Response to combined BRAF/MEK inhibition in adult BRAF V600E mutant spinal pilocytic astrocytoma.

Pilocytic astrocytomas are World Health Organisation (WHO) grade I tumors, occurring predominantly supratentorially and in the pediatric population. Although the mainstay of treatment is local therapies such as surgery, targeted systemic therapies may be necessary for recurrent or unresectable disease. The majority of sporadic pilocytic astrocytomas are associated with the BRAF-KIAA fusion gene, which results in constitutive activation of the MAP Kinase pathway.