Shweta Gera, Mark Ettel, Gabriel Acosta Gonzalez, Melissa Wilson and Ruliang Xu
Context: BRAF mutations lead to constitutive activation of downstream signaling in the Mitogen-activated protein (MAP) kinase pathway, and can serve as a molecular therapeutic target for BRAF inhibitors in melanoma. However, there is a scant data on BRAF mutations in angiosarcoma and its response to BRAF inhibitor treatment. The aim of this study was to evaluate for BRAF mutation in metastatic angiosarcoma and its response to BRAF inhibitor treatment.
Methods and results: We retrospectively identified cases of hepatic metastatic angiosarcoma in the departmental archives from 2006 to 2015. Total six cases of metastatic angiosarcoma to the liver were retrieved. Histologically, all tumors were high-grade except one that was low-grade. Four of six were epithelioid type and two were mixed epithelioid and spindle cell types. Immunohistochemical (IHC) stain for BRAF V600E mutation was performed which showed one case positive for BRAF V600E mutation. For the positive case, targeted gene sequencing (total 50-gene panel including BRAF) was followed which confirmed BRAF V600E (c.1799T>A) mutation. The patient with BRAF mutated angiosarcoma received Vemurafenib, a BRAF inhibitor, for treatment and showed a significant response to therapy.
Conclusion: BRAF V600E mutations can occur in a subset of metastatic angiosarcoma to the liver, and can serve as a molecular target for treatment with a BRAF inhibitor.
