The efficacy of carmustine wafers for older patients with glioblastoma multiforme: prolonging survival

Exploring the vast potentials and probable limitations of novel and nanostructured implantable drug delivery systems for cancer treatment

Conventional cancer chemotherapy regimens, albeit successful to some extent, suffer from some significant drawbacks, such as high-dose requirements, limited bioavailability, low therapeutic indices, emergence of multiple drug resistance, off-target distribution, and adverse effects. The main goal of developing implantable drug delivery systems (IDDS) is to address these challenges and maintain anti-cancer drugs directly at the intended sites of therapeutic action while minimizing inevitable side effects. IDDS possess numerous advantages over conventional drug delivery, including controlled drug release patterns, one-time drug administration, as well as loading and stabilizing poorly water-soluble chemotherapy drugs. Here, we summarized conventional and novel (three-dimensional (3D) printing and microfluidic) preparation techniques of different IDDS, including nanofibers, films, hydrogels, wafers, sponges, and osmotic pumps. These systems could be designed with high biocompatibility and biodegradability features using a wide variety of natural and synthetic polymers. We also reviewed the published data on these systems in cancer therapy with a particular focus on their release behavior. Various release profiles could be attained in IDDS, which enable predictable, adjustable, and sustained drug releases. Furthermore, multi-step or stimuli-responsive drug release could be obtained in these systems. The studies mentioned in this article have proven the effectiveness of IDDS for treating different cancer types with high prevalence, including breast cancer, and aggressive cancer types, such as glioblastoma and liver cancer. Additionally, the challenges in applying IDDS for efficacious cancer therapy and their potential future developments are also discussed. Considering the high potential of IDDS for further advancements, such as programmable release and degradation features, further clinical trials are needed to ensure their efficiency. The overall goal of this review is to expand our understanding of the behavior of commonly investigated IDDS and to identify the barriers that should be addressed in the pursuit of more efficient therapies for cancer. See also the graphical abstract(Fig. 1).

Carmustine wafer implantation for supratentorial glioblastomas, IDH-wildtype in "extreme" neurosurgical conditions

We assessed the feasibility of Carmustine wafer implantation in "extreme" conditions (i.e. patients > 80 years and Karnofsky Performance Status score < 50) and of implantation ≥ 12 Carmustine wafers in adult patients harbouring a newly diagnosed supratentorial glioblastoma, IDH-wildtype. We performed an observational, retrospective single-centre cohort study at a tertiary surgical neuro-oncological centre between January 2006 and December 2021. Four hundred eighty patients who benefited from a surgical resection at first-line treatment were included. We showed that Carmustine wafer implantation in patients > 80 years, in patients with a Karnofsky performance status score < 50, and that implantation ≥ 12 Carmustine wafers (1) did not increase overall postoperative complication rates, (2) did not affect the completion of standard radiochemotherapy protocol, (3) did not worsen the postoperative Karnofsky Performance Status scores, and (4) did not significantly affect the time to oncological treatment. We showed that the implantation of ≥ 12 Carmustine wafers improved progression-free survival (31.0 versus 10.0 months, p = 0.025) and overall survival (39.0 versus 16.5 months, p = 0.041) without increasing postoperative complication rates. Carmustine wafer implantation during the surgical resection of a newly diagnosed supratentorial glioblastoma, IDH-wildtype is safe and efficient in patients > 80 years and in patients with preoperative Karnofsky Performance Status score < 50. The number of Carmustine wafers should be adapted (up to 16 in our experience) to the resection cavity to improve survival without increasing postoperative overall complication rates.

The clinical significance of radiological changes associated with gliadel implantation in patients with recurrent high grade glioma

Gliadel occasionally induces edema following its implantation. We aimed to correlate such post-surgical radiological changes to its efficacy and subsequent survival. Fifty-six patients with recurrent high grade glioma were treated between 2005 and 2016 with Gliadel implantation. Volumetric measurements of MRI features, including FLAIR abnormalities, tumor bulk (volume of gadolinium enhancement on T1) and resection cavity volumes over time were conducted. To assess dynamics over time, linear regression trendlines for each of these were calculated and examined to correlate with survival. Median follow-up after resection was 21.5 months. Median survival post-Gliadel implantation and overall survival since diagnosis were 12 months and 22 months, respectively. A subgroup of patients (n = 6) with a transient increase in FLAIR changes volume over time survived significantly longer post-Gliadel compared to those who did not demonstrate such change (36 vs 12 months, p = .03). Positive trends, representing overall growth in volume over time, of tumor bulk and resection cavity predicted survival in multivariate analyses (hazard ratios 7.9 and 84, p = .003 and .002, respectively). Increase in tumor bulk and resection cavity over time were associated with decreased survival, while transient FLAIR increase was a favorable prognostic factor. This may represent a transient inflammatory process in the tumor, possibly stemming from a presumed immune-mediated anti-tumor response.

Poly-guanidine shows high cytotoxicity in glioma cell cultures and glioma stem cells

Glioblastoma multiforme (GBM) is a malignant CNS tumor with a poor prognosis. GBM shows aberrant glycosylation with hypersialylation. This property is a potential target for therapy. This study investigates the growth inhibitory efficacy of poly-guanidine (GuaDex), with an affinity for sialic acid (Sia). Glioma cell cultures and patient-derived glioma cell lines (PDGCLs) expressing Prominin-1 (CD133) were used. Human fibroblasts and astrocyte-derived cells were used as controls. Temozolomide (standard GBM drug, TMZ) and DMSO were used as a comparison. GuaDex at 1–10 µM concentrations, were incubated for 3.5–72 h and with PDGCLs cells for 6–24 h. The cytotoxicity was estimated with a fluorometric cytotoxicity assay (FMCA). Fluorescence-labelled GuaDex was used to study the cell interactions. Sia expression was confirmed with a fluorescence labelled Sia binding lectin. Expression of glial fibrillary acidic protein was determined. GuaDex induction of growth inhibition was fast, showing after less than 5 min incubation while the control cells were not affected even after 50 min incubation. The growth inhibitory effect on PDGCLs spheroids was persistent still showing after 4 weeks post-treatment. The growth inhibition of GuaDex was induced at low µM concentrations while TMZ induced only a slight inhibition at mM concentrations. GuaDex efficacy appears significant and warrants further studies.

