Pluripotent stem cell-derived epithelium misidentified as brain microvascular endothelium requires ETS factors to acquire vascular fate.

Cells derived from pluripotent sources in vitro must resemble those found in vivo as closely as possible at both transcriptional and functional levels in order to be a useful tool for studying diseases and developing therapeutics. Recently, differentiation of human pluripotent stem cells (hPSCs) into brain microvascular endothelial cells (ECs) with blood-brain barrier (BBB)-like properties has been reported. These cells have since been used as a robust in vitro BBB model for drug delivery and mechanistic understanding of neurological diseases. However, the precise cellular identity of these induced brain microvascular endothelial cells (iBMECs) has not been well described. Employing a comprehensive transcriptomic metaanalysis of previously published hPSC-derived cells validated by physiological assays, we demonstrate that iBMECs lack functional attributes of ECs since they are deficient in vascular lineage genes while expressing clusters of genes related to the neuroectodermal epithelial lineage (Epi-iBMEC). Overexpression of key endothelial ETS transcription factors (ETV2, ERG, and FLI1) reprograms Epi-iBMECs into authentic endothelial cells that are congruent with bona fide endothelium at both transcriptomic as well as some functional levels. This approach could eventually be used to develop a robust human BBB model in vitro that resembles the human brain EC in vivo for functional studies and drug discovery.

Using a Capsular Tension Ring (CTR) Inserter for CTR Explantation in Cases of Posteriorly Dislocated Intraocular Lens-CTR-Capsule Complex.

PURPOSE: Explantation of a dislocated capsular tension ring (CTR) from the vitreous cavity can be challenging, typically requiring a bimanual hand-shake technique or cutting the CTR into segments. We present three cases of dislocated intraocular lens (IOL)-CTR-capsule complexes in which CTRs were explanted efficiently and safely by using a CTR inserter (CTR-I) through a clear corneal incision. METHODS: Retrospective case series. RESULTS: Capsular tension rings were successfully explanted by freeing the eyelet of the CTR from the capsule, engaging it with the CTR-I hook and retracting the CTR into the device's shaft while maintaining the entire IOL-CTR-capsule complex in a safe position behind the iris plane. No complications of the procedure were observed in all three cases. All patients had subsequent uneventful IOL exchange through sutureless scleral fixation during the same surgery. CONCLUSION: The CTR inserter provides a simple and efficient approach to CTR removal from IOL-CTR-capsule complexes dislocated into the vitreous cavity. Greater awareness of this technique among providers is needed.

THE EFFECT OF ELECTIVE CATARACT EXTRACTION BY PHACOEMULSIFICATION IN EYES WITH VITREOMACULAR TRACTION SYNDROME.

PURPOSE: To evaluate the effect of cataract extraction (CE) by phacoemulsification on the vitreomacular interface (VMI) of eyes with preexisting vitreomacular traction (VMT). METHODS: Retrospective, observational case series. Patients with VMT who elected to proceed with CE, before any vitreoretinal intervention, were studied. Eyes with at least a 12-month follow-up period were included. The status of the vitreomacular adhesion at different time points was assessed using spectral-domain optical coherence tomography. The best-corrected visual acuity was recorded at different time points. Other macular and systemic comorbidities were documented. RESULTS: Fifteen eyes from 15 phakic patients with symptomatic VMT were included. Six of them were male subjects. Seven patients had diabetes mellitus and two of them also had nonproliferative diabetic retinopathy. The preoperative macular comorbidities included macular hole in six eyes (Stage 1 in 3 eyes and Stage 2 or 3 in another 3 eyes), epiretinal membrane in five eyes, and cystoid macular edema in four eyes. After uncomplicated CE, the VMT was released in 5 eyes, whereas in 10 eyes, CE did not significantly change the status of the vitreomacular adhesion. Three of 3 eyes with preexisting full-thickness macular hole (Stage 2 or 3 macular hole) were found to have Stage 4 macular hole shortly after CE. In seven of seven patients with diabetes mellitus, the status of the vitreomacular interface did not change after CE. Eventually, 7 of 15 patients underwent additional pars plana vitrectomy. Compared with the baseline vision, and vision before other interventions, the visual acuity after CE improved in 5 patients, remained unchanged in 7 patients, and decreased in the 3 patients with Stage 2 or 3 macular hole. The mean preoperative and early postoperative visual acuity was 20/59 and 20/68, respectively (P > 0.05). CONCLUSION: The effect of CE in phakic eyes with known VMT varies significantly. In the current case series, every eye with VMT and Stage 2 or 3 macular hole ended up with Stage 4 macular hole, although the VMT did not change significantly in the eyes of diabetic patients. Studies with larger sample size are needed to further elucidate the impact of elective CE on VMT.

