Yazmin Odia

A phase II trial of single-agent bevacizumab in patients with recurrent anaplastic glioma

The purpose of this study was to evaluate the activity of single-agent bevacizumab in patients with recurrent anaplastic glioma and assess correlative advanced imaging parameters. Patients with recurrent anaplastic glioma were treated with bevacizumab 10 mg/kg every 2 weeks. Complete patient evaluations were repeated every 4 weeks. Correlative dynamic contrast-enhanced MR and (18)fluorodeoxyglucose PET imaging studies were obtained to evaluate physiologic changes in tumor and tumor vasculature at time points including baseline, 96 h after the first dose, and after the first 4 weeks of therapy. Median overall survival was 12 months (95% confidence interval [CI]: 6.08-22.8). Median progression-free survival was 2.93 months (95% CI: 2.01-4.93), and 6-month progression-free survival was 20.9% (95% CI: 10.3%-42.5%). Thirteen (43%) patients achieved a partial response. The most common grade ≥ 3 treatment-related toxicities were hypertension, hypophosphatemia, and thromboembolism. Single-agent bevacizumab produces significant radiographic response in patients with recurrent anaplastic glioma but did not meet the 6-month progression-free survival endpoint. Early change in enhancing tumor volume at 4 days after start of therapy was the most significant prognostic factor for overall and progression-free survival.

Yes-Associated Protein 1 Is Widely Expressed in Human Brain Tumors and Promotes Glioblastoma Growth

The hippo pathway and its downstream mediator yes-associated protein 1 (YAP1) regulate mammalian organ size in part through modulating progenitor cell numbers. YAP1 has also been implicated as an oncogene in multiple human cancers. Currently, little is known about the expression of YAP1 either in normal human brain tissue or in central nervous system neoplasms. We used immunohistochemistry to evaluate nuclear YAP1 expression in the fetal and normal adult human brains and in 264 brain tumors. YAP1 was expressed infetal and adult brain regions known to harbor neural progenitor cells, but there was little YAP1 immunoreactivity in the adult cerebral cortex. YAP1 protein was also readily detected in the nuclei ofhuman brain tumors. In medulloblastoma, the expression varied between histologic subtypes and was most prominent in nodular/desmoplastic tumors. In gliomas, it was frequently expressed in infiltrating astrocytomas and oligodendrogliomas but rarely in pilocytic astrocytomas. Using a loss-of-function approach, we show thatYAP1 promoted growth of glioblastoma cell lines in vitro. High levels of YAP1 messenger RNA expression were associated with aggressive molecular subsets of glioblastoma and with a nonsignificanttrend toward reduced mean survival in human astrocytoma patients. These findings suggest that YAP1 may play an important rolein normal human brain development and that it could represent a new target in human brain tumors.

Molecular and morphologic correlates of the alternative lengthening of telomeres phenotype in high-grade astrocytomas

Recent studies suggest that the telomere maintenance mechanism known as alternative lengthening of telomeres (ALT) is relatively more common in specific glioma subsets and strongly associated with ATRX mutations. We retrospectively examined 116 high‐grade astrocytomas (32 pediatric glioblastomas, 65 adult glioblastomas, 19 anaplastic astrocytomas) with known ALT status using tissue microarrays to identify associations with molecular and phenotypic features. Immunohistochemistry was performed using antibodies against ATRX, DAXX, p53 and IDH1R132H mutant protein. EGFR amplification was evaluated by fluorescence in situ hybridization (FISH). Almost half of fibrillary and gemistocytic astrocytomas (44%) demonstrated ALT. Conversely all gliosarcomas (n = 4), epithelioid (n = 2), giant cell (n = 2) and adult small cell astrocytomas (n = 7) were ALT negative. The ALT phenotype was positively correlated with the presence of round cells (P = 0.002), microcysts (P < 0.0002), IDH1 mutant protein (P < 0.0001), ATRX protein loss (P < 0.0001), strong P53 immunostaining (P < 0.0001) and absence of EGFR amplification (P = 0.004). There was no significant correlation with DAXX expression. We conclude that ALT represents a specific phenotype in high‐grade astrocytomas with distinctive pathologic and molecular features. Future studies are required to clarify the clinical and biological significance of ALT in high‐grade astrocytomas.

Severe Leukoencephalopathy Following Acute Oxycodone Intoxication

BackgroundPost-opioid toxic encephalopathy is described associated with the synthetic opioid, methadone, and after heroin intoxication, (inhaled, injected or ingested).MethodsWe describe the clinical and radiologic findings of a 46-year-old man with oxycodone and oxycontin overdose who developed multifocal encephalopathy and severe cerebellitis causing acute obstructive hydrocephalus, and discuss the possible mechanisms involved.ResultsBrain MRI showed a non-vascular distribution of diffusion positive lesions in both cerebellar hemispheres and globi pallidi with preserved cerebral perfusion, suggesting an inflammatory process. Management required ventilatory support and intraventricular catheter placement.ConclusionsTo our knowledge, this is the first report of this condition associated with oxycodone and oxycontin ingestion. The occurrence of this rare toxic encephalopathy may be related to distribution patterns of opioid receptor subtypes, genetic susceptibility, sensitization, and other specific comorbidities.

