Placebo-controlled trial of safety and efficacy of intraoperative controlled delivery by biodegradable polymers of chemotherapy for recurrent gliomas. The Polymer-brain Tumor Treatment Group

Role of the blood-brain barrier in metastatic disease of the central nervous system

Systemic therapy is an important backbone in the multimodal treatment approach of brain metastases. However, the blood-brain barrier or, more correctly, the blood-tumor barrier, as the properties of tumor-associated vessels differ from the physiologic state, potentially limits the passage of systemic drugs. Indeed, several preclinical and clinical investigations showed that the distribution of drugs is very heterogeneous within a given brain metastasis, despite the contrast enhancement in magnetic resonance imaging. Brain metastases may show lower intratumoral concentrations of some drugs as compared to extracranial tumor sites, resulting in mixed responses. Therefore, a more profound understanding of the role of the blood-brain/blood-tumor barrier is needed to effectively formulate clinical trial approaches on systemic therapy options in patients with brain metastases.

SEOM clinical guidelines for diagnosis and treatment of glioblastoma (2017)

Glioblastoma (GB) is the most common brain malignancy and accounts for over 50% of all high-grade gliomas. Radiotherapy (RT) with concomitant and adjuvant temozolomide (TMZ) chemotherapy is the current standard of care for patients with newly diagnosed GB up to age 70. Recently, a new standard of care has been adopted for elderly patients (≥ 65 years) based on short course of RT and TMZ. Several clinically relevant molecular markers that assist in diagnosis and prognosis have recently been identified. The treatment for recurrent GB is not well defined, and decision-making is usually based on prior strategies as well as several clinical and radiological factors. The presence of neurologic deficits and seizures can significantly impact quality of life.

Glioblastoma Treatment in the Elderly

Although current treatment advances prolong patient survival, treatment for glioblastoma (GBM) in the elderly has become an emerging issue. The definition of "elderly" differs across articles; GBM predominantly occurs at an age ≥65 years, and the prognosis worsens with increasing age. Regarding molecular markers, isocitrate dehydrogenase (IDH) mutations are less common in the elderly with GBM. Meanwhile, O6-methylguanine DNA methyltransferase (MGMT) promoter methylation has been identified in approximately half of patients with GBM. Surgery should be considered as the first-line treatment even for elderly patients, and maximum safe resection is recommended if feasible. Concurrently, radiotherapy is the standard adjuvant therapy. Hypofractionated radiotherapy (e.g., 40 Gy/15 Fr) is suitable for elderly patients. Studies also supported the concurrent use of temozolomide (TMZ) with radiotherapy. In cases wherein elderly patients cannot tolerate chemoradiation, TMZ monotherapy is an effective option when MGMT promoter methylation is verified. Conversely, tumors with MGMT unmethylated promoter may be treated with radiotherapy alone to reduce the possible toxicity of TMZ. Meanwhile, the efficacy of bevacizumab (BEV) in elderly patients remains unclear. Similarly, further studies on the efficacy of carmustine wafers are needed. Based on current knowledge, we propose a treatment diagram for GBM in the elderly.

Rationale and design of the 500-patient, 3-year, and prospective Vigilant ObservatIon of GlIadeL WAfer ImplaNT registry

Implantation of biodegradable wafers impregnated with carmustine (BCNU) is one of the few chemotherapeutic modalities that have been evaluated in Phase III trials and approved by the US FDA for treatment of newly diagnosed high-grade glioma and recurrent glioblastoma. Enrolling up to 500 patients for 3-year follow-up at over 30 sites, the prospective Vigilant ObservatIon of GlIadeL WAfer ImplaNT (VIGILANT) registry (NCT02684838) will evaluate BCNU wafers for treatment of CNS malignancies in contemporary practice and in the new era of molecular tumor analysis. Subgroup analyses will include tumor type, molecular marker status, and treatment combinations. Interim analyses from the VIGILANT registry will be reported until complete results are available in 2024.

Pivotal therapeutic trials for infiltrating gliomas and how they affect clinical practice

The therapeutic landscape of the management of low- and high-grade infiltrating gliomas continues to evolve. Daily clinical decision making in neuro-oncology clinics across the US is frequently challenging, especially for anaplastic and low grade primary brain tumors. The focus of this review is centered on treatments which are approved by the FDA and/or featured in the NCCN Guidelines. Systemic therapy trials using a variety of agents such as temozolomide, bevacizumab, and procarbazine, lomustine, vincristine (PCV), and lastly trials of local therapies including surgical trials using carmustine impregnated wafers as well as trials investigating the administration of tumor treating fields are evaluated. Pivotal trials on the treatment of the primary brain tumors are discussed in detail along with associated correlative studies.

High encapsulation and localized delivery of curcumin from an injectable hydrogel

Most chemotherapy currently available for cancer treatment has limited potential to successful clinical cancer therapy, mainly due to low encapsulating capacity of drugs and unavailable pharmacologically beneficial concentrations at the tumor site. Herein, a novel yet simple strategy is developed to enhance drug encapsulating capacity and localized drug concentration using an injectable hydrogel based on thiolated chitosan (TCS) and poly(ethylene glycol) diacrylate (PEGDA). Almost 100% of encapsulating capacity is achieved when anti-cancer drug curcumin is encapsulated in the system. The interaction of curcumin with PEGDA is determined by fluorescence spectroscopy and the binding constant is calculated, followed by a simulation by a docking study using AutoDock. To improve the anti-tumor activity and achieve effective local concentrations, lysozyme is introduced into the system. Sustained curcumin release in a controlled lysozyme-responsive behaviour is observed, which enables the drug concentration to reach the therapeutic threshold promptly. The system displays efficient intracellular curcumin release to promote cancer cells apoptosis in vitro. In addition, the system effectively delays the tumor growth and reduces adverse effects in tumor-bearing nude mice. The strategy of localized, high encapsulation of drug by using an injectable hydrogel would be particularly beneficial with many insoluble anti-cancer drugs.

Natural Bioactive Compounds: Alternative Approach to the Treatment of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most frequent, primary malignant brain tumor prevalent in humans. GBM characteristically exhibits aggressive cell proliferation and rapid invasion of normal brain tissue resulting in poor patient prognosis. The current standard of care of surgical resection followed by radiotherapy and chemotherapy with temozolomide is not very effective. The inefficacy of the chemotherapeutic agents may be attributed to the challenges in drug delivery to the tumor. Several epidemiological studies have demonstrated the chemopreventive role of natural, dietary compounds in the development and progression of cancer. Many of these studies have reported the potential of using natural compounds in combination with chemotherapy and radiotherapy as a novel approach for the effective treatment of cancer. In this paper, we review the role of several natural compounds individually and in combination with chemotherapeutic agents in the treatment of GBM. We also assess the potential of drug delivery approaches such as the Gliadel wafers and role of nanomaterial based drug delivery systems for the effective treatment of GBM.

