We report actionable targets, including frequent FGFR1 mutation in optic-pathway PA that makes them excellent candidates to anti-FGFR therapies, and BRAF non-canonical mutations in PA.
With recent findings of less frequent or absent FGFR1-ITD in pilocytic astrocytomas or rosette-forming glioneuronal tumors, the analysis of FGFR1 aberrations, especially FGFR1-ITD, was suggested to be helpful to discriminate DNTs from their histological mimics.
In the present study we searched for FGFR1-ITD by droplet digital PCR (DDPCR™) and for FGFR1 point mutations by HRM-sequencing in a series of formalin-fixed paraffin-embedded (FFPE) LGNTs including 12 DNT, 2 oligodendrogliomas lacking IDH mutation and 1p/19q co- deletion (pediatric-type oligodendrogliomas; PTOs), 3 pediatric diffuse astrocytomas (PDAs), 14 gangliogliomas (GGs) and 5 pilocytic astrocytomas (PAs).
Pediatric LGG show alterations in FGFR1 and BRAF in pilocytic astrocytomas and FGFR1 alterations in diffuse astrocytomas, each converging on the mitogen-activated protein kinase signaling pathway.