Current treatment options in oncology
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Curr Treat Options Oncol · Aug 2016
ReviewDeficient Mismatch Repair and the Role of Immunotherapy in Metastatic Colorectal Cancer.
Division of colorectal cancers (CRCs) into molecular subsets yields important consequences for prognosis and therapeutic response. The microsatellite instability (MSI) immune subgroup, accounting for 15 % of early-stage and 3 % of metastatic CRCs, are a result of deficient cellular DNA mismatch repair (dMMR) mechanisms. dMMR CRCs are notable for greater survivability, yet lack of benefit from fluoropyrimidine-based therapy in early-stage disease as compared to proficient DNA mismatch repair (pMMR) CRCs but are substantially lethal when metastatic. ⋯ Next, we will discuss the previous and ongoing clinical trials specifically designed to evaluate immunotherapeutic treatment of dMMR CRCs. Building on the success of the early immune checkpoint inhibitor clinical trials for dMMR CRC, combinations with other anti-tumor immunotherapies may provide an even more robust response, thereby, creating an alternative treatment regimen for those who have failed standard therapies or possibly resulting in prophylactic therapies for patients with highly oncogenic hereditary mismatch repair deficiencies.
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Curr Treat Options Oncol · Aug 2016
ReviewTargeted Therapeutics in Patients With High-Grade Gliomas: Past, Present, and Future.
High-grade gliomas remain incurable despite current therapies, which are plagued by high morbidity and mortality. Molecular categorization of glioma subtypes using mutations in isocitrate dehydrogenase 1/2 (IDH1/2), TP53, and ATRX; codeletion of chromosomes 1p and 19q; DNA methylation; and amplification of genes such as epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor, alpha polypeptide provides a more accurate prognostication and biologic classification than classical histopathological diagnoses, and a number of molecular markers are being incorporated in the new World Health Organization classification of gliomas. However, despite the improved understanding of the molecular subtypes of gliomas and the underlying alterations in specific signaling pathways, these observations have so far failed to result in the successful application of targeted therapies, as has occurred in other solid tumors. ⋯ Mutations in the IDH1/2 genes are central to gliomagenesis in a high proportion of grade II and III gliomas, and ongoing trials are examining vaccines against IDH1, small molecular inhibitors of IDH1 and IDH2, and metabolic components including NAD+ depletion to target IDH-mutated gliomas. The central role of DNA methylation in a subset of gliomas may be targetable, but better understanding of the relation between epigenetic alterations and resulting tumor biology appears necessary. Ultimately, given the prior failure of single-agent targeted therapy in high-grade gliomas, it appears that novel combinatorial therapy or targeted drugs with immunomodulatory or epigenetic approaches will likely be necessary to successfully combat these challenging tumors.