent total cystectomy and ileal conduit diversion. Despite 4 cycles of gemcitabine and cisplatin chemotherapy and 3 courses of pembrolizumab, the left obturator lymph node enlarged. Cancer multi-gene panel testing confirmed the BRAF G469A mutation and trametinib was recommended. Three months after the initiation of trametinib (2 mg, qd), the left obturator lymph node shrank by more than 50%. The disease has remained stable for more than 18 months.

Conclusion

The present case indicates the potential of trametinib to treat mBUC patients with the BRAF G469A mutation in this setting.

BRAF mutation in myeloid neoplasm: incidences and clinical outcomes

The presence of BRAF mutation in hematological malignancies, excluding Hairy cell leukemia, and its significance as a driver mutation in myeloid neoplasms (MNs) remains largely understudied. This research aims to evaluate patient characteristics and outcomes of BRAF-mutated MNs. Among a cohort of 6667 patients, 48 (0.7%) had BRAF-mutated MNs. Notably, three patients exhibited sole BRAF mutation, providing evidence supporting the hypothesis of BRAF's role as a driver mutation in MNs. In acute myeloid leukemia, the majority of patients had secondary acute myeloid leukemia, accompanied by poor-risk cytogenic and RAS pathway mutations. Although the acquisition of BRAF mutation during disease progression did not correlate with unfavorable outcomes, its clearance through chemotherapy or stem cell transplant exhibited favorable outcomes (median overall survival of 34.8 months versus 10.4 months, p = 0.047). Furthermore, G469A was the most frequently observed BRAF mutation, differing from solid tumors and hairy cell leukemia, where V600E mutations were predominant.