Safety profile of carmustine wafers in malignant glioma: a review of controlled trials and a decade of clinical experience

Is Carmustine Wafer Implantation in Progressive High-Grade Gliomas a Relevant Therapeutic Option? Complication Rate, Predictors of Complications and Onco-Functional Outcomes in a Series of 53 Cases

Background/Objectives: The aim was to determine the complication rate and the predictors of complications and survival in high-grade glioma surgically managed at progression with implantation of Carmustine wafers. Methods: A retrospective series of 53 consecutive patients operated on between 2017 and 2022 was built. Results: The median age was 55 ± 10.9 years. The rates of global and infectious complications were 35.8% and 18.9%, respectively. In multivariate analysis, patients with a preoperative neurological deficit were more prone to develop a postoperative complication (HR = 5.35 95% CI 1.49-19.26, p = 0.01). No predictor of infectious complication was identified. In the grade 4 glioma subgroup (n = 44), progression-free and overall survival (calculated starting from the reresection) reached 3.95 months, 95% CI 2.92-5.21 and 11.51 months, 95% CI 9.11-17.18, respectively. Preoperative KPS > 80% (HR = 0.97 95% CI 0.93-0.99, p = 0.04), Gross Total Resection (HR = 0.38 95% CI 0.18-0.80, p = 0.01), and 3-month postoperative KPS > 80% (HR = 0.35 95% CI 0.17-0.72, p = 0.004) were predictors of prolonged overall survival. Conclusions: Surgical resection is a relevant option in high-grade gliomas at progression, especially in patients with a preoperative KPS > 80%, without preoperative neurological deficit, and amenable to complete resection. In patients elected for surgery, Carmustine wafer implantation is associated with a high rate of complications. It is consequently critical to closely monitor the patients for whom this option is chosen.

Spatiotemporally sequential delivery of biomimetic liposomes potentiates glioma chemotherapy

As one of the most challenging cancers, glioma still lacks efficient therapeutic treatment in clinics. The dilemmas of nanodrug-based therapies for glioma are due not only the limited permeability of the blood-brain barrier (BBB) but also the deficiency of targeting tumor lesions. Thus, spatiotemporally sequential delivery of therapeutics from BBB-crossing to glioma accumulation is considered a strategy to obtain better outcomes. Here, we developed a biomimetic chemotherapy nanodrug composed of the hybrid membrane envelope of U87 cell membranes and RAW264.7 cell membranes, and the core of paclitaxel (PTX)-loaded liposome (PTX@C-MMCL). In the research, PTX@C-MMCL showed superior ability to cross the BBB via RAW264.7 cell membranes and accurate targeting to the brain tumor lesions relying on the homotypic targeting capacity of U87 cell membranes. Furthermore, PTX@C-MMCL can maintain a prolonged circulation in vivo. Importantly, PTX@C-MMCL effectively inhibited the development of glioma. Conclusively, our biomimetic nanodrug holds great potential for brain tumor targeting therapy.

Molecular Pathways Implicated in Radioresistance of Glioblastoma Multiforme: What Is the Role of Extracellular Vesicles?

Glioblastoma multiforme (GBM) is a primary brain tumor that is very aggressive, resistant to treatment, and characterized by a high degree of anaplasia and proliferation. Routine treatment includes ablative surgery, chemotherapy, and radiotherapy. However, GMB rapidly relapses and develops radioresistance. Here, we briefly review the mechanisms underpinning radioresistance and discuss research to stop it and install anti-tumor defenses. Factors that participate in radioresistance are varied and include stem cells, tumor heterogeneity, tumor microenvironment, hypoxia, metabolic reprogramming, the chaperone system, non-coding RNAs, DNA repair, and extracellular vesicles (EVs). We direct our attention toward EVs because they are emerging as promising candidates as diagnostic and prognostication tools and as the basis for developing nanodevices for delivering anti-cancer agents directly into the tumor mass. EVs are relatively easy to obtain and manipulate to endow them with the desired anti-cancer properties and to administer them using minimally invasive procedures. Thus, isolating EVs from a GBM patient, supplying them with the necessary anti-cancer agent and the capability of recognizing a specified tissue-cell target, and reinjecting them into the original donor appears, at this time, as a reachable objective of personalized medicine.

Tyrosine Kinase Inhibitors for Glioblastoma Multiforme: Challenges and Opportunities for Drug Delivery

Glioblastoma multiforme (GBM) is an aggressive brain tumor with high mortality rates. Due to its invasiveness, heterogeneity, and incomplete resection, the treatment is very challenging. Targeted therapies such as tyrosine kinase inhibitors (TKIs) have great potential for GBM treatment, however, their efficacy is primarily limited by poor brain distribution due to the presence of the blood-brain barrier (BBB). This review focuses on the potential of TKIs in GBM therapy and provides an insight into the reasons behind unsuccessful clinical trials of TKIs in GBM despite the success in treating other cancer types. The main section is dedicated to the use of promising drug delivery strategies for targeted delivery to brain tumors. Use of brain targeted delivery strategies can help enhance the efficacy of TKIs in GBM. Among various drug delivery approaches used to bypass or cross BBB, utilizing nanocarriers is a promising strategy to augment the pharmacokinetic properties of TKIs and overcome their limitations. This is because of their advantages such as the ability to cross BBB, chemical stabilization of drug in circulation, passive or active targeting of tumor, modulation of drug release from the carrier, and the possibility to be delivered via non-invasive intranasal route.

Polymer nanocarriers for targeted local delivery of agents in treating brain tumors

Glioblastoma (GBM), the deadliest brain cancer, presents a multitude of challenges to the development of new therapies. The standard of care has only changed marginally in the past 17 years, and few new chemotherapies have emerged to supplant or effectively combine with temozolomide. Concurrently, new technologies and techniques are being investigated to overcome the pharmacokinetic challenges associated with brain delivery, such as the blood brain barrier (BBB), tissue penetration, diffusion, and clearance in order to allow for potent agents to successful engage in tumor killing. Alternative delivery modalities such as focused ultrasound and convection enhanced delivery allow for the local disruption of the BBB, and the latter in particular has shown promise in achieving broad distribution of agents in the brain. Furthermore, the development of polymeric nanocarriers to encapsulate a variety of cargo, including small molecules, proteins, and nucleic acids, have allowed for formulations that protect and control the release of said cargo to extend its half-life. The combination of local delivery and nanocarriers presents an exciting opportunity to address the limitations of current chemotherapies for GBM toward the goal of improving safety and efficacy of treatment. However, much work remains to establish standard criteria for selection and implementation of these modalities before they can be widely implemented in the clinic. Ultimately, engineering principles and nanotechnology have opened the door to a new wave of research that may soon advance the stagnant state of GBM treatment development.

Cerebral Edema Due to Chemotherapeutic Wafer Implantation for Malignant Glioma: Registry Study of Correlation with Perioperative Epileptic Seizures

Factors predicting adverse events following implantation with wafers containing 1,3-bis (2-chloroethyl) -1-nitrosourea (carmustine, BCNU), which is used in local chemotherapy for malignant gliomas (MGs), are unknown. The association between cerebral edema (CE), which often occurs after implantation, and perioperative seizures, which are often observed in MG cases, is under debate. This study investigated risk factors for CE associated with BCNU wafer implantation and their relationship with perioperative seizures. A total of 31 surgical cases involving 28 adult patients who underwent BCNU wafer implantation for MGs were investigated and classified into those with and without postoperative transient CE. We assessed the correlations between CE caused by BCNU implantation and various factors, including postoperative epileptic seizures. World Health Organization (WHO) grade III MGs significantly affected postoperative CE (p = 0.003) and the occurrence of seizures (p = 0.0004). Factors predictive of postoperative seizures were WHO grade III MGs (p = 0.0026), increased postoperative CE (p = 0.0272), and history of preoperative seizures (p = 0.0316). Postoperative CE, WHO grade III MGs, and a history of preoperative seizures might predict the postoperative occurrence of seizures, necessitating stringent management of seizures and CE in the affected patients.