ONE-YEAR OUTCOMES OF A NOVEL SURGICAL TECHNIQUE FOR SUTURELESS INTRASCLERAL FIXATION OF A THREE-PIECE INTRAOCULAR LENS USING A 30-GAUGE NEEDLE.

PURPOSE: To present the 1-year results of a surgical technique for the sutureless intrascleral fixation of a 3-piece intraocular lens using a 30-gauge needle. METHODS: A retrospective chart review of a consecutive series of 9 eyes of 8 patients who underwent sutureless intrascleral fixation of posterior chamber intraocular lens using a 30-gauge needle was performed. Patients were required to have at least 1 year of follow-up to be included in the analysis. Short-term data were collected 1 month after surgery, and long-term data were collected 1 year after surgery. Data collected included visual acuity, lens stability, intraocular pressure, and the development of complications. RESULTS: Visual acuity improved from Snellen 20/309 preoperatively to Snellen 20/27 at postoperative Month 12 (P = 0.03). Short-term complications included increased intraocular pressure (n = 4) and corneal edema (n = 2). Long-term complications included exposed superior haptic (n = 1) and recurrent anterior chamber inflammation (n = 1). CONCLUSION: The novel surgical technique for sutureless intrascleral fixation of a 3-piece intraocular lens is well tolerated 1 year after surgery.

ONE-YEAR OUTCOMES OF A NOVEL SURGICAL APPROACH FOR FIXATION OF A POSTERIOR CHAMBER INTRAOCULAR LENS USING GORE-TEX SUTURE.

PURPOSE: To report the 1-year outcomes of a novel surgical technique for the fixation of a CZ70BD intraocular lens with Gore-Tex suture using cow-hitch knots. METHODS: A retrospective chart review of 15 patients (13 men and 2 women) who underwent fixation of a posterior chamber intraocular lens with Gore-Tex suture was performed. Short- and long-term outcomes data were collected 1 month and 1 year after surgery, respectively. RESULTS: Fourteen of the 15 patients met inclusion criteria and were included in the analysis. Mean visual acuity improved significantly from Snellen 20/491 preoperatively to Snellen 20/59 at postoperative month 12 (P = 0.002). The most common short-term complications included increased intraocular pressure (n = 6) and cystoid macular edema (n = 4). The most common long-term complications included increased intraocular pressure (n = 2) and iris capture of the intraocular lens (n = 2). CONCLUSIONS: One-year outcome data suggest that this technique is a reasonable surgical option for secondary intraocular lens placement in patients who lack capsular support.

Incorporating genomic signatures into surgical and medical decision-making for elderly glioblastoma patients.

Glioblastoma (GBM) is the most common type of malignant primary brain tumor in adults. It is a uniformly fatal disease (median overall survival 16 months) even with aggressive resection and an adjuvant temozolomide-based chemoradiation regimen. Age remains an independent risk factor for a poor prognosis. Several factors contribute to the dismal outcomes in the elderly population with GBM, including poor baseline health status, differences in underlying genomic alterations, and variability in the surgical and medical management of this subpopulation. The latter arises from a lack of adequate representation of elderly patients in clinical trials, resulting in limited data on the response of this subpopulation to standard treatment. Results from retrospective and some prospective studies have indicated that resection of only contrast-enhancing lesions and administration of hypofractionated radiotherapy in combination with temozolomide are effective strategies for optimizing survival while maintaining baseline quality of life in elderly GBM patients; however, survival remains dismal relative to that in a younger cohort. Here, the authors present historical context for the current strategies used for the multimodal management (surgical and medical) of elderly patients with GBM. Furthermore, they provide insights into elderly GBM patient-specific genomic signatures such as isocitrate dehydrogenase 1/2 (IDH1/2) wildtype status, telomerase reverse transcriptase promoter (TERTp) mutations, and somatic copy number alterations including CDK4/MDM2 coamplification, which are becoming better understood and could be utilized in a clinical trial design and patient stratification to guide the development of more effective adjuvant therapies specifically for elderly GBM patients.

