End-of-life care for glioma patients; the caregivers' perspective.

PURPOSE: Gliomas are primary brain tumors with a life-limiting course of disease, and the last weeks of life are often characterized by neurological deficits that affect communication and personality. End-of-life treatment in this patient group therefore requires specific approaches. To date, little data is available on patients' and caregivers' needs and experiences in the last phase of the disease. METHODS: In this observational study, relatives of patients treated at the University Hospital Zurich, Switzerland and deceased 2015-2017 due to glioma progression were contacted to complete a structured questionnaire assessing caregivers experience within the last weeks of the disease. RESULTS: The survey was sent to 120 relatives of deceased patients with a glioma (WHO grades II-IV) (median patient age: 62 years; 73.8% male). Forty-three questionnaires were returned (37.7%). Approximately half of the patients were taken care of at home in the last 4 weeks of the disease, mainly with the assistance of in-home nursing care, of which eventually 14 patients (63.6%) died at home. While caregivers reported high satisfaction with medical and nursing care, psychological support was rated average to poor on a 10-point scale. Free comment fields were used widely, revealing open questions and needs of the relatives. CONCLUSIONS: This study illustrates the need for a more patient-centered end-of-life care including higher psychological support mechanisms, and a higher inclusion and consideration of relatives and caregivers into the care focus. Earlier discussion of end-of-life preferences could prevent hospitalizations in the last phase of life and could improve patients' and caregivers' quality of life.

Complementary and alternative medicine use by glioma patients in Switzerland.

BACKGROUND: During the course of disease, most glioma patients learn that there is no cure for their tumor. It is therefore not uncommon for patients or caregivers to seek complementary and alternative medicine (CAM) treatments. Patterns of CAM use vary across the globe, but little is known about the type of, and motivation for, CAM use in most countries. METHODS: Here we conducted a cross-sectional survey of CAM use in patients harboring gliomas of World Health Organization (WHO) grades II to IV at 3 specialized neuro-oncology centers in Switzerland. RESULTS: Of 208 patients who returned the survey, approximately half reported having used or using CAM. CAM use was associated with younger age. Patients suffering from WHO grade II gliomas were less likely to indicate CAM use. The leading motivation for CAM use was to contribute actively to the treatment of the disease. CAM use was commonly not counseled or supervised by a health care professional. Cost and issues of reimbursement were not an important factor in the decision against or for CAM use. CONCLUSIONS: Physicians caring for glioma patients should be aware of and explore CAM use to better understand patients' attitudes toward their disease, to provide counseling, and to identify potential interactions of CAM with standard treatments for gliomas.

The natural HLA ligandome of glioblastoma stem-like cells: antigen discovery for T cell-based immunotherapy.

Glioblastoma is the most frequent malignant primary brain tumor. In a hierarchical tumor model, glioblastoma stem-like cells (GSC) play a major role in tumor initiation and maintenance as well as in therapy resistance and recurrence. Thus, targeting this cellular subset may be key to effective immunotherapy. Here, we present a mass spectrometry-based analysis of HLA-presented peptidomes of GSC and glioblastoma patient specimens. Based on the analysis of patient samples (n = 9) and GSC (n = 3), we performed comparative HLA peptidome profiling against a dataset of normal human tissues. Using this immunopeptidome-centric approach we could clearly delineate a subset of naturally presented, GSC-associated HLA ligands, which might serve as highly specific targets for T cell-based immunotherapy. In total, we identified 17 antigens represented by 41 different HLA ligands showing natural and exclusive presentation both on GSC and patient samples. Importantly, in vitro immunogenicity and antigen-specific target cell killing assays suggest these peptides to be epitopes of functional CD8+ T cell responses, thus rendering them prime candidates for antigen-specific immunotherapy of glioblastoma.

The influence of intraoperative resection control modalities on survival following gross total resection of glioblastoma.