LINC00883 Promotes Drug Resistance of Glioma Through a microRNA-136/NEK1-Dependent Mechanism

Objective

Accumulating evidence has highlighted the roles of long noncoding RNAs (lncRNAs) as competing endogenous RNAs (ceRNAs) of microRNAs (miRNAs) through their binding sites in the progression of glioma. Hereby, we aim to explore the role of LINC00883 as a regulator of miR-136 and its target, NIMA-related kinase 1 (NEK1), thus, its involvement in the drug resistance of glioma cells.

Methods and Results

Mechanistic investigations by dual-luciferase reporter, RNA pull-down, and RNA-binding protein immunoprecipitation (RIP) assays indicated that LINC00883 bound to miR-136, thereby blocking miR-136-induced downregulation of NEK1. Through gain-of-function experiments in U251 cells that presented a high drug resistance, we found that ectopic expression of LINC00883 resulted in increased MRP (encoding multidrug resistance-associated protein), limited cell apoptosis, and increased proliferation. Expectedly, depleting LINC00883 yielded tumor-suppressive and anti-chemoresistance effects on U251 cells by increasing miR-136 and inhibiting NEK1. Next, drug-resistant glioma cell line SOWZ1, drug-sensitive glioma cell line SOWZ2, and drug-resistant glioma cell line SOWZ2-BCNU (SOWZ2 cultured in BCNU) were applied to validate the roles of LINC00883 in the regulation of multidrug resistance. LINC00883 knockdown suppressed the viability of SWOZ1, SWOZ2, and SWOZ2-BCNU cells.

Conclusion

In conclusion, LINC00883 knockdown reduces drug resistance in glioma. Hence, our study provides a future strategy to prevent drug resistance-induced therapeutic failure in glioma.

BLZ945 derivatives for PET imaging of colony stimulating factor-1 receptors in the brain

BACKGROUND

The kinase colony stimulating factor-1 receptor (CSF-1R) has recently been identified as a novel therapeutic target for decreasing tumor associated macrophages and microglia load in cancer treatment. In glioblastoma multiforme (GBM), a high-grade cancer in the brain with extremely poor prognosis, macrophages and microglia can make up to 50% of the total tumor mass. Currently, no non-invasive methods are available for measuring CSF-1R expression in vivo. The aim of this work is to develop a PET tracer for imaging of CSF-1R receptor expression in the brain for future GBM patient selection and treatment monitoring.

METHODS

BLZ945 and a derivative that potentially allows for fluorine-18 labeling were synthesized and evaluated in vitro to determine their affinity towards CSF-1R. BLZ945 was radiolabeled with carbon-11 by N-methylation of des-methyl-BLZ945 using [11C]CH3I. Following administration to healthy mice, metabolic stability of [11C]BLZ945 in blood and brain and activity distribution were determined ex vivo. PET scanning was performed at baseline, efflux transporter blocking, and CSF-1R blocking conditions. Finally, [11C]BLZ945 binding was evaluated in vitro by autoradiography on mouse brain sections.

RESULTS

BLZ945 was the most potent compound in our series with an IC50 value of 6.9 ± 1.4 nM. BLZ945 was radiolabeled with carbon-11 in 20.7 ± 1.1% decay corrected radiochemical yield in a 60 min synthesis procedure with a radiochemical purity of >95% and a molar activity of 153 ± 34 GBq·μmol-1. Ex vivo biodistribution showed moderate brain uptake and slow wash-out, in addition to slow blood clearance. The stability of BLZ945 in blood plasma and brain was >99% at 60 min post injection. PET scanning demonstrated BLZ945 to be a substrate for efflux transporters. High brain uptake was observed, which was shown to be mostly non-specific. In accordance, in vitro autoradiography on brain sections revealed high non-specific binding.

CONCLUSIONS

[11C]BLZ945, a CSF-1R PET tracer, was synthesized in high yield and purity. The tracer has high potency for the target, however, future studies are warranted to address non-specific binding and tracer efflux before BLZ945 or derivatives could be translated into humans for brain imaging.

Enhancement of Therapies for Glioblastoma (GBM) Using Nanoparticle-based Delivery Systems

Glioblastoma multiforme (GBM) is the most aggressive type of malignant brain tumor. Current FDA-approved treatments include surgical resection, radiation, and chemotherapy, while hyperthermia, immunotherapy, and most relevantly, nanoparticle (NP)-mediated delivery systems or combinations thereof have shown promise in preclinical studies. Drug-carrying NPs are a promising approach to brain delivery as a result of their potential to facilitate the crossing of the blood-brain barrier (BBB) via two main types of transcytosis mechanisms: adsorptive-mediated transcytosis (AMT) and receptor-mediated transcytosis (RMT). Their ability to accumulate in the brain can thus provide local sustained release of tumoricidal drugs at or near the site of GBM tumors. NP-based drug delivery has the potential to significantly reduce drug-related toxicity, increase specificity, and consequently improve the lifespan and quality of life of patients with GBM. Due to significant advances in the understanding of the molecular etiology and pathology of GBM, the efficacy of drugs loaded into vectors targeting this disease has increased in both preclinical and clinical settings. Multitargeting NPs, such as those incorporating multiple specific targeting ligands, are an innovative technology that can lead to decreased off-target effects while simultaneously having increased accumulation and action specifically at the tumor site. Targeting ligands can include antibodies, or fragments thereof, and peptides or small molecules, which can result in a more controlled drug delivery system compared to conventional drug treatments. This review focuses on GBM treatment strategies, summarizing current options and providing a detailed account of preclinical findings with prospective NP-based approaches aimed at improving tumor targeting and enhancing therapeutic outcomes for GBM patients.

Drug eluting implants in pharmaceutical development and clinical practice

Introduction: Drug eluting implants offer patient convenience and improved compliance through less frequent dosing, eliminating repeated, painful injections and providing localized, site specific delivery with applications in contraception, ophthalmology, and oncology.Areas covered: This review provides an overview of available implant products, design approaches, biodegradable and non-biodegradable polymeric materials, and fabrication techniques with a focus on commercial applications and industrial drug product development. Developing trends in the field, including expanded availability of suitable excipients, development of novel materials, scaled down manufacturing process, and a wider understanding of the implant development process are discussed and point to opportunities for differentiated drug eluting implant products.Expert opinion: In the future, long-acting implants will be important clinical tools for prophylaxis and treatment of global health challenges, especially for infectious diseases, to reduce the cost and difficulty of treating chronic indications, and to prolong local delivery in difficult to administer parts of the body. These products will help improve patient safety, adherence, and comfort.