Grading meningiomas utilizing multiparametric MRI with inclusion of susceptibility weighted imaging and quantitative susceptibility mapping.

BACKGROUND AND PURPOSE: The ability to predict high-grade meningioma preoperatively is important for clinical surgical planning. The purpose of this study is to evaluate the performance of comprehensive multiparametric MRI, including susceptibility weighted imaging (SWI) and quantitative susceptibility mapping (QSM) in predicting high-grade meningioma both qualitatively and quantitatively. METHODS: Ninety-two low-grade and 37 higher grade meningiomas in 129 patients were included in this study. Morphological characteristics, quantitative histogram analysis of QSM and ADC images, and tumor size were evaluated to predict high-grade meningioma using univariate and multivariate analyses. Receiver operating characteristic (ROC) analyses were performed on the morphological characteristics. Associations between Ki-67 proliferative index (PI) and quantitative parameters were calculated using Pearson correlation analyses. RESULTS: For predicting high-grade meningiomas, the best predictive model in multivariate logistic regression analyses included calcification (ß=0.874, P=0.110), peritumoral edema (ß=0.554, P=0.042), tumor border (ß=0.862, P=0.024), tumor location (ß=0.545, P=0.039) for morphological characteristics, and tumor size (ß=4×10-5, P=0.004), QSM kurtosis (ß=-5×10-3, P=0.058), QSM entropy (ß=-0.067, P=0.054), maximum ADC (ß=-1.6×10-3, P=0.003), ADC kurtosis (ß=-0.013, P=0.014) for quantitative characteristics. ROC analyses on morphological characteristics resulted in an area under the curve (AUC) of 0.71 (0.61-0.81) for a combination of them. There were significant correlations between Ki-67 PI and mean ADC (r=-0.277, P=0.031), 25th percentile of ADC (r=-0.275, P=0.032), and 50th percentile of ADC (r=-0.268, P=0.037). CONCLUSIONS: Although SWI and QSM did not improve differentiation between low and high-grade meningiomas, combining morphological characteristics and quantitative metrics can help predict high-grade meningioma.

Tubular brain tumor biopsy improves diagnostic yield for subcortical lesions.

PURPOSE: Molecular data has become an essential part of the updated World Health Organization (WHO) grading of central nervous system tumors. However, stereotactic needle biopsies provide only small volume specimens and limit the extent of histologic and molecular testing that can be performed. We assessed the use of a tubular retractor-based minimally invasive biopsy technique to provide improved tissue yield and diagnostic data compared to needle biopsy. METHODS: Eighteen patients underwent an open transtubular biopsy compared to 146 stereotactic biopsies during the years of 2010-2018. RESULTS: Tubular biopsies resulted in a higher volume of tissue provided to the pathologist than needle biopsies (1.26 cm3 vs. 0.3 cm3; p < 0.0001). There was a higher rate of non-diagnostic sample with stereotactic compared to transtubular biopsy (13% vs. 0%; p = 0.13). Six patients who underwent stereotactic biopsy required reoperation for diagnosis, while no transtubular biopsy patient required reoperation in order to obtain a diagnostic specimen. Postoperative hematoma was the most common post-operative complication in both groups. CONCLUSIONS: Stereotactic transtubular biopsies are a viable alternative to stereotactic needle biopsies with excellent rates of diagnostic success and acceptable morbidity relative to the needle biopsy technique. As molecular data begins to increasingly drive treatment decisions, additional biopsy techniques that afford large tissue volumes may be necessary to adapt to the new needs of pathologists and treating oncologists.

