Glioblastoma multiforme: pathology, natural history and treatment

A Multiparametric Pharmacogenomic Strategy for Drug Repositioning predicts Therapeutic Efficacy for Glioblastoma Cell Lines

Background

Poor prognosis of glioblastoma patients and the extensive heterogeneity of glioblastoma at both the molecular and cellular level necessitates developing novel individualized treatment modalities via genomics-driven approaches.

Methods

This study leverages numerous pharmacogenomic and tissue databases to examine drug repositioning for glioblastoma. RNAseq of glioblastoma tumor samples from The Cancer Genome Atlas (TCGA, n=117) were compared to “normal” frontal lobe samples from Genotype-Tissue Expression Portal (GTEX, n=120) to find differentially expressed genes (DEGs). Using compound-gene expression data and drug activity data from the Library of Integrated Network-Based Cellular Signatures (LINCS, n=66,512 compounds) CCLE (71 glioma cell lines), and Chemical European Molecular Biology Laboratory (ChEMBL) platforms, we employed a summarized reversal gene expression metric (sRGES) to “reverse” the resultant disease signature for GBM and its subtypes. A multi-parametric strategy was employed to stratify compounds capable of blood brain barrier penetrance with a favorable pharmacokinetic profile (CNS-MPO).

Results

Significant correlations were identified between sRGES and drug efficacy in GBM cell lines in both ChEMBL(r=0.37,p<.001) and Cancer Therapeutic Response Portal (CTRP) databases (r=0.35, p<0.001). Our multiparametric algorithm identified two classes of drugs with highest sRGES and CNS-MPO: HDAC inhibitors (vorinostat and entinostat) and topoisomerase inhibitors suitable for drug repurposing.

Conclusions

Our studies suggest that reversal of glioblastoma disease signature correlates with drug potency for various GBM subtypes. This multiparametric approach may set the foundation for an early-phase personalized -omics clinical trial for glioblastoma by effectively identifying drugs that are capable of reversing the disease signature and have favorable pharmacokinetic and safety profiles.

Allicin Inhibits Proliferation by Decreasing IL-6 and IFN-β in HCMV-Infected Glioma Cells

PURPOSE

Allicin, an extract of garlic, has antitumor effects in multiple tumor types. However, the efficacy of allicin for treating glioblastoma has not yet been examined. This study examined the antitumor effect of allicin on human cytomegalovirus (HCMV)-infected glioblastoma multiforme (GBM) and its role in cytokine signaling.

MATERIALS AND METHODS

HCMV-infected glioblastoma was modeled by transfection of U87MG glioblastoma cells with HMCV proteins. MTT assay was used to assess the effect of allicin on the proliferation of glioma cells. Western blot analysis was used to detect the effect of allicin on the expression of intermediate-early gene 2 (IE2) and p53. Reverse transcription-quantitative polymerase chain reaction was used to assess and the levels of interleukin (IL)-6 and interferon (IFN)-β. Single cell gel electrophoresis was used to analyze changes in radiotherapy-induced DNA damage.

RESULTS

Transfection of the IE2 protein led to decreased p53 expression and increased glioblastoma cell proliferation. Allicin inhibited this proliferation in a dose- and time-dependent manner. An inhibitory effect on cytokine release was observed in GBM cells treated with allicin. After treatment with allicin, p53 levels increased significantly, whereas expression of the inflammatory factors such as IL-6 and IFN-β decreased. U87MG cells treated with allicin and 10 Gy irradiation had increased intracellular DNA damage compared to either treatment alone.

CONCLUSION

Allicin inhibited proliferation of glioblastoma cells in vitro. Allicin also inhibited cytokine release, upregulated p53 activity, and increased the sensitivity of glioblastoma to radiotherapy. These results suggest that allicin is effective against HCMV-infected glioblastomas.

Cross-species transcriptional analysis reveals conserved and host-specific neoplastic processes in mammalian glioma

Glioma is a unique neoplastic disease that develops exclusively in the central nervous system (CNS) and rarely metastasizes to other tissues. This feature strongly implicates the tumor-host CNS microenvironment in gliomagenesis and tumor progression. We investigated the differences and similarities in glioma biology as conveyed by transcriptomic patterns across four mammalian hosts: rats, mice, dogs, and humans. Given the inherent intra-tumoral molecular heterogeneity of human glioma, we focused this study on tumors with upregulation of the platelet-derived growth factor signaling axis, a common and early alteration in human gliomagenesis. The results reveal core neoplastic alterations in mammalian glioma, as well as unique contributions of the tumor host to neoplastic processes. Notable differences were observed in gene expression patterns as well as related biological pathways and cell populations known to mediate key elements of glioma biology, including angiogenesis, immune evasion, and brain invasion. These data provide new insights regarding mammalian models of human glioma, and how these insights and models relate to our current understanding of the human disease.

Flexible ligated ruthenium(II) self-assemblies sensitizes glioma tumor initiating cells in vitro

The tumorigenic potentials of residual cancer stem-like cells within tumors represent limitations of current cancer therapies. Here, the authors describe the effects of synthesized flexible, ligated, supramolecular self-assembled chair type tetranuclear ruthenium (II) metallacycles (2–5) on glioblastoma and glioma stem like cells. These self-assemblies were observed to be selectively toxic to glioma cells and CD133-positive glioma stem like cells population. Of the self-assembled compounds tested, metallacycle 4 more efficiently induced glioma stem like cells death within a brain cancer cell population and simultaneously inhibited the formation of free-floating gliospheres by reducing the sphere size. Detailed cell death studies revealed that treatment with metallacycle 4 reduced mitochondrial membrane potentials (an indicator of apoptosis) of glioma stem like cells. These results shows the elimination of cancer stem-like cells using an appropriate ligand binding adaptor offers a potential means of developing metal-based compounds for the treatment of chemo-resistant tumors.