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.

Stereotactic Laser Interstitial Thermal Therapy for Recurrent High-Grade Gliomas

BACKGROUND

The value of maximal safe cytoreductive surgery in recurrent high-grade gliomas (HGGs) is gaining wider acceptance. However, patients may harbor recurrent tumors that may be difficult to access with open surgery. Laser interstitial thermal therapy (LITT) is emerging as a technique for treating a variety of brain pathologies, including primary and metastatic tumors, radiation necrosis, and epilepsy.

OBJECTIVE

To review the role of LITT in the treatment of recurrent HGGs, for which current treatments have limited efficacy, and to discuss the possible role of LITT in the disruption of the blood-brain barrier to increase delivery of chemotherapy locoregionally.

METHODS

A MEDLINE search was performed to identify 17 articles potentially appropriate for review. Of these 17, 6 reported currently commercially available systems and as well as magnetic resonance thermometry to monitor the ablation and, thus, were thought to be most appropriate for this review. These studies were then reviewed for complications associated with LITT. Ablation volume, tumor coverage, and treatment times were also reviewed.

RESULTS

Sixty-four lesions in 63 patients with recurrent HGGs were treated with LITT. Frontal (n = 34), temporal (n = 14), and parietal (n = 16) were the most common locations. Permanent neurological deficits were seen in 7 patients (12%), vascular injuries occurred in 2 patients (3%), and wound infection was observed in 1 patient (2%). Ablation coverage of the lesions ranged from 78% to 100%.

CONCLUSION

Although experience using LITT for recurrent HGGs is growing, current evidence is insufficient to offer a recommendation about its role in the treatment paradigm for recurrent HGGs.

ABBREVIATIONS

BBB, blood-brain barrierFDA, US Food and Drug AdministrationGBM, glioblastoma multiformeHGG, high-grade gliomaLITT, laser interstitial thermal therapy.

Biological basis and clinical study of glycogen synthase kinase- 3β-targeted therapy by drug repositioning for glioblastoma

Background

Glycogen synthase kinase (GSK)-3β has emerged as an appealing therapeutic target for glioblastoma (GBM). Here, we investigated the therapeutic effect of the current approved drugs against GBM via inhibition of GSK3β activity both, in experimental setting and in a clinical study for recurrent GBM patients by repositioning existent drugs in combination with temozolomide (TMZ).

Materials and Methods

Progression-free and overall survival rates were compared between patients with low or high expression of active GSK3β in the primary tumor. GBM cells and a mouse model were examined for the effects of GSK3β-inhibitory drugs, cimetidine, lithium, olanzapine, and valproate. The safety and efficacy of the cocktail of these drugs (CLOVA cocktail) in combination with TMZ were tested in the mouse model and in a clinical study for recurrent GBM patients.

Results

Activation of GSK3β in the tumor inversely correlated with patient survival as an independent prognostic factor. CLOVA cocktail significantly inhibited cell invasion and proliferation. The patients treated with CLOVA cocktail in combination with TMZ showed increased survival compared to the control group treated with TMZ alone.

Conclusions

Repositioning of the GSK3β-inhibitory drugs improved the prognosis of refractory GBM patients with active GSK3β in tumors. Combination of CLOVA cocktail and TMZ is a promising approach for recurrent GBM.

The Role of Immune Checkpoint Inhibition in the Treatment of Brain Tumors

The standard of care for malignant gliomas of the brain has changed very little over the last few decades, and does not offer a cure for these rare, but fatal, tumors. The field of immunotherapy has brought potent new drugs into the oncological armamentarium, and is becoming recognized as a potentially important arm in the treatment of glioblastoma for adults. Immune checkpoints are inhibitory receptors found on immune cells that, when stimulated, cause those immune cells to become quiescent. While this is a natural mechanism to prevent excessive inflammatory damage and autoimmunity in otherwise healthy tissues, cancer cells may utilize this process to grow in the absence of targeted immune destruction. Antibodies derived to block the stimulation of these negative checkpoints, allowing immune cells to remain activated and undergo effector function, are a growing area of immunotherapy. These therapies have seen much success in both the preclinical and clinical arenas for various tumors, particularly melanoma and nonsmall-cell lung cancer. Multiple clinical trials are underway to determine if these drugs have efficacy in glioblastoma. Here, we review the current evidence, from early preclinical data to lessons learned from clinical trials outside of glioblastoma, to assess the potential of immune checkpoint inhibition in the treatment of brain tumors and discuss how this therapy may be implemented with the present standard of care.

Nanomaterials for convection-enhanced delivery of agents to treat brain tumors

Nanomaterials represent a promising and versatile platform for the delivery of therapeutics to the brain. Treatment of brain tumors has been a long-standing challenge in the field of neuro-oncology. The current standard of care - a multimodal approach of surgery, radiation and chemotherapy - yields only a modest therapeutic benefit for patients with malignant gliomas. A major obstacle for treatment is the failure to achieve sufficient delivery of therapeutics at the tumor site. Recent advances in local drug delivery techniques, along with the development of highly effective brain-penetrating nanocarriers, have significantly improved treatment and imaging of brain tumors in preclinical studies. The major advantage of this combined strategy is the ability to optimize local therapy, by maintaining an effective and sustained concentration of therapeutics in the brain with minimal systemic toxicity. This review highlights some of the latest developments, significant advancements and current challenges in local delivery of nanomaterials for the treatment of brain tumors.

Adult Glioblastoma

Glioblastoma (GBM) is a rare tumor and one of the most challenging malignancies to treat in all of oncology. Although advances have been made in the treatment of GBM, encouraging outcomes typically are not observed; patients diagnosed with these tumors generally have a dismal prognosis and poor quality of life as the disease progresses. This review summarizes the clinical presentation of GBM, diagnostic methods, evidentiary basis for the current standards of care, and investigational approaches to treat or manage GBM. Because the track record for developing effective therapies for GBM has been dismal, we also review the challenges to successful therapeutic and biomarker development.

