LGG-12. ANGIOCENTRIC GLIOMA - EXPLORING A NOVEL THERAPEUTIC OPTION

Abstract

Angiocentric glioma (AG) is a slow-growing WHO grade I tumor classified as “other glioma” in 2016. Commonest location is supratentorial with a few reported elsewhere. Resection is curative. Treatment poses a challenge when resection is unattainable because of location. Per literature review 23 published articles described some form of therapy for AG. Only one article reported two cases receiving chemotherapy, vinblastine with bevacizumab in first, everolimus in second. The best response was stable disease. Almost all AGs have MYB rearrangement, often with its fusion partner QKI. On analysis of functional significance of MYB-QKI-driven transcriptional events with Connectivity Map, tyrosine kinase receptor c-KIT was highly upregulated. A 7 yo male presented with headache, nausea, vomiting and unsteady gait with CT head showing intraventricular mass and hydrocephalus. MRI brain showed tumor centered in third ventricle extending to thalami bilaterally. Only partial resection was feasible. Pathology review identified the tumor as AG with MYB rearrangement. Initially we observed without treatment, but 10 months later MRI showed slight tumor progression. We started standard LGG treatment with weekly carboplatin and vincristine. The tumor slowly grew and nine months into chemotherapy, alternative options were pursued. Based on effect of MYB-QKI rearrangement on c-kit, dasatinib was started. He is tolerating it well and is neurologically stable. Six months into treatment MRI shows a stable tumor. Due to the slow growth rate at baseline, he needs longer follow-up to reach a definitive conclusion about role of dasatinib in progressive AG and its potential as targeted therapy for AG.