Gather wisdom to overcome barriers: Well-designed nano-drug delivery systems for treating gliomas

Due to the special physiological and pathological characteristics of gliomas, most therapeutic drugs are prevented from entering the brain. To improve the poor prognosis of existing therapies, researchers have been continuously developing non-invasive methods to overcome barriers to gliomas therapy. Although these strategies can be used clinically to overcome the blood‒brain barrier (BBB), the accurate delivery of drugs to the glioma lesions cannot be ensured. Nano-drug delivery systems (NDDS) have been widely used for precise drug delivery. In recent years, researchers have gathered their wisdom to overcome barriers, so many well-designed NDDS have performed prominently in preclinical studies. These meticulous designs mainly include cascade passing through BBB and targeting to glioma lesions, drug release in response to the glioma microenvironment, biomimetic delivery systems based on endogenous cells/extracellular vesicles/protein, and carriers created according to the active ingredients of traditional Chinese medicines. We reviewed these well-designed NDDS in detail. Furthermore, we discussed the current ongoing and completed clinical trials of NDDS for gliomas therapy, and analyzed the challenges and trends faced by clinical translation of these well-designed NDDS.

Glioblastoma pharmacotherapy: A multifaceted perspective of conventional and emerging treatments (Review)

Due to its localisation, rapid onset, high relapse rate and resistance to most currently available treatment methods, glioblastoma multiforme (GBM) is considered to be the deadliest type of all gliomas. Although surgical resection, chemotherapy and radiotherapy are among the therapeutic strategies used for the treatment of GBM, the survival rates achieved are not satisfactory, and there is an urgent need for novel effective therapeutic options. In addition to single-target therapy, multi-target therapies are currently under development. Furthermore, drugs are being optimised to improve their ability to cross the blood-brain barrier. In the present review, the main strategies applied for GBM treatment in terms of the most recent therapeutic agents and approaches that are currently under pre-clinical and clinical testing were discussed. In addition, the most recently reported experimental data following the testing of novel therapies, including stem cell therapy, immunotherapy, gene therapy, genomic correction and precision medicine, were reviewed, and their advantages and drawbacks were also summarised.

Discriminating surgical bed cysts from bacterial brain abscesses after Carmustine wafer implantation in newly diagnosed IDH-wildtype glioblastomas

Carmustine wafers can be implanted in the surgical bed of high-grade gliomas, which can induce surgical bed cyst formation, leading to clinically relevant mass effect. An observational retrospective monocentric study was conducted including 122 consecutive adult patients with a newly diagnosed supratentorial glioblastoma who underwent a surgical resection with Carmustine wafer implantation as first line treatment (2005-2018). Twenty-two patients (18.0%) developed a postoperative contrast-enhancing cyst within the surgical bed: 16 surgical bed cysts and six bacterial abscesses. All patients with a surgical bed cyst were managed conservatively, all resolved on imaging follow-up, and no patient stopped the radiochemotherapy. Independent risk factors of formation of a postoperative surgical bed cyst were age ≥ 60 years (p = 0.019), number of Carmustine wafers implanted ≥ 8 (p = 0.040), and partial resection (p = 0.025). Compared to surgical bed cysts, the occurrence of a postoperative bacterial abscess requiring surgical management was associated more frequently with a shorter time to diagnosis from surgery (p = 0.009), new neurological deficit (p < 0.001), fever (p < 0.001), residual air in the cyst (p = 0.018), a cyst diameter greater than that of the initial tumor (p = 0.027), and increased mass effect and brain edema compared to early postoperative MRI (p = 0.024). Contrast enhancement (p = 0.473) and diffusion signal abnormalities (p = 0.471) did not differ between postoperative bacterial abscesses and surgical bed cysts. Clinical and imaging findings help discriminate between surgical bed cysts and bacterial abscesses following Carmustine wafer implantation. Surgical bed cysts can be managed conservatively. Individual risk factors will help tailor their steroid therapy and imaging follow-up.

Implantation of Carmustine wafers after resection of malignant glioma with and without opening of the ventricular system

OBJECTIVE

Implantation of biodegradable Carmustine wafers in patients with malignant glioma is not generally recommended when the ventricular system is opened during tumor resection. Thrombin/fibrinogenn-covered collagen fleeces showed promising results in sufficiently closing ventricular defects. The aim of this study was to evaluate the postoperative morbidity in patients with implanted Carmustine wafers either with opened or intact ventricular system.

METHODS

A consecutive series of patients who underwent resection of malignant glioma with implantation of Carmustine wafers was analyzed. In case of opening of the ventricular system, the defect in the ventricle wall was sealed using a collagen sponge coated with fibrinogen and thrombin prior to the implantation of the wafers. Postoperative adverse events (AE) and Karnofsky performance status scale (KPS) at follow up were compared between both groups.

RESULTS

Fifty-four patients were included. The ventricular system was opened in 33 patients and remained intact in 21 patients. Both groups were comparable in terms of age, rate of primary and recurrent glioma, preoperative KPS, rate of gross total resection and number of implanted wafers. Postoperative AEs occurred in 9/33 patients (27.3%) with opened and in 5/21 patients (23.8%) with intact ventricular system (p = 0.13). At follow-up assessments, KPS was not significantly different between both groups (p = 0.18). Opened ventricular system was not associated with a higher incidence of postoperative AEs (p = 0.98).

CONCLUSION

Appropriate closure of opened ventricular system during resection of malignant glioma allows for a safe implantation of Carmustine wafers and is not associated with a higher incidence of postoperative AEs.

Targeted Chemotherapy of Glioblastoma Spheroids with an Iontronic Pump

Successful treatment of glioblastoma multiforme (GBM), the most lethal tumor of the brain, is presently hampered by (i) the limits of safe surgical resection and (ii) "shielding" of residual tumor cells from promising chemotherapeutic drugs such as Gemcitabine (Gem) by the blood brain barrier (BBB). Here, the vastly greater GBM cell-killing potency of Gem compared to the gold standard temozolomide is confirmed, moreover, it shows neuronal cells to be at least 104-fold less sensitive to Gem than GBM cells. The study also demonstrates the potential of an electronically-driven organic ion pump ("GemIP") to achieve controlled, targeted Gem delivery to GBM cells. Thus, GemIP-mediated Gem delivery is confirmed to be temporally and electrically controllable with pmol min-1 precision and electric addressing is linked to the efficient killing of GBM cell monolayers. Most strikingly, GemIP-mediated GEM delivery leads to the overt disintegration of targeted GBM tumor spheroids. Electrically-driven chemotherapy, here exemplified, has the potential to radically improve the efficacy of GBM adjuvant chemotherapy by enabling exquisitely-targeted and controllable delivery of drugs irrespective of whether these can cross the BBB.

Frontiers in the treatment of glioblastoma: Past, present and emerging

Glioblastoma (GBM) is one of the most aggressive cancers of the brain. Despite extensive research over the last several decades, the survival rates for GBM have not improved and prognosis remains poor. To date, only a few therapies are approved for the treatment of GBM with the main reasons being: 1) significant tumour heterogeneity which promotes the selection of resistant subpopulations 2) GBM induced immunosuppression and 3) fortified location of the tumour in the brain which hinders the delivery of therapeutics. Existing therapies for GBM such as radiotherapy, surgery and chemotherapy have been unable to reach the clinical efficacy necessary to prolong patient survival more than a few months. This comprehensive review evaluates the current and emerging therapies including those in clinical trials that may potentially improve both targeted delivery of therapeutics directly to the tumour site and the development of agents that may specifically target GBM. Particular focus has also been given to emerging delivery technologies such as focused ultrasound, cellular delivery systems nanomedicines and immunotherapy. Finally, we discuss the importance of developing novel materials for improved delivery efficacy of nanoparticles and therapeutics to reduce the suffering of GBM patients.