Texture analysis on conventional MRI images accurately predicts early malignant transformation of low-grade gliomas.

OBJECTIVES: Texture analysis performed on MRI images can provide additional quantitative information that is invisible to human assessment. This study aimed to evaluate the feasibility of texture analysis on preoperative conventional MRI images in predicting early malignant transformation from low- to high-grade glioma and compare its utility to histogram analysis alone. METHODS: A total of 68 patients with low-grade glioma (LGG) were included in this study, 15 of which showed malignant transformation. Patients were randomly divided into training (60%) and testing (40%) sets. Texture analyses were performed to obtain the most discriminant factor (MDF) values for both training and testing data. Receiver operating characteristic (ROC) curve analyses were performed on MDF values and 9 histogram parameters in the training data to obtain cutoff values for determining the correct rates of discrimination between two groups in the testing data. RESULTS: The ROC analyses on MDF values resulted in an area under the curve (AUC) of 0.90 (sensitivity 85%, specificity 84%) for T2w FLAIR, 0.92 (86%, 94%) for ADC, 0.96 (97%, 84%) for T1w, and 0.82 (78%, 75%) for T1w + Gd and correctly discriminated between the two groups in 93%, 100%, 93%, and 92% of cases in testing data, respectively. In the astrocytoma subgroup, AUCs were 0.92 (88%, 83%) for T2w FLAIR and 0.90 (92%, 74%) for T1w + Gd and correctly discriminated two groups in 100% and 92% of cases. The MDF outperformed all 9 of the histogram parameters. CONCLUSION: Texture analysis on conventional preoperative MRI images can accurately predict early malignant transformation of LGGs, which may guide therapeutic planning. KEY POINTS: • Texture analysis performed on MRI images can provide additional quantitative information that is invisible to human assessment. • Texture analysis based on conventional preoperative MR images can accurately predict early malignant transformation from low- to high-grade glioma. • Texture analysis is a clinically feasible technique that may provide an alternative and effective way of determining the likelihood of early malignant transformation and help guide therapeutic decisions.

Integrated PET-MRI for Glioma Surveillance: Perfusion-Metabolism Discordance Rate and Association With Molecular Profiling.

OBJECTIVE: Both 18F-FDG PET and perfusion MRI are commonly used techniques for posttreatment glioma surveillance. Using integrated PET-MRI, we assessed the rate of discordance between simultaneously acquired FDG PET images and dynamic contrast-enhanced (DCE) perfusion MR images and determined whether tumor genetics predicts discordance. MATERIALS AND METHODS: Forty-one consecutive patients with high-grade gliomas (20 with grade IV gliomas and 21 with grade III gliomas) underwent a standardized tumor protocol performed using an integrated 3-T PET-MRI scanner. Quantitative measures of standardized uptake value, plasma volume, and permeability were obtained from segmented whole-tumor volumes of interest and targeted ROIs. ROC curve analysis and the Youden index were used to identify optimal cutoffs for FDG PET and DCE-MRI. Two-by-two contingency tables and percent agreement were used to assess accuracy and concordance. Twenty-six patients (63%) from the cohort underwent next-generation sequencing for tumor genetics. RESULTS: The best-performing FDG PET and DCE-MRI cutoffs achieved sensitivities of 94% and 91%, respectively; specificities of 56% and 89%, respectively; and accuracies of 80% and 83%, respectively. FDG PET and DCE-MRI findings were discordant for 11 patients (27%), with DCE-MRI findings correct for six of these patients (55%). Tumor grade, tumor volume, bevacizumab exposure, and time since radiation predicted discordance between FDG PET and DCE-MRI findings, with an ROC AUC value of 0.78. Isocitrate dehydrogenase gene and receptor tyrosine kinase gene pathway mutations increased the ROC AUC value to 0.83. CONCLUSION: FDG PET and DCE-MRI show comparable accuracy and sensitivity in identifying tumor progression. These modalities were shown to have discordant findings for more than a quarter of the patients assessed. Tumor genetics may contribute to perfusion-metabolism discordance, warranting further investigation.