Dendritic cell vaccine for recurrent high-grade gliomas in pediatric and adult subjects: clinical trial protocol

BACKGROUND

Although there have been significant advances in understanding the basic pathogenesis of glioblastoma multiforme, the median survival of patients has changed little in the past 25 years. Recent studies have suggested that immune modulation through dendritic cell (DC) vaccines may stimulate the immune system against tumor antigens and potentially increase survival.

OBJECTIVE

To determine whether the use of adjuvant vaccination with autologous DCs (matured in situ after being loaded with tumor cell lysate derived from autologous refractory gliomas) is safe, feasible, and beneficial for adult and pediatric patients with recurrent high-grade gliomas.

METHODS

The study design is a single-center, nonrandomized, open phase I clinical trial. A total of 20 patients with malignant gliomas will be enrolled preoperatively over 2 years. Patients will be given adjuvant vaccination with autologous DCs loaded with tumor lysate after maximal safe surgical resection.

EXPECTED OUTCOMES

Using topical imiquimod before vaccination, it is anticipated that the immune response in vaccinated patients and potentially Overall survival will be greater than that demonstrated in the literature. We anticipate that there will be minimal side effects (minor dermatitis) associated with this treatment.

DISCUSSION

In the current trial, we assess immune response, safety, and survival using a novel vaccine protocol developed in Belgium that seems to markedly increase survival of certain subjects. Nevertheless, larger randomized clinical studies need to be performed to evaluate fully the efficacy of this therapy for both recurrent and newly diagnosed glioblastoma.

Targeting cancer stem cells for treatment of glioblastoma multiforme

Cancer stem cells (CSCs) in glioblastoma multiforme (GBM) are radioresistant and chemoresistant, which eventually results in tumor recurrence. Targeting CSCs for treatment is the most crucial issue. There are five methods for targeting the CSCs of GBM. One is to develop a new chemotherapeutic agent specific to CSCs. A second is to use a radiosensitizer to enhance the radiotherapy effect on CSCs. A third is to use immune cells to attack the CSCs. In a fourth method, an agent is used to promote CSCs to differentiate into normal cells. Finally, ongoing gene therapy may be helpful. New therapeutic agents for targeting a signal pathway, such as epidermal growth factor (EGF) and vascular epidermal growth factor (VEGF) or protein kinase inhibitors, have been used for GBM but for CSCs the effects still require further evaluation. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as cyclooxygenase-2 (Cox-2) inhibitors have proven to be effective for increasing radiation sensitivity of CSCs in culture. Autologous dendritic cells (DCs) are one of the promising immunotherapeutic agents in clinical trials and may provide another innovative method for eradication of CSCs. Bone-morphogenetic protein 4 (BMP4) is an agent used to induce CSCs to differentiate into normal glial cells. Research on gene therapy by viral vector is also being carried out in clinical trials. Targeting CSCs by eliminating the GBM tumor may provide an innovative way to reduce tumor recurrence by providing a synergistic effect with conventional treatment. The combination of conventional surgery, chemotherapy, and radiotherapy with stem cell-orientated therapy may provide a new promising treatment for reducing GBM recurrence and improving the survival rate.

B7-H4 expression is elevated in human U251 glioma stem-like cells and is inducible in monocytes cultured with U251 stem-like cell conditioned medium

Previous studies indicated that B7-H4, the youngest B7 family, negatively regulates T cell-mediated immunity and is significantly overexpressed in many human tumors. Tumor stem cells are purported to play a role in tumor renewal and resistance to radiation and chemotherapy. However, the link between B7-H4 and tumor stem cells is unclear. In this study, we investigated B7-H4 expression in the medium of human glioma U251 cell cultures. Immunofluorescence results showed that U251 cells cultured in serum-free medium (supplemented with 2% B27, 20 ng/mL epidermal growth factor, 20 ng/mL basic fibroblast growth factor) maintained stem-like cell characteristics, including expression of stem cell marker CD133 and the neural progenitor cell markers nestin and SOX2. In contrast, U251 cells cultured in serum-containing medium highly expressed differentiation marker glial fibrillary acidic protein. Flow cytometry analysis showed serum-free medium-cultured U251 cells expressed higher intracellular B7-H4 than serum-containing medium-cultured U251 cells (24%–35% vs. 8%–11%, P < 0.001). Immunofluorescence in purified monocytes from normal human peripheral blood mononuclear cells revealed moderate expression of B7-H4 after stimulation with conditioned medium from U251 cells cultured in serum-containing medium. Moreover, conditioned medium from U251 stem-like cells had a significant stimulation effect on B7-H4 expression compared with serum-containing conditioned medium (P < 0.01). Negative costimulatory molecule B7-H4 was preferentially expressed in U251 stem-like cells, and conditioned medium from these cells more effectively induced monocytes to express B7-H4 than conditioned medium from U251 cells cultured in the presence of serum. Our results show that U251 stem-like cells may play a more crucial role in tumor immunoloregulation with high expression of B7-H4.

CCL5, CCR1 and CCR5 in murine glioblastoma: immune cell infiltration and survival rates are not dependent on individual expression of either CCR1 or CCR5

Glioblastoma multiforme (GBM) is the most malignant brain tumor. Microglia/macrophages are found within human GBM where they likely promote tumor progression. We report that CCL5, CCR1, and CCR5 are expressed in glioblastoma. Individual deletion of CCR1 or CCR5 had little to no effect on survival of tumor bearing mice, or numbers of glioblastoma-infiltrated microglia/macrophages or lymphocytes. CCL5 promoted in vitro migration of wild type, CCR1- or CCR5-deficient microglia/macrophages that was blocked by the dual CCR1/CCR5 antagonist, Met-CCL5. These data suggest that CCL5 functions within the glioblastoma microenvironment through CCR1 and CCR5 in a redundant manner.