Polymeric Biomaterial Scaffolds for Tumoricidal Stem Cell Glioblastoma Therapy

Glioblastoma (GBM) is the most common primary brain tumor and has a poor prognosis; as such, there is an urgent need to develop innovative new therapies. Tumoricidal stem cells are an emerging therapy that has the potential to combat limitations of traditional local and systemic chemotherapeutic strategies for GBM by providing a source for high, sustained concentrations of tumoricidal agents locally to the tumor. One major roadblock for tumoricidal stem cell therapy is that the persistence of tumoricidal stem cells injected as a cell suspension into the GBM surgical resection cavity is limited. Polymeric biomaterial scaffolds have been utilized to enhance the delivery of tumoricidal stem cells in the surgical resection cavity and extend their persistence in the brain, ultimately increasing their therapeutic efficacy against GBM. In this review, we examine three main scaffold categories explored for tumoricidal stem cell therapy: microcapsules, hydrogels, and electrospun scaffolds. Furthermore, considering the significant impact of surgery on the brain and recurrent GBM, we survey a brief history of orthotopic models of GBM surgical resection.

Malignant Intracranial High Grade Glioma and Current Treatment Strategy

Malignant high-grade glioma (HGG) is the most common and extremely fatal type of primary intracranial tumor. These tumors recurred within 2 to 3 cm of the primary region of tumor resection in the majority of cases. Furthermore, the blood-brain barrier significantly limited the access of many systemically administered chemotherapeutics to the tumor, pointing towards a stringent need for new therapeutic patterns. Therefore, targeting therapy using local drug delivery for HGG becomes a priority for the development of novel therapeutic strategies. The main objectives to the effective use of chemotherapy for HGG include the drug delivery to the tumor region and the infusion of chemotherapeutic agents into the vascular supply of a tumor directly, which could improve the pharmacokinetic profile by enhancing drug delivery to the neoplasm tissue. Herein, we reviewed clinical and molecular features, different methods of chemotherapy application in HGGs, especially the existing and promising targeting therapies using local drug delivery for HGG which could effectively inhibit tumor invasion, proliferation and recurrence of HGG to combat the deadly disease. Undoubtedly, novel chemical medicines targeting these HGG may represent one of the most important directions in the Neuro-oncology.

miRNA-26a expression influences the therapy response to carmustine wafer implantation in patients with glioblastoma multiforme

BACKGROUND

Glioblastoma multiforme is the most frequent malignant brain tumor in adults being marked with a very poor prognosis. Therapy concept implies concomitant radio-chemotherapy and facultative implantation of carmustine-eluted wafer. Current literature suggests microRNA 26a expression in glioblastoma to interact with alkylating chemotherapy. Subsequently, the aim of this study was to investigate the correlation of miRNA-26a expression and carmustine wafer implantation and its potential usefulness as a predictive marker for therapy response.

METHODS

In total, 229 patients with glioblastoma multiforme were included into the final analysis. Of them, 80 cases were recruited from the Saarland University Medical Center for a retrospective matched-pair analysis stratified after therapy regime: One group (carmustine wafer group; n=40) received concomitant radio-chemotherapy with carmustine wafer implantation. The other group (control group; n=40) only received concomitant radio-chemotherapy. The results were confirmed by comparing them with an independent dataset of 149 patients from the TCGA database. All tumor specimens were evaluated for miRNA-26a expression, MGMT promoter methylation, and IDH1 R132H mutation status, and the results were correlated with the clinical data.

RESULTS

Twenty-three patients in the carmustine wafer group showed low expression of miRNA-26a, while 17 patients showed a high expression. In the control group, 28 patients showed low expression, while 12 patients showed a high expression. The patients with high miRNA-26a expression in the carmustine wafer group were characterized by a significantly longer overall (hazard ratio [HR] 2.750 [95% CI 1.352-5.593]; p=0.004) and progression-free survival (HR 3.091 [95% CI 1.436-6.657]; p=0.003) than patients with low miRNA-26a expression. The 17 patients in the carmustine wafer group with high miRNA-26a expression showed a significantly longer progression-free survival (p=0.013) and overall survival (p=0.007) compared with the control group. There were no such correlations identified within the control group. TCGA datasets supported these findings.

CONCLUSIONS

MiRNA-26a expression turned out to be a promising predictor of therapy response and clinical outcome in glioblastoma patients treated with carmustine wafer implantation. For evaluation of the role of miRNA-26a in a combined therapy setting, further studies are needed in order to translate general findings to the patient's individual situation.

Risk of venous thromboembolism in patients with non-Hodgkin lymphoma surviving blood or marrow transplantation

BACKGROUND

Patients with non-Hodgkin lymphoma (NHL) have an increased risk of venous thromboembolism (VTE), particularly when they are receiving treatment. Blood or marrow transplantation (BMT) is recommended for relapsed/refractory NHL, and the risk of VTE after these patients undergo BMT is uncertain.

METHODS

Patients with NHL who survived 2 years or longer after BMT were surveyed for long-term health outcomes, including VTE. The median follow-up was 8.1 years (interquartile range, 5.6-12.9 years). The risk of VTE in 734 patients with NHL versus 897 siblings without a history of cancer and the risk factors associated with VTE were analyzed.

RESULTS

BMT survivors of NHL were at increased risk for VTE in comparison with siblings (odds ratio for allogeneic BMT survivors, 4.61; P < .0001; odds ratio for autologous BMT survivors, 1.75; P = .035). The cumulative incidence of VTE was 6.3% ± 0.9% at 5 years after BMT and 8.1% ± 1.1% at 10 years after BMT. In allogeneic BMT recipients, an increased body mass index (BMI; hazard ratio [HR] for BMI of 25-30 kg/m² , 3.52; 95% confidence interval [CI], 1.43-8.64; P = .006; HR for BMI > 30 kg/m² , 3.44; 95% CI, 1.15-10.23; P = .027) and a history of chronic graft-versus-host disease (HR, 3.33; 95% CI, 1.59-6.97; P = .001) were associated with an increased risk of VTE. Among autologous BMT recipients, a diagnosis of coronary artery disease (HR, 5.94; 95% CI, 1.7-20.71; P = .005) and prior treatment with carmustine (HR, 4.91; 95% CI, 1.66-14.51; P = .004) were associated with increased VTE risk.

CONCLUSIONS

Patients with NHL who survive BMT are at risk for developing late occurring VTE, and ongoing vigilance for this complication is required. Future studies assessing the role of thromboprophylaxis in high-risk patients with NHL are needed.

Designing Next-Generation Local Drug Delivery Vehicles for Glioblastoma Adjuvant Chemotherapy: Lessons from the Clinic

To date, the clinical outcomes and survival rates for patients with glioblastoma (GB) remain poor. A promising approach to disease-modification involves local delivery of adjuvant chemotherapy into the resection cavity, thus circumventing the restrictions imposed by the blood-brain barrier. The clinical performance of the only FDA-approved local therapy for GB [carmustine (BCNU)-loaded polyanhydride wafers], however, has been disappointing. There is an unmet medical need in the local treatment of GB for drug delivery vehicles that provide sustained local release of small molecules and combination drugs over several months. Herein, key quantitative lessons from the use of local and systemic adjuvant chemotherapy for GB in the clinic are outlined, and it is discussed how these can inform the development of next-generation therapies. Several recent approaches are highlighted, and it is proposed that long-lasting soft materials can capture the value of stiff BCNU-loaded wafers while addressing a number of unmet medical needs. Finally, it is suggested that improved communication between materials scientists, biomedical scientists, and clinicians may facilitate translation of these materials into the clinic and ultimately lead to improved clinical outcomes.

