Circulating PD-L1 levels change during bevacizumab-based treatment in recurrent glioma.

PURPOSE: In primary brain tumors, the efficacy of immune-modulating therapies is still under investigation as inflammatory responses are restricted by tight immunoregulatory mechanisms in the central nervous system. Here, we measured soluble PD-L1 (sPD-L1) in the plasma of patients with recurrent glioblastoma (GBM) and recurrent WHO grade II-III glioma treated with bevacizumab-based salvage therapy. METHODS: Thirty patients with recurrent GBM and 10 patients with recurrent WHO grade II-III glioma were treated with bevacizumab-based salvage therapy at the Medical University of Vienna. Prior to each treatment cycle, EDTA plasma was drawn and sPD-L1 was measured applying a sandwich ELISA with a lower detection limit of 0.050 ng/ml. Leukocyte counts and C-reactive protein (CRP) levels were measured according to institutional practice. RESULTS: Median number of sPD-L1 measurements was 6 per patient (range: 2-24). At baseline, no significant difference in sPD-L1 concentrations was observed between WHO grade II-III glioma and GBM. Intra-patient variability of sPD-L1 concentrations was significantly higher in WHO grade II-III glioma than in GBM (p = 0.014) and tendentially higher in IDH-mutant than in IDH-wildtype glioma (p = 0.149) In WHO grade II-III glioma, sPD-L1 levels were significantly lower after one administration of bevacizumab than at baseline (median: 0.039 ng/ml vs. 0.4855 ng/ml, p = 0.036). In contrast, no significant change could be observed in patients with GBM. CONCLUSIONS: Changes in systemic inflammation markers including sPD-L1 are observable in patients with recurrent glioma under bevacizumab-based treatment and differ between WHO grade II-III glioma and GBM.

Antibodies Against Hypothalamus and Pituitary Gland in Childhood-Onset Brain Tumors and Pituitary Dysfunction.

Purpose: To detect the presence of antipituitary (APA) and antihypothalamus antibodies (AHA) in subjects treated for brain cancers, and to evaluate their potential association with pituitary dysfunction. Methods: We evaluated 63 patients with craniopharyngioma, glioma, and germinoma treated with surgery and/or radiotherapy and/or chemotherapy at a median age of 13 years. Forty-one had multiple pituitary hormone deficiencies (MPHD), six had a single pituitary defect. GH was the most common defect (65.1%), followed by AVP (61.9%), TSH (57.1%), ACTH (49.2%), and gonadotropin (38.1%). APA and AHA were evaluated by simple indirect immunofluorescence method indirect immunofluorescence in patients and in 50 healthy controls. Results: Circulating APA and/or AHA were found in 31 subjects (49.2%) and in none of the healthy controls. In particular, 25 subjects out of 31 were APA (80.6%), 26 were AHA (83.90%), and 20 were both APA and AHA (64.5%). Nine patients APA and/or AHA have craniopharyngioma (29%), seven (22.6%) have glioma, and 15 (48.4%) have germinoma. Patients with craniopharyngioma were positive for at least one antibody in 39.1% compared to 33.3% of patients with glioma and to 78.9% of those with germinoma with an analogous distribution for APA and AHA between the three tumors. The presence of APA or AHA and of both APA and AHA was significantly increased in patients with germinoma. The presence of APA (P = 0.001) and their titers (P = 0.001) was significantly associated with the type of tumor in the following order: germinomas, craniopharyngiomas, and gliomas; an analogous distribution was observed for the presence of AHA (P = 0.002) and their titers (P = 0.012). In addition, we found a significant association between radiotherapy and APA (P = 0.03). Conclusions: Brain tumors especially germinoma are associated with the development of hypothalamic-pituitary antibodies and pituitary defects. The correct interpretation of APA/AHA antibodies is essential to avoid a misdiagnosis of an autoimmune infundibulo-neurohypophysitis or pituitary hypophysitis in patients with germinoma.