Congress of neurological surgeons systematic review and evidence-based guidelines update on the role of chemotherapeutic management and antiangiogenic treatment of newly diagnosed glioblastoma in adults

QUESTION

What is the role of temozolomide in the management of adult patients (aged 65 and under) with newly diagnosed glioblastoma?

TARGET POPULATION

These recommendations apply to adult patients diagnosed with newly diagnosed glioblastoma.

RECOMMENDATION

Level I: Concurrent and post-irradiation Temozolomide (TMZ) in combination with radiotherapy and post-radiotherapy as described by Stupp et al. is recommended to improve both PFS and OS in adult patients with newly diagnosed GBM. There is no evidence that alterations in the dosing regimen have additional beneficial effect.

QUESTION

Is there benefit to adjuvant temozolomide treatment in elderly patients (> 65 years old?).

TARGET POPULATION

These recommendations apply to adult patients diagnosed with newly diagnosed glioblastoma.

RECOMMENDATION

Level III: Adjuvant TMZ treatment is suggested as a treatment option to improve PFS and OS in adult patients (over 70 years of age) with newly diagnosed GBM.

QUESTION

What is the role of local regional chemotherapy with BCNU biodegradable polymeric wafers in adult patients with newly diagnosed glioblastoma?

TARGET POPULATION

These recommendations apply to adult patients diagnosed with newly diagnosed glioblastoma.

RECOMMENDATION

Level III: There is insufficient evidence for the use of BCNU wafers following resection in patients with newly diagnosed glioblastoma who undergo the Stupp protocol after surgery. Further studies of higher quality are suggested to understand the role of BCNU wafer and other locoregional therapy in the setting of Stupp Protocol.

QUESTION

What is the role of bevacizumab in the adult patient with newly diagnosed glioblastoma?

TARGET POPULATION

These recommendations apply to adult patients diagnosed with newly diagnosed glioblastoma.

RECOMMENDATION

Level I: Bevacizumab in general is not recommended in the initial treatment of adult patients with newly diagnosed GBM. It continues to be strongly recommended that patients with newly diagnosed GBM be enrolled in properly designed clinical trials to assess the benefit of novel chemotherapeutic agents compared to standard therapy.

Supramolecular Tubustecan Hydrogel as Chemotherapeutic Carrier to Improve Tumor Penetration and Local Treatment Efficacy

Local chemotherapy is a clinically proven strategy in treating malignant brain tumors. Its benefits, however, are largely limited by the rapid release and clearance of therapeutic agents and the inability to penetrate through tumor tissues. We report here on a supramolecular tubustecan (TT) hydrogel as both a therapeutic and drug carrier that enables long-term, sustained drug release and improved tumor tissue penetration. Covalent linkage of a tissue penetrating cyclic peptide to two camptothecin drug units creates a TT prodrug amphiphile that can associate into tubular supramolecular polymers and subsequently form a well-defined sphere-shaped hydrogel after injection into tumor tissues. The hollow nature of the resultant tubular assemblies allows for encapsulation of doxorubicin or curcumin for combination therapy. Our in vitro and in vivo studies reveal that these dual drug-bearing supramolecular hydrogels enhance tumor retention and penetration, serving as a local therapeutic depot for potent tumor regression, inhibition of tumor metastasis and recurrence, and mitigation of the off-target side effects.

Mapping the Human Kinome in Response to DNA Damage

We provide a catalog for the effects of the human kinome on cell survival in response to DNA-damaging agents, covering all major DNA repair pathways. By treating 313 kinase-deficient cell lines with ten diverse DNA-damaging agents, including seven commonly used chemotherapeutics, we identified examples of vulnerability and resistance that are kinase specific. To investigate synthetic lethal interactions, we tested the response to carmustine for 25 cell lines by establishing a phenotypic fluorescence-activated cell sorting (FACS) assay designed to validate gene-drug interactions. We show apoptosis, cell cycle changes, and DNA damage and proliferation after alkylation- or crosslink-induced damage. In addition, we reconstitute the cellular sensitivity of DYRK4, EPHB6, MARK3, and PNCK as a proof of principle for our study. Furthermore, using global phosphoproteomics on cells lacking MARK3, we provide evidence for its role in the DNA damage response. Our data suggest that cancers with inactivating mutations in kinases, including MARK3, are particularly vulnerable to alkylating chemotherapeutic agents.

Glioblastoma Treatments: An Account of Recent Industrial Developments

The different drugs and medical devices, which are commercialized or under industrial development for glioblastoma treatment, are reviewed. Their different modes of action are analyzed with a distinction being made between the effects of radiation, the targeting of specific parts of glioma cells, and immunotherapy. Most of them are still at a too early stage of development to firmly conclude about their efficacy. Optune, which triggers antitumor activity by blocking the mitosis of glioma cells under the application of an alternating electric field, seems to be the only recently developed therapy with some efficacy reported on a large number of GBM patients. The need for early GBM diagnosis is emphasized since it could enable the treatment of GBM tumors of small sizes, possibly easier to eradicate than larger tumors. Ways to improve clinical protocols by strengthening preclinical studies using of a broader range of different animal and tumor models are also underlined. Issues related with efficient drug delivery and crossing of blood brain barrier are discussed. Finally societal and economic aspects are described with a presentation of the orphan drug status that can accelerate the development of GBM therapies, patents protecting various GBM treatments, the different actors tackling GBM disease, the cost of GBM treatments, GBM market figures, and a financial analysis of the different companies involved in the development of GBM therapies.

Drug Delivery in Cancer Therapy, Quo Vadis?