Vesicular systems employing natural substances as promising drug candidates for MMP inhibition in glioblastoma: A nanotechnological approach

Glioblastoma multiforme (GBM), one of the most lethal Brain tumors, characterized by its high invasive nature and increased mortality rates forms a major bottleneck in transport of therapeutics across the Blood Brain Barrier (BBB). Matrix metalloproteinases (MMPs) are classified as enzymes, which are found to be up regulated in the Glioma tumor microenvironment and thus can be considered as a target for inhibition for curbing GBM. Many chemotherapeutics and techniques have been employed for inhibiting MMPs till now but all of them failed miserably and were withdrawn in clinical trials due to their inability in restricting the tumor growth or increasing the overall survival rates. Thus, the quest for finding the suitable MMP inhibitor is still on and there is a critical need for identification of novel compounds which can alter the BBB permeability, restrain tumor growth and prevent tumor recurrence. Currently, naturally derived substances are gaining widespread attention as tumor inhibitors and many studies have been reported by far highlighting their importance in restricting MMP expression thus serving as chemotherapeutics for cancer due to their minimal toxicity. These substances may serve as probable candidates for inhibiting MMP expression in GBM. However, targeting and delivering the inhibitor to its target site is an issue that needs to be overcome in order to attain maximum specificity and sustained release. The birth of nanotechnology served as a boon in delivering drugs to the most complicated areas thus paving way for Nano drug delivery. An efficient Nano carrier with ability to cross the BBB and competently kill the Glioma cells forms the prerequisite for GBM chemotherapy. Vesicular drug delivery systems are one such class of carriers, which have the capacity to release the drug at a predetermined rate at the target site thus minimizing any undesirable side effects. Exploiting vesicular systems as promising Nano drug carriers to formulate naturally derived substances, that can bypass the BBB and act as an inhibitor against MMPs in GBM is the main theme of this review.

Hyperbaric oxygen inhibits production of CD3+ T cells in the thymus and facilitates malignant glioma cell growth

Objective

Hyperbaric oxygen (HBO) is an emerging complementary alternative medical approach in glioma treatment. However, its mode of action is unknown, so this was investigated in the present study.

Methods

We constructed an intracranial glioma model of congenic C57BL/6J mice. Glioma growth under HBO stimulation was assessed by bioluminescent imaging and magnetic resonance imaging. Flow cytometry assessed direct effects of HBO on reactive oxygen species (ROS) signaling of transplanted glioma cells and organs, and quantified mature T cells and subgroups in tumors, the brain, and blood.

Results

HBO promoted the growth of transplanted GL261-Luc glioma in the intracranial glioma mouse model. ROS signaling of glioma cells and brain cells was significantly downregulated under HBO stimulation, but thymus ROS levels were significantly upregulated. CD3+ T cells were significantly downregulated, while both Ti/Th cells (CD3+CD4+) and Ts/Tc cells (CD3+CD8+) were inhibited in tumors of the HBO group. The percentage of regulatory T cells in Ti/Th (CD3+CD4+) cells was elevated in the tumors and thymuses of the HBO group.

Conclusion

HBO induced ROS signaling in the thymus, inhibited CD3+ T cell generation, and facilitated malignant glioma cell growth in vivo in the intracranial glioma mouse model.

Drug-induced thrombocytopenia: Focus on platelet apoptosis

Thrombocytopenia is a serious and potentially fatal complication of drug therapy that results either from a decrease in bone marrow platelet production or the excessive destruction of circulating platelets. Although multiple mechanisms are responsible for deregulated platelet clearance, the role of programmed platelet death (apoptosis) in drug-induced thrombocytopenia has been relatively under-investigated until recently. Here we review apoptotic signaling pathways in platelets, with a focus on current data that provide mechanistic insights into drug-induced apoptosis and thrombocytopenia.

Carmustine wafer implantation for high-grade gliomas: Evidence-based safety efficacy and practical recommendations from the Neuro-oncology Club of the French Society of Neurosurgery

There is a growing body of evidence that carmustine wafer implantation during surgery is an effective therapeutic adjunct to the standard combined radio-chemotherapy regimen using temozolomide in newly diagnosed and recurrent high-grade glioma patient management with a statistically significant survival benefit demonstrated across several randomized clinical trials, as well as prospective and retrospective studies (grade A recommendation). Compelling clinical data also support the safety of carmustine wafer implantation (grade A recommendation) in these patients and suggest that observed adverse events can be avoided in experienced neurosurgeon hands. Furthermore, carmustine wafer implantation does not seem to impact negatively on the quality of life and the completion of adjuvant oncological treatments (grade C recommendation). Moreover, emerging findings support the potential of high-grade gliomas molecular status, especially the O(6)-Methylguanine-DNA Methyltransferase promoter methylation status, in predicting the efficacy of such a surgical strategy, especially at recurrence (grade B recommendation). Finally, carmustine wafer implantation appears to be cost-effective in high-grade glioma patients when performed by an experienced team and when total or subtotal resection can be achieved. Altogether, these data underline the current need for a new randomized clinical trial to assess the impact of a maximal safe resection with carmustine wafer implantation followed by the standard combined chemoradiation protocol stratified by molecular status in high-grade glioma patients.

Evaluation of surgical decision making and resulting outcome in patients with highly eloquent glioblastoma: Results of a multicenter assessment

INTRODUCTION

Treatment of glioblastoma(GB) patients amenable only for a subtotal resection(STR) is controversial. Since outcome of patients is affected by surgical management, our aim was to assess surgical decision making and resulting outcome in patients with highly eloquent GBs.

PATIENTS AND METHODS

We retrospectively assessed GB patients with intended sub-total resection (STR) or stereotactic biopsy (STX) of 3 neurooncological centers operated between 2008 and 2013. A volumetric assessment of overall extent of resection(oEoR), presence of complications, new permanent neurological deficits(nPNDs) was performed. A central reviewer reassessed all cases blinded and gave recommendation on surgical management and on a potential EoR(pEoR) based on imaging data. We compared outcome data using Mann-Whitney-U-test and Sign-Rank-Test. Survival was assessed based on Kaplan-Meier-estimates.

RESULTS

97 patients were included. In 17 patients received STX, 70 patients a STR and 10 patients a near total resection (NTR, EoR>95%). Median OS was significantly different from STX patients only if NTR was reached (16 vs. 7 months, p=0.042). The central reviewer recommended a more aggressive strategy(NTR or STR resp.) in 41 patients and a less aggressive strategy in 13 patients. Overall, management recommendation was significantly different to clinical treatment (p<0.001). Mean pEoR was significantly higher than oEoR (85.7% vs. 71.3%, p=0.001). Regarding the different OR subgroups, no significant differences were found in the NTR group(12/13 ties, p=1) and in STX group (14/17 ties, p=0.125). In STR group, a significant difference was found (p=0.001). In 38/69 patients a NTR and in 13/77 patients a STX was recommended.

CONCLUSION

Surgery in GB patients with intended STR requires precise preoperative planning since potential EoR is mainly underestimated. Especially, patients with lesions amenable for a NTR should not be missed.

T7 Peptide-Functionalized PEG-PLGA Micelles Loaded with Carmustine for Targeting Therapy of Glioma

Glioma is regarded as the deadliest and most common brain tumor because of the extremely difficult surgical excision ascribed from its invasive nature. In addition, the natural blood-brain barrier (BBB) greatly restricts the therapeutics' penetration into the central nervous system. Carmustine (BCNU) is a widely used antiglioma drug in clinical applications. However, its serious complications prevent it from being applied in a clinical setting to some extent. Thus, it is urgent to explore novel BCNU delivery systems specially designed for glioma. Development of polymeric nanoparticles offers a favorable alternative to serve this purpose. Particularly, use of poly(lactic-co-glycolic acid) (PLGA) has been shown to be advantageous for its favorable biodegradability and biocompatibility, which ensure safe therapies. In this study, T7 peptide-conjugated, BCNU-loaded micelles were constructed successfully via the emulsion-solvent evaporation method. The micelles were characterized by transmission electron microscopy and dynamic light scattering in detail, and the capacity of BBB crossing was studied. The in vivo detecting results of the targeting effect using the BODIPY probe evidenced that T7-modified micelles showed a more pronounced accumulation and accumulated in the tumor more efficiently than in the unconjugated probe. Meanwhile, the targeting group exhibited the best curative effect accompanied with the lowest loss in body weight, the smallest tumor size, and an obviously prolonged survival time among the groups. In the near future, we believe the targeted delivery system specially designed for BCNU is expected to provide sufficient evidence to proceed to clinical trials.