The Role of Cancer Stem Cells (CD133+) in Malignant Gliomas

Malignant gliomas, particularly glioblastoma multiforme (GBM) tumors, are very difficult to treat by conventional approaches. Although most of the tumor mass can be removed by surgical resection, radiotherapy, and chemotherapy, it eventually recurs. There is growing evidence that cancer stem cells (CSCs) play an important role in tumor recurrence. These stem cells are radioresistant and chemoresistant. The most commonly used tumor marker for CSCs is CD133. The amount of CSC component is closely correlated with tumor malignancy grading. Isolating, identifying, and treating CSCs as the target is crucial for treating malignant gliomas. CSC-associated vascular endothelial growth factor (VEGF) promotes tumor angiogenesis, tumor hemorrhage, and tumor infiltration. Micro-RNA (miRNA) plays a role in CSC gene expression, which may regulate oncogenesis or suppression to influence tumor development or progression. The antigenesis of CSCs and normal stem cells may be different. The CSCs may escape the T-cell immune response. Identifying a new specific antigen from CSCs for vaccine treatment is a key point for immunotherapy. On the other hand, augmented treatment with radiosensitizer or chemosensitizer may lead to reduction of CSCs and lead to CSCs being vulnerable to radiotherapy and chemotherapy. The control of signaling pathway and cell differentiation to CSC growth is another new hope for treatment of malignant gliomas. Although the many physiological behavioral differences between CSCs and normal stem cells are unclear, the more we know about these differences the better we will be able to treat CSCs effectively.

Canadian recommendations for the treatment of glioblastoma multiforme

Recommendation 1

Management of patients with glioblastoma multiforme (gbm) should be highly individualized and should take a multidisciplinary approach involving neuro-oncology, neurosurgery, radiation oncology, and pathology, to optimize treatment outcomes. Patients and caregivers should be kept informed of the progress of treatment at every stage.

Recommendation 2

Sufficient tissue should be obtained during surgery for cytogenetic analysis and, whenever feasible, for tumour banking.

Recommendation 3

Surgery is an integral part of the treatment plan, to establish a histopathologic diagnosis and to achieve safe, maximal, and feasible tumour resection, which may improve clinical signs and symptoms.

Recommendation 4

The preoperative imaging modality of choice is magnetic resonance imaging (mri) with gadolinium as the contrast agent. Other imaging modalities, such as positron emission tomography with [¹⁸F]-fluoro-deoxy-d-glucose, may also be considered in selected cases. Postoperative imaging (mri or computed tomography) is recommended within 72 hours of surgery to evaluate the extent of resection.

Recommendation 5

Postoperative external-beam radiotherapy is recommended as standard therapy for patients with gbm. The recommended dose is 60 Gy in 2-Gy fractions. The recommended clinical target volume should be identified with gadolinium-enhanced T1-weighted mri, with a margin in the order of 2–3 cm. Target volumes should be determined based on a postsurgical planning mri. A shorter course of radiation may be considered for older patients with poor performance status.

Recommendation 6

During rt, temozolomide 75 mg/m² should be administered concurrently for the full duration of radio-therapy, typically 42 days. Temozolomide should be given approximately 1 hour before radiation therapy, and at the same time on the days that no radiotherapy is scheduled.

Recommendation 7

Adjuvant temozolomide 150 mg/m², in a 5/28-day schedule, is recommended for cycle 1, followed by 5 cycles if well tolerated. Additional cycles may be considered in partial responders. The dose should be increased to 200 mg/m² at cycle 2 if well tolerated. Weekly monitoring of blood count is advised during chemoradiation therapy in patients with a low white blood cell count. Pneumocystis carinii pneumonia has been reported, and prophylaxis should be considered.

Recommendation 8

For patients with stable clinical symptoms during combined radiotherapy and temozolomide, completion of 3 cycles of adjuvant therapy is generally advised before a decision is made about whether to continue treatment, because pseudo-progression is a common phenomenon during this time. The recommended duration of therapy is 6 months. A longer duration may be considered in patients who show continuous improvement on therapy.

Recommendation 9

Selected patients with recurrent gbm may be candidates for repeat resection when the situation appears favourable based on an assessment of individual patient factors such as medical history, functional status, and location of the tumour. Entry into a clinical trial is recommended for patients with recurrent disease.

Recommendation 10

The optimal chemotherapeutic strategy for patients who progress following concurrent chemoradiation has not been determined. Therapeutic and clinical–molecular studies with quality of life outcomes are needed.

Intralesional lymphokine-activated killer cells as adjuvant therapy for primary glioblastoma

Despite recent advances, median survival for patients with resectable glioblastoma multiforme (GBM) is only 12 to 15 months. We previously observed minimal toxicity and a 9.0-month median survival after treatment with intralesional autologous lymphokine-activated killer (LAK) cells in 40 patients with recurrent GBM. In this study, GBM patients were treated with adjuvant intralesional LAK cells. Eligible patients had completed primary therapy for GBM without disease progression. LAK cells were produced by incubating autologous peripheral blood mononuclear cells with interleukin-2 for 3 to 7 days and then placed into the surgically exposed tumor cavity by a neurosurgeon. The 19 men and 14 women had a median age of 57 years. Prior therapy included surgical resection (97%), partial brain irradiation (97%), gamma knife radiosurgery (97%), and temozolomide chemotherapy (70%). Median time from diagnosis to LAK cell therapy was 5.3 months (range: 3.0 to 11.1 mo). LAK cell treatment was well tolerated; average length of hospitalization was 3 days. At the time of this analysis, 27 patients have died; the median survival from the date of original diagnosis is 20.5 months with a 1-year survival rate of 75%. In subset analyses, superior survival was observed for patients who received higher numbers of CD3+/CD16+/CD56+ (T-LAK) cells in the cell products, which was associated with not taking corticosteroids in the month before leukopheresis. Intralesional LAK cell therapy is safe and the survival sufficiently encouraging to warrant further evaluation in a randomized phase 2 trial of intralesional therapies with LAK or carmustine-impregnated wafers.

