Temozolomide Versus Procarbazine, Lomustine, and Vincristine in Recurrent High-Grade Glioma

Perspectives of Medical Specialists on Sharing Decisions in Cancer Care: A Qualitative Study Concerning Chemotherapy Decisions With Patients With Recurrent Glioblastoma

BACKGROUND

In cancer care, difficult decisions concerning advanced treatment need to be made, weighing possible life prolongation against harmful side effects. Treatment is frequently started, showing the need to explore how decisions are made. Little is known about the perspectives of physicians on sharing decision making with patients. This qualitative study aimed to describe the perspectives of medical specialists on the decision-making process with patients with glioblastoma concerning starting new treatment.

METHODS

Qualitative interviews were held with medical specialists. One focus group was organized with medical professionals. Their opinions about elements of shared decision making and the applicability in the context of patients with glioblastoma were assessed. The topic list for the focus group was based on the analysis of the interviews. Qualitative analysis of the transcripts was performed by three researchers independently.

RESULTS

Medical specialists considered shared decision making to be important; however, they did not adhere to its elements. Stopping treatment was not considered equal to continuing treatment. Exploration of the patients' wishes was done implicitly, and shared responsibility for the decision was not highly recognized. The main barriers to shared decision making were preferences of both patients and specialists for starting or continuing treatment and assumptions of physicians about knowing what patients want.

CONCLUSION

Medical specialists recognized the importance of patient involvement but experienced difficulty in sharing decision making in practice. Elements of shared decision making are partly followed but do not guide decision making. To improve cancer care, education of medical specialists and adjustment to the elements are needed to involve patients.

Clinical benefit from resection of recurrent glioblastomas: results of a multicenter study including 503 patients with recurrent glioblastomas undergoing surgical resection

BACKGROUND

While standards for the treatment of newly diagnosed glioblastomas exist, therapeutic regimens for tumor recurrence remain mostly individualized. The role of a surgical resection of recurrent glioblastomas remains largely unclear at present. This study aimed to assess the effect of repeated resection of recurrent glioblastomas on patient survival.

METHODS

In a multicenter retrospective-design study, patients with primary glioblastomas undergoing repeat resections for recurrent tumors were evaluated for factors affecting survival. Age, Karnofsky performance status (KPS), extent of resection (EOR), tumor location, and complications were assessed.

RESULTS

Five hundred and three patients (initially diagnosed between 2006 and 2010) undergoing resections for recurrent glioblastoma at 20 institutions were included in the study. The patients' median overall survival after initial diagnosis was 25.0 months and 11.9 months after first re-resection. The following parameters were found to influence survival significantly after first re-resection: preoperative and postoperative KPS, EOR of first re-resection, and chemotherapy after first re-resection. The rate of permanent new deficits after first re-resection was 8%.

CONCLUSION

The present study supports the view that surgical resections of recurrent glioblastomas may help to prolong patient survival at an acceptable complication rate.

Multimodality therapy approaches, local and systemic treatment, compared with chemotherapy alone in recurrent glioblastoma

BACKGROUND

Long-term local control in Glioblastoma is rarely achieved and nearly all patients relapse. In this study we evaluated the clinical effect of different treatment approaches in recurrent patients.

METHODS

Forty-three patients, with median age of 51 years were evaluated for salvage treatment: re-resection and/or re-irradiation plus chemotherapy or chemotherapy alone. Response was recorded using the Response Assessment in Neuro-Oncology criteria. Hematologic and non-hematologic toxicities were graded according to Common Terminology Criteria for Adverse Events 4.0. Twenty-one patients underwent chemotherapy combined with local treatment, surgery and/or radiation therapy, and 22 underwent chemotherapy only.

RESULTS

The median follow up was 7 months (range 3-28 months). The 1 and 2-years Progression Free Survival was 65 and 10 % for combined treatment and 22 and 0 % for chemotherapy alone (p < 0.01). The 1 and 2-years overall survival was 69 and 29 % for combined and 26 and 0 % for chemotherapy alone (p < 0.01). No toxicity greater than grade 2 was recorded.

CONCLUSION

These data showed that in glioblastoma recurrence the combination of several approaches in a limited group of patients is more effective than a single treatment alone. This stress the importance of multimodality treatment whenever clinically feasible.

Inhibition of multidrug resistance protein 1 (MRP1) improves chemotherapy drug response in primary and recurrent glioblastoma multiforme

Glioblastoma multiforme (GBM) is a highly aggressive brain cancer with extremely poor prognostic outcome despite intensive treatment. All chemotherapeutic agents currently used have no greater than 30–40% response rate, many fall into the range of 10–20%, with delivery across the blood brain barrier (BBB) or chemoresistance contributing to the extremely poor outcomes despite treatment. Increased expression of the multidrug resistance protein 1(MRP1) in high grade glioma, and it's role in BBB active transport, highlights this member of the ABC transporter family as a target for improving drug responses in GBM. In this study we show that small molecule inhibitors and gene silencing of MRP1 had a significant effect on GBM cell response to temozolomide (150 μM), vincristine (100 nM), and etoposide (2 μM). Pre-treatment with Reversan (inhibitor of MRP1 and P-glycoprotein) led to a significantly improved response to cell death in the presence of all three chemotherapeutics, in both primary and recurrent GBM cells. The presence of MK571 (inhibitor of MRP1 and multidrug resistance protein 4 (MRP4) led to an enhanced effect of vincristine and etoposide in reducing cell viability over a 72 h period. Specific MRP1 inhibition led to a significant increase in vincristine and etoposide-induced cell death in all three cell lines assessed. Treatment with MK571, or specific MRP1 knockdown, did not have any effect on temozolomide drug response in these cells. These findings have significant implications in providing researchers an opportunity to improve currently used chemotherapeutics for the initial treatment of primary GBM, and improved treatment for recurrent GBM patients.

Anaplastic glioma: current treatment and management

Anaplastic glioma (AG) is divided into three morphology-based groups (anaplastic astrocytoma, anaplastic oligodendroglioma, anaplastic oligoastrocytoma) as well as three molecular groups (glioma-CpG island methylation phenotype [G-CIMP] negative, G-CIMP positive non-1p19q codeleted tumors and G-CIMP positive codeleted tumors). The RTOG 9402 and EORTC 26951 trials established radiotherapy plus (procarbazine, lomustine, vincristine) chemotherapy as the standard of care in 1p/19q codeleted AG. Uni- or non-codeleted AG are currently best treated with radiotherapy only or alkylator-based chemotherapy only as determined by the NOA-04 trial. Maturation of NOA-04 and results of the currently accruing studies, CODEL (for codeleted AG) and CATNON (for uni or non-codeleted AG), will likely refine current up-front treatment recommendations for AG.