The purpose of the present study is to analyze the impact of intraoperative resection control modalities on overall survival (OS) and progression-free survival (PFS) following gross total resection (GTR) of glioblastoma. We analyzed data of 76 glioblastoma patients (30f, mean age 57.4 ± 11.6 years) operated at our institution between 2009 and 2012. Patients were only included if GTR was achieved as judged by early postoperative high-field MRI. Intraoperative technical resection control modalities comprised intraoperative ultrasound (ioUS, n = 48), intraoperative low-field MRI (ioMRI, n = 22), and a control group without either modality (n = 11). The primary endpoint of our study was OS, and the secondary endpoint was PFS-both analyzed in Kaplan-Meier plots and Cox proportional hazards models. Median OS in all 76 glioblastoma patients after GTR was 20.4 months (95 % confidence interval (CI) 18.5-29.0)-median OS in patients where GTR was achieved using ioUS was prolonged (21.9 months) compared to those without ioUS usage (18.8 months). A multiple Cox model adjusting for age, preop Karnofsky performance status, tumor volume, and the use of 5-aminolevulinic acid showed a beneficial effect of ioUS use, and the estimated hazard ratio was 0.63 (95 % CI 0.31-1.2, p = 0.18) in favor of ioUS, however not reaching statistical significance. A similar effect was found for PFS (hazard ratio 0.59, p = 0.072). GTR of glioblastoma performed with ioUS guidance was associated with prolonged OS and PFS. IoUS should be compared to other resection control devices in larger patient cohorts.

Interferon-ß Modulates the Innate Immune Response against Glioblastoma Initiating Cells.

Immunotherapy targeting glioblastoma initiating cells (GIC) is considered a promising strategy. However, GIC are prone to evade immune response and there is a need for potent adjuvants. IFN-ß might enhance the immune response and here we define its net effect on the innate immunogenicity of GIC. The transcriptomes of GIC treated with IFN-ß and controls were assessed by microarray-based expression profiling for altered expression of immune regulatory genes. Several genes involved in adaptive and innate immune responses were regulated by IFN-ß. We validated these results using reverse transcription (RT)-PCR and flow cytometry for corresponding protein levels. The up-regulation of the NK cell inhibitory molecules HLA-E and MHC class I was balanced by immune stimulating effects including the up-regulation of nectin-2. In 3 out of 5 GIC lines tested we found a net immune stimulating effect of IFN-ß in cytotoxicity assays using NKL cells as effectors. IFN-ß therefore warrants further investigation as an adjuvant for immunotherapy targeting GIC.

Primary glioblastoma cultures: can profiling of stem cell markers predict radiotherapy sensitivity?

Human glioblastomas may be hierarchically organized. Within this hierarchy, glioblastoma-initiating cells have been proposed to be more resistant to radiochemotherapy and responsible for recurrence. Here, established stem cell markers and stem cell attributed characteristics such as self-renewal capacity and tumorigenicity have been profiled in primary glioblastoma cultures to predict radiosensitivity. Furthermore, the sensitivity to radiotherapy of different subpopulations within a single primary glioblastoma culture was analyzed by a flow cytometric approach using Nestin, SRY (sex-determining region Y)-box 2 (SOX2) and glial fibrillary acidic protein. The protein expression of Nestin and SOX2 as well as the mRNA levels of Musashi1, L1 cell adhesion molecule, CD133, Nestin, and pleiomorphic adenoma gene-like 2 inversely correlated with radioresistance in regard to the clonogenic potential. Only CD44 protein expression correlated positively with radioresistance. In terms of proliferation, Nestin protein expression and Musashi1, pleiomorphic adenoma gene-like 2, and CD133 mRNA levels are inversely correlated with radioresistance. Higher expression of stem cell markers does not correlate with resistance to radiochemotherapy in the cancer genome atlas glioblastoma collective. SOX2 expressing subpopulations exist within single primary glioblastoma cultures. These subpopulations predominantly form the proliferative pool of the primary cultures and are sensitive to irradiation. Thus, profiling of established stem cell markers revealed a surprising result. Except CD44, the tested stem cell markers showed an inverse correlation between expression and radioresistance. Markers used to define glioma-initiating cells (GIC) are generally not defining a more resistant, but rather a more sensitive group of glioma cells. An exemption is CD44 expression. Also proliferation of the GIC culture itself was not systematically associated with radiosensitivity or - resistance, but a SOX-2 positive, proliferative subgroup within a GIC culture is showing the highest radiosensitivity.

Cilengitide treatment of newly diagnosed glioblastoma patients does not alter patterns of progression.