Recent Advances of Dendritic Cells (DCs)-Based Immunotherapy for Malignant Gliomas

Immunotherapy is a new light of hope for the treatment of malignant gliomas. The brain is no longer believed to be an immunologically privileged organ. The major advantage of immunotherapy is the tumor-specific cytotoxic effect on the tumor cells with minimal side effects. Autologous dendritic cells (DCs)-based immunotherapy is a promising and feasible method. DCs are the most potent antigen-presenting cells (APCs). DCs prime T lymphocytes by epitopic major histocompatibility (MHC) class I and II for CD8+ cytotoxic T lymphocytes (CTLs) and CD4+ T helper cells, respectively. From the tissue specimen examination after DCs-based immunotherapy, CD8+ CTLs have replaced T regulatory cells (Tregs) as the major dominant tissue infiltrating lymphocytes (TILs). CD8+ CTLs play a key role in the tumor response, which may also be effective against cancer stem cells. DCs themselves also produce many cytokines including interferon-γ and interleukin (IL-2) to kill the tumor cells. From the preliminary better outcomes in the literature for malignant gliomas, DC-based immunotherapy may improve tumor response by increasing the survival rate and time. It is recommended that DC-based immunotherapy is applied as soon as possible with conjunctive radiotherapy and chemotherapy. Malignant gliomas have heterogeneity of tissue-associated antigens (TAAs). To find universal common antigens through different kinds of tumor culture may be the essential issue for tumor vaccine development in the future.

Localized BCNU chemotherapy and the multimodal management of malignant glioma

BACKGROUND

Gliomas account for 42% of all primary CNS neoplasms and 77% of all malignant primary CNS neoplasms. Unfortunately the high-grade variant of gliomas, glioblastoma multiforme (GBM), is difficult to treat and generally considered incurable. Survival rates are generally poor, and neurological morbidity in the setting of disease progression is high. Fortunately, significant progress has been achieved in the past decade in our understanding of the molecular biology of this aggressive tumour histology and, as a consequence, there is renewed clinical trial activity in this area focused on improving quality of life, treatment-related morbidity and outcomes.

METHODS

A review of literature from June 2005 to June 2008 was conducted on multimodal treatment of malignant glioma (MG) patients, using specific search criteria in Medline, EMBASE, and BIOSIS. Abstracts from relevant US and European medical (cancer) meetings were also evaluated.

RESULTS

The established therapies for MG include surgery, radiotherapy (RT), and local or systemic chemotherapy. However, over the last 10 years only two chemotherapeutic agents have received regulatory approval for treatment of MG: polifeprosan 20 with carmustine (BCNU implant) and temozolomide (TMZ), an imidazotetrazine derivative of dacarbazine. More recent advances in the treatment of brain tumours have been in the development of multimodal approaches. Specific interest in the combination of BCNU implant and TMZ has arisen due to the demonstrable depletion by TMZ of the DNA repair enzyme responsible for resistance to a nitrosourea such as BCNU. Further interest in this combination stems from the observation that there is a difference in the time to peak effect for each agent. Additional emerging data suggest that multimodal therapy with maximal resection and BCNU implants, followed by adjuvant therapy with radiation and TMZ, is effective and well-tolerated in patients with initial high-grade, resectable MG.

CONCLUSIONS

The increasing body of efficacy data suggests that this combination of BCNU implants and TMZ within a multimodal treatment strategy including surgery and RT may provide an enhanced benefit compared with the use of either of these agents alone in select patients with high-grade glioma.

Parotid gland metastasis from glioblastoma multiforme: a case report and review of the literature

We describe a rare case of glioblastoma multiforme with extracranial metastasis to the right parotid gland. A 58-year-old man presented with a parotid tumor and facial paralysis 15 months after craniotomy and partial lobectomy for glioblastoma multiforme of the right temporal lobe. Diagnosis was confirmed by ultrasound guided core-needle biopsy. By this means, a second hospitalization with open surgical biopsy of the parotid gland under general anesthesia for diagnosis only was avoided in this obviously palliative situation. The possible mechanisms of metastasic spread in this highly aggressive tumor and its diagnostic investigation are discussed and compared with the literature.

Recent progress in immunotherapy for malignant glioma: treatment strategies and results from clinical trials

BACKGROUND

Despite advances in surgical and adjuvant radiation therapy and chemotherapy strategies, malignant gliomas continue to be associated with poor prognoses.

METHODS

We review immune-mediated treatment approaches for malignant glioma and the relevance of recent clinical trials and their outcomes. We specifically address the increasing evidence implicating the role of cytotoxic T cells in ensuring adequate immune-mediated clearance of neoplastic cells and the need for the optimization of therapies that can elicit and support such antitumor T-cell activity.

RESULTS

The poor outcome of this disease has spurred the search for novel experimental therapies that can address and overcome the root biological phenomena associated with the lethality of this disease. The use of immunotherapy to bolster the otherwise impaired antitumor immune responses in glioma patients has received increasing attention.