Biodegradable brain-penetrating DNA nanocomplexes and their use to treat malignant brain tumors

The discovery of powerful genetic targets has spurred clinical development of gene therapy approaches to treat patients with malignant brain tumors. However, lack of success in the clinic has been attributed to the inability of conventional gene vectors to achieve gene transfer throughout highly disseminated primary brain tumors. Here, we demonstrate ex vivo that small nanocomplexes composed of DNA condensed by a blend of biodegradable polymer, poly(β-amino ester) (PBAE), with PBAE conjugated with 5kDa polyethylene glycol (PEG) molecules (PBAE-PEG) rapidly penetrate healthy brain parenchyma and orthotopic brain tumor tissues in rats. Rapid diffusion of these DNA-loaded nanocomplexes observed in fresh tissues ex vivo demonstrated that they avoided adhesive trapping in the brain owing to their dense PEG coating, which was critical to achieving widespread transgene expression throughout orthotopic rat brain tumors in vivo following administration by convection enhanced delivery. Transgene expression with the PBAE/PBAE-PEG blended nanocomplexes (DNA-loaded brain-penetrating nanocomplexes, or DNA-BPN) was uniform throughout the tumor core compared to nanocomplexes composed of DNA with PBAE only (DNA-loaded conventional nanocomplexes, or DNA-CN), and transgene expression reached beyond the tumor edge, where infiltrative cancer cells are found, only for the DNA-BPN formulation. Finally, DNA-BPN loaded with anti-cancer plasmid DNA provided significantly enhanced survival compared to the same plasmid DNA loaded in DNA-CN in two aggressive orthotopic brain tumor models in rats. These findings underscore the importance of achieving widespread delivery of therapeutic nucleic acids within brain tumors and provide a promising new delivery platform for localized gene therapy in the brain.

Injection of Chemotherapeutic Microspheres and Glioma III: Parameters to Optimize Efficacy

Injectable microspheres may provide a means of providing local, sustained exposure of glioma to chemotherapeutics to improve patient survival. Using a rodent model of surgically resected glioma, we previously demonstrated that direct injections of chemotherapeutic microspheres into the tissue surrounding a resection cavity provide superior survival effects over injections of the same microspheres directly into the surgical cavity. The present experiments extended this novel observation by exploring several parameters related to the use of intraparenchymal injections of chemotherapeutic microspheres to treat glioma. Using a rat model of resected glioma, several principles regarding the use of local sustained release carboplatin microspheres were established. First, an inverted U dose–response was observed, wherein further dose escalation beyond the optimal dose was not efficacious and indeed produced significant local toxicity. Second, it was necessary to expose approximately 40% of the tumor margin to sustained release carboplatin in order to increase survival in this model. Survival was not enhanced when the proportion of the tumor margin exposed to carboplatin was only 20%. Third, the distribution of the chemotherapeutic microsphere injections along the tumor perimeter was shown to be important, requiring that the entire perimeter be proportionately exposed to the chemotherapeutic agent. Together, these data continue to support the development of chemotherapeutic microspheres for treating glioma. However, they also caution that a number of fundamental parameters can profoundly influence the efficacy that might be expected from local sustained delivery. Careful attention to these principles is not only required if chemotherapeutic microspheres are to be used efficaciously, but these principles should provide a foundation to further optimize the potential of this and other polymeric delivery systems under development for local, intraparenchymal drug delivery to glioma.

Injection of Chemotherapeutic Microspheres and Glioma IV: Eradicating Tumors in Rats

Polymer microspheres can be easily injected into the brain to provide a local and sustained delivery of chemotherapeutics to a tumor or surrounding tissue subject to high rates of tumor recurrence following surgery. Building on previous studies that established the clear advantage of local, peritumoral injections of sustained release microspheres, the following experiments utilized two different approaches for maximizing the survival benefit in glioma-bearing rats. In the first experiment, a previously grown cortical tumor was debulked and animals received either one or two treatments with carboplatin-loaded microspheres (either 200 or 800 μg total carboplatin per treatment). In each case, the microspheres were injected along the perimeter of the resection cavity with each treatment separated by 20 days. Survival studies clearly demonstrated that two, temporally spaced injections were superior to a single series of injections. At the lowest dose tested (200 μg), median survival was increased an additional 40% over that in animals receiving one treatment. At the higher dose (800 μg), one third of the animals receiving two separate treatments were long-term survivors (>150 days) and showed complete eradication of the tumor on histological examination. In the second experiment, we directly compared the efficacy produced by sustained release carboplatin or 1,3-bis[2-chloroethyl]-1-nitrourea (BCNU) alone versus injecting carboplatin and BCNU-loaded micro-spheres blended together as a single suspension. Carboplatin and BCNU both enhanced survival, with BCNU being significantly less effective than carboplatin. However, the greatest improvements in survival were seen when a blended suspension of carboplatin and BCNU microspheres was injected around the surgical cavity. In contrast, spatially alternating injections of BCNU and carboplatin microspheres was significantly less effective and the increase in survival was no greater than that achieved with BCNU alone. These data offer further support for the potential utility of local, sustained release chemotherapeutic microspheres for treating glioma. Moreover, they suggest that injectable chemotherapeutic microspheres may offer important advantages by (a) permitting multiple, temporally spaced injections to be made, as needed, and (b) providing the opportunity to deliver combinations of several different efficacious drugs directly to the tumor site to enhance survival beyond what can be achieved with delivery of any single chemotherapeutic agent.

On glioblastoma and the search for a cure: where do we stand?

Although brain tumours have been documented and recorded since the nineteenth century, 2016 marked 90 years since Percival Bailey and Harvey Cushing coined the term "glioblastoma multiforme". Since that time, although extensive developments in diagnosis and treatment have been made, relatively little improvement on prognosis has been achieved. The resilience of GBM thus makes treating this tumour one of the biggest challenges currently faced by neuro-oncology. Aggressive and robust development, coupled with difficulties of complete resection, drug delivery and therapeutic resistance to treatment are some of the main issues that this nemesis presents today. Current treatments are far from satisfactory with poor prognosis, and focus on palliative management rather than curative intervention. However, therapeutic research leading to developments in novel treatment stratagems show promise in combating this disease. Here we present a review on GBM, looking at the history and advances which have shaped neurosurgery over the last century that cumulate to the present day management of GBM, while also exploring future perspectives in treatment options that could lead to new treatments on the road to a cure.