BRAF-V600E mutant papillary craniopharyngioma dramatically responds to combination BRAF and MEK inhibitors

We present a patient with BRAF-V600E mutant papillary craniopharyngioma successfully treated with combination BRAF (dabrafenib 150 mg twice daily) and MEK (trametinib 2 mg daily) inhibitors after her unresectable tumor proved refractory to radiation. Serial brain MRIs and PET revealed marked tumor reduction with gradual neurological improvement and permanent panhypopituitarism.

Comprehensive Genomic Profiling of Esthesioneuroblastoma Reveals Additional Treatment Options

BACKGROUND Esthesioneuroblastoma (ENB), also known as olfactory neuroblastoma, is a rare malignant neoplasm of the olfactory mucosa. Despite surgical resection combined with radiotherapy and adjuvant chemotherapy, ENB often relapses with rapid progression. Current multimodality, nontargeted therapy for relapsed ENB is of limited clinical benefit. MATERIALS AND METHODS We queried whether comprehensive genomic profiling (CGP) of relapsed or refractory ENB can uncover genomic alterations (GA) that could identify potential targeted therapies for these patients. CGP was performed on formalin-fixed, paraffin-embedded sections from 41 consecutive clinical cases of ENBs using a hybrid-capture, adaptor ligation based next-generation sequencing assay to a mean coverage depth of 593X. The results were analyzed for base substitutions, insertions and deletions, select rearrangements, and copy number changes (amplifications and homozygous deletions). RESULTS Clinically relevant GA (CRGA) were defined as GA linked to drugs on the market or under evaluation in clinical trials. A total of 28 ENBs harbored GA, with a mean of 1.5 GA per sample. Approximately half of the ENBs (21, 51%) featured at least one CRGA, with an average of 1 CRGA per sample. The most commonly altered gene was TP53 (17%), with GA in PIK3CA, NF1, CDKN2A, and CDKN2C occurring in 7% of samples. CONCLUSION We report comprehensive genomic profiles for 41 ENB tumors. CGP revealed potential new therapeutic targets, including targetable GA in the mTOR, CDK and growth factor signaling pathways, highlighting the clinical value of genomic profiling in ENB. IMPLICATIONS FOR PRACTICE Comprehensive genomic profiling of 41 relapsed or refractory ENBs reveals recurrent alterations or classes of mutation, including amplification of tyrosine kinases encoded on chromosome 5q and mutations affecting genes in the mTOR/PI3K pathway. Approximately half of the ENBs (21, 51%) featured at least one clinically relevant genomic alteration (CRGA), with an average of 1 CRGA per sample. The most commonly altered gene was TP53 (17%), and alterations in PIK3CA, NF1, CDKN2A, or CDKN2C were identified in 7% of samples. Responses to treatment with the kinase inhibitors sunitinib, everolimus, and pazopanib are presented in conjunction with tumor genomics.

A glioblastoma neurosphere line with alternative lengthening of telomeres

Neoplastic cells must maintain telomeres in order to replicate extensively, often by inducing telomerase activity. However, some tumors use a telomerase-independent mechanism dependent upon homologous recombination known as alternative lengthening of telomeres (ALT) [1]. ALT has been identified in 11–24 % of glioma tissue samples [2–4], but has been demonstrated in only one glioma cell line (TG20) [5]. In this brief letter, we describe a second ALT-positive glioblastoma (GBM) cell line.

A Phase II trial of tandutinib (MLN 518) in combination with bevacizumab for patients with recurrent glioblastoma

AIM A Phase II trial of bevacizumab plus tandutinib. METHODS We enrolled 41 recurrent, bevacizumab-naive glioblastoma patients for a trial of bevacizumab plus tandutinib. Median age was 55 and 71% were male. Treatment consisted of tandutinib 500 mg two-times a day (b.i.d.) and bevacizumab 10 mg/kg every 2 weeks starting day 15. Of 37 (90%) evaluable, nine (24%) had partial response. RESULTS & CONCLUSION Median overall and progression-free survival was 11 and 4.1 months; progression-free survival at 6 months was 23%. All patients suffered treatment-related toxicities; common grade ≥3 toxicities were hypertension (17.1%), muscle weakness (17.1%), lymphopenia (14.6%) and hypophosphatemia (9.8%). Four of six with grade ≥3 tandutinib-related myasthenic-like muscle weakness had electromyography-proven neuromuscular junction pathology. Tandutinib with bevacizumab was as effective but more toxic than bevacizumab monotherapy.