CONCLUSIONS

An effective treatment paradigm for malignant gliomas may eventually require a multifaceted approach combining two or more different immunotherapeutic strategies. Such scenarios may involve the use of local cytokine gene therapy to enhance glioma-cell immunogenicity in conjunction with dendritic cell-based active vaccination to stimulate systemic tumoricidal T-cell immunity. Given the heterogeneity of this disease process and the potential risk of immunoediting out a selected, treatment-refractory tumor cell population, the concurrent use of multiple modalities that target disparate tumor characteristics may be of greatest therapeutic relevance.

Human gliosarcoma-associated ganglioside composition is complex and distinctive as evidenced by high-performance mass spectrometric determination and structural characterization

Gangliosides (GGs), involved in malignant alteration and tumor progression/invasiveness, are considered as tumor biomarkers or therapeutic targets. Here, we describe the first systematic GG composition characterization in human gliosarcoma versus normal brain tissue using our recently developed mass spectrometry (MS) methods, based on nano-electrospray (nano-ESI), Fourier-transform ion cyclotron resonance (FT-ICR), and chip nano-ESI quadrupole time-of-flight (QTOF), complemented by thin-layer chromatographic (TLC) analysis and quantification. Combined MS enabled detection and structural assignment of 73 distinct GG species: many more than reported so far for investigated gliomas. Apart from the 7.4-times lower total GG content, gliosarcoma contained all major brain-associated species, however, in very altered proportions, exhibiting a highly distinctive pattern: GD3 (48.9%)>GD1a/nLD1>GD2/GT3>GM3>GT1b>GM2>GM1a/GM1b/nLM1>LM1>GD1b>GQ1b. MS also revealed abundant O-Ac-GD3; its sequencing provided structural evidence to postulate a novel O-Ac-GD3 isomer O-acetylated at the inner Neu5Ac-residue, previously not structurally confirmed. The high sensitivity and mass accuracy permitted the assignment of unusual minor species: GM4, Hex-HexNAc-nLM1, Gal-GD1, Fuc-GT1, GalNAc-GT1, O-Ac-GM3, di- O-Ac-GD3O-Ac-GD3, and O-Ac-GT3, not previously reported as glioma-associated. The gliosarcoma-expressed GA2 might represent a marker distinguishing astrocytic from oligodendroglial tumors. This is, to our knowledge, so far the most complete GG composition characterization of certain glioma, which demonstrates that our MS-based approach could provide essential structural information relevant to glycosphingolipid role(s) in brain tumor biology, differential diagnosis/prognosis and novel treatment concepts.

New trends in the medical management of glioblastoma multiforme: the role of temozolomide chemotherapy

Standard care for newly diagnosed glioblastoma multiforme (GBM) previously consisted of resection to the greatest extent feasible, followed by radiotherapy. The role of chemotherapy was controversial and its efficacy was marginal at best. Five years ago temozolomide (TMZ) was approved specifically for the treatment of recurrent malignant glioma. The role of TMZ chemotherapy administered alone or as an adjuvant therapy for newly diagnosed GBM has been evaluated in a large randomized trial whose results suggested a significant prolongation of survival following treatment. Findings of correlative molecular studies have indicated that methylguanine methyltransferase promoter methylation may be used as a predictive factor in selecting patients most likely to benefit from such treatment. In this short review the authors summarize the current role of TMZ chemotherapy in the management of GBM, with an emphasis on approved indications and practical aspects.

Case—control study of stereotactic radiosurgery for recurrent glioblastoma multiforme

Object. The role of stereotactic radiosurgery (SRS) for recurrent glioblastoma multiforme (GBM) was evaluated in a case—control study.

Methods. All patients who underwent SRS for recurrent GBM before March 2003 formed the case group. A control group of patients who did not undergo SRS was created from an institutional database, and each case was matched for known prognostic factors in GBM. The medical and neuroimaging records of all the patients were reviewed, and survival and treatment outcomes were recorded.

The case and control groups were well matched with regard to demographics and pre-SRS interventions. In the control group, the date on which magnetic resonance imaging identified a recurrent lesion that would have been eligible for SRS was deemed the “SRS” date. The number of surgeries performed in the control group was statistically higher than that in the case group. The median duration of overall survival from diagnosis was 26 months in the case group and 23 months in the control group. From the date of SRS or “SRS”, the median duration of survival was 11 months in the case group and 10 months in the control group, a difference that was not statistically significant.

Conclusions. It appears that a subgroup of patients with GBMs has a higher than expected median survival duration despite the initial prognostic factors. In patients with localized recurrences, survival may be prolonged by applying aggressive local disease management by using either SRS or resection to equal advantage.

Cutaneous metastasis from an intracranial glioblastoma multiforme

A 34-year-old white man with a history of an intracranial glioblastoma multiforme was treated with surgical excision and radiotherapy. Five months later, the patient had a rapidly growing scalp mass develop. This lesion was excised, and the histology revealed a tumor that was similar to the originally resected intracranial glioblastoma. Immunohistochemistry for general neuroepithelial derivation (S-100 protein) and for glial fibrillary acidic protein (GFAP) was positive, whereas mesenchymal, epithelial, and neuronal markers were negative. This immunohistochemistry pattern was identical to the original tumor. Although metastasis of this tumor is not uncommon, metastasis to the skin has never been reported. To our knowledge, this is the first reported case of cutaneous metastasis from glioblastoma in the world literature.