The treatment of malignancies has undergone dramatic changes in the past few decades. Advances in drug delivery techniques and nanotechnology have allowed for new formulations of old drugs, so as to improve the pharmacokinetics, to enhance accumulation in solid tumors, and to reduce the significant toxic effects of these important therapeutic agents. Here, we review the published clinical data in cancer therapy of several major drug delivery systems, including targeted radionuclide therapy, antibody-drug conjugates, liposomes, polymer-drug conjugates, polymer implants, micelles, and nanoparticles. The clinical outcomes of these delivery systems from various phases of clinical trials are summarized. The success and limitations of the drug delivery strategies are discussed based on the clinical observations. In addition, the challenges in applying drug delivery for efficacious cancer therapy, including physical barriers, tumor heterogeneity, drug resistance, and metastasis, are discussed along with future perspectives of drug delivery in cancer therapy. In doing so, we intend to underscore that efficient delivery of cancer therapeutics to solid malignancies remains a major challenge in cancer therapy, and requires a multidisciplinary approach that integrates knowledge from the diverse fields of chemistry, biology, engineering, and medicine. The overall objective of this review is to improve our understanding of the clinical fate of commonly investigated drug delivery strategies, and to identify the limitations that must be addressed in future drug delivery strategies, toward the pursuit of curative therapies for cancer.

Combining Clinical and Molecular Data to Predict the Benefits of Carmustine Wafers in Newly Diagnosed High-Grade Gliomas

PURPOSE OF REVIEW

The purpose of this study was to retrospectively evaluate the use of carmustine wafers (CWs) in the management of high-grade gliomas (HGGs). The data from our monoinstitutional series was compared with studies reported in the literature. Special emphasis was placed on the evaluation of side effects and the analysis of extent of resection and molecular profile as risk factors.

RECENT FINDINGS

The implantation of CWs into the resection cavity during HGG treatment to deliver localized chemotherapy, followed by the Stupp protocol, remains debated in a clinical setting, largely due to the lack of appropriate phase III studies. Given the high expense and poorly characterized side effects associated with CW treatment, identification of patients most likely to benefit from this therapy could be clinically relevant. CWs may represent an effective and safe first-line treatment for patients with HGG that exhibit complete tumor resection and harboring a methylated MGMT promoter. Our investigation showed a much larger group of patients exhibiting long-term survival (> = 36 months), strongly supporting a potential survival benefit conferred via CW treatment. The pre-surgical definition of the MGMT promoter status could be of clinical use in identifying "good responders" to CW implantation.

Advances in Brain Tumor Surgery for Glioblastoma in Adults

Glioblastoma (GBM) is the most common primary intracranial neoplasia, and is characterized by its extremely poor prognosis. Despite maximum surgery, chemotherapy, and radiation, the histological heterogeneity of GBM makes total eradication impossible, due to residual cancer cells invading the parenchyma, which is not otherwise seen in radiographic images. Even with gross total resection, the heterogeneity and the dormant nature of brain tumor initiating cells allow for therapeutic evasion, contributing to its recurrence and malignant progression, and severely impacting survival. Visual delimitation of the tumor’s margins with common surgical techniques is a challenge faced by many surgeons. In an attempt to achieve optimal safe resection, advances in approaches allowing intraoperative analysis of cancer and non-cancer tissue have been developed and applied in humans resulting in improved outcomes. In addition, functional paradigms based on stimulation techniques to map the brain’s electrical activity have optimized glioma resection in eloquent areas such as the Broca’s, Wernike’s and perirolandic areas. In this review, we will elaborate on the current standard therapy for newly diagnosed and recurrent glioblastoma with a focus on surgical approaches. We will describe current technologies used for glioma resection, such as awake craniotomy, fluorescence guided surgery, laser interstitial thermal therapy and intraoperative mass spectrometry. Additionally, we will describe a newly developed tool that has shown promising results in preclinical experiments for brain cancer: optical coherence tomography.

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.

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.

Immunological Aspects of Malignant Gliomas

Glioblastoma Multiforme (GBM) is the most common malignant primary brain neoplasm having a mean survival time of <24 months. This figure remains constant, despite significant progress in medical research and treatment. The lack of an efficient anti-tumor immune response and the micro-invasive nature of the glioma malignant cells have been explained by a multitude of immune-suppressive mechanisms, proven in different models. These immune-resistant capabilities of the tumor result in a complex interplay this tumor shares with the immune system. We present a short review on the immunology of GBM, discussing the different unique pathological and molecular features of GBM, current treatment modalities, the principles of cancer immunotherapy and the link between GBM and melanoma. Current knowledge on immunological features of GBM, as well as immunotherapy past and current clinical trials, is discussed in an attempt to broadly present the complex and formidable challenges posed by GBM.

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.

Non-virally engineered human adipose mesenchymal stem cells produce BMP4, target brain tumors, and extend survival

There is a need for enabling non-viral nanobiotechnology to allow safe and effective gene therapy and cell therapy, which can be utilized to treat devastating diseases such as brain cancer. Human adipose-derived mesenchymal stem cells (hAMSCs) display high anti-glioma tropism and represent a promising delivery vehicle for targeted brain tumor therapy. In this study, we demonstrate that non-viral, biodegradable polymeric nanoparticles (NPs) can be used to engineer hAMSCs with higher efficacy (75% of cells) than leading commercially available reagents and high cell viability. To accomplish this, we engineered a poly(beta-amino ester) (PBAE) polymer structure to transfect hAMSCs with significantly higher efficacy than Lipofectamine™ 2000. We then assessed the ability of NP-engineered hAMSCs to deliver bone morphogenetic protein 4 (BMP4), which has been shown to have a novel therapeutic effect by targeting human brain tumor initiating cells (BTIC), a source of cancer recurrence, in a human primary malignant glioma model. We demonstrated that hAMSCs genetically engineered with polymeric nanoparticles containing BMP4 plasmid DNA (BMP4/NP-hAMSCs) secrete BMP4 growth factor while maintaining their multipotency and preserving their migration and invasion capacities. We also showed that this approach can overcome a central challenge for brain therapeutics, overcoming the blood brain barrier, by demonstrating that NP-engineered hAMSCs can migrate to the brain and penetrate the brain tumor after both intranasal and systemic intravenous administration. Critically, athymic rats bearing human primary BTIC-derived tumors and treated intranasally with BMP4/NP-hAMSCs showed significantly improved survival compared to those treated with control GFP/NP-hAMCSs. This study demonstrates that synthetic polymeric nanoparticles are a safe and effective approach for stem cell-based cancer-targeting therapies.