Extent of resection and Carmustine wafer implantation safely improve survival in patients with a newly diagnosed glioblastoma: a single center experience of the current practice

For newly diagnosed glioblastomas treated with resection in association with the standard combined chemoradiotherapy, the impact of Carmustine wafer implantation remains debated regarding postoperative infections, quality of life, and feasibility of adjuvant oncological treatments. To assess together safety, tolerance and efficacy of Carmustine wafer implantation and of extent of resection for glioblastoma patients in real-life experience. Observational retrospective monocentric study including 340 consecutive adult patients with a newly diagnosed supratentorial glioblastoma who underwent surgical resection with (n = 123) or without (n = 217) Carmustine wafer implantation as first-line oncological treatment. Carmustine wafer implantation and extent of resection did not significantly increase postoperative complications, including postoperative infections (p = 0.269, and p = 0.446, respectively). Carmustine wafer implantation and extent of resection did not significantly increase adverse events during adjuvant oncological therapies (p = 0.968, and p = 0.571, respectively). Carmustine wafer implantation did not significantly alter the early postoperative Karnofsky performance status (p = 0.402) or the Karnofsky performance status after oncological treatment (p = 0.636) but a subtotal or total surgical resection significantly improved those scores (p < 0.001, and p < 0.001, respectively). Carmustine wafer implantation, subtotal and total resection, and standard combined chemoradiotherapy were independently associated with longer event-free survival (adjusted Hazard Ratio (aHR), 0.74 [95% CI 0.55-0.99], p = 0.043; aHR, 0.70 [95% CI 0.54-0.91], p = 0.009; aHR, 0.40 [95% CI 0.29-0.55], p < 0.001, respectively) and with longer overall survival (aHR, 0.69 [95% CI 0.49-0.96], p = 0.029; aHR, 0.52 [95% CI 0.38-0.70], p < 0.001; aHR, 0.58 [95% CI 0.42-0.81], p = 0.002, respectively). Carmustine wafer implantation in combination with maximal resection, followed by standard combined chemoradiotherapy is safe, efficient, and well-tolerated in newly diagnosed supratentorial glioblastomas in adults.

Differentiating between Central Nervous System Lymphoma and High-grade Glioma Using Dynamic Susceptibility Contrast and Dynamic Contrast-enhanced MR Imaging with Histogram Analysis

Purpose:

We evaluated the diagnostic performance of histogram analysis of data from a combination of dynamic susceptibility contrast (DSC)-MRI and dynamic contrast-enhanced (DCE)-MRI for quantitative differentiation between central nervous system lymphoma (CNSL) and high-grade glioma (HGG), with the aim of identifying useful perfusion parameters as objective radiological markers for differentiating between them.

Methods:

Eight lesions with CNSLs and 15 with HGGs who underwent MRI examination, including DCE and DSC-MRI, were enrolled in our retrospective study. DSC-MRI provides a corrected cerebral blood volume (cCBV), and DCE-MRI provides a volume transfer coefficient (K^trans) for transfer from plasma to the extravascular extracellular space. K^trans and cCBV were measured from a round region-of-interest in the slice of maximum size on the contrast-enhanced lesion. The differences in t values between CNSL and HGG for determining the most appropriate percentile of K^trans and cCBV were investigated. The differences in K^trans, cCBV, and K^trans/cCBV between CNSL and HGG were investigated using histogram analysis. Receiver operating characteristic (ROC) analysis of K^trans, cCBV, and K^trans/cCBV ratio was performed.

Results:

The 30th percentile (C30) in K^trans and 80th percentile (C80) in cCBV were the most appropriate percentiles for distinguishing between CNSL and HGG from the differences in t values. CNSL showed significantly lower C80 cCBV, significantly higher C30 K^trans, and significantly higher C30 K^trans/C80 cCBV than those of HGG. In ROC analysis, C30 K^trans/C80 cCBV had the best discriminative value for differentiating between CNSL and HGG as compared to C30 K^trans or C80 cCBV.

Conclusion:

The combination of K^trans by DCE-MRI and cCBV by DSC-MRI was found to reveal the characteristics of vascularity and permeability of a lesion more precisely than either K^trans or cCBV alone. Histogram analysis of these vascular microenvironments enabled quantitative differentiation between CNSL and HGG.

Nivolumab for patients with recurrent glioblastoma progressing on bevacizumab: a retrospective case series

A single institution retrospective evaluation of nivolumab following disease progression on bevacizumab in adults with recurrent glioblastoma (GBM) with an objective of determining progression free survival (PFS). There is no accepted therapy for recurrent GBM after failure of bevacizumab. 16 adults, ages 52-72 years (median 62), with recurrent GBM were treated. All patients had previously been treated with surgery, concurrent radiotherapy and temozolomide, and post-radiotherapy temozolomide. Bevacizumab (with or without lomustine) was administered to all patients at first recurrence. Patients were treated with nivolumab only (3 mg/kg) once every 2 weeks at second recurrence. One cycle of nivolumab was defined as 2 treatments. Neurological evaluation was performed bi-weekly and neuroradiographic assessment every 4 weeks. A total of 37 treatment cycles (median 2) were administered of nivolumab in which there were 14 Grade 2 adverse events (AEs) and Grade 3 AEs in two patients. No Grade 4 or 5 AEs were seen. Following 1 month of nivolumab, seven patients demonstrated progressive disease and discontinued therapy. No patient demonstrated a response though nine patients demonstrated neuroradiographic stable response. Survival in the entire cohort ranged from 2 to 6 months with a median of 3.5 months (CI 2.8, 4.2). Median and 6-month PFS at 6 months was 2.0 months (range 1-5 months; CI 1.3, 2.7) and 0% respectively. Nivolumab salvage therapy demonstrated no survival advantage in patients with recurrent bevacizumab refractory GBM emphasizing a continued unmet need in neuro-oncology.

Redox-Activatable ATP-Depleting Micelles with Dual Modulation Characteristics for Multidrug-Resistant Cancer Therapy

A fast adenosine triphosphate (ATP)-depleting micellar system that is activated by intracellular redox for the codelivery of anticancer drug paclitaxel (PTX) and small interference RNA (siRNA) targeting polo-like kinase1 (PLK1) is developed to address the key challenges of multidrug-resistant (MDR) cancer therapy. The ATP-depleting micelle is self-assembled from a redox-responsive amphiphilic polymer (termed as bPEG-SS-P123-PEI (PSPP)) that is composed of biocompatible branched polyethylene glycol (PEG) with 8 arms (bPEG), ATP-depleting Pluronic P123 (P123), and cationic low molecular weight polyethylenimine (PEI) blocks. Upon critical micelle concentration, the PSPP unimer self-assembles into a well-ordered multilayered nanostructure and is able to load PTX and siRNA targeting PLK1. The cleavage of disulfide linkages at intracellular glutathione-rich reduction milieu not only promotes PTX and siRNA release, but also activates the fast ATP-depletion action that is critical in preventing intracellular PTX efflux by multidrug-resistant cancer cells. The combination of ATP depletion and siRNA inhibition by PSPP micelles is found to provide dual modulations for resensitizing multidrug-resistant cancer cells for PTX treatment. As a result, the codelivery of PTX and PLK1 siRNA exerts a stronger combinational effect against tumor growth in MDR tumor models in vivo. The development of fast ATP-depleting nanomicelle represents an original delivery strategy for the distinctive dual modulation of cancer MDR with spatial and temporal control.