Malignant glioma cells use MHC class II transactivator (CIITA) promoters III and IV to direct IFN-gamma-inducible CIITA expression and can function as nonprofessional antigen presenting cells in endocytic processing and CD4(+) T-cell activation

Malignant gliomas (MGs), lethal human central nervous system (CNS) neoplasms, contain tumor infiltrating lymphocytes (TIL). Although MHC class II molecules are frequently detected on MG cells, suggesting that they may be capable of antigen (Ag) presentation to CD4(+) T cells, deficiencies in CD4(+) T-cell activation are associated with these nonimmunogenic tumors. We evaluated regulation of the MHC class II transactivator (CIITA), the key intermediate that controls class II expression, in MG cells and tested whether MG cells could process native Ag. After interferon-gamma (IFN-gamma) stimulation, MG cells upregulated CIITA and class II molecules. IFN-gamma-inducible CIITA expression in MG cells, as well as primary human astrocytes, was directed by two CIITA promoters, pIV, the promoter for IFN-gamma-inducible CIITA expression in nonprofessional antigen-presenting cells (APC), and pIII, the promoter that directs constitutive CIITA expression in B cells. Both pIII and pIV directed CIITA transcription in vivo in MGs and ex vivo in IFN-gamma-activated primary MG cultures. We also demonstrate for the first time that MG cells can process native Ag for presentation to CD4(+) MHC class II-restricted Th1 cells, indicating that MG cells can serve as nonprofessional APC. CIITA may be a key target to modulate MHC class II expression, which could augment immunogenicity, Ag presentation, and CD4(+) T-cell activation in MG therapy.

Evaluation of pre-radiotherapy cyclophosphamide in patients with newly diagnosed glioblastoma multiforme. Writing Committee for The Brain Tumor Center at Duke

Cyclophosphamide is an alkylating agent that has shown activity in the treatment of pediatric brain tumors, including high-grade gliomas. This study was designed to evaluate the response of patients with newly diagnosed glioblastoma multiforme to pre-radiotherapy cyclophosphamide. Fourteen patients with glioblastoma multiforme were treated with high-dose cyclophosphamide (2 g/m2/day for 2 doses every 28 days) followed by either sargramostim or filgrastin. Sargramostim was given 250 microg/m2 subcutaneously twice a day continuing through the leukocyte nadir until the absolute neutrophil count was more than 1000 cells/microl for 2 consecutive days. The filgrastin dose was 10 microg/kg given subcutaneously once daily until the post nadir absolute neutrophil count was > or = 10,000 cells/microl. A total of 46 courses was given. Four patients received a total of 3 courses, 7 patients completed 4 courses and 3 patients received 2 courses. Three patients demonstrated complete response; 3 stable disease; and 8 progressive disease. The most common toxicity was hematologic, requiring platelet and packed red blood cell transfusions, with 13 admissions for neutropenia with fever. There were no deaths related to infection or bleeding. These results suggest that high-dose cyclophosphamide has modest activity with acceptable toxicity against newly diagnosed glioblastoma multiforme.

A retrospective analysis of postradiation chemotherapy in 133 patients with glioblastoma multiforme

The impact on survival of postradiation nitrosourea-containing chemotherapy (CHT) in patients with glioblastoma multiforme (GM) was analyzed retrospectively in 133 patients who completed the planned radiotherapy out of 173 observed cases. Thirty-five patients were < 50 years old, 89 were males, 20 had performance status (PS) < 70 and 72 > or = 70. Surgery was followed by radiotherapy in all cases (50-60 Gy in 95 patients, 61-70 Gy in 38 patients). At the end of radiotherapy, 43 patients received CHT, whereas 90 patients did not receive further therapy. At univariate analysis, age < 50 years, feminine gender, subtotal or total resection, radiotherapy doses > 60 Gy, and CHT had an independent prognostic value. Our results suggest that chemotherapy improves 2-year survival rates from 12% to 28% in GM. The sequence of treatment, new drugs, and combinations should be further explored.

Phase II clinical trial of didemnin B in patients with recurrent or refractory anaplastic astrocytoma or glioblastoma multiforme (NSC 325319)

The activity of didemnin B, a natural product derived from the Caribbean Tunic was assessed in 16 patients with Glioblastoma multiforme. Didemnin B was administered intravenously by a short infusion at a dose of 4.3 mg/m2 and subsequently escalated to 6.3 mg/m2. No anti-tumor activity was observed. Toxicity consisted of fatigue, weakness, stomatitis, mild blood count changes, nausea and vomiting and occasional fever. Based on these results further studies with didemnin B in patients with Glioblastoma multiforme are not recommended.

Prognostic value of flow cytometry and correlation to some conventional prognostic factors: a retrospective study of archival specimens of 134 astrocytomas

The S-phase fraction and the DNA ploidy type in 134 astrocytomas (18 Grade II, 46 Grade III, and 70 Grade IV astrocytomas) were studied using flow cytometry in a retrospective study of archival tumor specimens. A high grade of malignancy was associated with both a high S-phase fraction (p < 0.0001) and an aneuploid DNA pattern (p < 0.0001). There was no aneuploid DNA pattern found in the fibrillary astrocytomas (World Health Organization (WHO) Grade II); where-as the aneuploid pattern was observed in 80% of all the glioblastomas multiforme (WHO Grade IV). The age and gender of the patients were not significantly related to the flow cytometry parameters. The survival of patients with Grade II or III astrocytomas was significantly longer when their tumors exhibited a tetraploid DNA pattern or had a low S-phase fraction. In patients with Grade IV tumors, there was no correlation between length of survival and either the DNA ploidy or the S-phase fraction. In a multivariate Cox regression analysis of data obtained in patients with Grade II and III astrocytomas, age, grade of malignancy, DNA ploidy, and S-phase fraction were independent prognostic factors.

Prognostic factors for glioblastoma multiforme--development of a prognostic index

The prognosis for glioblastoma multiforme is generally poor. However, it can be useful to identify groups of patients with varying prognosis. Based on data from 495 consecutive patients admitted to the Norwegian Radium Hospital during 1980-1994, multivariable methods were used to identify prognostic factors independently associated with length of survival. A prognostic index was derived in 384 randomly selected patients, and tested in 111 other patients. Performance status, dexamethasone dependency, age group, surgery and behavioural changes were prognostic discriminators. On this basis a prognostic index was made and three separate subsets with different survival prognoses could be identified. The prognostic index was then tested among 20% of the patients and shown to predict reliable survival curves. In the subset with the highest index (high risk subset) almost all patients in the main group as well as in the the test group were dead within 18 months.

