Background: Mutations in the v-raf murine sarcoma viral oncogenes homolog B1 (BRAF), most commonly of the V600E type, are present in a variety of human malignancies including malignant melanoma, papillary thyroid cancers, and hairy-cell leukemia and specific therapeutically active BRAF inhibitors exist. We aimed to investigate BRAF V600E protein expression in primary central nervous system lymphoma (PCNSL).
Methods: We investigated BRAF V600E expression in formalin-fixed and paraffin-embedded surgical tissue specimens of 20 immunocompetent patients with PCNSL using the mutation-specific monoclonal mouse antibody VE1.
Results: Ten male and 10 female patients with a median age of 60 years (range, 44 to 71 y) at time of operation were included. All cases were qualified as diffuse large B-cell lymphomas. None of the investigated cases demonstrated specific immunoreactivity for BRAF V600E mutation.
Conclusions: Our data provide evidence that the BRAF V600E mutation is not pathobiologically relevant in PCNSL and as a consequence is not a feasible drug target in this tumor type.