Do glioma patients derive any therapeutic benefit from taking a higher cumulative dose of temozolomide regimens?: a meta-analysis

Temozolomide (TMZ) is an oral alkylating agent with established effects on the central nervous system of glioblastoma (GBM) patients. Clinical trials have demonstrated a significant impact on overall survival (OS) with TMZ. Ever since, several TMZ regimens have been designed to improve treatment efficacy by increasing the cumulative dose per cycle. We report a meta-analysis to systematically evaluate different treatment schedules of TMZ in GBM patients.All searches that were conducted in the Cochrane library, Science Direct, and PubMed Databases, and 3 randomized controlled trials (1141 patients) were included. OS and progression-free survival (PFS) were the primary outcomes to be pooled.Unexpectedly, this analysis did not reveal any OS or PFS advantage for the high cumulative dose (HCD) regimen compared with the normal cumulative dose regimen (1141 total patients; hazard ratio [HR] 1.07, 95% CI 0.94-1.22, P = 0.31). Then after analyzing the characteristics of the results from each trial, we found that the regimen with a higher peak concentration during a short-term period (daily doses ≥150 mg/m/d within ≤7 days/cycle) always had a more superior clinical benefit. So we generated a new pooled HR of 1.10 with a 95% CI of 0.96-1.25 (P = 0.17), which prefers the high peak concentration schedule even without a significant difference. The adverse outcome also indicates a significant increased risk of leukopenia (risk ratio 1.59, 95% CI 1.03-2.46, P = 0.04) among the HCD group.Our study suggests that increasing the cumulative dose per cycle is not an ideal way to improve the efficacy of TMZ, and it will lead to increased risk for leukopenia. Future trials should be designed to examine schedules of higher peak concentration rather than the cumulative dose per cycle.

Radiotherapy and temozolomide for anaplastic astrocytic gliomas

We previously reported results of a phase II non-comparative trial that randomized patients with glioblastoma following radiotherapy to one of two different temozolomide schedules, followed by 13-cis-retinoic acid (RA) maintenance. Here we report the results of an exploratory cohort of patients accrued with anaplastic astrocytic tumors. Patients with newly diagnosed anaplastic astrocytoma (AA) or anaplastic oligo-astrocytoma (AOA) were treated with concurrent radiotherapy (60 Gy over 6 weeks) and temozolomide (75 mg/m(2)), and six adjuvant 28-day cycles of either dose-dense (150 mg/m(2), days 1-7, 15-21) or metronomic (50 mg/m(2), days 1-28) temozolomide. Subsequently, maintenance RA (100 mg/m(2), days 1-21/28) was administered until disease progression. All outcome measures were descriptive without intention to compare between treatment arms. Survival was measured by the Kaplan-Meier method. There were 31 patients (21 men, 10 women) with median age 48 years (range 28-74), median KPS 90 (range 60-100). Extent of resection was gross-total in 35%, subtotal 23%, and biopsy 42%. Histology was AA in 90%, and AOA in 10%. MGMT promoter methylation was methylated in 20%, unmethylated in 50%, and uninformative in 30% of 30 tested. Median progression-free survival was 2.1 years (95% CI 0.95-Not Reached), and overall survival 2.9 years (95 % CI 2.0-Not Reached). We report outcomes among a homogeneously treated population with anaplastic astrocytic tumors. Survival was unexpectedly short compared to other reports. These data may be useful as a contemporary historic control for other ongoing or future randomized trials.

Chemotherapy in glioma

The treatment of glial brain tumors begins with surgery, and standard adjuvant treatment at the end of the past millennium for high-grade glioma and high-risk low-grade glioma was radiotherapy and chemotherapy was given at recurrence. However, over the past 10 years much has changed regarding the role of chemotherapy in gliomas and it is now clear that chemotherapy has a role in the treatment of almost all newly diagnosed diffuse gliomas (WHO grade II-IV). This is the result of several prospective studies that showed survival benefit after combined chemoradiotherapy with temozolomide in glioblastoma (WHO grade IV) or after procarbazine, CCNU (lomustine) and vincristine chemotherapy in diffuse low-grade (WHO grade II) and anaplastic (WHO grade III) glioma. The current standard of treatment for diffuse gliomas is described in this overview and in addition some attention is given to targeted therapies.

Biomarkers for glioma immunotherapy: the next generation

The term "biomarker" historically refers to a single parameter, such as the expression level of a gene or a radiographic pattern, used to indicate a broader biological state. Molecular indicators have been applied to several aspects of cancer therapy: to describe the genotypic and phenotypic state of neoplastic tissue for prognosis, to predict susceptibility to anti-proliferative agents, to validate the presence of specific drug targets, and to evaluate responsiveness to therapy. For glioblastoma (GBM), immunohistochemical and radiographic biomarkers accessible to the clinical lab have informed traditional regimens, but while immunotherapies have emerged as potentially disruptive weapons against this diffusely infiltrating, heterogeneous tumor, biomarkers with strong predictive power have not been fully established. The cancer immunotherapy field, through the recently accelerated expansion of trials, is currently leveraging this wealth of clinical and biological data to define and revise the use of biomarkers for improving prognostic accuracy, personalization of therapy, and evaluation of responses across the wide variety of tumors. Technological advancements in DNA sequencing, cytometry, and microscopy have facilitated the exploration of more integrated, high-dimensional profiling of the disease system-incorporating both immune and tumor parameters-rather than single metrics, as biomarkers for therapeutic sensitivity. Here we discuss the utility of traditional GBM biomarkers in immunotherapy and how the impending transformation of the biomarker paradigm-from single markers to integrated profiles-may offer the key to bringing predictive, personalized immunotherapy to GBM patients.

The future of high-grade glioma: Where we are and where are we going

High-grade glioma (HGG) are optimally treated with maximum safe surgery, followed by radiotherapy (RT) and/or systemic chemotherapy (CT). Recently, the treatment of newly diagnosed anaplastic glioma (AG) has changed, particularly in patients with 1p19q codeleted tumors. Results of trials currenlty ongoing are likely to determine the best standard of care for patients with noncodeleted AG tumors. Trials in AG illustrate the importance of molecular characterization, which are germane to both prognosis and treatment. In contrast, efforts to improve the current standard of care of newly diagnosed glioblastoma (GB) with, for example, the addition of bevacizumab (BEV), have been largely disappointing and furthermore molecular characterization has not changed therapy except in elderly patients. Novel approaches, such as vaccine-based immunotherapy, for newly diagnosed GB are currently being pursued in multiple clinical trials. Recurrent disease, an event inevitable in nearly all patients with HGG, continues to be a challenge. Both recurrent GB and AG are managed in similar manner and when feasible re-resection is often suggested notwithstanding limited data to suggest benefit from repeat surgery. Occassional patients may be candidates for re-irradiation but again there is a paucity of data to commend this therapy and only a minority of selected patients are eligible for this approach. Consequently systemic therapy continues to be the most often utilized treatment in recurrent HGG. Choice of therapy, however, varies and revolves around re-challenge with temozolomide (TMZ), use of a nitrosourea (most often lomustine; CCNU) or BEV, the most frequently used angiogenic inhibitor. Nevertheless, no clear standard recommendation regarding the prefered agent or combination of agents is avaliable. Prognosis after progression of a HGG remains poor, with an unmet need to improve therapy.

Glioblastoma in the elderly

There is no generally agreed upon standard of care treatment for elderly patients (age ≥70 years) with glioblastoma (GBM). Treatment options range from supportive care only, radiation therapy (RT) only (most often given in a shortened hypofractionated schedule), temozolomide (TMZ) chemotherapy only, and the combination RT + TMZ, followed by post-RT TMZ as is the current standard of care for younger good performance patients with newly diagnosed GBM.

