IMMUNOHISTOCHEMISTRY: BRAF V600E

BRAF IS A MEMBER OF THE MITOGEN-ACTIVATED PROTEIN/EXTRACELLULAR SIGNAL-REGULATED (MAP/ERK) KINASE PATHWAY, WHICH PLAYS A ROLE IN CELL PROLIFERATION AND DIFFERENTIATION. DYSREGULATION OF THIS PATHWAY IS A KEY FACTOR IN TUMOR PROGRESSION & CELL PROLIFERATION. THIS GENETIC ALTERATION HAS BEEN DETECTED IN A VARIETY OF TUMORS LIKE MELANOMA, COLORECTAL CANCER, PAPILLARY THYROID CARCINOMA, HAIRY CELL LEUKEMIA, LANGERHANS CELL HISTIOCYTOSIS & PLEOMORPHIC XANTHOASTROCYTOMAS. TARGETED THERAPIES DIRECTED TO COMPONENTS OF THIS PATHWAY HAVE DEMONSTRATED SOME SUCCESS WITH INCREASES BOTH IN PROGRESSION-FREE AND OVERALL SURVIVAL. APPROXIMATELY 44% TO 70% OF MELANOMA CASES HAVE A BRAF MUTATION, AND OF THOSE, APPROXIMATELY 50% TO 90% ARE THE V600E MUTATION.