Glioma is the most common form of primary malignant brain tumor in adults, with approximately 4 cases per 100 000 people each year. Gliomas, like many tumors, are thought to primarily metabolize glucose for energy production; however, the reliance upon glycolysis has recently been called into question. In this study, we aimed to identify the metabolic fuel requirements of human glioma cells.
Meningiomas are the most common primary intracranial tumors in adults. Identification of SMO and AKT1 mutations in meningiomas has raised the hope for targeted therapies. It would be useful to know the precise frequency of these mutations in anatomical subgroups and clarify their prognostic value.
In previous clinical trials, antiangiogenic therapies such as bevacizumab did not show efficacy in patients with newly diagnosed glioblastoma (GBM). This may be a result of the heterogeneity of GBM, which has a variety of imaging-based phenotypes and gene expression patterns. In this study, we sought to identify a phenotypic subtype of GBM patients who have distinct tumor-image features and molecular activities and who may benefit from antiangiogenic therapies.
BackgroundSpinal astrocytomas are rare intramedullary CNS tumors for which there is limited consensus on treatment; the importance of the extent of resection (EOR), postoperative radiotherapy, and chemotherapy remains poorly understood. We report on outcomes associated with surgery, postoperative radiotherapy, and chemotherapy in a series of patients treated at M. D. Anderson Cancer Center (MDACC) with the aim of elucidating the role of these treatments in spinal astrocytomas.MethodsWe retrospectively reviewed charts from a series of 83 patients with histologically confirmed spinal astrocytoma treated at MDACC during 1990-2011. Data collected included patient demographic characteristics, prognostic indicators, and treatment modality at diagnosis. We analyzed overall survival (OS) and progression-free survival (PFS) for pilocytic (World Health Organization [WHO] grade I) and infiltrative (WHO grades II, III, and IV) astrocytomas, separately. Multivariate analysis was performed for the infiltrative patients but not the pilocytic patients because of a limited number of cases.ResultsHigher WHO grade among all patients was associated with worse OS (P < .0001) and PFS (P = .0003). Among patients with infiltrative tumors, neither EOR nor radiotherapy was associated with a difference in outcomes in multivariate analysis; however, among patients with infiltrative astrocytomas, chemotherapy was significantly associated with improved PFS (hazard ratio = .22, P = .0075) but not OS (hazard ratio = .89, P = .83) in multivariate analysis.ConclusionWHO grade was the strongest prognostic indicator in patients with spinal cord astrocytomas. Our results also show that chemotherapy improved PFS in infiltrative astrocytomas in multivariate analysis, but neither EOR nor radiation therapy influenced outcomes in this group.
Adaptive immune resistance in the tumor microenvironment appears to attenuate the immunotherapeutic targeting of glioblastoma (GBM). In this study, we identified a tumor-infiltrating myeloid cell (TIM) population that expands in response to dendritic cell (DC) vaccine treatment. The aim of this study was to understand how this programmed death ligand 1 (PD-L1)-expressing population restricts activation and tumor-cytolytic function of vaccine-induced tumor-infiltrating lymphocytes (TILs).
Toca 511, a gamma retroviral replicating vector encoding cytosine deaminase, used in combination with 5-fluorocytosine (5-FC) kills tumor by local production of 5-fluorouracil (5-FU), inducing local and systemic immunotherapeutic response resulting in long-term survival after cessation of 5-FC. Toca 511 and Toca FC (oral extended-release 5-FC) are under investigation in patients with recurrent high-grade glioma. Lomustine is a treatment option for patients with high-grade glioma.
Prodrug-activator gene therapy with Toca 511, a tumor-selective retroviral replicating vector (RRV) encoding yeast cytosine deaminase, is being evaluated in recurrent high-grade glioma patients. Nonlytic retroviral infection leads to permanent integration of RRV into the cancer cell genome, converting infected cancer cell and progeny into stable vector producer cells, enabling ongoing transduction and viral persistence within tumors. Cytosine deaminase in infected tumor cells converts the antifungal prodrug 5-fluorocytosine into the anticancer drug 5-fluorouracil, mediating local tumor destruction without significant systemic adverse effects.
Toca 511 (vocimagene amiretrorepvec) is a retroviral replicating vector encoding an optimized yeast cytosine deaminase (CD). Tumor-selective expression of CD converts the prodrug, 5-fluorocytosine (5-FC), into the active chemotherapeutic, 5-fluorouracil (5-FU). This therapeutic approach is being tested in a randomized phase II/III trial in recurrent glioblastoma and anaplastic astrocytoma (NCT0241416). The aim of this study was to identify the immune cell subsets contributing to antitumor immune responses following treatment with 5-FC in Toca 511-expressing gliomas in a syngeneic mouse model.
Tumor treating fields (TTFields) are low-intensity electric fields alternating at an intermediate frequency (200kHz), which have been demonstrated to block cell division and interfere with organelle assembly. This novel treatment modality has shown promise in a variety of tumor types. It has been evaluated in randomized phase 3 trials in glioblastoma (GBM) and demonstrated to prolong progression-free survival (PFS) and overall survival (OS) when administered together with standard maintenance temozolomide (TMZ) chemotherapy in patients with newly diagnosed GBM. TTFields are continuously delivered by 4 transducer arrays consisting each of 9 insulated electrodes that are placed on the patient’s shaved scalp and connected to a portable device. Here we summarize the preclinical data and mechanism of action, the available clinical data, and further outlook of this treatment modality in brain tumors and other cancer indications.
Clinical genomics platforms are needed to identify targetable alterations, but implementation of these technologies and best practices in routine clinical pediatric oncology practice are not yet well established.