MGMT Promoter Methylation Is a Strong Prognostic Biomarker for Benefit from Dose-Intensified Temozolomide Rechallenge in Progressive Glioblastoma: The DIRECTOR Trial

PURPOSE

Rechallenge with temozolomide (TMZ) at first progression of glioblastoma after temozolomide chemoradiotherapy (TMZ/RT→TMZ) has been studied in retrospective and single-arm prospective studies, applying temozolomide continuously or using 7/14 or 21/28 days schedules. The DIRECTOR trial sought to show superiority of the 7/14 regimen.

EXPERIMENTAL DESIGN

Patients with glioblastoma at first progression after TMZ/RT→TMZ and at least two maintenance temozolomide cycles were randomized to Arm A [one week on (120 mg/m(2) per day)/one week off] or Arm B [3 weeks on (80 mg/m(2) per day)/one week off]. The primary endpoint was median time-to-treatment failure (TTF) defined as progression, premature temozolomide discontinuation for toxicity, or death from any cause. O(6)-methylguanine DNA methyltransferase (MGMT) promoter methylation was prospectively assessed by methylation-specific PCR.

RESULTS

Because of withdrawal of support, the trial was prematurely closed to accrual after 105 patients. There was a similar outcome in both arms for median TTF [A: 1.8 months; 95% confidence intervals (CI), 1.8-3.2 vs. B: 2.0 months; 95% CI, 1.8-3.5] and overall survival [A: 9.8 months (95% CI, 6.7-13.0) vs. B: 10.6 months (95% CI, 8.1-11.6)]. Median TTF in patients with MGMT-methylated tumors was 3.2 months (95% CI, 1.8-7.4) versus 1.8 months (95% CI, 1.8-2) in MGMT-unmethylated glioblastoma. Progression-free survival rates at 6 months (PFS-6) were 39.7% with versus 6.9% without MGMT promoter methylation.

CONCLUSIONS

Temozolomide rechallenge is a treatment option for MGMT promoter-methylated recurrent glioblastoma. Alternative strategies need to be considered for patients with progressive glioblastoma without MGMT promoter methylation.

Salvage therapy with lomustine for temozolomide refractory recurrent anaplastic astrocytoma: a retrospective study

There is no standard therapy for recurrent anaplastic astrocytoma (AA). Assess response and toxicity of lomustine (CCNU) in recurrent AA following prior surgery, radiotherapy and TMZ in a retrospective case series. Thirty-five adults (18 males; 17 females: median age 42.5 years) with TMZ refractory recurrent AA were treated with lomustine. Seven patients were treated at 1st recurrence and 28 patients were treated at 2nd recurrence. Prior salvage therapy included re-resection in 19, TMZ in 20 and radiotherapy in 7. A cycle of lomustine was defined as 110 mg/m(2) on day 1 only administered once every 6-8 weeks. Success of treatment was defined as progression free survival at 6 months of 40 % or better. Grade 3 or 4 toxicities included anemia (14 patients), constipation (1), fatigue (4), lymphopenia (5), nausea/vomiting (2), neutropenia (8) and thrombocytopenia (10). No grade five toxicities were seen. The median number of cycles of therapy was 3 (range 1-6). Best radiographic response was progressive disease in 14 (40 %), stable disease in 19 (54 %) and partial response in 2 (5.7 %). Median progression free survival (PFS) was 4.5 months (range 1.5-12 months), 6-month PFS was 40 % and 12 month PFS was 11.4 %. Median survival after onset of CCNU was 9.5 months (range 2.5-15 months). Median overall survival was 2.7 years (range 1.7-4.3). In this small retrospective series of patients with recurrent AA refractory to TMZ, lomustine appears to have modest single agent with manageable toxicity. Confirmation in a larger series of similar patients is required.

Dose-dense temozolomide: is it still promising?

Glioblastoma (GBM) has proven to be incurable despite recent progress on its standard of care using temozolomide (TMZ) as the main trunk of initial therapy for newly diagnosed GBM. One of the main reasons accounting for the dismal prognosis is attributed to lack of active therapeutic regimens at recurrence. Since TMZ is the most active cytotoxic agent against GBM, and the standard dosing of TMZ has shown favorable safety profile in clinical trials, re-challenge with TMZ in increased dose density schedules for recurrent tumors that have evaded from prior standard TMZ therapy appears to be a rational approach and has been intensively exploited. A number of phase II clinical trials using different alternating scheduling of dose-dense TMZ (ddTMZ) have shown superior efficacy over the standard TMZ or historical controls with other alkylating agents including nitrosoureas and procarbazine. One ddTMZ schedule, consisting of a 21-days on/7-days off regimen was applied to newly-diagnosed GBM as the adjuvant monotherapy after completion of combined radiation and TMZ and failed to demonstrate survival benefit in a large phase III trial (RTOG 0525). Thus its role in TMZ-pretreated, recurrent GBM should be carefully pursuit in randomized trials, e.g., planned JCOG 1308 trial comparing a 7-days on/7-days off ddTMZ regimen used upfront at the first relapse followed by bevacizumab on progression versus bevacizumab alone, investigating whether insertion of ddTMZ prior to bevacizumab could bestow better outcome in the recurrent setting. In this article, mode of action, past trials, and future directions of ddTMZ therapy are discussed.

Pharmacologic therapies for malignant glioma: a guide for clinicians

This review covers the medical options for malignant gliomas based on the results of recent clinical trials and updated information on molecular markers of prognostic and predictive value. In addition to alkylating agents, the antiangiogenic drug bevacizumab is increasingly used, particularly in cases of recurrence. Supportive care, including antiedema agents, antiepileptic drugs and anticoagulants, represent complementary treatment approaches of the utmost clinical importance.

Current and investigational drug strategies for glioblastoma

Medical treatments for glioblastoma face several challenges. Lipophilic alkylators remain the mainstay of treatment, emphasising the primacy of good blood-brain barrier penetration. Temozolomide has emerged as a major contributor to improved patient survival. The roles of procarbazine and vincristine in the procarbazine, lomustine and vincristine (PCV) schedule have attracted scrutiny and several lines of evidence now support the use of lomustine as effective single-agent therapy. Bevacizumab has had a convoluted development history, but clearly now has no major role in first-line treatment, and may even be detrimental to quality of life in this setting. In later disease, clinically meaningful benefits are achievable in some patients, but more impressively the combination of bevacizumab and lomustine shows early promise. Over the last decade, investigational strategies in glioblastoma have largely subscribed to the targeted kinase inhibitor paradigm and have mostly failed. Low prevalence dominant driver lesions such as the FGFR-TACC fusion may represent a niche role for this agent class. Immunological, metabolic and radiosensitising approaches are being pursued and offer more generalised efficacy. Finally, trial design is a crucial consideration. Progress in clinical glioblastoma research would be greatly facilitated by improved methodologies incorporating: (i) routine pharmacokinetic and pharmacodynamic assessments by preoperative dosing; and (ii) multi-stage, multi-arm protocols incorporating new therapy approaches and high-resolution biology in order to guide necessary improvements in science.