Comparison of outcomes between a less experienced surgeon using a fully endoscopic technique and a very experienced surgeon using a microscopic transsphenoidal technique for pituitary adenoma

OBJECT

The comparative efficacy of microscopic and fully endoscopic transsphenoidal surgery for pituitary adenomas has not been well studied despite the adoption of fully endoscopic surgery by many pituitary centers. The influence of surgeon experience has also not been examined in this setting. The authors therefore compared the extent of tumor resection (EOR) and the endocrine outcomes of 1 very experienced surgeon performing a microscopic transsphenoidal surgery technique with those of a less experienced surgeon using a fully endoscopic transsphenoidal surgery technique for resection of nonfunctioning pituitary adenomas in a concurrent series of patients.

METHODS

Post hoc analysis was conducted of a cohort of adult patients prospectively enrolled in a pituitary adenoma quality-of-life study between October 2011 and June 2014. Patients were followed up for 6 months after surgery. Patients were treated either by a less experienced surgeon (100 independent cases) who practices fully endoscopic surgery exclusively or by a very experienced surgeon (1800 independent cases) who practices microscopic surgery exclusively. Patient demographic characteristics, tumor characteristics, hypopituitarism, complications, and length of hospital stay were analyzed. Tumor volumes and EOR were determined by formal volumetric analysis involving manual segmentation of MR images performed before surgery and within 6 months after surgery. Logistic regression analysis was used to determine predictors of EOR.

RESULTS

Fifty-five patients underwent fully endoscopic transsphenoidal surgery, and 80 patients underwent fully microscopic transsphenoidal surgery. The baseline characteristics of the 2 treatment groups were well matched. EOR was similar between the endoscopic and microscopic groups, respectively, as estimated by gross-total resection rate (78.2% vs 81.3%, p = 0.67), percentage of tumor resected (99.2% vs 98.7%, p = 0.42), and volume of residual tumor (0.12 cm3 vs 0.20 cm3, p = 0.41). Multivariate modeling suggested that preoperative tumor volume was the most important predictor of EOR (p = 0.001). No difference was found in the development of anterior gland dysfunction (p > 0.14), but there was a higher incidence of permanent posterior gland dysfunction in the microscopic group (p = 0.04). Combined rates of major complications and unplanned readmissions were lower in the endoscopic group (p = 0.02), but individual complications were not significantly different.

CONCLUSIONS

A less experienced surgeon using a fully endoscopic technique was able to achieve outcomes similar to those of a very experienced surgeon using a microscopic technique in a cohort of patients with nonfunctioning tumors smaller than 60 cm3. The study raises the provocative notion that certain advantages afforded by the fully endoscopic technique may impact the learning curve in pituitary surgery for nonfunctioning adenomas.

Complications of glioma surgery

Even with current advances in adjunctive therapies, including radiation, chemotherapy, and various clinical trials of gene therapy and immunotherapy, surgical resection remains one of the most effective treatment for intra-axial gliomas. Survival in these patients has been shown to be related to the extent of resection. In some cases, it can provide cures of long-term remission; in others, it can provide disease control when combined with the above adjunctive treatments. However, surgical resection carries its own risks and complications. These complications can be broadly divided into neurologic, regional, and systemic, including direct cortical and vascular injury, surgical wound complications, and postsurgical medical complications. Certain patient characteristics, including Karnofsky performance status score (KPS) and pathology of the tumor, have been shown to have an impact on the risk of postsurgical complications. Advancement in preoperative and intraoperative adjunct technology such as cortical mapping and navigation has improved the surgeon's ability to safely and maximally resect the tumors. It is therefore important to understand the perioperative complications after craniotomy and tumor resection and factors affecting morbidity and mortality in order for surgeons to optimally select and counsel patients who will benefit the most from surgical resection. This chapter will focus on the complications associated with craniotomy for intrinsic glioma and ways of avoiding these events.

MGMT inactivation and clinical response in newly diagnosed GBM patients treated with Gliadel

We examined the relationship between the O(6)-methylguanine-methyltransferase (MGMT) methylation status and clinical outcomes in newly diagnosed glioblastoma multiforme (GBM) patients who were treated with Gliadel wafers (Eisai, Tokyo, Japan). MGMT promoter methylation has been associated with increased survival among patients with GBM who are treated with various alkylating agents. MGMT promoter methylation, in DNA from 122 of 160 newly diagnosed GBM patients treated with Gliadel, was determined by a quantitative methylation-specific polymerase chain reaction, and was correlated with overall survival (OS) and recurrence-free survival (RFS). The MGMT promoter was methylated in 40 (32.7%) of 122 patients. The median OS was 13.5 months (95% confidence interval [CI] 11.0-14.5) and RFS was 9.4 months (95% CI 7.8-10.2). After adjusting for age, Karnofsky performance score, extent of resection, temozolomide (TMZ) and radiation therapy (RT), the newly diagnosed GBM patients with MGMT methylation had a 15% reduced mortality risk, compared to patients with unmethylated MGMT (hazard ratio 0.85; 95% CI 0.56-1.31; p=0.46). The patients aged over 70 years with MGMT methylation had a significantly longer median OS of 13.5 months, compared to 7.6 months in patients with unmethylated MGMT (p=0.027). A significant difference was also found in older patients, with a median RFS of 13.1 versus 7.6 months for methylated and unmethylated MGMT groups, respectively (p=0.01). Methylation of the MGMT promoter in newly diagnosed GBM patients treated with Gliadel, RT and TMZ, was associated with significantly improved OS compared to the unmethylated population. In elderly patients, methylation of the MGMT promoter was associated with significantly better OS and RFS.

Delivery of local therapeutics to the brain: working toward advancing treatment for malignant gliomas

Malignant gliomas, including glioblastoma and anaplastic astrocytomas, are characterized by their propensity to invade surrounding brain parenchyma, making curative resection difficult. These tumors typically recur within two centimeters of the resection cavity even after gross total removal. As a result, there has been an emphasis on developing therapeutics aimed at achieving local disease control. In this review, we will summarize the current developments in the delivery of local therapeutics, namely direct injection, convection-enhanced delivery and implantation of drug-loaded polymers, as well as the application of these therapeutics in future methods including microchip drug delivery and local gene therapy.

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.

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.