CLINICAL FINDINGS IN TRIAMCINOLONE-ASSOCIATED MACULOPATHY.

PURPOSE: To describe a crystalline retinopathy observed in patients greater than 1 year after intravitreal injection of triamcinolone acetonide (IVTA). METHODS: A retrospective, interventional, noncomparative, single-center case series of patients who received IVTA and developed subsequent crystalline retinopathy lasting greater than 1 year after injection. RESULTS: Eighteen eyes of 16 patients in which preretinal crystals were observed >1 year after IVTA were included in the study, with a mean follow-up (range) of 5.8 years (1.1-9.2) after IVTA. The crystals were refractile, not visible on fluorescein nor indocyanine green angiography, exhibited slow dissolution and movement, and were occasionally distributed in a circular fashion. Optical coherence tomography confirmed the preretinal and/or subhyaloid location of crystals. CONCLUSION: Macular crystals can persist for years after IVTA. The crystals localize to the preretinal or subhyaloid space, are angiographically silent, can exhibit slow dissolution and movement, may be distributed in a circular fashion reflecting the bursa premacularis, and appear nonpathologic.

INTRAVITREAL OCRIPLASMIN IN CLINICAL PRACTICE: Predictors of Success, Visual Outcomes, and Complications.

PURPOSE: To investigate predictors of success, visual outcomes, and complications of intravitreal ocriplasmin for the treatment of symptomatic vitreomacular adhesion in a clinical care setting. METHODS: Retrospective chart review of 49 consecutive eyes of 47 patients who received intravitreal ocriplasmin. Spectral domain optical coherence tomography scans were examined for vitreomacular traction (VMT) release, full-thickness macular hole (FTMH) closure, and other changes in retinal anatomy. RESULTS: Pharmacologic VMT release occurred in 41% of eyes; positive predictors included age ≤75 years (P = 0.001), phakic status (P = 0.016), VMT width ≤750 µm (P = 0.001), and absence of retinal comorbidities (P = 0.035). Pharmacologic FTMH closure occurred in 25% of cases; positive predictors included successful VMT release (P = 0.042), better preinjection best-corrected visual acuity (P = 0.036), and smaller FTMH aperture width (P = 0.033). Eyes that achieved VMT release and did not undergo surgery attained significant improvement in best-corrected visual acuity (P = 0.015). Complications included subfoveal lucency (33%), ellipsoid zone disruption (33%), and FTMH base enlargement (75%). Only FTMH base enlargement resulted in worse visual outcomes (P = 0.024). Subgroup analysis of 14 eyes with ideal characteristics (all positive predictors listed above) yielded a 93% VMT release rate. CONCLUSION: Proper case selection may facilitate successful pharmacologic vitreolysis with ocriplasmin, improve visual outcomes, and minimize potential complications.

Detailed longitudinal sampling of glioma stem cells in situ reveals Chr7 gain and Chr10 loss as repeated events in primary tumor formation and recurrence.

Intratumoral heterogeneity at the genetic, epigenetic, transcriptomic, and morphologic levels is a commonly observed phenomenon in many aggressive cancer types. Clonal evolution during tumor formation and in response to therapeutic intervention can be predicted utilizing reverse engineering approaches on detailed genomic snapshots of heterogeneous patient tumor samples. In this study, we developed an extensive dataset for a GBM case via the generation of polyclonal and monoclonal glioma stem cell lines from initial diagnosis, and from multiple sections of distant tumor locations of the deceased patient's brain following tumor recurrence. Our analyses revealed the tissue-wide expansion of a new clone in the recurrent tumor and chromosome 7 gain and chromosome 10 loss as repeated genomic events in primary and recurrent disease. Moreover, chromosome 7 gain and chromosome 10 loss produced similar alterations in mRNA expression profiles in primary and recurrent tumors despite possessing other highly heterogeneous and divergent genomic alterations between the tumors. We identified ETV1 and CDK6 as putative candidate genes, and NFKB (complex), IL1B, IL6, Akt and VEGF as potential signaling regulators, as potentially central downstream effectors of chr7 gain and chr10 loss. Finally, the differences caused by the transcriptomic shift following gain of chromosome 7 and loss of chromosome 10 were consistent with those generally seen in GBM samples compared to normal brain in large-scale patient-tumor data sets.