The integrin antagonist cilengitide has been explored as an adjunct with anti-angiogenic properties to standard of care temozolomide chemoradiotherapy (TMZ/RT → TMZ) in newly diagnosed glioblastoma. Preclinical data as well as anecdotal clinical observations indicate that anti-angiogenic treatment may result in altered patterns of tumor progression. Using a standardized approach, we analyzed patterns of progression on MRI in 21 patients enrolled onto a phase 2 trial of cilengitide added to TMZ/RT → TMZ in newly diagnosed glioblastoma. Thirty patients from the experimental treatment arm of the EORTC/NCIC pivotal TMZ trial served as a reference. MRIcro software was used to map location and extent of initial preoperative and recurrent tumors on MRI of both groups into the same stereotaxic space which were then analyzed using an automated tool of image analysis. Clinical and outcome data of the cilengitide-treated patients were similar to those of the EORTC/NCIC trial except for a higher proportion of patients with a methylated O(6)-methylguanyl-DNA-methyltransferase gene promoter. Analysis of recurrence pattern revealed neither a difference in the size of the recurrent tumor nor in the distance of the recurrences from the preoperative tumor location between groups. Overall frequencies of distant recurrences were 20 % in the reference group and 19 % (4/21 patients) in the cilengitide group. Compared with TMZ/RT → TMZ alone, the addition of cilengitide does not alter patterns of progression. This analysis does not support concerns that integrin antagonism by cilengitide may induce a more aggressive phenotype at progression, but also provides no evidence for an anti-invasive activity of cilengitide in patients with newly diagnosed glioblastoma.

Carboplatin and Etoposide in Heavily Pretreated Patients with Progressive High-Grade Glioma.

BACKGROUND: Treatment of recurrent anaplastic glioma and glioblastoma remains a particular challenge in neurooncology. The lack of controlled trials results in poor evidence for all therapeutic options. Upon recurrence, many patients are treated with bevacizumab or one of the frequently used nitrosoureas such as lomustine. However, patients who still present in overall good condition after failure of multiple lines of therapy may ask for additional therapy. METHODS: Here, we report our experience with the use of carboplatin in combination with etoposide as fourth- or fifth-line therapy in patients with progressive high-grade glioma. RESULTS: The median Karnofsky performance status at the beginning of treatment was 80%. The median progression-free survival (PFS) was 2.5 months. PFS at 6 months was 0%. Administration of carboplatin and etoposide was associated with grade 3 or 4 hematotoxicity in 8 of 12 patients. CONCLUSION: Carboplatin in combination with etoposide has an unfavorable risk-benefit profile in heavily pretreated glioma patients.

A disintegrin and metalloproteinases 10 and 17 modulate the immunogenicity of glioblastoma-initiating cells.

BACKGROUND: There are emerging reports that the family of a disintegrin and metalloproteinases (ADAM) are involved in the maintenance of the malignant phenotype of glioblastomas. Notably, ADAM proteases 10 and 17 might impair the immune recognition of glioma cells via the activating immunoreceptor NKG2D by cleavage of its ligands from the cell surface. Glioblastoma-initiating cells (GIC) with stem cell properties have been identified as an attractive target for immunotherapy. However, GIC immunogenicity seems to be low. METHODS AND RESULTS: Here,we show that ADAM10 and ADAM17 are expressed on the cell surface of GIC and contribute to an immunosuppressive phenotype by cleavage of ULBP2. The cell surface expression of ULBP2 is enhanced upon blocking ADAM10 and ADAM17, and treatment with ADAM10 and ADAM17specific inhibitors leads to enhanced immunerecognition of GIC by natural killer cells. CONCLUSIONS: Therefore, ADAM10 and ADAM17 constitute suitable targets to boost an immune response against GIC.

Treatment of primary CNS lymphoma.

OPINION STATEMENT: Primary central nervous system lymphoma is a particular challenge in clinical neuro-oncology. In contrast to most other malignant brain tumors, it may be considered a curable disease at least in younger patients who can tolerate intensive treatment regimens. Yet, therapeutic progress has been limited with little measurable improvement in outcome over the last two decades, mainly due to the low incidence of this tumor, which impedes the execution of large randomized clinical trials, and the failure of most large cooperative groups to conduct such trials. Whenever possible, high-dose methotrexate (HD-MTX) is the backbone of the therapeutic regimen. Response rates can be increased by the addition of second agents like ifosfamide or cytarabine, however, their impact on overall survival is less clear. Similarly, the use of the anti-CD20 antibody rituximab, commonly used in the treatment of B cell lymphomas outside the CNS, remains controversial and has not been examined in adequate clinical trials. The prognosis of patients, who do not qualify for HD-MTX-based chemotherapy, is considerably poorer. Radiation therapy is an active treatment with high response rates but does typically not result in long-lasting remissions. It remains an important therapeutic option as a salvage therapy in patients progressing on or no longer responding to HD-MTX-based treatment. The combination of HD-MTX and radiation therapy does not prolong overall survival. It is associated with significant neurotoxicity, and it should be avoided. Another matter of debate is whether consolidation therapy by other means, such as high-dose chemotherapy followed by stem cell support, is the most promising regimen. Given these numerous uncertainties, neuro-oncologists should strive for a treatment of PCNSL patients within clinical trials to allow for the development of improved therapeutic regimens.