The butterfly effect on glioblastoma: is volumetric extent of resection more effective than biopsy for these tumors?

A subset of patients with glioblastoma (GBM) have butterfly GBM (bGBM) that involve both cerebral hemispheres by crossing the corpus callosum. The prognoses, as well as the effectiveness of surgery and adjuvant therapy, are unclear because studies are few and limited. The goals of this study were to: (1) determine if bGBM have worse outcomes than patients with non-bGBM, (2) determine if surgery is more effective than biopsy, and (3) identify factors independently associated with improved outcomes for these patients. Adult patients who underwent surgery for a newly diagnosed primary GBM at an academic tertiary-care institution between 2007 and 2012 were retrospectively reviewed and tumors were volumetrically measured. Of the 336 patients with newly diagnosed GBM who were operated on, 48 (14 %) presented with bGBM, where 29 (60 %) and 19 (40 %) underwent surgical resection and biopsy, respectively. In multivariate analysis, a bGBM was independently associated with poorer survival [HR (95 % CI) 1.848 (1.250-2.685), p < 0.003]. In matched-pair analysis, patients who underwent surgical resection had improved median survival than biopsy patients (7.0 vs. 3.5 months, p = 0.03). In multivariate analysis, increasing percent resection [HR (95 % CI) 0.987 (0.977-0.997), p = 0.01], radiation [HR (95 % CI) 0.431 (0.225-0.812), p = 0.009], and temozolomide [HR (95 % CI) 0.413 (0.212-0. 784), p = 0.007] were each independently associated with prolonged survival among patients with bGBM. This present study shows that while patients with bGBM have poorer prognoses compared to non-bGBM, these patients can also benefit from aggressive treatments including debulking surgery, maximal safe surgical resection, temozolomide chemotherapy, and radiation therapy.

The role of Gliadel wafers in the treatment of high-grade gliomas

Glioblastoma multiforme (GBM) is the most aggressive brain tumor. Standard treatment includes surgery, radiation and chemotherapy. Prognosis is dismal with an average survival of approximately 1 year. Gliadel wafers are one treatment option, working as a source for local chemotherapy delivery. Their use is controversial with questionable survival benefit and potential side effects. We reviewed the literature in an effort to clarify their role in the treatment of high-grade gliomas. A systematic PubMed search was performed using the keywords 'Gliadel', 'carmustine' or 'BCNU wafers' in newly diagnosed high-grade glioma patients. Treatment regimen, and median survival were analyzed. Adverse event ratio was calculated by computing the number of adverse events in a study per patient receiving carmustine wafers. Nineteen studies with 795 patients were included in our review. Survival was 8.7-22.6 months with a mean overall survival (OS) of 16.2 months (control survival is approximately 14 months with surgery and adjuvant chemoradiotherapy). Adverse event ratio using Gliadel wafersin control group. Complication rate was 42.7%. Gliadel wafers may marginally increase survival and local control in newly diagnosed GBM patients but are associated with a high complication rate; therefore, we do not recommend using Gliadel wafers in patients with GBM. Further research may be warranted once a safer alternative to Gliadel wafers has been introduced.

Treatment of glioblastoma in elderly patients

Although glioblastoma occurs mostly in elderly patients, there is a paucity of trials addressing patients older than 70 years of age. Age, by itself, constitutes an unfavorable prognostic factor, which is probably due to unpropitious genetic features, but also due to iatrogenic defeatism. However, many retrospective studies report a survival benefit achieved by aggressive surgical resection seeking gross total removal of contrast-enhancing tumor according to preoperative MRI. Combined radiochemotherapy with concomitant and adjuvant temozolomide has not been investigated in prospective trials. Numerous retrospective studies and a meta-analysis suggest benefit from combined treatment. Prospective randomized trials only evaluated either temozolomide or radiotherapy. Single-treatment hypofractionated radiotherapy performed superior to conventional fractionation. In patients with methylated MGMT promoter, first-line dose-dense temozolomide facilitates prolonged survival. However, there is no comparison with combined radiochemotherapy as the standard-of-care in adult patients. Comorbidity is more frequent in elderly patients, but does not correlate with preterm termination of temozolomide treatment. This review article compiles data proposing a straightforward glioblastoma treatment, irrespective of age.

Biodegradable polymeric nanoparticles show high efficacy and specificity at DNA delivery to human glioblastoma in vitro and in vivo

Current glioblastoma therapies are insufficient to prevent tumor recurrence and eventual death. Here, we describe a method to treat malignant glioma by nonviral DNA delivery using biodegradable poly(β-amino ester)s (PBAEs), with a focus on the brain tumor initiating cells (BTICs), the tumor cell population believed to be responsible for the formation of new tumors and resistance to many conventional therapies. We show transfection efficacy of >60% and low biomaterial-mediated cytotoxicity in primary human BTICs in vitro even when the BTICs are grown as 3-D oncospheres. Intriguingly, we find that these polymeric nanoparticles show intrinsic specificity for nonviral transfection of primary human BTICs over primary healthy human neural progenitor cells and that this specificity is not due to differences in cellular growth rate or total cellular uptake of nanoparticles. Moreover, we demonstrate that biodegradable PBAE/DNA nanoparticles can be fabricated, lyophilized, and then stored for at least 2 years without losing efficacy, increasing the translational relevance of this technology. Using lyophilized nanoparticles, we show transgene expression by tumor cells after intratumoral injection into an orthotopic murine model of human glioblastoma. PBAE/DNA nanoparticles were more effective than naked DNA at exogenous gene expression in vivo, and tumor cells were transfected more effectively than noninvaded brain parenchyma in vivo. This work shows the potential of nonviral gene delivery tools to target human brain tumors.

When gross total resection of a glioblastoma is possible, how much resection should be achieved?

OBJECTIVE

The efficacy of extensive resection on prolonging survival for patients with glioblastoma (GBM) is controversial because prior studies have included tumors with dissimilar resection capabilities. The true isolated effect of increasing resection on survival for GBM therefore remains unclear.

METHODS

Adult patients who underwent surgery of an intracranial newly diagnosed GBM at an academic tertiary-care institution from 2007 to 2011 were reviewed. Preoperative images were reviewed by 3 neurosurgeons independently. Tumors considered amenable to gross total resection based on preoperative imaging by all neurosurgeons were included. Multivariate proportional hazards regression analysis was used to identify if an association existed between residual volume (RV) and extent of resection (EOR) with survival.