Interferon alpha-2a and external beam radiotherapy in the initial management of patients with glioma: a pilot study of the National Biotherapy Study Group

The National Biotherapy Study Group conducted a phase I/II trial of alpha-interferon (IFN) plus radiation therapy (RT) in glioma patients to confirm the feasibility of combining these two modalities. Patients newly diagnosed gliomasreceived external beam RT as 180 cGy in 33 fractions over six to seven weeks, five days a week, and IFN at a dose of 3 MIU SC Monday, Wednesday and Friday of each week. IFN was increased to 5 MIU after two weeks and was given for up to 16 weeks. Patients were monitored for toxicity and failure-free and overall survival. There were 12 men and seven women with an age range of 24-77, and a median age of 64 years. There were 12 glioblastomas and seven advanced astrocytomas. Complete surgical resection was carried out in two patients, nine had a partial resection, and eight had a biopsy only. Two patients in the latter group deteriorated rapidly and received < 2 weeks of RT/IFN. One patient stopped IFN because of a skin rash, another stopped because of concurrent pneumonia, and one patient was noncompliant. RT and IFN were well-tolerated; 14 of the 19 patients completed the eight weeks of IFN/RT. However, only three patients took IFN for the maximum of 16 weeks. The only grade 4 toxicities noted were increases SGOT in three, increases alk phos in two, and severe fatigue in four patients. The median failure-free survival was two months, median survival was 7.5 months, and four patients survived beyond one year. The longest survivor was 29.1 months, and one patient is still alive after 20.7 months. IFN/RT can be safely co-administered in patients with gliomas. A randomized trial would be needed to establish clinical benefit.

Loco-regional immunotherapy with recombinant interleukin-2 and adherent lymphokine-activated killer cells (A-LAK) in recurrent glioblastoma patients

Nine patients with recurrent glioblastoma were given autologous adherent lymphokine-activated killer (A-LAK) cells and interleukin-2 (IL-2) administered directly into the tumor cavity through an Ommaya tube placed during surgery/biopsy. The immunotherapy was well tolerated and the response rate was 33% (one complete response, two partial responses, four with stable disease and two with progressive disease). However, survival 18 months from initial diagnosis did not differ from that reported in the literature for patients treated conventionally. Serial determinations of IL-2 in the tumor cavity during the course of treatment revealed that IL-2 concentrations were sufficient to maintain lymphocyte activation. Since steroid medication was discontinued during treatment and A-LAK cells have greater antitumor activity than standard LAK cells, other factors are discussed that might explain the limited results.

Pilot study of 6 weeks of chemoradiotherapy with 5 FU and hydroxyurea in malignant gliomas

In an attempt to improve the primary treatment of malignant gliomas we used a concomitant 6-week course of chemoradiotherapy with 5 fluorouracil (5 FU) and hydroxyurea (HU) in 24 adults with anaplastic astrocytoma (AA) (7 cases) or glioblastomas (GLB) (17 cases). This patient population was characterised by a poor prognostic profile; 50% of cases had biopsic or subtotal surgery and 70% had GLB. Patients received 2 Gy/day 18 MV photons with 300 mg/m2 of 5 FU in continuous infusion and 500 mg x 4/day per os of HU, five days per week during 6 weeks. Treatment was poorly tolerated in terms of toxicity and implied heavy logistics (hospitalization, central venous access) worsening the quality of life which is already bad in malignant gliomas. Unfortunately we did not improve median survival which does not exceed 26 weeks with 7 long survivors (> 49 weeks). This pilot study does not offer any benefits over current standard approaches. Aggressive locoregional approaches such as this should perhaps be attempted in patients with a better profile.

Radiosensitivity testing of human malignant gliomas

Radiotherapy remains the main treatment modality for patients with malignant gliomas and is the only treatment which significantly prolongs survival. Clonogenic and tetrazolium based colorimetric assays (MTT) of early passage cultures have been performed following 2 Gy doses of x-rays in order to determine if in vitro radiosensitivity is a factor in response to treatment. Of 47 biopsies received, 39 were established in primary culture. A value of surviving fraction to 2 Gy (SF2) was obtained in 85% of growth assays and 64% of clonogenic assays. The mean SF2 value for the MTT was 0.56 which was significantly higher than the 0.42 obtained for the clonogenic assay. There was, however, reasonable qualitative agreement in assessing relative radiosensitivity/radioresistance (r = 0.7). Mean SF2 values for grade 3 tumors were 0.52 (MTT) and 0.35 (clonogenic) as against mean SF2 values of 0.63 (MTT) and 0.47 (clonogenic assay) for grade 4 tumors. In 24 patients with adequate follow-up, no direct correlation was found between SF2 and survival, although mean SF2 values for patients surviving greater than 18 months was significantly less (p = 0.01) than patients surviving less than 18 months as determined by the MTT assay.