On the behavior of an eye encircled by a scleral buckle.

A mechanics based mathematical model for the behavior of an eye encircled by a scleral buckle, a procedure used by surgeons to correct retinal detachment, is developed. Closed form analytical solutions are obtained, and results of numerical simulations based on those solutions are presented. The effects of material and geometric parameters of the scleral buckle, as well as of the ocular pressure, on the deformation and volume change of the eye are studied. Critical behavior is identified, and correlations are drawn with regard to the properties of the buckle, the associated deformation of the eye, and the ocular pressure. The results indicate that a judicious choice of the buckle parameters is advisable for planning surgery. In particular, the initial (undeformed) radius of the buckle is seen to have the dominant influence with regard to deformation of the eye, while the thickness (height) and width, and hence the shape, of the buckle are seen to have minimal influence and may be chosen for other reasons, such as to maximize the comfort of the patient.

A phase II trial of enzastaurin (LY317615) in combination with bevacizumab in adults with recurrent malignant gliomas.

We evaluated the efficacy of combination enzastaurin (LY317615) and bevacizumab for recurrent malignant gliomas and explored serologic correlates. We enrolled 81 patients with glioblastomas (GBM, n = 40) and anaplastic gliomas (AG, n = 41). Patients received enzastaurin as a loading dose of 1125 mg, followed by 500 or 875 mg daily for patients on non-enzyme-inducing or enzyme-inducing antiepileptics, respectively. Patients received bevacizumab 10 mg/kg intravenously biweekly. Clinical evaluations were repeated every 4 weeks. Magnetic resonance imaging was obtained at baseline and every 8 weeks from treatment onset. Phosphorylated glycogen synthase kinase (GSK)-3 levels from peripheral blood mononuclear cells (PBMCs) were checked with each MRI. Median overall survival was 7.5 and 12.4 months for glioblastomas and anaplastic glioma cohorts, with median progression-free survivals of 2.0 and 4.4 months, respectively. Of GBM patients, 3/40 (7.5 %) were not evaluable, while 8/37 (22 %) had partial or complete response and 20/37 (54 %) had stable disease for 2+ months. Of the 39 evaluable AG patients, 18 (46 %) had an objective response, and 16 (41 %) had stable disease for 2+ months. The most common grade 3+ toxicities were lymphopenia (15 %), hypophosphatemia (8.8 %) and thrombotic events (7.5 %). Two (2.5 %) GBM patients died suddenly; another death (1.3 %) occurred from intractable seizures. Phosphorylated GSK-3 levels from PBMCs did not correlate with treatment response. A minimally important improvement in health-related quality of life was self-reported in 7-9/24 (29.2-37.5 %). Early response based on Levin criteria was significantly associated with significantly longer progression free survival for glioblastomas. Enzastaurin (LY317615) in combination with bevacizumab for recurrent malignant gliomas is well-tolerated, with response and progression-free survival similar to bevacizumab monotherapy.

Epigenetic-mediated dysfunction of the bone morphogenetic protein pathway inhibits differentiation of glioblastoma-initiating cells.

Despite similarities between tumor-initiating cells with stem-like properties (TICs) and normal neural stem cells, we hypothesized that there may be differences in their differentiation potentials. We now demonstrate that both bone morphogenetic protein (BMP)-mediated and ciliary neurotrophic factor (CNTF)-mediated Jak/STAT-dependent astroglial differentiation is impaired due to EZH2-dependent epigenetic silencing of BMP receptor 1B (BMPR1B) in a subset of glioblastoma TICs. Forced expression of BMPR1B either by transgene expression or demethylation of the promoter restores their differentiation capabilities and induces loss of their tumorigenicity. We propose that deregulation of the BMP developmental pathway in a subset of glioblastoma TICs contributes to their tumorigenicity both by desensitizing TICs to normal differentiation cues and by converting otherwise cytostatic signals to proproliferative signals.