RESULTS

Of the 292 patients with newly diagnosed GBM, 84 (29%) were amenable to gross total resection. The median (interquartile range) pre and postoperative tumor volumes were 27 (13.8-54.4) and 0.9 (0-2.7) cm(3), respectively. The mean percent resection was 91.7% ± 1.3%. In multivariate analysis, after controlling for age, functional status, and adjuvant therapies, RV (hazards ratio [HR] [95% confidence interval (CI)] = 1.114 [1.033-1.193], P = 0.006) and EOR (HR [95% CI] = 0.959 [0.934-0.985], P = 0.003) were each independently associated with survival. The RV and EOR with the greatest reduction in the risk of death was <2 cm(3) and >95%, respectively. Likewise, RV (HR [95% CI] = 1.085 [1.010-1.178], P = 0.01) and EOR (HR [95% CI] = 0.962 [0.930-0.998], P = 0.04) each remained independently associated with recurrence.

CONCLUSION

This is the first study to evaluate RV and EOR in a more uniform population of patients with tumors of similar surgical capabilities. This study shows that achieving a decreased RV and/or an increased EOR is independently associated with survival and recurrence in those patients with tumors with similar resection capacities.

Establishing percent resection and residual volume thresholds affecting survival and recurrence for patients with newly diagnosed intracranial glioblastoma

INTRODUCTION

Surgery is first-line therapy for glioblastoma, and there is evidence that gross total resection is associated with improved survival. Gross total resection, however, is not always possible, and relationships among extent (percent) of resection (EOR), residual volume (RV), and survival are unknown. The goals were to evaluate whether there is an association between EOR and RV with survival and recurrence and to establish minimum EOR and maximum RV thresholds.

METHODS

Adult patients who underwent primary glioblastoma surgery from 2007 to 2011 were retrospectively reviewed. Three-dimensional volumetric tumor measurements were made. Multivariate proportional hazards regression analysis was used to evaluate the relationship between EOR and RV with survival and recurrence.

RESULTS

Of 259 patients, 203 (78%) died and 156 (60%) had tumor recurrence. The median survival and progression-free survival were 13.4 and 8.9 months, respectively. The median (interquartile range) pre- and postoperative tumor volumes were 32.2 (14.0-56.3) and 2.1 (0.0-7.9) cm(3), respectively. EOR was independently associated with survival (hazard ratio [HR], 0.995; 95% confidence interval [CI]: 0.990-0.998; P = .008) and recurrence (HR [95% CI], 0.992 [0.983-0.998], P = .005). The minimum EOR threshold for survival (P = .0006) and recurrence (P = .005) was 70%. RV was also associated with survival (HR [95% CI], 1.019 [1.006-1.030], P = .004) and recurrence (HR [95% CI], 1.024 [1.001-1.044], P = .03). The maximum RV threshold for survival (P = .01) and recurrence (P = .01) was 5 cm(3).

CONCLUSION

This study shows for the first time that both EOR and RV are significantly associated with survival and recurrence, where the thresholds are 70% and 5 cm(3), respectively. These findings may help guide surgical and adjuvant therapies aimed at optimizing outcomes for glioblastoma patients.

Outcome of elderly patients undergoing awake-craniotomy for tumor resection

BACKGROUND

Awake-craniotomy allows maximal tumor resection, which has been associated with extended survival. The feasibility and safety of awake-craniotomy and the effect of extent of resection on survival in the elderly population has not been established. The aim of this study was to compare surgical outcome of elderly patients undergoing awake-craniotomy to that of younger patients.

METHODS

Outcomes of consecutive patients younger and older than 65 years who underwent awake-craniotomy at a single institution between 2003 and 2010 were retrospectively reviewed. The groups were compared for clinical variables and surgical outcome parameters, as well as overall survival.

RESULTS

A total of 334 young (45.4 ± 13.2 years, mean ± SD) and 90 elderly (71.7 ± 5.1 years) patients were studied. Distribution of gender, mannitol treatment, hemodynamic stability, and extent of tumor resection were similar. Significantly more younger patients had a better preoperative Karnofsky Performance Scale score (>70) than elderly patients (P = 0.0012). Older patients harbored significantly more high-grade gliomas (HGG) and brain metastases, and fewer low-grade gliomas (P < 0.0001). No significantly higher rate of mortality, or complications were observed in the elderly group. Age was associated with increased length of stay (4.9 ± 6.3 vs. 6.6 ± 7.5 days, P = 0.01). Maximal extent of tumor resection in patients with HGG was associated with prolonged survival in the elderly patients.

CONCLUSIONS

Awake-craniotomy is a well-tolerated and safe procedure, even in elderly patients. Gross total tumor resection in elderly patients with HGG was associated with prolonged survival. The data suggest that favorable prognostic factors for patients with malignant brain tumors are also valid in elderly patients.

Polifeprosan 20, 3.85% carmustine slow-release wafer in malignant glioma: evidence for role in era of standard adjuvant temozolomide

