Faculty Bibliography

OBJECTIVE: Pediatric optic pathway gliomas (OPGs) are often considered benign, but can have detrimental effects on the quality of life, impair vision and are a potentially lethal disease. The aim of this study is to report the characteristics and outcomes of surgically treated OPGs and to identify candidates for different treatment strategies. MATERIAL-METHODS: Retrospective chart review of consecutive pediatric patients with surgically treated OPGs by a single surgeon at our institution from 1985-2015. Three treatment pathways were defined: surgery without planned adjuvant therapy (1), surgery with planned adjuvant therapy (2) and patients with prior treatment (3). RESULTS:88 patients - 49 male and 39 female - were included in analysis. 8 patients had NF1. Pathology revealed pilocytic astrocytoma (85.2%), pilomyxoid astrocytoma (8%), and pilocytic/pilomyxoid astrocytoma (5.7%). Radiologic location of the tumor was: hypothalamic (87%), and involvement of only chiasmand/or tract in (13%).Median age at diagnosiswas 4 years, median age at surgery was 6 years, and median time from diagnosis to surgery was 1 year. At the time of the study: Pathway 1: 37 patients; median PFS 84 +/- 33.4; median OS of 118 months (range: 24 - 337 months); OS rate 68%. Pathway 2: 9 patients; median PFS 45 +/- 10.9 months; median OS of 127 months (range: 23 - 368 months); OS rate 67%. Pathway 3: 42 patients; median PFS 74 +/- 13.3 months; median OS of 69 months (range: 7 - 356) months; OS rate 76%.. CONCLUSIONS: The role of surgery in the treatment of pediatric OPGs depends on patient characteristics and tumor biology. With the adequate therapeutic strategy, long-term PFS and OS can be achieved

Glioblastoma (GBM) is a deadly primary brain malignancy with extensive intratumoral hypoxia. Hypoxic regions of GBM contain stem-like cells and are associated with tumor growth and angiogenesis. The molecular mechanisms that regulate tumor growth in hypoxic conditions are incompletely understood. Here, we use primary human tumor biospecimens and cultures to identify GPR133 (ADGRD1), an orphan member of the adhesion family of G-protein-coupled receptors, as a critical regulator of the response to hypoxia and tumor growth in GBM. GPR133 is selectively expressed in CD133+ GBM stem cells (GSCs) and within the hypoxic areas of PPN in human biospecimens. GPR133 mRNA is transcriptionally upregulated by hypoxia in hypoxia-inducible factor 1alpha (Hif1alpha)-dependent manner. Genetic inhibition of GPR133 with short hairpin RNA reduces the prevalence of CD133+ GSCs, tumor cell proliferation and tumorsphere formation in vitro. Forskolin rescues the GPR133 knockdown phenotype, suggesting that GPR133 signaling is mediated by cAMP. Implantation of GBM cells with short hairpin RNA-mediated knockdown of GPR133 in the mouse brain markedly reduces tumor xenograft formation and increases host survival. Analysis of the TCGA data shows that GPR133 expression levels are inversely correlated with patient survival. These findings indicate that GPR133 is an important mediator of the hypoxic response in GBM and has significant protumorigenic functions. We propose that GPR133 represents a novel molecular target in GBM and possibly other malignancies where hypoxia is fundamental to pathogenesis.

Introduction: Pediatric optic pathway gliomas (OPGs) are often considered benign, but can have detrimental effects on the quality of life, impair vision and are a potentially lethal disease. The aim of this study is to report the characteristics and outcomes of surgically treated pediatric OPGs and to identify candidates for different treatment strategies. Methods: Retrospective chart review of consecutive pediatric patients with surgically treated OPGs by a single surgeon at our institution from 1985-2015. Three treatment pathways were defined: (1) surgery without planned adjuvant therapy; (2) surgery with planned adjuvant therapy; and, (3) patients with prior treatment.Results: 100 patients-55 male and 45 female-were included in analysis. 8 patients had NF1. Pathology revealed pilocytic astrocytoma (45%), pilomyxoid astrocytoma (9%), ganglioglioma (3%), and unknown (35%). Radiologic location of the tumor was: hypothalamic 86%, involvement of only chiasm and/or tract in 12%. Median age at diagnosis was 4 years, median age at surgery was 6 years, and median time from diagnosis to surgery was 1 year. Pathway 1: 39 patients; median PFS 73+17 months; OS rate 74%; median follow-up 117 months. Pathway 2: 10 patients; median PFS 29+15 months; OS rate 70%; median follow-up 59 months. Pathway 3: 51 patients; median PFS 33+8 months; OS rate 80%; median follow-up was 73 months. Conclusion: The role of surgery in the treatment of pediatric OPGs depends on patient characteristics and tumor biology. With the adequate therapeutic strategy, long-term PFS and OS can be achieved