APO010, a synthetic hexameric CD95 ligand, induces death of human glioblastoma stem-like cells.

The treatment of glioblastoma remains a major challenge in the field of neuro-oncology. There is emerging evidence that glioblastomas consist of heterogeneous cell populations with a small subset of cells with stem cell-like properties which might be resistant to conventional therapy and are thus crucial for tumor recurrence. These glioma-initiating cells (GICs) are therefore an attractive therapeutic target. Death receptor activation is one promising approach of cancer therapy. The synthetic hexameric cluster of differentiation 95 (CD95) agonist APO010 exhibits strong antiglioma activity towards human glioma cell lines, as well as in cell cultures of primary glioblastoma. Here, we investigated the ability of APO010 to induce cell death in a panel of previously well-defined GIC lines. The GIC lines and their derived differentiated cultures expressed CD95 on the cell surface and were sensitive towards APO010-mediated cell death to a variable extent. Temozolomide enhanced sensitivity of GICs to APO010. APO010 warrants being further evaluated as a tool to target GICs.

Targeting apoptosis pathways in glioblastoma.

The treatment of glioblastoma remains a major challenge for clinicians since these highly aggressive brain tumors are relatively resistant towards radio- and chemotherapy. The pathways that control apoptosis are altered in glioblastoma cells leading to resistance towards apoptotic stimuli in general. In this review we describe the alterations affecting the p53 pathway, the BCL-2 protein family, the inhibitor of apoptosis proteins and several growth factor pathways involved in the regulation of programmed cell death and define possible targets for new therapies within these apoptotic pathways in glioblastomas. Moreover, we review strategies to target death receptor pathways, most notably to render the glioblastoma cells more susceptible towards this approach without enhancing toxicity in general. Most of the strategies targeting apoptosis in glioblastomas presented here are in a pre-clinical stage of development, however, they all share the ultimative goal to improve the outcome for glioblastoma patients.

HLA-E contributes to an immune-inhibitory phenotype of glioblastoma stem-like cells.

Cancer stem cells are an attractive target for immunotherapeutic approaches to glioblastoma. However, an immune inhibitory phenotype of cells currently classified as "glioma-initiating cells" (GIC) might counteract recognition by immune effector cells. Here, we investigate the contribution of the non-classical MHC molecule HLA-E to the immunosuppressive phenotype of GIC. HLA-E is expressed in GIC lines and its expression is reduced upon differentiation of GIC in serum-containing culture conditions. Constitutive HLA-E inhibits natural killer (NK) cell-mediated lysis of GIC since small-interfering RNA-mediated HLA-E gene silencing enhances the immunogenicity of GIC. Increased GIC lysis was observed both in the CD133+ and in the CD133- compartment. Furthermore, the use of interferon-γ as a possible agent to boost an immune response against glioblastoma cells might be limited by the concurrent upregulation of HLA-E.

Immunology of brain tumors.

Brain tumors of different origin, but notably malignant gliomas, are characterized by their immunosuppressive properties which allow them to escape the host's immune surveillance. The activating immune cell ligands that are expressed by tumor cells, together with potentially immunogenic antigens, are overridden by numerous immune inhibitory signals, with TGF-3 as the master immunosuppressive molecule (Figure 4.1).The ongoing investigation of mechanisms of tumor-derived immunosuppression allows for an increasing understanding of brain tumor immunology. Targeting different mechanisms of tumor-derived immunosuppression, such as inhibition of TGF-[, may represent a promising strategy for future immunotherapeutic approaches.

A specific miRNA signature in the peripheral blood of glioblastoma patients.

The prognosis of patients afflicted by glioblastoma remains poor. Biomarkers for the disease would be desirable in order to allow for an early detection of tumor progression or to indicate rapidly growing tumor subtypes requiring more intensive therapy. In this study, we investigated whether a blood-derived specific miRNA fingerprint can be defined in patients with glioblastoma. To this end, miRNA profiles from the blood of 20 patients with glioblastoma and 20 age- and sex-matched healthy controls were compared. Of 1158 tested miRNAs, 52 were significantly deregulated, as assessed by unadjusted Student's t-test at an alpha level of 0.05. Of these, two candidates, miR-128 (up-regulated) and miR-342-3p (down-regulated), remained significant after correcting for multiple testing by Benjamini-Hochberg adjustment with a p-value of 0.025. The altered expression of these two biomarkers was confirmed in a second cohort of glioblastoma patients and healthy controls by real-time PCR and validated for patients who had received neither radio- nor chemotherapy and for patients who had their glioblastomas resected more than 6 months ago. Moreover, using machine learning, a comprehensive miRNA signature was obtained that allowed for the discrimination between blood samples of glioblastoma patients and healthy controls with an accuracy of 81% [95% confidence interval (CI) 78-84%], specificity of 79% (95% CI 75-83%) and sensitivity of 83% (95% CI 71-85%). In summary, our proof-of-concept study demonstrates that blood-derived glioblastoma-associated characteristic miRNA fingerprints may be suitable biomarkers and warrant further exploration.