The Polifeprosan 20 with carmustine (BCNU, bis-chloroethylnitrosourea, Gliadel^®) polymer implant wafer is a biodegradable compound containing 3.85% carmustine which slowly degrades to release carmustine and protects it from exposure to water with resultant hydrolysis until the time of release. The carmustine implant wafer was demonstrated to improve survival in blinded placebo-controlled trials in selected patients with newly diagnosed or recurrent malignant glioma, with little increased risk of adverse events. Based on these trials and other supporting data, US and European regulatory authorities granted approval for its use in recurrent and newly diagnosed malignant glioma, and it remains the only approved local treatment. The preclinical and clinical data suggest that it is optimally utilized primarily in the proportion of patients who may have total or near total removal of gross tumor. The aim of this work was to review the evidence for the use of carmustine implants in the management of malignant astrocytoma (World Health Organization grades III and IV), including newly diagnosed and recurrent disease, especially in the setting of a standard of care that has changed since the randomized trials were completed. Therapy has evolved such that patients now generally receive temozolomide chemotherapy during and after radiotherapy treatment. For patients undergoing repeat resection for malignant glioma, a randomized, blinded, placebo-controlled trial demonstrated a median survival for 110 patients who received carmustine polymers of 31 weeks compared with 23 weeks for 122 patients who only received placebo polymers. The benefit achieved statistical significance only on analysis adjusting for prognostic factors rather than for the randomized groups as a whole (hazard ratio = 0.67, P = 0.006). A blinded, placebo-controlled trial has also been performed for carmustine implant placement in newly diagnosed patients prior to standard radiotherapy. Median survival was improved from 11.6 to 13.9 months (P = 0.03), with a 29% reduction in the risk of death. When patients with glioblastoma multiforme alone were analyzed, the median survival improved from 11.4 to 13.5 months, but this improvement was not statistically significant. When a Cox’s proportional hazard model was utilized to account for other potential prognostic factors, there was a significant 31% reduction in the risk of death (P = 0.04) in this subgroup. Data from other small reports support these results and confirm that the incidence of adverse events does not appear to be increased meaningfully. Given the poor prognosis without possibility of cure, these benefits from a treatment with a favorable safety profile were considered meaningful. There is randomized evidence to support the use of carmustine wafers placed during resection of recurrent disease. Therefore, although there is limited specific evidence, this treatment is likely to be efficacious in an environment when nearly all patients receive temozolomide as part of initial management. Given that half of the patients in the randomized trial assessing the value of carmustine implants in recurrent disease had received prior chemotherapy, it is likely that this remains a valuable treatment at the time of repeat resection, even after temozolomide. There are data from multiple reports to support safety. Although there is randomized evidence to support the use of this therapy in newly diagnosed patients who will receive radiotherapy alone, it is now standard to administer both adjuvant temozolomide and radiotherapy. There are survival outcome reports for small cohorts of patients receiving temozolomide with radiotherapy, but this information is not sufficient to support firm recommendations. Based on the rationale and evidence of safety, this approach appears to be a reasonable option as more information is acquired. Available data support the safety of using carmustine wafers in this circumstance, although special attention to surgical guidelines for implanting the wafers is warranted.

Multiple resections for patients with glioblastoma: prolonging survival

OBJECT

Glioblastoma is the most common and aggressive type of primary brain tumor in adults. These tumors recur regardless of intervention. This propensity to recur despite aggressive therapies has made many perceive that repeated resections have little utility. The goal of this study was to evaluate if patients who underwent repeat resections experienced improved survival as compared with patients with fewer numbers of resections, and whether the number of resections was an independent predictor of prolonged survival.

METHODS

The records of adult patients who underwent surgery for an intracranial primary glioblastoma at an academic tertiary-care institution between 1997 and 2007 were retrospectively reviewed. Multivariate proportionalhazards regression analysis was used to identify an association between glioblastoma resection number and survival after controlling for factors known to be associated with survival, such as age, functional status, periventricular location, extent of resection, and adjuvant therapy. Survival as a function of time was plotted using the Kaplan-Meier method, and survival rates were compared using log-rank analysis.

RESULTS

Five hundred seventy-eight patients with primary glioblastoma met the inclusion/exclusion criteria. At last follow-up, 354, 168, 41, and 15 patients underwent 1, 2, 3, or 4 resections, respectively. The median survival for patients who underwent 1, 2, 3, and 4 resections was 6.8, 15.5, 22.4, and 26.6 months (p < 0.05), respectively. In multivariate analysis, patients who underwent only 1 resection experienced shortened survival (relative risk [RR] 3.400, 95% CI 2.423-4.774; p < 0.0001) as compared with patients who underwent 2 (RR 0.688, 95% CI 0.525-0.898; p = 0.0006), 3 (RR 0.614, 95% CI 0.388-0.929; p = 0.02), or 4 (RR 0.600, 95% CI 0.238-0.853; p = 0.01) resections. These results were verified in a case-control evaluation, controlling for age, neurological function, periventricular tumor location, extent of resection, and adjuvant therapy. Patients who underwent 1, 2, or 3 resections had a median survival of 4.5, 16.2, and 24.4 months, respectively (p < 0.05). Additionally, the risk of infections or iatrogenic deficits did not increase with repeated resections in this patient population (p > 0.05).

CONCLUSIONS

Patients with glioblastoma will inevitably experience tumor recurrence. The present study shows that patients with recurrent glioblastoma can have improved survival with repeated resections. The findings of this study, however, may be limited by an intrinsic bias associated with patient selection. The authors attempted to minimize these biases by using strict inclusion criteria, multivariate analyses, and case-control evaluation.

Survival and treatment patterns of glioblastoma in the elderly: a population-based study

BACKGROUND

As the older segment of the population grows faster than any other age group, the number of elderly diagnosed with glioblastoma is expected to increase. The aim of this study was to explore survival and the treatment provided to elderly patients diagnosed with glioblastoma in a population-based setting. We further studied whether increased treatment aggressiveness may have contributed to a clinically important survival benefit in the elderly population.

METHODS

From the Norwegian Cancer Registry, we included 2882 patients who were diagnosed with glioblastoma between 1988 and 2008.

RESULTS

The proportion of patients ≥66 years was 42.5% (n = 1224), and 15.9% of patients (n = 459) were ≥75 years at diagnosis. Treatment patterns varied significantly between age groups (P < 0.001). Elderly patients (66 years) were less likely to receive multimodal treatment with resection combined with radiotherapy and/or chemotherapy. Elderly patients were more likely to receive a diagnosis of glioblastoma without histopathologic verification (P < 0.001). Among patients receiving multimodal treatment with surgical resection, radiotherapy, and chemotherapy, shorter survival was seen in the elderly (P < 0.001). Belonging to the age group ≥75 years was the strongest predictor of decreased survival (P < 0.001), thus seemingly of higher prognostic impact than the patterns of care. Increasing age, no tumor resection, no radiotherapy, and no chemotherapy were identified as independent predictors of reduced survival. There was a statistically significant, albeit debatable, clinically relevant survival advantage for the oldest patients (≥75 years) diagnosed in the last 5 years of the study.

CONCLUSIONS

Advancing age remains a very strong and independent negative prognostic factor in glioblastoma. Although there has been an increase in the aggressiveness of treatment provided to elderly with glioblastoma, the gain for the oldest age group seems at best very modest. The prognosis of the oldest age group remains very poor, despite multimodal treatment.