Gliadel wafer implantation combined with standard radiotherapy and concurrent followed by adjuvant temozolomide for treatment of newly diagnosed high-grade glioma: a systematic literature review

Since 2003, only two chemotherapeutic agents, evaluated in phase III trials, have been approved by the US Food and Drug Administration for treatment of newly diagnosed high-grade glioma (HGG): Gliadel wafers (intracranially implanted local chemotherapy) and temozolomide (TMZ) (systemic chemotherapy). Neither agent is curative, but each has been shown to improve median overall survival (OS) compared to radiotherapy (RT) alone. To date, no phase III trial has tested these agents when used in sequential combination; however, a number of smaller trials have reported favorable results. We performed a systematic literature review to evaluate the combination of Gliadel wafers with standard RT (60 Gy) plus concurrent and adjuvant TMZ (RT/TMZ) for newly diagnosed HGG. A literature search was conducted for the period of January 1995 to September 2015. Data were extracted and categorized, and means and ranges were determined. A total of 11 publications met criteria, three prospective trials and eight retrospective studies, representing 411 patients who received Gliadel plus standard RT/TMZ. Patients were similar in age, gender, and performance status. The weighted mean of median OS was 18.2 months (ten trials, n = 379, range 12.7 to 21.3 months), and the weighted mean of median progression-free survival was 9.7 months (seven trials, n = 287, range 7 to 12.9 months). The most commonly reported grade 3 and 4 adverse events were myelosuppression (10.22 %), neurologic deficit (7.8 %), and healing abnormalities (4.3 %). Adverse events reflected the distinct independent safety profiles of Gliadel wafers and RT/TMZ, with little evidence of enhanced toxicity from their use in sequential combination. In the 11 identified trials, an increased benefit from sequentially combining Gliadel wafers with RT/TMZ was strongly suggested. Median OS tended to be improved by 3 to 4 months beyond that observed for Gliadel wafers or TMZ when used alone in the respective phase III trials. Larger prospective trials of Gliadel plus RT/TMZ are warranted.

Quantitative analysis of brain edema in patients with malignant glioma treated with BCNU wafers

BCNU wafers are a form of interstitial chemotherapy that is expected to improve the survival of patients with malignant glioma. However, their adverse events, especially brain edema, sometimes cause significant clinical symptoms. In this study, we performed a volumetric analysis of brain edema after the implantation of BCNU wafers and reported on the clinical course, and exacerbation factors of brain edema. Twelve patients who underwent surgical resection of supratentorial malignant glioma and BCNU wafer implantation, were enrolled. Radiographic quantitative analysis was conducted and compared with a historical control. The volume change in brain edema was divided into three groups and correlation with clinical symptoms was then evaluated. Compared with the control group, the brain edema in the BCNU wafer implantation group was significantly prolonged after surgery. Radiographic volumetric analysis revealed an increase of more than 25% at any time after surgery in four patients (33%) and a reduction of less than 25%, 1month after surgery in three patients (25%). Grade 3 clinical deterioration related to brain edema occurred in two patients and Grade 2 in one patient. Univariate analysis revealed that the radiographic deterioration of brain edema had no correlation with age, sex, diagnosis, tumor grade, preoperative volume of brain edema and tumor, residual tumor volume, or number of BCNU wafers. Radiographic quantitative analysis of brain edema indicated that BCNU wafer implantation may induce the prolongation and enlargement of brain edema with or without neurological deterioration. Brain edema may be controlled by intensive perioperative treatment with diuretics and corticosteroids.

Clinicopathological factors predictive of postoperative seizures in patients with gliomas

PURPOSE

Epilepsy is one of the most common manifestations in gliomas and has a severe effect on the life expectancy and quality of life of patients. The aim of our study was to assess the potential connections between clinicopathological factors and postoperative seizure.

METHOD

We retrospectively investigated a group of 147 Chinese high-grade glioma (HGG) patients with preoperative seizure to examine the correlation between postoperative seizure and clinicopathological factors and prognosis. Univariate analyses and multivariate logistic regression analyses were performed to identify factors associated with postoperative seizures. Survival function curves were calculated using the Kaplan-Meier method.

RESULTS

53 patients (36%) were completely seizure-free (Engel class I), and 94 (64%) experienced a postoperative seizure (Engel classes II, III, and IV). A Chi-squared analysis showed that anaplastic oligodendroglioma/anaplastic oligoastrocytoma (AO/AOA) (P=0.05), epidermal growth factor receptor (EGFR) expression (P=0.0004), O(6)-methylguanine DNA methyltransferase (MGMT) expression (P=0.011), and phosphatase and tensin homolog (PTEN) expression (P=0.045) were all significantly different. A logistic regression analysis showed that MGMT expression (P=0.05), EGFR expression (P=0.001), and AO/AOA (P=0.038) are independent factors of postoperative seizure. Patients with lower MGMT and EGFR expression and AO/AOA showed more frequent instances of postoperative seizure. Postoperative seizure showed no statistical significance on overall survival (OS) and progression-free survival (PFS).

CONCLUSION

Our study identified clinicopathological factors related to postoperative seizure in HGGs and found two predictive biomarkers of postoperative seizure: MGMT and EGFR. These findings provided insight treatment strategies aimed at prolonging survival and improving quality of life.

Polymeric drug delivery for the treatment of glioblastoma

Glioblastoma (GBM) remains an almost universally fatal diagnosis. The current therapeutic mainstay consists of maximal safe surgical resection followed by radiation therapy (RT) with concomitant temozolomide (TMZ), followed by monthly TMZ (the "Stupp regimen"). Several chemotherapeutic agents have been shown to have modest efficacy in the treatment of high-grade glioma (HGG), but blood-brain barrier impermeability remains a major delivery obstacle. Polymeric drug-delivery systems, developed to allow controlled local release of biologically active substances for a variety of conditions, can achieve high local concentrations of active agents while limiting systemic toxicities. Polymerically delivered carmustine (BCNU) wafers, placed on the surface of the tumor-resection cavity, can potentially provide immediate chemotherapy to residual tumor cells during the standard delay between surgery and chemoradiotherapy. BCNU wafer implantation as monochemotherapy (with RT) in newly diagnosed HGG has been investigated in 2 phase III studies that reported significant increases in median overall survival. A number of studies have investigated the tumoricidal synergies of combination chemotherapy with BCNU wafers in newly diagnosed or recurrent HGG, and a primary research focus has been the integration of BCNU wafers into multimodality therapy with the standard Stupp regimen. Overall, the results of these studies have been encouraging in terms of safety and efficacy. However, the data must be qualified by the nature of the studies conducted. Currently, there are no phase III studies of BCNU wafers with the standard Stupp regimen. We review the rationale, biochemistry, pharmacokinetics, and research history (including toxicity profile) of this modality.