APO010, a synthetic hexameric CD95 ligand, induces human glioma cell death in vitro and in vivo.

Death receptor targeting has emerged as one of the promising novel approaches of cancer therapy. The activation of one such prototypic death receptor, CD95 (Fas/APO-1), has remained controversial because CD95 agonistic molecules have exhibited either too strong toxicity or too little activity. The natural CD95 ligand (CD95L) is a cytokine, which needs to trimerize to mediate a cell death signal. Mega-Fas-Ligand, now referred to as APO010, is a synthetic hexameric CD95 agonist that exhibits strong antitumor activity in various tumor models. Here, we studied the effects of APO010 in human glioma models in vitro and in vivo. Compared with a cross-linked soluble CD95L or a CD95-agonistic antibody, APO010 exhibited superior activity in glioma cell lines expressing CD95 and triggered caspase-dependent cell death. APO010 reduced glioma cell viability in synergy when combined with temozolomide. The locoregional administration of APO010 induced glioma cell death in vivo and prolonged the survival of tumor-bearing mice. A further exploration of APO010 as a novel antiglioma agent is warranted.

SC68896, a novel small molecule proteasome inhibitor, exerts antiglioma activity in vitro and in vivo.

PURPOSE: Glioblastomas are among the most lethal neoplasms, with a median survival of <1 year. Modulation of the proteasome function has emerged as a novel approach to cancer pharmacotherapy. Here, we characterized the antitumor properties of SC68896, a novel small molecule proteasome inhibitor. EXPERIMENTAL DESIGN: Different tumor cell lines were tested by crystal violet staining for sensitivity to SC68896, given alone or in combination with death ligands. The molecular mechanisms mediating SC68896-induced cell death and changes in cell cycle progression were assessed by immunoblot and flow cytometry. An orthotopic human glioma xenograft model in nude mice was used to examine the in vivo activity of SC68896. RESULTS: SC68896 inhibits the proliferation of cell lines of different types of cancer, including malignant glioma. Exposure of LNT-229 glioma cells to SC68896 results in a concentration- and time-dependent inhibition of the proteasome, with a consequent accumulation of p21 and p27 proteins, cell cycle arrest, caspase cleavage, and induction of apoptosis. Using RNA interference, we show that the effect of SC68896 on glioma cells is facilitated by wild-type p53. SC68896 sensitizes glioma cells to tumor necrosis factor-related apoptosis-inducing ligand and CD95 ligand and up-regulates the cell surface expression of the tumor necrosis factor-related apoptosis-inducing ligand receptor cell death receptors 4 and 5, which may contribute to this sensitization. Intracerebral glioma-bearing nude mice treated either i.p. or intratumorally with SC68896 experience prolonged survival. CONCLUSIONS: SC68896 is the first proteasome inhibitor that exerts antiglioma activity in vivo. It may represent a novel prototype agent for the treatment of malignant gliomas and warrants clinical evaluation.

ACNU-based chemotherapy for recurrent glioma in the temozolomide era.

No standard of care for patients with recurrent glioblastoma has been defined since temozolomide has become the treatment of choice for patients with newly diagnosed glioblastoma. This has renewed interest in the use of nitrosourea-based regimens for patients with progressive or recurrent disease. The most commonly used regimens are carmustine (BCNU) monotherapy or lomustine (CCNU) combined with procarbazine and vincristine (PCV). Here we report our institutional experience with nimustine (ACNU) alone (n=14) or in combination with other agents (n=18) in 32 patients with glioblastoma treated previously with temozolomide. There were no complete and two partial responses. The progression-free survival (PFS) rate at 6 months was 20% and the survival rate at 12 months 26%. Grade III or IV hematological toxicity was observed in 50% of all patients and led to interruption of treatment in 13% of patients. Non-hematological toxicity was moderate to severe and led to interruption of treatment in 9% of patients. Thus, in this cohort of patients pretreated with temozolomide, ACNU failed to induce a substantial stabilization of disease in recurrent glioblastoma, but caused a notable hematotoxicity. This study does not commend ACNU as a therapy of first choice for patients with recurrent glioblastomas pretreated with temozolomide.