Theranostic 3-Dimensional nano brain-implant for prolonged and localized treatment of recurrent glioma

Localized and controlled delivery of chemotherapeutics directly in brain-tumor for prolonged periods may radically improve the prognosis of recurrent glioblastoma. Here, we report a unique method of nanofiber by fiber controlled delivery of anti-cancer drug, Temozolomide, in orthotopic brain-tumor for one month using flexible polymeric nano-implant. A library of drug loaded (20 wt%) electrospun nanofiber of PLGA-PLA-PCL blends with distinct in vivo brain-release kinetics (hours to months) were numerically selected and a single nano-implant was formed by co-electrospinning of nano-fiber such that different set of fibres releases the drug for a specific periods from days to months by fiber-by-fiber switching. Orthotopic rat glioma implanted wafers showed constant drug release (116.6 μg/day) with negligible leakage into the peripheral blood (<100 ng) rendering ~1000 fold differential drug dosage in tumor versus peripheral blood. Most importantly, implant with one month release profile resulted in long-term (>4 month) survival of 85.7% animals whereas 07 day releasing implant showed tumor recurrence in 54.6% animals, rendering a median survival of only 74 days. In effect, we show that highly controlled drug delivery is possible for prolonged periods in orthotopic brain-tumor using combinatorial nanofibre libraries of bulk-eroding polymers, thereby controlling glioma recurrence.

Hyperthermia and chemotherapy using Fe(Salen) nanoparticles might impact glioblastoma treatment

We previously reported that μ-oxo N,N’-bis(salicylidene)ethylenediamine iron [Fe(Salen)], a magnetic organic compound, has direct anti-tumor activity, and generates heat in an alternating magnetic field (AMF). We showed that Fe(Salen) nanoparticles are useful for combined hyperthermia-chemotherapy of tongue cancer. Here, we have examined the effect of Fe(Salen) on human glioblastoma (GB). Fe(Salen) showed in vitro anti-tumor activity towards several human GB cell lines. It inhibited cell proliferation, and its apoptosis-inducing activity was greater than that of clinically used drugs. Fe(Salen) also showed in vivo anti-tumor activity in the mouse brain. We evaluated the drug distribution and systemic side effects of intracerebrally injected Fe(Salen) nanoparticles in rats. Further, to examine whether hyperthermia, which was induced by exposing Fe(Salen) nanoparticles to AMF, enhanced the intrinsic anti-tumor effect of Fe(Salen), we used a mouse model grafted with U251 cells on the left leg. Fe(Salen), BCNU, or normal saline was injected into the tumor in the presence or absence of AMF exposure. The combination of Fe(Salen) injection and AMF exposure showed a greater anti-tumor effect than did either Fe(Salen) or BCNU alone. Our results indicate that hyperthermia and chemotherapy with single-drug nanoparticles could be done for GB treatment.

Chloroethylating nitrosoureas in cancer therapy: DNA damage, repair and cell death signaling

Chloroethylating nitrosoureas (CNU), such as lomustine, nimustine, semustine, carmustine and fotemustine are used for the treatment of malignant gliomas, brain metastases of different origin, melanomas and Hodgkin disease. They alkylate the DNA bases and give rise to the formation of monoadducts and subsequently interstrand crosslinks (ICL). ICL are critical cytotoxic DNA lesions that link the DNA strands covalently and block DNA replication and transcription. As a result, S phase progression is inhibited and cells are triggered to undergo apoptosis and necrosis, which both contribute to the effectiveness of CNU-based cancer therapy. However, tumor cells resist chemotherapy through the repair of CNU-induced DNA damage. The suicide enzyme O⁶-methylguanine-DNA methyltransferase (MGMT) removes the precursor DNA lesion O⁶-chloroethylguanine prior to its conversion into ICL. In cells lacking MGMT, the formed ICL evoke complex enzymatic networks to accomplish their removal. Here we discuss the mechanism of ICL repair as a survival strategy of healthy and cancer cells and DNA damage signaling as a mechanism contributing to CNU-induced cell death. We also discuss therapeutic implications and strategies based on sequential and simultaneous treatment with CNU and the methylating drug temozolomide.

Phase I/II Study of Temozolomide Plus Nimustine Chemotherapy for Recurrent Malignant Gliomas: Kyoto Neuro-oncology Group

The objective of this phase I/II study was to examine the efficacy and toxicity profile of temozolomide (TMZ) plus nimustine (ACNU). Patients who had received a standard radiotherapy with one or two previous chemo-regimens were enrolled. In phase I, the maximum-tolerated dose (MTD) by TMZ (150 mg/m2/day) (Day 1-5) plus various doses of ACNU (30, 35, 40, 45 mg/m2/day) (Day 15) per 4 weeks was defined on a standard 3 + 3 design. In phase II, these therapeutic activity and safety of this regimen were evaluated. Forty-nine eligible patients were enrolled. The median age was 50 years-old. Eighty percent had a KPS of 70-100. Histologies were glioblastoma (73%), anaplastic astrocytoma (22%), anaplastic oligodendroglioma (4%). In phase I, 15 patients were treated at four cohorts by TMZ plus ACNU. MTD was TMZ (150 mg/m2) plus ACNU (40 mg/m2). In phase II, 40 patients were treated at the dose of cohort 3 (MTD). Thirty-five percent of patients experienced grade 3 or 4 toxicities, mainly hematologic. The overall response rate was 11% (4/37). Sixty-eight percent (25/37) had stable disease. Twenty-two percent (8/37) showed progression. Progression-free survival (PFS) rates at 6 and 12 months were 24% (95% CI, 12-35%) and 8% (95% CI, 4-15%). Median PFS was 13 months (95% CI, 9.2-17.2 months). Overall survival (OS) at 6 and 12 were 78% (95% CI, 67-89%) and 49% (95% CI, 33-57%). Median OS was 11.8 months (95% CI, 8.2-14.5 months). This phase I/II study showed a moderate toxicity in hematology and may has a promising efficacy in OS, without inferiority in PFS.