Chronic Phase Intracranial Hemorrhage Caused by Ruptured Pseudoaneurysm Induced by Carmustine Wafer Implantation for Insulo-opercular Anaplastic Astrocytoma: A Case Report

Carmustine wafers improve the survival of patients with high-grade gliomas, but several adverse events have been reported. A 42-year-old man with left insulo-opercular anaplastic astrocytoma developed a massive intra-cavital hematoma with subarachnoid hemorrhage caused by ruptured pseudoaneurysm of the left middle cerebral artery (MCA) adjacent to the site of carmustine wafers implanted 6 months previously. Intraoperative finding demonstrated a dissection of the insular portion of the MCA, and pathological examination identified the resected pseudoaneurysm. This case demonstrates that carmustine wafers can cause changes in local vessels. Therefore, implantation of carmustine wafers near to important vessels passing close to the resection cavity should be considered with great caution.

The role of Gliadel wafers in the treatment of newly diagnosed GBM: a meta-analysis

Background

Standard treatment for high-grade glioma (HGG) includes surgery followed by radiotherapy and/or chemotherapy. Insertion of carmustine wafers into the resection cavity as a treatment for malignant glioma is currently a controversial topic among neurosurgeons. Our meta-analysis focused on whether carmustine wafer treatment could significantly benefit the survival of patients with newly diagnosed glioblastoma multiforme (GBM).

Method

We searched the PubMed and Web of Science databases without any restrictions on language using the keywords “Gliadel wafers”, “carmustine wafers”, “BCNU wafers”, or “interstitial chemotherapy” in newly diagnosed GBM for the period from January 1990 to March 2015. Randomized controlled trials (RCTs) and cohort studies/clinical trials that compared treatments designed with and without carmustine wafers and which reported overall survival or hazard ratio (HR) or survival curves were included in this study. Moreover, the statistical analysis was conducted by the STATA 12.0 software.

Results

Six studies including two RCTs and four cohort studies, enrolling a total of 513 patients (223 with and 290 without carmustine wafers), matched the selection criteria. Carmustine wafers showed a strong advantage when pooling all the included studies (HR =0.63, 95% confidence interval (CI) =0.49–0.81; P=0.019). However, the two RCTs did not show a statistical increase in survival in the group with carmustine wafer compared to the group without it (HR =0.51, 95% CI =0.18–1.41; P=0.426), while the cohort studies demonstrated a significant survival increase (HR =0.59, 95% CI =0.44–0.79; P<0.0001).

Conclusion

Carmustine-impregnated wafers play a significant role in improving survival when used for patients with newly diagnosed GBM. More studies should be designed for newly diagnosed GBM in the future.

Surgery for Glioblastoma: Impact of the Combined Use of 5-Aminolevulinic Acid and Intraoperative MRI on Extent of Resection and Survival

Background

There is rising evidence that in glioblastoma(GBM) surgery an increase of extent of resection(EoR) leads to an increase of patient’s survival. Based on histopathological assessments tumor depiction of Gd-DTPA enhancement and 5-aminolevulinic-acid-fluorescence(5-ALA) might be synergistic for intraoperative resection control.

Objective

To assess impact of additional use of 5-ALA in intraoperative MRI(iMRI) assisted surgery of GBMs on extent of resection(EoR), progression free survival(PFS) and overall survival(OS).

Methods

We prospectively enrolled 33 patients with GBMs eligible for gross-total-resection(GTR) and performed a combined approach using 5-ALA and iMRI. As a control group, we performed a retrospective matched pair assessment, based on 144 patients with iMRI-assisted surgery. Matching criteria were, MGMT promotor methylation, recurrent surgery, eloquent location, tumor size and age. Only patients with an intended GTR and primary GBMs were included. We calculated Kaplan Mayer estimates to compare OS and PFS using the Log-Rank-Test. We used the T-test to compare volumetric results of EoR and the Chi-Square-Test to compare new permanent neurological deficits(nPND) and general complications between the two groups.

Results

Median follow up was 31 months. No significant differences between both groups were found concerning the matching criteria. GTR was achieved significantly more often (p <0.010) using 5-ALA&iMRI (100%) compared to iMRI alone(82%). Mean EoR was significantly(p<0.004) higher in 5-ALA&iMRI-group(99.7%) than in iMRI-alone-group(97.4%) Rate of complications did not differ significantly between groups(21% iMRI-group,27%5-ALA&iMRI-group,p<0.518). nPND were found in 6% in both groups. Median PFS (6mo resp.;p<0.309) and median OS(iMRI:17mo;5-ALA&iMRI-group:18mo;p<0.708)) were not significantly different between both groups.

Conclusion

We found a significant increase of EoR when combining 5-ALA&iMRI compared to use of iMRI alone. Maximizing EoR did not lead to an increase of complications or neurological deficits if used with neurophysiological monitoring in eloquent lesions. No final conclusion can be drawn whether a further increase of EoR benefits patient’s progression free survival and overall survival.

Risk of surgical site infection in 401 consecutive patients with glioblastoma with and without carmustine wafer implantation

OBJECTIVES

Patients with glioblastoma (GBM) have an inherently shortened survival because of their disease. It has been recently shown that carmustine wafers in addition to other therapies (surgery, temozolomide, and radiation) can further extend survival. There is concern, however, that these therapies may increase infection risk. The goals of this study were to calculate the incidence of postoperative infection, evaluate if carmustine wafers changes the risk of infection and identify factors independently associated with an infection following GBM surgery.

METHODS

All patients who underwent non-biopsy, surgical resection of an intracranial GBM from 2007 to 2011 at a single institution were retrospectively reviewed. Stepwise multivariate proportional hazards regression analysis was used to identify factors associated with infection, including the use of carmustine wafers. Variables with P < 0.05 were considered statistically significant.

RESULTS

Four hundred and one patients underwent resection of an intracranial GBM during the reviewed period, and 21 (5%) patients developed an infection at a median time of 40 [28-286] days following surgery. The incidence of infection was not higher in patients who had carmustine wafers, and this remained true in multivariate analyses to account for differences in treatment cohorts. The factors that remained significantly associated with an increased risk of infection were prior surgery [RR (95% CI); 2.026 (1.473-4.428), P = 0.01], diabetes mellitus [RR (95% CI); 6.090 (1.380-9.354)], P = 0.02], and increasing duration of hospital stay [RR (95% CI); 1.048 (1.006-1.078); P = 0.02], where the greatest risk occurred with hospital stays > 5 days [RR (95% CI); 3.904 (1.003-11.620), P = 0.05].

DISCUSSION

These findings may help guide treatment regimens aimed at minimizing infection for patients with GBM.

Survival outcomes and safety of carmustine wafers in the treatment of high-grade gliomas: a meta-analysis

Carmustine wafers (CW; Gliadel(®) wafers) are approved to treat newly-diagnosed high-grade glioma (HGG) and recurrent glioblastoma. Widespread use has been limited for several reasons, including concern that their use may preclude enrollment in subsequent clinical trials due to uncertainty about confounding of results and potential toxicities. This meta-analysis estimated survival following treatment with CW for HGG. A literature search identified relevant studies. Overall survival (OS), median survival, and adverse events (AEs) were summarized. Analysis of variance evaluated effects of treatment (CW vs non-CW) and diagnosis (new vs recurrent) on median survival. The analysis included 62 publications, which reported data for 60 studies (CW: n = 3,162; non-CW: n = 1,736). For newly-diagnosed HGG, 1-year OS was 67 % with CW and 48 % without; 2-year OS was 26 and 15 %, respectively; median survival was 16.4 ± 21.6 months and 13.1 ± 29.9 months, respectively. For recurrent HGG, 1-year OS was 37 % with CW and 34 % without; 2-year OS was 15 and 12 %, respectively; median survival was 9.7 ± 20.9 months and 8.6 ± 22.6 months, respectively. Effects of treatment (longer median survival with CW than without; P = 0.043) and diagnosis (longer median survival for newly-diagnosed HGG than recurrent; P < 0.001) on median survival were significant, with no significant treatment-by-diagnosis interaction (P = 0.620). The most common AE associated with wafer removal was surgical site infection (SSI); the most common AEs for repeat surgery were mass effect, SSI, hydrocephalus, cysts in resection cavity, acute hematoma, wound healing complications, and brain necrosis. These data may be useful in the context of utilizing CW in HGG management, and in designing future clinical trials to allow CW-treated patients to participate in experimental protocols.