Prognostic and predictive markers in recurrent high grade glioma; results from the BR12 randomised trial

We evaluated the prognostic and predictive value of a range of molecular changes in the setting of a randomised trial comparing standard PCV (procarbazine, CCNU (1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea) and vincristine) chemotherapy with the standard temozolomide (TMZ) 5-day (200 mg/m²/day) schedule and a 21-day (100 mg/m²/day) schedule in chemo-naïve, high-grade glioma (non-oligodendroglial tumours; WHO (World Health Organisation) grades III and IV) patients at first progression following radiotherapy.

354 samples (79.2%) from the first operation of the 447 randomised patients provided enough tumour DNA for some or all parts of the study. Genome-wide array comparative genomic hybridisation (aCGH), mutation analysis of IDH1/2 and TP53 and methylation analyses of the MGMT CpG-island was done.

84% of grade III tumours and 17% of grade IV had IDH1 or IDH2 mutations that conferred a better prognosis in both; MGMT methylation (defined as average value across 16 CpGs ≥ 10%) occurred in 75% of tumours and was also associated with improved survival. Both were of independent prognostic value after accounting for clinical factors and tumour grade. None of the molecular changes investigated gave clear evidence of a predictive benefit of TMZ over PCV or 21-day TMZ over 5-day TMZ although power was limited and a role for MGMT methylation could not be ruled out. Loss of 1p and 19q was seen in only 4 patients although hemizygous loss of 1p36 occurred in 20%.

The findings support reports that IDH1/2 mutations and MGMT methylation can be used in addition to tumour grade and clinical factors to predict survival in patients with recurrent high grade gliomas when treated with any of the therapy regimes used.

Histone deacetylase inhibitors in glioblastoma: pre-clinical and clinical experience

Epigenetic mechanisms are increasingly recognized as a major factor contributing to pathogenesis of cancer including glioblastoma, the most common and most malignant primary brain tumour in adults. Enzymatic modifications of histone proteins regulating gene expression are being exploited for therapeutic drug targeting. Over the last decade, numerous studies have shown promising results with histone deacetylase (HDAC) inhibitors in various malignancies. This article provides a brief overview of mechanism of anti-cancer effect and pharmacology of HDAC inhibitors and summarizes results from pre-clinical and clinical studies in glioblastoma. It analyses experience with HDAC inhibitors as single agents as well as in combination with targeted agents, cytotoxic chemotherapy and radiotherapy. Hallmark features of glioblastoma, such as uncontrolled cellular proliferation, invasion, angiogenesis and resistance to apoptosis, have been shown to be targeted by HDAC inhibitors in experiments with glioblastoma cell lines. Vorinostat is the most advanced HDAC inhibitor that entered clinical trials in glioblastoma, showing activity in recurrent disease. Multiple phase II trials with vorinostat in combination with targeted agents, temozolomide and radiotherapy are currently recruiting. While the results from pre-clinical studies are encouraging, early clinical trials showed only modest benefit and the value of HDAC inhibitors for clinical practice will need to be confirmed in larger prospective trials. Further research in epigenetic mechanisms driving glioblastoma pathogenesis and identification of molecular subtypes of glioblastoma is needed. This will hopefully lead to better selection of patients who will benefit from treatment with HDAC inhibitors.

Progression-free survival as a surrogate endpoint for overall survival in glioblastoma: a literature-based meta-analysis from 91 trials

Background

The aim of this study was to determine correlations between progression-free survival (PFS) and the objective response rate (ORR) with overall survival (OS) in glioblastoma and to evaluate their potential use as surrogates for OS.

Method

Published glioblastoma trials reporting OS and ORR and/or PFS with sufficient detail were included in correlative analyses using weighted linear regression.

Results

Of 274 published unique glioblastoma trials, 91 were included. PFS and OS hazard ratios were strongly correlated; R² = 0.92 (95% confidence interval [CI], 0.71–0.99). Linear regression determined that a 10% PFS risk reduction would yield an 8.1% ± 0.8% OS risk reduction. R² between median PFS and median OS was 0.70 (95% CI, 0.59–0.79), with a higher value in trials using Response Assessment in Neuro-Oncology (RANO; R² = 0.96, n = 8) versus Macdonald criteria (R² = 0.70; n = 83). No significant differences were demonstrated between temozolomide- and bevacizumab-containing regimens (P = .10) or between trials using RANO and Macdonald criteria (P = .49). The regression line slope between median PFS and OS was significantly higher in newly diagnosed versus recurrent disease (0.58 vs 0.35, P = .04). R² for 6-month PFS with 1-year OS and median OS were 0.60 (95% CI, 0.37–0.77) and 0.64 (95% CI, 0.42–0.77), respectively. Objective response rate and OS were poorly correlated (R² = 0.22).

Conclusion

In glioblastoma, PFS and OS are strongly correlated, indicating that PFS may be an appropriate surrogate for OS. Compared with OS, PFS offers earlier assessment and higher statistical power at the time of analysis.

Diffuse intrinsic pontine glioma treated with prolonged temozolomide and radiotherapy--results of a United Kingdom phase II trial (CNS 2007 04)

Diffuse intrinsic pontine glioma (DIPG) has a dismal prognosis with no chemotherapy regimen so far resulting in any significant improvement over standard radiotherapy. In this trial, a prolonged regimen (21/28d) of temozolomide was studied with the aim of overcoming O(6)-methylguanine methyltransferase (MGMT) mediated resistance. Forty-three patients with a defined clinico-radiological diagnosis of DIPG received radiotherapy and concomitant temozolomide (75 mg/m(2)) after which up to 12 courses of 21d of adjuvant temozolomide (75-100mg/m(2)) were given 4 weekly. The trial used a 2-stage design and passed interim analysis. At diagnosis median age was 8 years (2-20 years), 81% had cranial nerve abnormalities, 76% ataxia and 57% long tract signs. Median Karnofsky/Lansky score was 80 (10-100). Patients received a median of three courses of adjuvant temozolomide, five received all 12 courses and seven did not start adjuvant treatment. Three patients were withdrawn from study treatment due to haematological toxicity and 10 had a dose reduction. No other significant toxicity related to temozolomide was noted. Overall survival (OS) (95% confidence interval (CI)) was 56% (40%, 69%) at 9 months, 35% (21%, 49%) at 1 year and 17% (7%, 30%) at 2 years. Median survival was 9.5 months (range 7.5-11.4 months). There were five 2-year survivors with a median age of 13.6 years at diagnosis. This trial demonstrated no survival benefit of the addition of dose dense temozolomide, to standard radiotherapy in children with classical DIPG. However, a subgroup of adolescent DIPG patients did have a prolonged survival, which needs further exploration.

