Glioblastoma (GBM), the most common primary malignant brain tumor in adults, is associated with significant morbidity and mortality despite maximal safe resection followed by chemo- and radiotherapy. GBMs contain self-renewing, tumorigenic glioma stem cells that contribute to tumor initiation, heterogeneity, therapeutic resistance, and recurrence. Intratumoral heterogeneity (ITH) of GBMs is also a major contributing factor to poor clinical outcomes associated with these high-grade glial tumors. Herein, the authors summarize recent discoveries and advances in the molecular and phenotypic characterization of GBMs with particular focus on ITH. In so doing, they attempt to highlight recent advances in molecular signatures/properties and metabolic alterations in an effort to clarify translational implications that may ultimately improve clinical outcomes.
Joshua D. Bernstock, James H. Mooney, Adeel Ilyas, Gustavo Chagoya, Dagoberto Estevez-Ordonez, Ahmed Ibrahim and Ichiro Nakano
Kathrin Zimmerman, Bobby May, Katherine Barnes, Anastasia Arynchyna, Elizabeth N. Alford, Gustavo Chagoya, Caroline Arata Wessinger, Laura E. Dreer, Inmaculada Aban, James M. Johnston, Curtis J. Rozzelle, Jeffrey P. Blount and Brandon G. Rocque
Hydrocephalus is a chronic medical condition that has a significant impact on children and their caregivers. The objective of this study was to measure the quality of life (QOL) of children with hydrocephalus, as assessed by both caregivers and patients.
Pediatric patients with hydrocephalus and their caregivers were enrolled during routine neurosurgery clinic visits. The Hydrocephalus Outcomes Questionnaire (HOQ), a report of hydrocephalus-related QOL, was administered to both children with hydrocephalus (self-report) and their caregivers (proxy report about the child). Patients with hydrocephalus also completed measures of anxiety, depression, fatigue, traumatic stress, and headache. Caregivers completed a proxy report of child traumatic stress and a measure of caregiver burden. Demographic information was collected from administration of the Psychosocial Assessment Tool (version 2.0) and from the medical record. Child and caregiver HOQ scores were analyzed and correlated with clinical, demographic, and psychological variables.
The mean overall HOQ score (parent assessment of child QOL) was 0.68. HOQ Physical Health, Social-Emotional Health, and Cognitive Health subscore averages were 0.69, 0.73, and 0.54, respectively. The mean overall child self-assessment (cHOQ) score was 0.77, with cHOQ Physical Health, Social-Emotional Health, and Cognitive Health subscore means of 0.84, 0.79, and 0.66, respectively. Thirty-nine dyads were analyzed, in which both a child with hydrocephalus and his or her caregiver completed the cHOQ and HOQ. There was a positive correlation between parent and child scores (p < 0.004 for all subscores). Child scores were consistently higher than parent scores. Variables that showed association with caregiver-assessed QOL in at least one domain included child age, etiology of hydrocephalus, and history of endoscopic third ventriculostomy. There was a significant negative relationship (rho −0.48 to −0.60) between child-reported cHOQ score and child-reported measures of posttraumatic stress, anxiety, depression, and fatigue. There was a similar significant relationship between caregiver report of child’s QOL (HOQ) and caregiver assessment of the child’s posttraumatic stress symptoms as well as their assessment of burden of care (rho = −0.59 and rho = −0.51, respectively). No relationship between parent-reported HOQ and child-reported psychosocial factors was significant. No clinical or demographic variables were associated with child self-assessed cHOQ.
Pediatric patients with hydrocephalus consistently rate their own QOL higher than their caregivers do. Psychological factors such as anxiety and posttraumatic stress may be associated with lower QOL. These findings warrant further exploration.
Travis J. Atchley, Galal A. Elsayed, Blake Sowers, Harrison C. Walker, Gustavo Chagoya, Matthew C. Davis, Joshua D. Bernstock, Nidal B. Omar, Daxa M. Patel and Barton L. Guthrie
The objective of this study was to determine the incidence of seizures following deep brain stimulation (DBS) electrode implantation and to evaluate factors associated with postoperative seizures.
The authors performed a single-center retrospective case-control study. The outcome of interest was seizure associated with DBS implantation. Univariate analyses were performed using the Student t-test for parametric continuous outcomes. The authors used the Kruskal-Wallis test or Wilcoxon rank-sum test for nonparametric continuous outcomes, chi-square statistics for categorical outcomes, and multivariate logistic regression for binomial variables.
A total of 814 DBS electrode implantations were performed in 645 patients (478 [58.7%] in men and 520 [63.9%] in patients with Parkinson’s disease). In total, 22 (3.4%) patients who had undergone 23 (2.8%) placements experienced seizure. Of the 23 DBS implantation–related seizures, 21 were new-onset seizures (3.3% of 645 patients) and 2 were recurrence or worsening of a prior seizure disorder. Among the 23 cases with postimplantation-related seizure, epilepsy developed in 4 (17.4%) postoperatively; the risk of DBS-associated epilepsy was 0.50% per DBS electrode placement and 0.63% per patient. Nine (39.1%) implantation-related seizures had associated postoperative radiographic abnormalities. Multivariate analyses suggested that age at surgery conferred a modest increased risk for postoperative seizures (OR 1.06, 95% CI 1.02–1.10). Sex, primary diagnosis, electrode location and sidedness, and the number of trajectories were not significantly associated with seizures after DBS surgery.
Seizures associated with DBS electrode placement are uncommon, typically occur early within the postoperative period, and seldom lead to epilepsy. This study suggests that patient characteristics, such as age, may play a greater role than perioperative variables in determining seizure risk. Multiinstitutional studies may help better define and mitigate the risk of seizures after DBS surgery.
Daisuke Yamashita, Joshua D. Bernstock, Galal Elsayed, Hirokazu Sadahiro, Ahmed Mohyeldin, Gustavo Chagoya, Adeel Ilyas, James Mooney, Dagoberto Estevez-Ordonez, Shinobu Yamaguchi, Victoria L. Flanary, James R. Hackney, Krishna P. Bhat, Harley I. Kornblum, Nicola Zamboni, Sung-Hak Kim, E. Antonio Chiocca and Ichiro Nakano
Despite an aggressive multimodal therapeutic regimen, glioblastoma (GBM) continues to portend a grave prognosis, which is driven in part by tumor heterogeneity at both the molecular and cellular levels. Accordingly, herein the authors sought to identify metabolic differences between GBM tumor core cells and edge cells and, in so doing, elucidate novel actionable therapeutic targets centered on tumor metabolism.
Comprehensive metabolic analyses were performed on 20 high-grade glioma (HGG) tissues and 30 glioma-initiating cell (GIC) sphere culture models. The results of the metabolic analyses were combined with the Ivy GBM data set. Differences in tumor metabolism between GBM tumor tissue derived from within the contrast-enhancing region (i.e., tumor core) and that from the peritumoral brain lesions (i.e., tumor edge) were sought and explored. Such changes were ultimately confirmed at the protein level via immunohistochemistry.
Metabolic heterogeneity in both HGG tumor tissues and GBM sphere culture models was identified, and analyses suggested that tyrosine metabolism may serve as a possible therapeutic target in GBM, particularly in the tumor core. Furthermore, activation of the enzyme tyrosine aminotransferase (TAT) within the tyrosine metabolic pathway influenced the noted therapeutic resistance of the GBM core.
Selective inhibition of the tyrosine metabolism pathway may prove highly beneficial as an adjuvant to multimodal GBM therapies.