Antitumor and Immunomodulatory Activities of Ganoderma lucidum Polysaccharides in Glioma-Bearing Rats.

Malignant gliomas are the most common brain tumors with high rates of recurrence and mortality. Novel approaches are in research, and immunotherapy emerges as a promising strategy. Recently, scientific attention has been focused on Ganoderma lucidum polysaccharides (GL-PS), one of the critical bioactive components of G lucidum, which have been recognized as a promising natural source of immunomodulatory and anticancer compounds. It remains unknown whether the GL-PS have any immunomodulatory and anticancer effects on brain glioma. This study was designed to identify and characterize the antitumor action and influence of immune system of GL-PS in glioma-bearing rats. Results showed that GL-PS increased the concentration of serum interleukin-2, tumor necrosis factor-α, and interferon-γ, and enhanced the cytotoxic activity of natural killer cells and T cells, promoting the functional maturation of dendritic cells, thus resulting in the inhibition of glioma growth and prolonged survival of rats. Therefore, GL-PS may be potentially useful as part of the treatment regimen to regulate host immune responses and increase the antitumor effects of immunotherapy for glioma.

Characterization of the serum metabolome following radiation treatment in patients with high-grade gliomas.

BACKGROUND: Glioblastomas progress rapidly making response evaluation using MRI insufficient since treatment effects are not detectable until months after initiation of treatment. Thus, there is a strong need for supplementary biomarkers that could provide reliable and early assessment of treatment efficacy. Analysis of alterations in the metabolome may be a source for identification of new biomarker patterns harboring predictive information. Ideally, the biomarkers should be found within an easily accessible compartment such as the blood. METHOD: Using gas-chromatographic- time-of-flight-mass spectroscopy we have analyzed serum samples from 11 patients with glioblastoma during the initial phase of radiotherapy. Fasting serum samples were collected at admittance, on the same day as, but before first treatment and in the morning after the second and fifth dose of radiation. The acquired data was analyzed and evaluated by chemometrics based bioinformatics methods. Our findings were compared and discussed in relation to previous data from microdialysis in tumor tissue, i.e. the extracellular compartment, from the same patients. RESULTS: We found a significant change in metabolite pattern in serum comparing samples taken before radiotherapy to samples taken during early radiotherapy. In all, 68 metabolites were lowered in concentration following treatment while 16 metabolites were elevated in concentration. All detected and identified amino acids and fatty acids together with myo-inositol, creatinine, and urea were among the metabolites that decreased in concentration during treatment, while citric acid was among the metabolites that increased in concentration. Furthermore, when comparing results from the serum analysis with findings in tumor extracellular fluid we found a common change in metabolite patterns in both compartments on an individual patient level. On an individual metabolite level similar changes in ornithine, tyrosine and urea were detected. However, in serum, glutamine and glutamate were lowered after treatment while being elevated in the tumor extracellular fluid. CONCLUSION: Cross-validated multivariate statistical models verified that the serum metabolome was significantly changed in relation to radiation in a similar pattern to earlier findings in tumor tissue. However, all individual changes in tissue did not translate into changes in serum. Our study indicates that serum metabolomics could be of value to investigate as a potential marker for assessing early response to radiotherapy in malignant glioma.

Valproic acid inhibits angiogenesis in vitro and glioma angiogenesis in vivo in the brain.

Antiangiogenic strategy is promising for malignant glioma. Histone deacetylase inhibitors (HDACIs) are unique anticancer agents that exhibit antiangiogenic effects. The in vitro and in vivo antiangiogenic effects of HDACIs, valproic acid (VPA), were investigated in malignant glioma in the brain. In vitro, VPA preferentially inhibited endothelial cell proliferation compared to glioma cell proliferation at the optimum concentration in a dose-dependent manner. VPA reduced vascular endothelial growth factor (VEGF) secretion of glioma cells in a dose-dependent manner under both normoxic and hypoxic conditions. VPA was also found to inhibit tube formation in the angiogenesis assay. In vivo, treatment with VPA combined with irinotecan reduced the number of vessels expressing factor VIII in the brain tumor model. VPA inhibits glioma angiogenesis by direct (inhibition of endothelial cell proliferation and tube formation) and indirect (decreased secretion of VEGF by glioma cells) mechanisms. These data suggest a potential role for VPA as an adjuvant therapy for patients with malignant glioma.