Treatment of newly diagnosed malignant glioma in the elderly people: new trials that impact therapy

Glioblastoma (GB), World Health Organization Grade 4 glioma, is the most common malignant primary brain tumour with an annual incidence of 12,943 cases in the United States . It is a tumour of the elderly people with a median age of onset of 64 years, although children and young adults are also affected. GB is associated with a poor prognosis; despite best treatment, most community-based patients will not survive 1 year . Cures are rare and overall survival rates at 2 and 5 years are 26-48% and 12%, respectively, in highly selected, contemporary, clinical trial eligible patients . For protocol eligible US patients, the median survival is 16-17 months, which is partly a reflection of improved supportive care, recognition of pseudoprogression, exclusion of patients undergoing biopsy only and availability of bevacizumab at recurrence . Initial treatment for patients with high performance [Karnofsky Performance Status (KPS) > 60 and age < 71 years) consists of maximal safe surgical resection followed by adjuvant focal, external beam radiotherapy (RT) with concurrent temozolomide (TMZ) chemotherapy and post-RT TMZ for 6 months . TMZ and carmustine (BCNU) biodegradable wafer (Gliadel) are the only adjuvant chemotherapies that have improved survival in randomised GB clinical trials . The current standard treatment is based upon a European Organization for Research and Treatment of Cancer (EORTC) and National Cancer Institute of Canada (NCIC) randomised, phase 3 trial of 573 patients with newly diagnosed GB (age 19-71 years and World Health Organization Performance Status ≤ 2) that compared RT alone [total dose 60 Gray (Gy)] to TMZ chemotherapy in combination with RT (total 60 Gy), followed by 6 months of post-RT TMZ (4,6,8).

O6-methylguanine DNA methyltransferase as a promising target for the treatment of temozolomide-resistant gliomas

Temozolomide (TMZ) is an alkylating agent currently used as first-line therapy for gliomas treatment due to its DNA-damaging effect. However, drug resistance occurs, preventing multi-cycle use of this chemotherapeutic agent. One of the major mechanisms of cancer drug resistance is enhanced activity of a DNA repair enzyme, O(6)-methylguanine-DNA-methyltransferase (MGMT), which counteracts chemotherapy-induced DNA alkylation and is a key component of chemoresistance. MGMT repairs TMZ-induced DNA lesions, O(6)-meG, by transferring the alkyl group from guanine to a cysteine residue. This review provides an overview of recent advances in the field, with particular emphasis on the inhibitors of MGMT and underlying mechanisms. Literature search was performed through PubMed and all relevant articles were reviewed, with particular attention to MGMT, its role in TMZ-resistant gliomas, effects of MGMT inhibitors and the underlying mechanisms. Several strategies are currently being pursued to improve the therapeutic efficacy of TMZ via inhibition of MGMT to reduce chemoresistance and improve overall survival. MGMT may be a promising target for the treatment of TMZ-resistant gliomas.

Dose-dense temozolomide for newly diagnosed glioblastoma: a randomized phase III clinical trial

PURPOSE

Radiotherapy with concomitant and adjuvant temozolomide is the standard of care for newly diagnosed glioblastoma (GBM). O(6)-methylguanine-DNA methyltransferase (MGMT) methylation status may be an important determinant of treatment response. Dose-dense (DD) temozolomide results in prolonged depletion of MGMT in blood mononuclear cells and possibly in tumor. This trial tested whether DD temozolomide improves overall survival (OS) or progression-free survival (PFS) in patients with newly diagnosed GBM.

PATIENTS AND METHODS

This phase III trial enrolled patients older than age 18 years with a Karnofsky performance score of ≥ 60 with adequate tissue. Stratification included clinical factors and tumor MGMT methylation status. Patients were randomly assigned to standard temozolomide (arm 1) or DD temozolomide (arm 2) for 6 to 12 cycles. The primary end point was OS. Secondary analyses evaluated the impact of MGMT status.

RESULTS

A total of 833 patients were randomly assigned to either arm 1 or arm 2 (1,173 registered). No statistically significant difference was observed between arms for median OS (16.6 v 14.9 months, respectively; hazard ratio [HR], 1.03; P = .63) or median PFS (5.5 v 6.7 months; HR, 0.87; P = .06). Efficacy did not differ by methylation status. MGMT methylation was associated with improved OS (21.2 v 14 months; HR, 1.74; P < .001), PFS (8.7 v 5.7 months; HR, 1.63; P < .001), and response (P = .012). There was increased grade ≥ 3 toxicity in arm 2 (34% v 53%; P < .001), mostly lymphopenia and fatigue.

CONCLUSION

This study did not demonstrate improved efficacy for DD temozolomide for newly diagnosed GBM, regardless of methylation status. However, it did confirm the prognostic significance of MGMT methylation. Feasibility of large-scale accrual, prospective tumor collection, and molecular stratification was demonstrated.

Dose-dense temozolomide for newly diagnosed glioblastoma: a randomized phase III clinical trial

PURPOSE

Radiotherapy with concomitant and adjuvant temozolomide is the standard of care for newly diagnosed glioblastoma (GBM). O(6)-methylguanine-DNA methyltransferase (MGMT) methylation status may be an important determinant of treatment response. Dose-dense (DD) temozolomide results in prolonged depletion of MGMT in blood mononuclear cells and possibly in tumor. This trial tested whether DD temozolomide improves overall survival (OS) or progression-free survival (PFS) in patients with newly diagnosed GBM.

PATIENTS AND METHODS

This phase III trial enrolled patients older than age 18 years with a Karnofsky performance score of ≥ 60 with adequate tissue. Stratification included clinical factors and tumor MGMT methylation status. Patients were randomly assigned to standard temozolomide (arm 1) or DD temozolomide (arm 2) for 6 to 12 cycles. The primary end point was OS. Secondary analyses evaluated the impact of MGMT status.

RESULTS

A total of 833 patients were randomly assigned to either arm 1 or arm 2 (1,173 registered). No statistically significant difference was observed between arms for median OS (16.6 v 14.9 months, respectively; hazard ratio [HR], 1.03; P = .63) or median PFS (5.5 v 6.7 months; HR, 0.87; P = .06). Efficacy did not differ by methylation status. MGMT methylation was associated with improved OS (21.2 v 14 months; HR, 1.74; P < .001), PFS (8.7 v 5.7 months; HR, 1.63; P < .001), and response (P = .012). There was increased grade ≥ 3 toxicity in arm 2 (34% v 53%; P < .001), mostly lymphopenia and fatigue.

CONCLUSION

This study did not demonstrate improved efficacy for DD temozolomide for newly diagnosed GBM, regardless of methylation status. However, it did confirm the prognostic significance of MGMT methylation. Feasibility of large-scale accrual, prospective tumor collection, and molecular stratification was demonstrated.

Factors predicting temozolomide induced clinically significant acute hematologic toxicity in patients with high-grade gliomas: a clinical audit

INTRODUCTION

Myelo-suppression, the dose-limiting toxicity of alkylating cytotoxic agents is generally perceived to be uncommon with temozolomide (TMZ), a novel oral second generation imidazotetrazinone prodrug, with a reported incidence of 5-10% of grade 3-4 acute hematologic toxicity. We were observing a higher incidence of clinically significant myelo-toxicity with the standard schedule of TMZ, particularly in females, prompting us to do a clinical audit in our patient population.