Quantitative Analyses of Synergistic Responses between Cannabidiol and DNA-Damaging Agents on the Proliferation and Viability of Glioblastoma and Neural Progenitor Cells in Culture

Evidence suggests that the nonpsychotropic cannabis-derived compound, cannabidiol (CBD), has antineoplastic activity in multiple types of cancers, including glioblastoma multiforme (GBM). DNA-damaging agents remain the main standard of care treatment available for patients diagnosed with GBM. Here we studied the antiproliferative and cell-killing activity of CBD alone and in combination with DNA-damaging agents (temozolomide, carmustine, or cisplatin) in several human GBM cell lines and in mouse primary GBM cells in cultures. This activity was also studied in mouse neural progenitor cells (NPCs) in culture to assess for potential central nervous system toxicity. We found that CBD induced a dose-dependent reduction of both proliferation and viability of all cells with similar potencies, suggesting no preferential activity for cancer cells. Hill plot analysis indicates an allosteric mechanism of action triggered by CBD in all cells. Cotreatment regimens combining CBD and DNA-damaging agents produced synergistic antiproliferating and cell-killing responses over a limited range of concentrations in all human GBM cell lines and mouse GBM cells as well as in mouse NPCs. Remarkably, antagonistic responses occurred at low concentrations in select human GBM cell lines and in mouse GBM cells. Our study suggests limited synergistic activity when combining CBD and DNA-damaging agents in treating GBM cells, along with little to no therapeutic window when considering NPCs.

Clinical predictors for survival and treatment outcome of high-grade glioma in Prasat Neurological Institute

OBJECTIVE

The aim was to identify clinical predictors for survival and examine treatment outcome in patients with high-grade glioma (HGG).

MATERIALS AND METHODS

The authors retrospectively reviewed medical records of patients who was diagnosed HGG between January 2007 and December 2009. Demographic data, radiological data and treatment data of patients were reviewed and analyzed.

RESULTS

A total of 100 patients were analyzed. There was no difference in demographic data between Grade III and IV glioma. Patients with HGG had median survival time (MST) 18 months, The MST of patients with Grade III and IV glioma were 26 and 13 months, respectively. In this study, only anaplastic oligoastrocytoma and radiotherapy did impact strongly on survival of patients with HGG. In patients with Grade III and IV glioma, radiotherapy found to have influence on survival.

CONCLUSION

Patients with HGG in Prasat Neurological Institute had short survival resemble to other previous study. The clinical predictors for survival of patients were identified on multivariate analysis.

Biomaterial-Based Implantable Devices for Cancer Therapy

This review article focuses on the current local therapies mediated by implanted macroscaled biomaterials available or proposed for fighting cancer and also highlights the upcoming research in this field. Several authoritative review articles have collected and discussed the state-of-the-art as well as the advancements in using biomaterial-based micro- and nano-particle systems for drug delivery in cancer therapy. On the other hand, implantable biomaterial devices are emerging as highly versatile therapeutic platforms, which deserve an increased attention by the healthcare scientific community, as they are able to offer innovative, more effective and creative strategies against tumors. This review summarizes the current approaches which exploit biomaterial-based devices as implantable tools for locally administrating drugs and describes their specific medical applications, which mainly target resected brain tumors or brain metastases for the inaccessibility of conventional chemotherapies. Moreover, a special focus in this review is given to innovative approaches, such as combined delivery therapies, as well as to alternative approaches, such as scaffolds for gene therapy, cancer immunotherapy and metastatic cell capture, the later as promising future trends in implantable biomaterials for cancer applications.

Convection-enhanced Delivery of Therapeutics for Malignant Gliomas

Convection-enhanced delivery (CED) circumvents the blood–brain barrier by delivering agents directly into the tumor and surrounding parenchyma. CED can achieve large volumes of distribution by continuous positive-pressure infusion. Although promising as an effective drug delivery method in concept, the administration of therapeutic agents via CED is not without challenges. Limitations of distribution remain a problem in large brains, such as those of humans. Accurate and consistent delivery of an agent is another challenge associated with CED. Similar to the difficulties caused by immunosuppressive environments associated with gliomas, there are several mechanisms that make effective local drug distribution difficult in malignant gliomas. In this review, methods for local drug application targeting gliomas are discussed with special emphasis on CED. Although early clinical trials have failed to demonstrate the efficacy of CED against gliomas, CED potentially can be a platform for translating the molecular understanding of glioblastomas achieved in the laboratory into effective clinical treatments. Several clinical studies using CED of chemotherapeutic agents are ongoing. Successful delivery of effective agents should prove the efficacy of CED in the near future.

Polylactic acid (PLA) controlled delivery carriers for biomedical applications

Polylactic acid (PLA) and its copolymers have a long history of safety in humans and an extensive range of applications. PLA is biocompatible, biodegradable by hydrolysis and enzymatic activity, has a large range of mechanical and physical properties that can be engineered appropriately to suit multiple applications, and has low immunogenicity. Formulations containing PLA have also been Food and Drug Administration (FDA)-approved for multiple applications making PLA suitable for expedited clinical translatability. These biomaterials can be fashioned into sutures, scaffolds, cell carriers, drug delivery systems, and a myriad of fabrications. PLA has been the focus of a multitude of preclinical and clinical testing. Three-dimensional printing has expanded the possibilities of biomedical engineering and has enabled the fabrication of a myriad of platforms for an extensive variety of applications. PLA has been widely used as temporary extracellular matrices in tissue engineering. At the other end of the spectrum, PLA's application as drug-loaded nanoparticle drug carriers, such as liposomes, polymeric nanoparticles, dendrimers, and micelles, can encapsulate otherwise toxic hydrophobic anti-tumor drugs and evade systemic toxicities. The clinical translation of these technologies from preclinical experimental settings is an ever-evolving field with incremental advancements. In this review, some of the biomedical applications of PLA and its copolymers are highlighted and briefly summarized.

Triolein Emulsion Infusion Into the Carotid Artery Increases Brain Permeability to Anticancer Agents

BACKGROUND

Triolein emulsion infusion into the carotid artery has been reported to induce temporary and reversible opening of the blood-brain barrier by increasing vascular permeability.

OBJECTIVE

To evaluate the effect of triolein emulsion infusion on brain permeance by anticancer agents.