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.

Double-edged Sword in the Placement of Carmustine (BCNU) Wafers along the Eloquent Area: A Case Report

Although direct Gliadel^® wafer implantation into the resection cavity has been shown to significantly improve survival in patients with high-grade gliomas, several complications have been associated with the implantations of Gliadel wafers, including brain edema, healing delay, cerebral spinal fluid leak, intracranial infections, and cyst formation. The brain edema that is associated with Gliadel wafer implantation might result in neurological deficits and significant morbidities and mortalities. In particular, it is not clear if they should be placed in the eloquent areas, such as language areas, motor areas, and areas related to cognitive function, even if these areas contain a remnant tumor. Here, we present a case of profound brain edema along the pyramidal tract due to Gliadel wafer implantation, which resulted in severe neurological deficits. This treatment represents a double-edged sword due to the possibility of severe symptomatic brain edema along the eloquent area, even though Gliadel wafers might be effective in controlling local tumor growth. We should keep in mind that Gliadel wafer placement in eloquent areas may result in severe disadvantages to patients and a loss of their quality of life.

Safety evaluation of high-dose BCNU-loaded biodegradable implants in Chinese patients with recurrent malignant gliomas

OBJECTIVES

Malignant gliomas are common primary brain tumors with dismal prognosis. The blood-brain barrier and unacceptable systemic toxicity limit the employment of chemotherapeutic agents. BCNU-impregnated biodegradable polymers (Gliadel®) have been demonstrated to prolong the survival of patients with malignant gliomas. Until now, no biodegradable drug delivery system has been commercially available in China. In the present study, we evaluated the safety of implants with high-dose BCNU in Chinese patients with recurrent malignant gliomas.

PATIENTS AND METHODS

Adults with supratentorial recurrent malignant glioma were eligible. High-dose BCNU-loaded PLGA implants (20mg of BCNU in each implant) were placed in the debulking cavity. The implants were investigated by a classical 3+3 design. Four levels of BCNU, up to 12 implants, were evaluated. Pharmacokinetic sampling was performed. The toxicity of the implants and the survival of patients were recorded.

RESULTS

Fifteen recurrent patients were enrolled with 12 glioblastomas and 3 anaplastic gliomas. Among 15 patients, 3 were treated with 3 implants (60 mg of BCNU), 3 with 6 implants (120 mg), 3 with 9 implants (180 mg) and 6 with 12 implants (240 mg). No dose-limiting toxicity was observed in the cohort of patients. Subgaleal effusion was the most common adverse event, presenting in 7 patients (46.7%). The median overall survival (OS) was 322 days (95% CI, 173-471 days). The 6-month, 1-year and 2-year survival rates were 66.7%, 40% and 13.3%, respectively.

CONCLUSIONS

The high-dose BCNU-loaded PLGA implants were safe for Chinese patients with recurrent malignant gliomas and further investigation for efficacy is warranted.

Validation of an imageable surgical resection animal model of Glioblastoma (GBM)

BACKGROUND

Glioblastoma (GBM) is the most common and malignant primary brain tumour having a median survival of just 12-18 months following standard therapy protocols. Local recurrence, post-resection and adjuvant therapy occurs in most cases.

NEW METHOD

U87MG-luc2-bearing GBM xenografts underwent 4.5mm craniectomy and tumour resection using microsurgical techniques. The cranial defect was repaired using a novel modified cranial window technique consisting of a circular microscope coverslip held in place with glue.

RESULTS

Immediate post-operative bioluminescence imaging (BLI) revealed a gross total resection rate of 75%. At censor point 4 weeks post-resection, Kaplan-Meier survival analysis revealed 100% survival in the surgical group compared to 0% in the non-surgical cohort (p=0.01). No neurological defects or infections in the surgical group were observed. GBM recurrence was reliably imaged using facile non-invasive optical bioluminescence (BLI) imaging with recurrence observed at week 4.

COMPARISON WITH EXISTING METHOD(S)

For the first time, we have used a novel cranial defect repair method to extend and improve intracranial surgical resection methods for application in translational GBM rodent disease models. Combining BLI and the cranial window technique described herein facilitates non-invasive serial imaging follow-up.

CONCLUSION

Within the current context we have developed a robust methodology for establishing a clinically relevant imageable GBM surgical resection model that appropriately mimics GBM recurrence post resection in patients.

Evaluation of post-operative complications associated with repeat resection and BCNU wafer implantation in recurrent glioblastoma

BACKGROUND

Patients with glioblastoma treated with BCNU wafer implantation for recurrence frequently receive frontline chemoradiotherapy with temozolomide as part of the Stupp protocol. A retrospective investigation was conducted of surgical complications in a cohort of these patients treated at a single institution.

METHODS

We searched our institutional database for patients treated between January 2006 and October 2012 who had recurrent glioblastoma previously treated with open surgery followed by the Stupp protocol and then underwent repeat resection with or without BCNU wafers for recurrent disease. Rates of select post-operative complications within 3 months of surgery were estimated.

RESULTS

We identified 95 patients with glioblastoma who underwent resection followed by the Stupp protocol as frontline treatment. At disease recurrence (first and second recurrence), 63 patients underwent repeat resection with BCNU wafer implantation and 32 without implantation. Generally, BCNU wafer use was associated with minor to moderate increases in rates of select complications versus non-implantation-wound healing abnormalities (14.2 vs. 6.2 %), cerebrospinal fluid leak (7.9 vs. 3.1 %), hydrocephalus requiring ventriculoperitoneal shunt (6.3 vs. 9.3 %), chemical meningitis (3.1 vs. 0 %), cerebral infections (3.1 vs. 0 %), cyst formation (3.1 vs. 3.1 %), cerebral edema (4.7 vs. 0 %), and empyema formations (1.5 vs. 0 %). Performance status was well maintained post-operatively in both groups. Median progression-free survival from the time of first recurrence was 6.0 and 5.0 months, respectively.

CONCLUSIONS

The use of the Stupp protocol as frontline therapy in patients with glioblastoma does not preclude the use of BCNU wafers at the time of progression.

Delayed post-operative haemorrhage after carmustine wafer implantation: a case series from two UK centres

OBJECT

Significant haemorrhage following intracranial tumour resection may occur in 1-2% of cases and the majority occur within the first few hours post-operatively. Implantation of carmustine wafers has been associated with increased operative site complications in some series, but post-operative haematoma is not routinely reported. We analyzed the characteristics of post-operative haemorrhage after carmustine wafer insertion.

METHODS

We performed a retrospective audit of surgical site haematoma after tumour resection and insertion of carmustine wafers in two neurosurgical units in the UK (University Hospital of North Staffordshire, Stoke-on-Trent, March 2003 - July 2012; Wessex Neurological Centre, Southampton, October 2005 - January 2013).

RESULTS

During the specified time periods, carmustine wafers were inserted in 181 operations in 177 patients. We identified acute operative site haematomas after carmustine wafer insertion in 8 (4.4%) patients. All presented in a delayed fashion on or after Day 2 post-operatively. In contrast, acute operative site haematoma was present in 4/491 (0.81%) of patients who underwent resection without gliadel wafer insertion.

CONCLUSIONS

In contrast to the expected timing of bleeding following intracranial tumour resection, all carmustine wafer patients who experienced haemorrhage presented in a delayed fashion on or after Day 2 post-operatively. The causative factors for universally delayed post-operative haematoma after carmustine wafer insertion are unclear and further studies are required to characterize this phenomenon.