METHODS

One hundred two adults (>18 years of age) treated with TMZ either for newly diagnosed or recurrent/progressive high-grade glioma constituted the study cohort. Clinically significant acute hematologic toxicity was defined as any one or more of the following: any grade 3-4 hematologic toxicity; omission of daily TMZ dose for ≥ 3 consecutive days during concurrent phase; deferral of subsequently due TMZ cycle by ≥ 7 days during adjuvant phase; dose reduction or permanent discontinuation of TMZ; use of growth factors, platelets or packed-cell transfusions during the course of TMZ. Uni-variate and multi-variate analysis was performed to correlate incidence of acute hematologic toxicity with baseline patient, disease, and treatment characteristics.

RESULTS

The incidence of clinically significant neutropenia and thrombocytopenia was 7% and 12% respectively. Seven (7%) patients needed packed-cells, growth factors, and/or platelet transfusions. Grade 3-4 lymphopenia though common (32%) was self-limiting and largely asymptomatic. Two (2%) patients, both women succumbed to community acquired pneumonia during adjuvant TMZ. Multi-variate logistic regression analysis identified female gender, grade IV histology, baseline total leukocyte count <7700/mm(3) and baseline serum creatinine ≥1mg/dl as factors associated with significantly increased risk of clinically significant acute hematologic toxicity.

CONCLUSION

The incidence of TMZ induced clinically significant neutropenia and thrombocytopenia was low in our patient population. Severe lymphopenia though high was largely asymptomatic and self-limiting. Gender, grade, leukocyte count, and serum creatinine were significant independent predictors of severe acute myelo-toxicity.

Bridging science and clinical practice: how to use molecular markers when caring for a patient with brain cancer

Technical advances in genomic and proteomic profiling and bioinformatics have resulted in the identification of a large number of possible prognostic, predictive, and diagnostic molecular markers in glial tumors. Increasingly, clinical trials are incorporating tissue analyses to prospectively and retrospectively study the value of these and yet-to-be defined markers. Once validated, markers form the basis for increasingly stringent classification schemes and the development of personalized, targeted therapies. Descriptions of molecular marker findings, many not validated as clinically relevant, are filling pathology reports, and patients arrive to clinic with the latest journal article requesting marker assessment. Although some practitioners may choose to incorporate these findings into clinical decision making, empirical data supporting these decisions is limited to a few specific circumstances. This article reviews three markers-codeletion of 1p/19q, methylation of the O6-methylguanine-DNA methyltransferase (MGMT) promoter, and the presence of IDH1/2 mutation-for which there exists high or moderate levels of evidence of current clinical utility for guiding diagnostic, prognostic, and treatment decisions.

Cell-based immunotherapy against gliomas: from bench to bedside

Glioblastoma (GBM) comprises 51% of all gliomas and is the most malignant form of brain tumors with a median survival of 18-21 months. Standard-of-care treatment includes maximal surgical resection of the tumor mass in combination with radiation and chemotherapy. However, as the poor survival rate indicates, these treatments have not been effective in preventing disease progression. Cellular immunotherapy is currently being explored as therapeutic approach to treat malignant brain tumors. In this review, we discuss advances in active, passive, and vaccine-based immunotherapeutic strategies for gliomas both at the bench and in the clinic.

Glioma cell death induced by irradiation or alkylating agent chemotherapy is independent of the intrinsic ceramide pathway

BACKGROUND/AIMS

Resistance to genotoxic therapy is a characteristic feature of glioma cells. Acid sphingomyelinase (ASM) hydrolyzes sphingomyelin to ceramide and glucosylceramide synthase (GCS) catalyzes ceramide metabolism. Increased ceramide levels have been suggested to enhance chemotherapy-induced death of cancer cells.

METHODS

Microarray and clinical data for ASM and GCS in astrocytomas WHO grade II-IV were acquired from the Rembrandt database. Moreover, the glioblastoma database of the Cancer Genome Atlas network (TCGA) was used for survival data of glioblastoma patients. For in vitro studies, increases in ceramide levels were achieved either by ASM overexpression or by the GCS inhibitor DL-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (PPMP) in human glioma cell lines. Combinations of alkylating chemotherapy or irradiation and ASM overexpression, PPMP or exogenous ceramide were applied in parental cells. The anti-glioma effects were investigated by assessing proliferation, metabolic activity, viability and clonogenicity. Finally, viability and clonogenicity were assessed in temozolomide (TMZ)-resistant cells upon treatment with PPMP, exogenous ceramide, alkylating chemotherapy, irradiation or their combinations.

RESULTS

Interrogations from the Rembrandt and TCGA database showed a better survival of glioblastoma patients with low expression of ASM or GCS. ASM overexpression or PPMP treatment alone led to ceramide accumulation but did not enhance the anti-glioma activity of alkylating chemotherapy or irradiation. PPMP or exogenous ceramide induced acute cytotoxicity in glioblastoma cells. Combined treatments with chemotherapy or irradiation led to additive, but not synergistic effects. Finally, no synergy was found when TMZ-resistant cells were treated with exogenous ceramide or PPMP alone or in combination with TMZ or irradiation.

CONCLUSION

Modulation of intrinsic glioma cell ceramide levels by ASM overexpression or GCS inhibition does not enhance the anti-glioma activity of alkylating chemotherapy or irradiation.

Temozolomide for high grade glioma

BACKGROUND

High grade glioma (HGG) is an aggressive form of brain cancer. Treatment of HGG usually entails biopsy, or resection if safe, followed by radiotherapy. Temozolomide is a novel oral chemotherapy drug that penetrates into the brain and purportedly has a low incidence of adverse events.

OBJECTIVES

To assess whether temozolomide has any advantage for treating HGG in either primary or recurrent disease settings.

SEARCH METHODS

The following databases were searched: CENTRAL (Issue 10, 2012), MEDLINE, EMBASE, Science Citation Index, Physician Data Query and the Meta-Register of Controlled Trials in October, 2012. Reference lists of identified studies were searched. The Journal of Neuro-Oncology and Neuro-oncology were handsearched from 1999 to 2012 including conference abstracts. We contacted neuro-oncologists regarding ongoing and unpublished trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) where the interventions were the use of temozolomide during primary therapy or for recurrent disease. Comparisons included no chemotherapy, non-temozolomide chemotherapy or different dosing schedules of temozolomide. Patients included those of all ages with histologically proven HGG.

DATA COLLECTION AND ANALYSIS

Two review authors undertook the quality assessment and data extraction. Outcome measures included: overall survival (OS); progression-free survival (PFS); quality of life (QoL); and adverse events.