METHODS

In the doxorubicin study. 2.4 mg/kg doxorubicin was injected immediately after triolein emulsion (1%, 1.5%, and 2%) infusion into rabbit carotid arteries. Two hours later, bilateral hemispheres and eyeballs were harvested, and doxorubicin concentrations were measured fluorometrically. Doxorubicin ratios of ipsilateral/contralateral hemispheres were compared with those of doxorubicin controls by use of the Kruskal-Wallis test followed by the Dunn test. In the cisplatin study, 10 mg/kg cisplatin was injected immediately after 2% triolein emulsion infusion into rat carotid arteries. Ipsilateral hemispheres were harvested 2, 6, 12, 24, and 36 hours after treatment. Time-dependent cisplatin concentrations were determined by liquid chromatography/electrospray ionization-tandem mass spectrometry/mass spectrometry.

RESULTS

Doxorubicin concentrations were significantly higher in ipsilateral hemispheres and eyeballs in all 3 triolein treatment groups than in doxorubicin controls. In the cisplatin study, cisplatin concentrations in the ipsilateral hemispheres peaked at 6 hours after infusion of cisplatin.

CONCLUSION

Brain permeance to anticancer agents was increased by triolein emulsion infusion, which suggests that triolein infusion might be a useful adjuvant treatment for brain tumors.

Tumor-targeted nanotherapeutics: overcoming treatment barriers for glioblastoma

Glioblastoma (GBM) is a highly aggressive and lethal form of primary brain cancer. Numerous barriers exist to the effective treatment of GBM including the tightly controlled interface between the bloodstream and central nervous system termed the 'neurovascular unit,' a narrow and tortuous tumor extracellular space containing a dense meshwork of proteins and glycosaminoglycans, and genomic heterogeneity and instability. A major goal of GBM therapy is achieving sustained drug delivery to glioma cells while minimizing toxicity to adjacent neurons and glia. Targeted nanotherapeutics have emerged as promising drug delivery systems with the potential to improve pharmacokinetic profiles and therapeutic efficacy. Some of the key cell surface molecules that have been identified as GBM targets include the transferrin receptor, low-density lipoprotein receptor-related protein, α_v β₃ integrin, glucose transporter(s), glial fibrillary acidic protein, connexin 43, epidermal growth factor receptor (EGFR), EGFR variant III, interleukin-13 receptor α chain variant 2, and fibroblast growth factor-inducible factor 14. However, most targeted therapeutic formulations have yet to demonstrate improved efficacy related to disease progression or survival. Potential limitations to current targeted nanotherapeutics include: (1) adhesive interactions with nontarget structures, (2) low density or prevalence of the target, (3) lack of target specificity, and (4) genetic instability resulting in alterations of either the target itself or its expression level in response to treatment. In this review, we address these potential limitations in the context of the key GBM targets with the goal of advancing the understanding and development of targeted nanotherapeutics for GBM. WIREs Nanomed Nanobiotechnol 2017, 9:e1439. doi: 10.1002/wnan.1439 For further resources related to this article, please visit the WIREs website.

Outcome of patients affected by newly diagnosed glioblastoma undergoing surgery assisted by 5-aminolevulinic acid guided resection followed by BCNU wafers implantation: a 3-year follow-up

The purpose of the study was to evaluate the clinical outcome of the association of BCNU wafers implantation and 5-aminolevulinic acid (5-ALA) fluorescence in the treatment of patients with newly diagnosed glioblastoma (ndGBM). Clinical and surgical data from patients who underwent 5-ALA surgery followed by BCNU wafers implantation were retrospectively evaluated (20 patients, Group I) and compared with data of patients undergoing surgery with BCNU wafers alone (42 patients, Group II) and 5-ALA alone (59 patients, Group III). Patients undergoing 5-ALA assisted resection followed by BCNU wafers implantation (Group I) resulted long survivors (>3 years) in 15 % of cases and showed a median PFS and MS of 11 and 22 months, respectively. Patients treated with BCNU wafers presented a significantly higher survival when tumor was removed with the assistance of 5-ALA (22 months with vs 18 months without 5-ALA, p < 0.0001); these data could be partially explained by the significantly higher CRET achieved in patients operated with 5-ALA assistance (80 % with vs 47 %% without 5-ALA). Moreover, patients of Group I showed a significant increased survival compared with Group III (5-ALA without BCNU) (22 months with vs 21 months without BCNU wafers, p = 0.0025) even with a comparable CRET (80 % vs 76 %, respectively). The occurrence of adverse events related to wafers did not significantly increase with 5-ALA (20 % with and 19 % without 5-ALA) and did not impact in survival outcome. In conclusion, our experience shows that on selected ndGBM patients 5-ALA technology and BCNU wafers implantation show a synergic action on patients' outcome without increasing adverse events occurrence.

Aptamer-Functionalized Nanoparticles as "Smart Bombs": The Unrealized Potential for Personalized Medicine and Targeted Cancer Treatment

Conventional delivery of chemotherapeutic agents leads to multiple systemic side effects and toxicity, limiting the doses that can be used. The development of targeted therapies to selectively deliver anti-cancer agents to tumor cells without damaging neighboring unaffected cells would lead to higher effective local doses and improved response rates. Aptamers are single-stranded oligonucleotides that bind to target molecules with both high affinity and high specificity. The high specificity exhibited by aptamers promotes localization and uptake by specific cell populations, such as tumor cells, and their conjugation to anti-cancer drugs has been explored for targeted therapy. Advancements in the development of polymeric nanoparticles allow anti-cancer drugs to be encapsulated in protective nonreactive shells for controlled drug delivery with reduced toxicity. The conjugation of aptamers to nanoparticle-based therapeutics may further enhance direct targeting and personalized medicine. Here we present how the combinatorial use of aptamer and nanoparticle technologies has the potential to develop "smart bombs" for targeted cancer treatment, highlighting recent pre-clinical studies demonstrating efficacy for the direct targeting to particular tumor cell populations. However, despite these pre-clinical promising results, there has been little progress in moving this technology to the bedside.

Frontal glioblastoma multiforme may be biologically distinct from non-frontal and multilobar tumors

Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults and carries a grim prognosis. Lobar GBM, notably those localized to the frontal lobe, are generally more amenable to complete surgical resection, and may carry a better prognosis. The biology of differently localized GBM has been reported scarcely in terms of prognostic markers, including isocitrate dehydrogenase 1 (IDH1) mutation and O(6)-methylguanine-methyltransferase (MGMT) methylation. To our knowledge, there has been no evaluation in the literature of different proliferation indexes in different GBM locations in the brain. We performed a retrospective evaluation of our prospectively collected database to assess the rate of IDH1 positivity, MGMT methylation and Ki67 index for GBM located in the frontal lobes alone, lobar GBM in other supra-tentorial lobes and multilobar GBM. IDH1 mutated tumors were localized in the frontal lobes in 50.0%, whereas only 20.3% of IDH1 wild-type tumors were localized in the frontal lobe (p=0.006); MGMT methylated tumors were localized in the frontal lobe in 32.0% of the cases. Only 13.75% of the MGMT unmethylated tumors were localized to the frontal lobe (p=0.005); Tumors with higher Ki67 proliferation index were more likely to be localized in the frontal lobe (40.6% vs. 19.5%, p=0.019). This is the largest cohort of GBM assessed for these purposes in the literature. Frontal lobe GBMs may be intrinsically biologically distinct from GBM in other lobes and from multilobar tumors.

