Testing for BRAF fusions in patients with advanced BRAF/NRAS/KIT wild-type melanomas permits to identify patients who could benefit of anti-MEK targeted therapy

Fusion-Associated Carcinomas of the Breast: Diagnostic, Prognostic, and Therapeutic Significance

Recurrent gene fusions comprise a class of viable genetic targets in solid tumors that have culminated several recent break-through cancer therapies. Their role in breast cancer, however, remains largely underappreciated due to the complexity of genomic rearrangements in breast malignancy. Just recently, we and others have identified several recurrent gene fusions in breast cancer with important clinical and biological implications. Examples of the most significant recurrent gene fusions to date include 1) ESR1-CCDC170 gene fusions in luminal B and endocrine resistant breast cancer that exert oncogenic function via modulating the HER2/HER3/SRC complex, 2) ESR1 exon 6 fusions in metastatic disease that drive estrogen-independent ER transcriptional activity, 3) BCL2L14-ETV6 fusions in a more aggressive form of the triple negative subtype that prime epithelial-mesenchymal transition and endow paclitaxel resistance, 4) the ETV6-NTRK3 fusion in secretory breast carcinoma that constitutively activates NTRK3 kinase, 5) the oncogenic MYB-NFIB fusion as a genetic driver underpinning adenoid cystic carcinomas of the breast that activates MYB pathway, and 6) the NOTCH/MAST kinase gene fusions that activate NOTCH and MAST signaling. Importantly, these fusions are enriched in more aggressive and lethal breast cancer presentations and appear to confer therapeutic resistance. Thus, these gene fusions could be utilized as genetic biomarkers to identify patients that require more intensive treatment and surveillance. In addition, kinase fusions are currently being evaluated in breast cancer clinical trials and on-going mechanistic investigation is exposing therapeutic vulnerabilities in patients with fusion positive disease. This article is protected by copyright. All rights reserved.