MAIN RESULTS

For primary therapy three RCTs were identified, enrolling a total of 745 patients, that investigated temozolomide in combination with radiotherapy versus radiotherapy alone for glioblastoma multiforme (GBM). Temozolomide increased OS (hazard ratio (HR) 0.60, 95% confidence interval (CI) 0.46 to 0.79, P value 0.0003) and increased PFS (HR 0.63, 95% CI 0.43 to 0.92, P value 0.02), when compared with radiotherapy alone, although these benefits only appear to emerge when therapy is given in both concomitant and adjuvant phases of treatment. A single RCT found that temozolomide did not have a statistically significant effect on QoL. Risk of haematological complications, fatigue and infections were increased with temozolomide.In recurrent HGG, two RCTs enrolling 672 patients in total found that temozolomide did not increase OS compared to standard chemotherapy (HR 0.9, 95% CI 0.76 to 1.06, P value 0.2) but it did increase PFS in a subgroup analysis of grade IV GBM tumours (HR 0.68, 95% CI 0.51 to 0.90, P value 0.008). Adverse events were similar between arms.In the elderly, 2 RCTs of 664 patients found OS and PFS was similar with temozolomide alone versus radiotherapy alone. QoL did not appear to differ between arms in a single trial but certain adverse events were significantly more common with temozolomide.

AUTHORS' CONCLUSIONS

Temozolomide when given in both concomitant and adjuvant phases is an effective primary therapy in GBM compared to radiotherapy alone. It prolongs survival and delays progression without impacting on QoL but it does increase early adverse events. In recurrent GBM, temozolomide compared with standard chemotherapy improves time-to-progression (TTP) and may have benefits on QoL without increasing adverse events but it does not improve overall. In the elderly, temozolomide alone appears comparable to radiotherapy in terms of OS and PFS but with a higher instance of adverse events.

Decision making and management of gliomas: practical considerations

Over the last decade, diagnostic options and introduction of novel treatments have expanded the armamentarium in the management of malignant glioma. Combined chemoradiotherapy has become the standard of care in glioblastoma up to the age of 70 years, while treatment in elderly patients or with lower grade glioma is less well defined. Molecular markers define different disease subtypes and allow for adapted treatment selection. This review focuses on simple questions arising in the daily management of patients.

Chemotherapy in low-grade gliomas

PURPOSE OF REVIEW

This review summarizes the recent studies in adults' diffuse low-grade gliomas (LGGs) chemotherapy, including response assessment and potential predictive biomarkers of chemosensitivity.

RECENT FINDINGS

Recent studies have confirmed that chemotherapy is an interesting treatment option in LGGs. About 25-50% of LGGs achieve radiological responses with temozolomide or a procarbazine-CCNU-vincristine (PCV) regimen. Clinical and quality-of-life improvements are commonly observed with more than half of the patients with epilepsy, demonstrating a significant reduction of seizure frequency. Dynamic volumetric studies have provided a better description of LGGs evolution after chemotherapy. They have shown that an ongoing volume decrease can be observed many months after chemotherapy discontinuation, particularly after PCV, raising the question of how and for how long should LGGs be treated. New response criteria have been defined by the Response Assessment in Neuro-Oncology group. In addition to 1p/19q codeletion and MGMT promoter methylation, IDH1 mutation might also be a potential predictive biomarker of chemosensitivity.

SUMMARY

It has now been widely accepted that chemotherapy is an interesting treatment option in LGGs. However, several questions remain unanswered regarding its optimal use. Ongoing phase III studies will allow a better delineation of the role of chemotherapy in LGGs and will also help to better determine the potential predictive value of a 1p/19q codeletion, a MGMT promoter methylation and an IDH1 mutation.

Efficacy of protracted temozolomide dosing is limited in MGMT unmethylated GBM xenograft models

BACKGROUND

Temozolomide (TMZ) is important chemotherapy for glioblastoma multiforme (GBM), but the optimal dosing schedule is unclear.

METHODS

The efficacies of different clinically relevant dosing regimens were compared in a panel of 7 primary GBM xenografts in an intracranial therapy evaluation model.

RESULTS

Protracted TMZ therapy (TMZ daily M-F, 3 wk every 4) provided superior survival to a placebo-treated group in 1 of 4 O(6)-DNA methylguanine-methyltransferase (MGMT) promoter hypermethylated lines (GBM12) and none of the 3 MGMT unmethylated lines, while standard therapy (TMZ daily M-F, 1 wk every 4) provided superior survival to the placebo-treated group in 2 of 3 MGMT unmethylated lines (GBM14 and GBM43) and none of the methylated lines. In comparing GBM12, GBM14, and GBM43 intracranial specimens, both GBM14 and GBM43 mice treated with protracted TMZ had a significant elevation in MGMT levels compared with placebo. Similarly, high MGMT was found in a second model of acquired TMZ resistance in GBM14 flank xenografts, and resistance was reversed in vitro by treatment with the MGMT inhibitor O(6)-benzylguanine, demonstrating a mechanistic link between MGMT overexpression and TMZ resistance in this line. Additionally, in an analysis of gene expression data, comparison of parental and TMZ-resistant GBM14 demonstrated enrichment of functional ontologies for cell cycle control within the S, G2, and M phases of the cell cycle and DNA damage checkpoints.

CONCLUSIONS

Across the 7 tumor models studied, there was no consistent difference between protracted and standard TMZ regimens. The efficacy of protracted TMZ regimens may be limited in a subset of MGMT unmethylated tumors by induction of MGMT expression.

The treatment of glioblastomas: a systematic update on clinical Phase III trials

Glioblastomas (GBMs) are invariably associated with unavoidable tumor recurrence and overall poor prognosis. The present study is to summarize the results of clinical Phase III studies on GBMs over the past seven years. A systematic literature search was performed using major electronic databases and by screening meeting abstracts. Totally, 16 studies of patients with newly diagnosed GBMs, recurrent GBMs, and elderly patients with GBMs were selected for this review. Although the outcomes of the experimental therapies were not encouraging, these studies produced a considerable amount of potentially clinically relevant information. Such aspects as surgical outcomes, radiation schedules, temozolomide (TMZ) schedules, methylation status of the O6-methylguanine DNA methyltransferase (MGMT) gene, combination of therapies, novel drug delivery methods and use of targeted agents have come to light and are being addressed here. In addition, we discuss the existing controversies of (1) surgical studies, (2) evaluations of recurrence, (3) salvage treatment bias, and (4) studies on elderly patients.

Surgical resection of malignant gliomas-role in optimizing patient outcome

Malignant gliomas represent one of the most devastating human diseases. Primary treatment of these tumours involves surgery to achieve tumour debulking, followed by a multimodal regimen of radiotherapy and chemotherapy. Survival time in patients with malignant glioma has modestly increased in recent years owing to advances in surgical and intraoperative imaging techniques, as well as the systematic implementation of randomized trial-based protocols and biomarker-based stratification of patients. The role and importance of several clinical and molecular factors-such as age, Karnofsky score, and genetic and epigenetic status-that have predictive value with regard to postsurgical outcome has also been identified. By contrast, the effect of the extent of glioma resection on patient outcome has received little attention, with an 'all or nothing' approach to tumour removal still taken in surgical practice. Recent studies, however, reveal that maximal possible cytoreduction without incurring neurological deficits has critical prognostic value for patient outcome and survival. Here, we evaluate state-of-the-art surgical procedures that are used in management of malignant glioma, with a focus on assessment criteria and value of tumour reduction. We highlight key surgical factors that enable optimization of adjuvant treatment to enhance patient quality of life and improve life expectancy.