Intratumoral temozolomide synergizes with immunotherapy in a T cell-dependent fashion

Despite temozolomide (TMZ) treatment, the prognosis for patients with glioblastoma multiforme is still dismal. As dose escalation of TMZ is limited by systemic toxicity, intratumoral delivery emerges as an attractive treatment modality, which may sustain cytotoxic drug concentrations intratumorally and induce immunogenic cell death. Both clinical and experimental gliomas have responded to immunotherapy, but the benefit of simultaneous chemo- and immunotherapy is inadequately studied. Here, we monitored survival of GL261-bearing C57BL/6 mice following a 3-day treatment with either intratumoral TMZ (micro-osmotic pump, 4.2 mg/kg/day) or systemic TMZ (i.p. injections, 50 mg/kg/day) alone, or combined with immunization using GM-CSF secreting GL261 cells. Peripheral and intratumoral leukocytes were analyzed by flow cytometry and immunohistochemistry. Intratumoral TMZ induced higher survival rate than systemic TMZ (45 vs. 8%). When T cells were depleted following intratumoral TMZ, the therapeutic effect was completely abrogated (0 % survival). Intratumoral TMZ synergistically increased survival rate of immunized mice (from 25 to 83%), while systemic TMZ failed (0%). While systemic TMZ induced a transient leukopenia, intratumoral TMZ and immunotherapy sustained the proliferation of CD8+ T cells and decreased the number of intratumoral immunosuppressive cells. In conclusion, intratumoral TMZ alone or in combination with immunotherapy could cure glioma-bearing mice, due to attenuation of local immunosuppression and increase in potential effector immune cells.

MGMT promoter methylation status and prognosis of patients with primary or recurrent glioblastoma treated with carmustine wafers

The prognostic role of O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation in glioblastoma patients treated with carmustine (BCNU) wafer implantation is unclear. Here, we report on a retrospective study of 47 patients with either newly diagnosed (30 patients) or recurrent (17 patients) glioblastoma (WHO grade IV) treated with BCNU (bis-chloroethylnitrosourea) wafers. Thirteen of the newly diagnosed patients received local BCNU and irradiation only (first-line BCNU), while 17 patients additionally received concomitant and adjuvant temozolomide (TMZ) radiochemotherapy (first-line BCNU + TMZ). Of the 17 patients treated for recurrent glioblastoma (second-line BCNU), 16 had received radiotherapy with concomitant and adjuvant TMZ as an initial treatment. Median overall survival (OS) did not significantly differ between 19 patients with MGMT promoter methylated tumors when compared to 28 patients with unmethylated tumors (18.9 vs 15.0 months; p = 0.1054). In the first-line BCNU + TMZ group, MGMT promoter methylation was associated with longer OS (21.0 vs 11.1 months, p = 0.0127), while no significant survival differences were detected in the other two subgroups. Progression-free survival did not significantly differ between patients with and without MGMT promoter methylated tumors in the entire patient cohort or any of the three subgroups. The first-line BCNU + TMZ group showed no significant difference in OS when compared to the first-line BCNU group (18.9 vs 14.7 months), but tended to have more therapy-related adverse effects (53% vs 24%, p = 0.105). In summary, MGMT promoter methylation showed a non-significant trend toward longer survival in our patient cohort. The combination of TMZ radiochemotherapy with local delivery of BCNU did not provide a significant survival benefit compared to local BCNU alone, but was associated with a higher rate of adverse effects. Owing to the small number of patients investigated, however, these findings would need to be corroborated in larger patient cohorts.

Growth pattern of tumor recurrence following bis-chloroethylnitrosourea (BCNU) wafer implantation in malignant glioma

Bis-chloroethylnitrosourea (BCNU; Gliadel, Eisai, Tokyo, Japan) is the only therapeutic agent for local chemotherapy of malignant gliomas approved by the US Food and Drug Administration and the European Medicines Agency. In a small patient cohort, it has previously been shown that glioblastomas recur locally despite treatment with BCNU. This raises concern about local treatment with BCNU as a stand-alone measure. The goal of this study was to analyze the growth pattern of tumor recurrence in a larger patient group: 41 patients were included in this study. Tumor recurrences were morphologically categorized as: local, diffuse, distant or multilocular. Thirty-three of the tumors (80%) that recurred were local or diffuse. These results show that BCNU implantation does not provide lasting local tumor control. Our data support the need to incorporate BCNU in to multimodal therapy schemes. The improved survival rates of patients who receive concomitant local and systemic adjuvant treatment support using local therapy to bridge the therapy-free interval of the initial postoperative phase.

Implanted carmustine wafers followed by concomitant radiochemotherapy to treat newly diagnosed malignant gliomas: prospective, observational, multicenter study on 92 cases

OBJECTIVES

Study the feasibility and effectiveness of a treatment associated surgery, intraoperative chemotherapy (carmustine wafers), and concomitant radiochemotherapy (temozolomide) for the management of newly diagnosed, high-grade gliomas.

METHODS

Prospective multicenter study conducted in 17 French centers with a total of 92 patients with newly diagnosed malignant glioma treated by surgery, implanted Carmustine wafers (Gliadel(®)) followed by concomitant radiochemotherapy by temozolomide (Temodar(®)). Clinical, imaging, and survival data were collected to study toxicity-induced adverse events and efficacy.

RESULTS

A total of 20.6 % presented with adverse events during surgery, potentially attributable to carmustine, including 5 severe infections. Afterwards, 37.2 % of patients showed adverse events during radiochemotherapy and 40 % during adjuvant chemotherapy by temozolomide. We report a 10.5-month, median, progression-free survival and an 18.8-month median overall survival. No significant statistical difference was observed according to age, Karnofsky Performance Scale, or grade of the tumor. A prognostic difference at the limit of the significance threshold was observed according to the extent of the resection.

CONCLUSIONS

Multimodal treatment associating implanted carmustine chemotherapy and concomitant radiochemotherapy with temozolomide seems to yield better survival rates than those usually described when carmustine or temozolomide are used alone independently from one another. These interesting results were obtained without increased adverse events and would need to be validated during a phase 3 study.

Safety and efficacy of Gliadel wafers for newly diagnosed and recurrent glioblastoma

BACKGROUND

Combining Gliadel wafers and radiochemotherapy with TMZ may carry the risk of increased adverse events (AE). We analyzed the efficacy and safety in patients with glioblastoma who underwent multimodal treatment with implantation of Gliadel wafers.

METHODS

One hundred sixty-five consecutive patients with newly diagnosed (77 patients) or recurrent (88 patients) glioblastoma were studied. Forty-seven patients underwent surgery + Gliadel. The impact of age (≥65 vs. <65), resection extent (gross total vs. partial), use of Gliadel and adjuvant treatment (TMZ vs. other schemes/no adjuvant therapy) on overall survival (OS, for patients with newly diagnosed glioblastoma) and on recurrence-survival (for patients with recurrent glioblastoma) was analyzed with Cox regression. The impact of age, history (newly diagnosed vs. recurrent glioblastoma), number of Gliadel wafers implanted (0 vs. <8 vs. 8), resection extent (gross-total vs. partial) and adjuvant treatment (TMZ vs. other schemes/no adjuvant therapy) on the occurrence of AE and on the occurrence of implantation site-related AE (ISAE) was analyzed with the logistic regression model. Significance was set at p < 0.05.

RESULTS

Multivariate analysis showed the only factor associated with longer survival, both for newly diagnosed and for recurrent GBM, was resection extent. Both patients with a higher number of wafers implanted and patients with recurrent tumors were significantly at risk for AE and ISAE. Patients with eight Gliadel wafers implanted had a 3-fold increased risk of AE and a 5.6-fold increased risk of ISAE, and patients with recurrent tumor had a 2.8-fold increased risk of AE and a 9.3-fold increased risk of ISAE.

CONCLUSIONS

Adding Gliadel to standard treatment did not significantly improve the outcome. The toxicity after Gliadel use was significantly higher, both for patients with newly diagnosed and patients with recurrent glioblastoma.