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.

IDH1 mutation may not be prognostically favorable in glioblastoma when controlled for tumor location: A case-control study

Isocitrate dehydrogenase 1 (IDH1) mutation is a known prognostic factor in glioblastoma multiforme (GBM). It has been well documented that patients with IDH1 mutant (IDH1-mu) GBM have a better outcome compared to patients with IDH1 wild-type (IDH1-WT) GBM. IDH1-mu tumors have been shown to be more commonly located in the frontal lobe, and less likely to be in multiple lobes. It is unclear whether differential location is part of the prognostically favorable profile of these tumors. We performed a case-control study, matching IDH1-mu GBMs to IDH1-WT GBMs that are controlled for age, sex and tumor location. There were 21 IDH1-mu tumors and 21 matched IDH1-WT tumors. Age, sex and tumor location were matched between the two groups. After controlling for the factors described, the IDH1-mu tumors were more likely to be secondary GBM (61.9% secondary vs. 14.3%, p=0.004). There was an insignificant trend towards smaller tumor volume in the IDH1-mu group (28.13±6.56 vs. 41.8±7.33 cm³, p=0.173). Extent of surgical resection was similar in both groups (mean 84.49% vs. 89.89%, p=0.419). There was no survival advantage for IDH1-mu tumors when controlled for location: 25.2months overall survival for IDH1-mu patients and 23.6 for IDH1-WT patients, p=0.794. IDH1 mutation may provide part of its prognostic significance by differential localization of tumor, both making IDH1-mu tumors more amenable to gross total resection and placing these tumors in less eloquent areas, thereby lowering neurological morbidity.

Influence of insurance status on survival of adults with glioblastoma multiforme: A population-based study

BACKGROUND

To the authors' knowledge, the impact of insurance status on the survival time of patients with glioblastoma multiforme (GBM) has not been fully understood. The objective of the current study was to clarify the association between insurance status and survival of patients with GBM by analyzing population-based data.

METHODS

The authors performed a cohort study using data from the Surveillance, Epidemiology, and End Results program. They included adult patients (aged ≥18 years) with GBM as their primary diagnosis from the years 2007 to 2012. Patients without information regarding insurance status were excluded. A survival analysis between insurance status and GBM-related death was performed using an accelerated failure time model. Demographic and clinical variables were included to adjust for confounding effects.

RESULTS

Among the 13,665 adult patients in the study cohort, 558 (4.1%) were uninsured, 1516 (11.1%) had Medicaid coverage, and 11,591 (84.8%) had non-Medicaid insurance. Compared with patients who were uninsured, insured patients were more likely to be older, female, white, married, and with a smaller tumor size at diagnosis. Accelerated failure time analysis demonstrated that older age (hazard ratio [HR], 1.04; P<.001), male sex (HR, 1.08; P<.001), large tumor size at the time of diagnosis (HR, 1.26; P<.001), uninsured status (HR, 1.14; P =.018), and Medicaid insurance (HR, 1.10; P =.006) were independent risk factors for shorter survival among patients with GBM, whereas radiotherapy (HR, 0.40; P<.001) and married status (HR, 0.86; P<.001) indicated a better outcome. The authors discovered an overall yearly progressive improvement in survival in patients with non-Medicaid insurance who were diagnosed from 2007 through 2011 (P =.015), but not in uninsured or Medicaid-insured patients.

CONCLUSIONS

Variations existed in insurance status within the GBM population. Uninsured status and Medicaid insurance suggested shorter survival compared with non-Medicaid insurance among a population of patients with GBM. Cancer 2016;122:3157-65. © 2016 American Cancer Society.

Concurrent Chemotherapy of Malignant Glioma in Rats by Using Multidrug-Loaded Biodegradable Nanofibrous Membranes

Glioblastoma multiforme has a poor prognosis and is highly chemoresistant. In this study, we implanted biodegradable 1,3-bis[2-chloroethyl]-1-nitroso-urea-, irinotecan-, and cisplatin-eluting poly[(d,l)-lactide-co-glycolide] (BIC/PLGA) and virgin nanofibrous membranes on the brain surface of C6 glioma-bearing rats in concurrent and virgin groups, respectively. The concentrations of all applied drugs were significantly higher in the brain than in the blood for more than 8 weeks in all studied rats. Tumor growth was more rapid in the vehicle-treated group, and tumor volumes were significantly higher in the vehicle-treated group. Moreover, the average survival time was significantly shorter in the vehicle-treated group (P = 0.026), and the BIC/PLGA nanofibrous membranes significantly reduced the risk of mortality (P < 0.001). Furthermore, the results suggested that the BIC/PLGA nanofibers reduced the malignancy of C6 glioma. The experimental findings indicate that the multianticancer drug (i.e., BIC)-eluting PLGA nanofibers are favorable candidates for treating malignant glioma.

Synthesis and Characterization of Salicylic Acid-Based Poly(Anhydride-Ester) Copolymers

A series of poly(anhydride-esters) based on poly(1,10-bis(o-car-boxyphenoxy)decanoate) (CPD) and poly(1,6-bis(p-carboxyphenoxy)hexane) (p-CPH) were synthesized by melt-condensation polymerization. Poly-(anhydride-esters) that contain CPD hydrolytically degraded into salicylic acid, however, these homopolymers have mechanical and thermal characteristics that limit their use in clinical applications. The synthesis and characterization of copolymers of CPD with p-CPH, a monomer known to generate mechanically stable homopolymers, was investigated. By changing the CPD to p-CPH monomer ratios, the salicylic acid loading and thermal/mechanical properties of the copolymers was a controlling factor; increasing the CPD concentration increased the salicylate loading but decreased the polymer stability; whereas increasing the p-CPH concentration increased the thermal and mechanical stability of the copolymers. Specifically, decreasing the CPD:p-CPH ratio resulted in lower salicylate loading and increased thermal decomposition temperatures. The glass transition temperatures (°C) varied from 27 to 38°C, a desirable range for elastomeric biomedical implants.