Preoperative 3T high field blood oxygen level dependent functional magnetic resonance imaging for glioma involving sensory cortical areas.

BACKGROUND: Localization of sensory cortical areas during the operation is essential to preserve the sensory function. Intraoperative direct electrostimulation under awake anesthesia is the golden standard but time-consuming. We applied 3T high field blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to identify the relationship between glioma and cortical sensory areas preoperatively and to guide intraoperative direct electrostimulation for quick and precise localization. METHODS: Five glioma patients with sensory cortex involvement by or next to the lesion had preoperative BOLD fMRI to determine the spatial relationship of cortical sensory areas to the tumours. Bilateral hand opposite movement was performed by these patients for fMRI. Precentral and postcentral gyri were identified by electrical stimulation during the operation. Karnofsky Performance Status scores of the patients' pre- and postoperative and the role of BOLD fMRI were evaluated. RESULTS: The cortical sensory areas were all activated in five glioma patients involving postcentral gyrus areas by BOLD fMRI with bilateral hand opposite movement. The detected activation areas corresponded with the results from cortical electrical stimulation. CONCLUSIONS: The relationship between cortical sensory areas and tumour can be accurately shown by BOLD fMRI before operation. And the information used to make the tumour resection could obtain good clinical results.

Lycopene in treatment of high-grade gliomas: a pilot study.

BACKGROUND: The therapeutic benefit of lycopene is well established for carcinoma prostate in various clinical trials and has been proposed for other malignancies including high-grade gliomas. SETTING AND DESIGN: Randomized placebo control study in the Department of Radiation Oncology of a teaching hospital. MATERIALS AND METHODS: Fifty patients with high-grade gliomas were treated with surgery followed by adjuvant radiotherapy and concomitant paclitaxel. Patients were randomized to receive either oral lycopene (Group A) 8 mg daily with radiotherapy or placebo (Group B). Pre-and post-radiotherapy plasma lycopene levels were measured using high-precision liquid chromatography. McDonald's criteria were used for response assessment. Magnetic resonance imaging (MRI) of brain and Single Photon Emission Computed Tomograph (SPECT) were done three-monthly for two visits and six-monthly thereafter. Primary endpoint was response at six months post radiotherapy. Statistical Analysis Used : The data was analyzed using SPSS Software v10.0 (SPSS corporation Chicago IL) by applying Student's t-test, ANOVA F test, Chi-square test and Karl Pearson Correlation Coefficient. RESULTS: Median age was 38 years. The commonest histology was glioblastoma multiforme (n = 32). Pre- and post-treatment plasma lycopene levels in the patients in Gropu A were 152 ng/ml and 316 ng/ml and in the patients in Group B were 93 ng/ml and 98 ng/ml (P = 0.009). There was non-significant differences in favor of lycopene between Group A and Group B with higher overall response at six months (P = 0.100), response at last follow-up (P = 0.171) and time to progression (40.83 vs. 26.74 weeks, P = 0.089)., The follow-up duration was significantly higher for Group A than Group B (66.29 vs. 38.71 weeks, P = 0.05). CONCLUSIONS: Addition of nutrition supplements such as lycopene may have potential therapeutic benefit in the adjuvant management of high-grade gliomas.

The effect of anticonvulsant drugs on blood levels of methotrexate.

The reduced bioavailability of chemotherapeutic agents is one of the reasons that explains the limited efficacy of adjuvant chemotherapy in high grade glioma patients. We report how even the results of high dose sequential chemotherapy can be influenced by antiepileptic drugs.