The prognosis of primary intracerebral tumours presenting with epilepsy: the outcome of medical and surgical management

It is not known whether conservative or early aggressive (resective surgery with or without radiotherapy) management is better for tumours presenting with epilepsy. The prognosis of 560 patients with a clinical and CT diagnosis of intrinsic supratentorial tumour was examined retrospectively. Epilepsy was the first symptom in 164 patients. Histological confirmation of diagnosis was available in 391 (70%) of cases. Median survival was 37 months in the group presenting with epilepsy and six months in those presenting with other symptoms (p less than 0.0001). Patients presenting with epilepsy were more likely to have a normal clinical examination, a non-enhancing low density lesion on CT scan and a low grade tumour. From Cox's stepwise proportional hazards model, significant independent variables adversely affecting prognosis were increasing age, focal neurological signs and enhancing CT lesions at diagnosis, non-resective surgery and male sex. Of those presenting with epilepsy 80 patients had surgical treatment within two months of CT diagnosis. The Cox's model failed to identify any beneficial effects for either early resective surgery or radiotherapy. In primary intracerebral tumours with presentations other than epilepsy, resective surgery and radiotherapy were amongst the important factors associated with prolonged survival. Primary intracerebral tumours presenting with epilepsy are relatively benign and their outcome appears to be chiefly determined by clinical factors.

The effects of local and systemic interferon beta (Fiblaferon) on supratentorial malignant cerebral glioma--a phase II study

In contrast to the highly promising and, with rates up to 40%, surprisingly high response rates of malignant supratentorial brain gliomas to post-operative adjuvant IFN beta therapy, we were unable to demonstrate any definite anti-proliferative, anti-tumor or immunomodulatory effects of interferon in a phase II study in 13 patients. We used high doses of an IFN beta, Fiblaferon, whose potency was repeatedly confirmed by pharmacokinetic investigations, for local and systemic administration, and the times of administration were those used in the Japanese comparative studies. The side effects observed proved to be related to the amount of IFN beta administered and its duration in our patients as well. In this context, the neurotoxic disturbances require particular attention. These resolved completely after discontinuation of IFN treatment, as do the haematological and liver enzyme disturbances after suspension of medication. We did not observe any improvement in the post-operative quality of life, nor, above all, any improvement in long-term prognosis resulting from a prolonged tumor-free remission period and prolongation of the actual post-operative survival time.

Prognostic factors for high-grade malignant glioma: development of a prognostic index. A Report of the Medical Research Council Brain Tumour Working Party

Although the prognosis of high grade malignant glioma patients is generally poor, it is possible to identify groups of patients with varying prognoses. Basing our results on the first MRC glioma study, multivariate methods were used to identify prognostic factors independently associated with the length of survival. Young age, the presence of fits, especially of long duration, extensive surgical removal of tumour and good clinical performance status were found to be the most important predictors of longer survival. The effect of tumour grade (3 or 4) was not significant, being considerably diluted by an association with extent of neurosurgery. A prognostic index was derived which split the patients into 6 groups of varying prognoses, with 2-year survival rates of between 1 and 32%. The results were verified in patients entered into a subsequent MRC trial. The successful identification of different prognostic groups suggests the use of this index as an aid in making treatment decisions for individual patients, and in interpreting the results of uncontrolled phase II studies.

Influence of host sex on the growth of a human glioblastoma line in athymic mice

Glioblastomas are generally thought to be more common in men than in women. In order to investigate the hormone-dependence of these tumours, we established a human glioblastoma line in athymic mice. The tumour cell type was characterized using immunocytochemical methods. The influence of host sex on growth was evaluated, and hormone receptors were characterized biochemically. The histological features of the initial tumour were conserved in the hetero-transplanted tumours, which consisted of vimentin and GFAP immunoreactive astrocytes. There was a highly significant difference in tumour growth between the two sexes (P less than 0.01). In the male mice, tumours were from 2.5 to 10 times larger than in the females, the latency periods were 30% shorter, and the growth phases were characterized by periods of slow or zero growth. In addition, androgen and oestrogen receptors were detected at low levels (80-270 fmol/g tumour) in the heterotransplanted tumours especially in the males. The fact that the male tumour growth profiles resembled those of some hormone-dependent lines, and that androgen receptors were found preferentially in the male rather than in female tumours would tend to indicate that there is a hormonal influence on the growth of the heterotransplanted tumours. These results provide further evidence for an influence of sex-steroid hormones on the growth of glioblastomas.

Immunology of central nervous system tumors

With progress in cellular immunology and the development of hybridoma technology, the idea of manipulating host-tumor immune interactions to improve the prognosis of brain tumors has aroused renewed interest. Although no brain tumor-specific antigens have been found, and in spite of the wide antigenic heterogeneity of brain tumor cells, some monoclonal antibodies possessing restricted specificity have been isolated and their potential clinical applications investigated. One of the most pronounced changes in the cellular immune responses of brain tumor patients is a profound depression of the T4-helper lymphocytes. Clinical and laboratory trials are under way to assess the ability of lymphokines, such as gamma-interferon or interleukin-2, to restore immunologic competence in these patients and potentiate a specific anti-tumor immunologic response. Recent work suggests that the endothelium-astrocyte complex may have a pivotal role in assisting the escape of brain tumors from the host's immunologic responses, since it is responsible for the intracerebral sequestration of antigens and local anti-tumor responses. In this review, the data on the antigenic properties of central nervous system tumors and the host's humoral and cellular immune responses to them are analyzed and potential immunologic therapies are discussed.

Radiation treatment with twice a day fractionation versus conventional fractionation in high grade astrocytoma. A retrospective study

A consecutive series of 73 patients with high grade astrocytoma treated by surgery and postoperative radiotherapy was analysed. A total tumour dose of 60 Gy was delivered with either 2 Gy daily fractions (24 patients) or twice a day 1.5 Gy fractions, with a 4-hour-interval (49 patients). The analysis of survival with respect to patient variables showed that age and performance status were significant prognostic factors. As the type of fractionation was not randomly assigned, the comparison between the conventional schedule (CF) and the multifractionated schedule (MFD) was performed by means of a multivariate analysis adjusting for basic prognostic factors; CF proved to be significantly superior to MFD. The possible reasons for the disagreement between our results and the theoretical expectations in favour of MFD are discussed.