ONE-YEAR OUTCOMES OF A NOVEL TECHNIQUE FOR RESCUING AND SCLERAL FIXATING A POSTERIOR DISLOCATED INTRAOCULAR LENS-BAG COMPLEX WITHOUT CONJUNCTIVAL OPENING (HOFFMAN POCKETS).

PURPOSE: To present the 1-year follow-up of a novel surgical technique that allows for suture fixation of a posteriorly dislocated lens-bag complex without the need for conjunctival incision. METHODS: A retrospective chart review of 19 patients who underwent posterior chamber intraocular lens rescue using the novel surgical technique was performed. Data were collected 1 year after surgery for all patients. RESULTS: Average preoperative vision was 20/500, whereas 3 months and 12 months postoperatively, the vision was 20/65 and 20/54, respectively. Three of 15 eyes had decentration of the sutured intraocular lens, 2 of which required additional surgical repair. CONCLUSION: Outcome data at 1 year support this novel technique as a viable option for the surgical repair of a dislocated lens-capsular bag complex.

Molecular characterizations of glioblastoma, targeted therapy, and clinical results to date.

During the last decade, extensive multiplatform genome-wide analysis has yielded a wealth of knowledge regarding the genetic and molecular makeup of glioblastoma multiforme (GBM). These profiling studies support the emerging view that GBM comprises a group of highly heterogeneous tumor types, each with its own distinct molecular and genetic signatures. This heterogeneity complicates the process of defining reliable intertumor/intratumor biological states, which will ultimately be needed for classifying tumors and for designing effective customized therapies that target resultant disease pathways. The increased understanding of the molecular pathogenesis of GBM has brought the hope and expectation that such knowledge will lead to better and more rational therapies directed toward specific molecular targets. To date, however, these expectations have largely been unrealized. This review discusses some of the principal genetic and epigenetic aberrations found in GBM that appear promising for targeted therapies now and in the near future, and it offers suggestions for future directions concerning the rather disappointing results of clinical trials to date.

A phase II trial of tamoxifen and bortezomib in patients with recurrent malignant gliomas.

NF-kB inhibition by bortezomib enhances tamoxifen-induced apoptosis in preclinical glioma models. We conducted a single institution, phase II trial to evaluate efficacy and safety of high dose tamoxifen with bortezomib in adults with recurrent malignant gliomas. The primary endpoint was radiographic response. Concurrent enzyme inducing anticonvulsants and grade ≥2 peripheral neuropathy were exclusion criteria. Patients received tamoxifen (120 mg PO twice daily) and bortezomib (1.3 mg/m2 IV on days 3, 6, 10, 13, 24, 27, 31, and 34) per 6-week cycles. We enrolled 42 patients with anaplastic gliomas (AGs, n = 12) and glioblastomas (GBMs, n = 30), 32 males and 10 females. Median age was 38 years (range 22-65) and 48 years (range 19-68) for AGs and GBMs, respectively. median karnofsky performance status was 90% (range 70-100) for AGs and 80% (range 60-100) for GBMs. Median prior therapies was 3, ranging 1-7. Grade ≥3 toxicities included lymphopenia (4/42), hypophosphatemia (3/42), thromobocytopenia (2/42), and 1/42 with hyponatremia, headache, dyspnea, or DVT. One patient withdrew consent, two were removed for toxicity, and all others discontinued for progression. Among 40 patients evaluable for response, only one achieved stable disease for 3 months; all others progressed rapidly. For AGs and GBMs respectively, median progression-free survival was 5.9 and 5.7 weeks and median overall survival was 25.6 and 14.7 weeks. The study was closed due to poor accrual and therapeutic futility. Combination tamoxifen and bortezomib has no activity in recurrent malignant gliomas. Poor penetration across blood brain barrier of bortezomib likely limited efficacy.