Adjuvant Procarbazine, Lomustine, and Vincristine Chemotherapy in Newly Diagnosed Anaplastic Oligodendroglioma: Long-Term Follow-Up of EORTC Brain Tumor Group Study 26951

Purpose

Anaplastic oligodendroglioma are chemotherapy-sensitive tumors. We now present the long-term follow-up findings of a randomized phase III study on the addition of six cycles of procarbazine, lomustine, and vincristine (PCV) chemotherapy to radiotherapy (RT).

Patients and Methods

Adult patients with newly diagnosed anaplastic oligodendroglial tumors were randomly assigned to either 59.4 Gy of RT or the same RT followed by six cycles of adjuvant PCV. An exploratory analysis of the correlation between 1p/19q status and survival was part of the study. Retrospectively, the methylation status of the methyl-guanine methyl transferase gene promoter and the mutational status of the isocitrate dehydrogenase (IDH) gene were determined. The primary end points were overall survival (OS) and progression-free survival based on intent-to-treat analysis.

Results

A total of 368 patients were enrolled. With a median follow-up of 140 months, OS in the RT/PCV arm was significantly longer (42.3 v 30.6 months in the RT arm, hazard ratio [HR], 0.75; 95% CI, 0.60 to 0.95). In the 80 patients with a 1p/19q codeletion, OS was increased, with a trend toward more benefit from adjuvant PCV (OS not reached in the RT/PCV group v 112 months in the RT group; HR, 0.56; 95% CI, 0.31 to 1.03). IDH mutational status was also of prognostic significance.

Conclusion

The addition of six cycles of PCV after 59.4 Gy of RT increases both OS and PFS in anaplastic oligodendroglial tumors. 1p/19q-codeleted tumors derive more benefit from adjuvant PCV compared with non–1p/19q-deleted tumors.

"One week on-one week off": efficacy and side effects of dose-intensified temozolomide chemotherapy: experiences of a single center

To evaluate in a single center retrospectively the efficacy and tolerability of a weekly regimen, which alternates temozolomide (TMZ) in patients with recurrent or progressive high-grade glioma (HGG). From January 2005 until June 2011, 54 patients with recurrent or progressive HGG were treated with TMZ 150 mg/m²/day on days 1-7 and 15-21 of a 28-day cycle ("one week on-one week off" scheme; TMZ 7/14) with individual dose adjustment depending on toxicity. The majority of patients (n = 48, 89 %) was treated at first tumor recurrence or progression. All patients had received prior radiotherapy with or without concomitantly administered TMZ and, optionally, adjuvant chemotherapy. After initiation of TMZ 7/14, MRI was obtained every 8-12 weeks. Tumor response or progression was assessed according to Macdonald criteria. Blood examinations were performed weekly. Toxicity was evaluated according to Common Terminology Criteria for Adverse Events (CTCAE; version 3.0). A total of 434 treatment weeks with TMZ 7/14 were delivered. The median number of treatment weeks was 7 (range, 1-41 weeks). No grade 4 hematological toxicity and no opportunistic infections occurred. Patients with neutropenia were not observed. Two patients developed grade 3 and 4 patients grade 2 leukocytopenia. Thrombocytopenia grade 3 and grade 2 occurred in 4 patients and 6 patients, respectively. The progression-free survival (PFS) rate at 6 months was 43 %. Median PFS from treatment initiation was 18 weeks (95 % CI, 14-22 weeks) and median overall survival (OS) was 37 weeks (95 % CI, 31-42 weeks). The rates for PFS and OS at 1 year were 24 and 28 %, respectively. Our data suggest that treatment with TMZ 7/14 is safe and effective in patients with recurrent or progressive HGG.

Standards of care for treatment of recurrent glioblastoma--are we there yet?

Newly diagnosed glioblastoma is now commonly treated with surgery, if feasible, or biopsy, followed by radiation plus concomitant and adjuvant temozolomide. The treatment of recurrent glioblastoma continues to be a moving target as new therapeutic principles enrich the standards of care for newly diagnosed disease. We reviewed PubMed and American Society of Clinical Oncology abstracts from January 2006 to January 2012 to identify clinical trials investigating the treatment of recurrent or progressive glioblastoma with nitrosoureas, temozolomide, bevacizumab, and/or combinations of these agents. At recurrence, a minority of patients are eligible for second surgery or reirradiation, based on appropriate patient selection. In temozolomide-pretreated patients, progression-free survival rates at 6 months of 20%-30% may be achieved either with nitrosoureas, temozolomide in various dosing regimens, or bevacizumab. Combination regimens among these agents or with other drugs have not produced evidence for superior activity but commonly produce more toxicity. More research is needed to better define patient profiles that predict benefit from the limited therapeutic options available after the current standard of care has failed.

SEOM guideline for the treatment of malignant glioma

High-grade gliomas are an infrequent disease diagnosed usually in the fifth or sixth decade. Careful histopathological diagnosis is essential because tumour grade and type condition the treatment. Magnetic resonance with gadolinium is considered the standard radiologic exploration and should be followed by tissue sampling. Treatment of these patients should be decided in a multidisciplinary committee. Surgery, radiotherapy and chemotherapy are the basis of patients' treatment, with the best results obtained when the three of them can be used.

Temozolomide dosing regimens for glioma patients

Even in modern times of high-precision brain surgery and irradiation, malignant gliomas belong to the deadliest types of cancer. Due to a marked primary and presumably also acquired resistance, the beneficial effects of cytotoxic chemotherapy are limited. Only one randomized clinical trial demonstrated a significant impact on overall survival with temozolomide. Ever since, there have been attempts to improve the efficacy of alkylating chemotherapy by modulating the distribution of dose in time aiming at a better treatment success. Apart from higher cumulative doses per cycle, better efficacy by depletion of the anti-alkylating O⁶-methylguanine-DNA methyltransferase (MGMT) protein has been a major goal of these regimens. After promising results of single-arm pilot studies, however, randomized studies have been disappointing so far. In this overview, the different strategies of dose-dense temozolomide regimen are highlighted and results of clinical trials put into perspective.

State of the art and perspectives in the treatment of glioblastoma

Glioblastoma is the most common malignant primary brain tumor. Cures are rare and median survival varies from several to 22 months. Standard treatment for good performance patients consists of maximal safe surgical resection followed by radiotherapy with concurrent temozolomide (TMZ) chemotherapy and six cycles of postradiotherapy TMZ. At recurrence, treatment options include repeat surgery (with or without Gliadel wafer placement), reirradiation or systemic therapy. Most patients with good performance status are treated with cytotoxic chemotherapy or targeted biologic therapy following or in lieu of repeat surgery. Cytotoxic chemotherapy options include nitrosoureas, rechallenge with TMZ, platins, phophoramides and topoisomerase inhibitors, although efficacy is limited. Despite the intense effort of developing biologic agents that target angiogenesis and growth and proliferative pathways, bevacizumab is the only agent that has shown efficacy in clinical trials. It was awarded accelerated approval in the USA after demonstrating an impressive radiographic response in two open-label, prospective Phase II studies. Two randomized, Phase III trials of upfront bevacizumab have completed and may demonstrate survival benefit; however, results are pending at this time. Given the limited treatment options at tumor recurrence, consideration for enrollment on a clinical trial is encouraged.