BACKGROUND: Epithelioid hemangioendothelioma (EHE) is a rare sarcoma of vascular origin, which is clinically and histologically intermediate between benign hemangioma and angiosarcoma. It is most commonly found in the liver, lung, and bone, however, 46 intracranial cases have been reported in the literature, of which this is the fifth reported suprasellar tumor. CASE DESCRIPTION: A 45-year-old woman developed progressive lethargy, somnolence, and memory decline over the course of 6 months. On computed tomography (CT), she was found to have a large hypothalamic mass and underwent subtotal resection via a bifrontal craniotomy. CONCLUSIONS: While primary intracranial EHE is an uncommon presentation of a rare tumor, the suprasellar region does not seem to be an unusual location when it does occur. Prognosis is generally good, and may be better for primary intracranial disease than that for EHE originating elsewhere. Surgery is the first line of therapy, with variable benefit from adjuvant chemotherapy or radiation when total resection is not possible. Chemotherapeutic approaches in current use are directed at preventing endothelial proliferation.

Background. Extraosseous Ewing's sarcoma in the spinal epidural space is a rare malignancy, especially in adults. Case Presentation. A 40-year-old male presented with back pain and urinary hesitancy. MRI revealed a thoracic extradural mass with no osseous involvement. He underwent surgery for gross total resection of the mass, which was diagnosed as Ewing's sarcoma. He was subsequently treated with chemoradiotherapy. He remains disease-free 1 year after surgery. Review of the literature indicated only 45 previously reported cases of spinal epidural extraosseous Ewing's sarcoma in adults. Conclusions. Extraosseous Ewing's sarcoma in the spinal epidural space is a rare clinical entity that should be included in the differential for spinal epidural masses. Its treatment is multidisciplinary but frequently requires surgical intervention due to compressive neurologic symptoms. Gross total resection appears to correlate with improved outcomes.

Computed tomography (CT) and magnetic resonance (MR) imaging have been widely used for visualizing the inside of the human body. However, in many cases, pathological diagnosis is conducted through a biopsy or resection of an organ to evaluate the condition of tissues as definitive diagnosis. To provide more advanced information onto CT or MR image, it is necessary to reveal the relationship between tissue information and image signals. We propose a registration scheme for a set of PT images of divided specimens and a 3D-MR image by reference to an optical macro image (OM image) captured by an optical camera. We conducted a fundamental study using a resected human brain after the death of a brain cancer patient. We constructed two kinds of registration processes using the OM image as the base for both registrations to make conversion parameters between the PT and MR images. The aligned PT images had shapes similar to the OM image. On the other hand, the extracted cross-sectional MR image was similar to the OM image. From these resultant conversion parameters, the corresponding region on the PT image could be searched and displayed when an arbitrary pixel on the MR image was selected. The relationship between the PT and MR images of the whole brain can be analyzed using the proposed method. We confirmed that same regions between the PT and MR images could be searched and displayed using resultant information obtained by the proposed method. In terms of the accuracy of proposed method, the TREs were 0.56+/-0.39mm and 0.87+/-0.42mm. We can analyze the relationship between tissue information and MR signals using the proposed method.

Inhibition of the vascular endothelial growth factor (VEGF) pathway has failed to improve overall survival of patients with glioblastoma (GBM). We previously showed that angiopoietin-2 (Ang-2) overexpression compromised the benefit from anti-VEGF therapy in a preclinical GBM model. Here we investigated whether dual Ang-2/VEGF inhibition could overcome resistance to anti-VEGF treatment. We treated mice bearing orthotopic syngeneic (Gl261) GBMs or human (MGG8) GBM xenografts with antibodies inhibiting VEGF (B20), or Ang-2/VEGF (CrossMab, A2V). We examined the effects of treatment on the tumor vasculature, immune cell populations, tumor growth, and survival in both the Gl261 and MGG8 tumor models. We found that in the Gl261 model, which displays a highly abnormal tumor vasculature, A2V decreased vessel density, delayed tumor growth, and prolonged survival compared with B20. In the MGG8 model, which displays a low degree of vessel abnormality, A2V induced no significant changes in the tumor vasculature but still prolonged survival. In both the Gl261 and MGG8 models A2V reprogrammed protumor M2 macrophages toward the antitumor M1 phenotype. Our findings indicate that A2V may prolong survival in mice with GBM by reprogramming the tumor immune microenvironment and delaying tumor growth.

Glioblastomas (GBMs) rapidly become refractory to anti-VEGF therapies. We previously demonstrated that ectopic overexpression of angiopoietin-2 (Ang-2) compromises the benefits of anti-VEGF receptor (VEGFR) treatment in murine GBM models and that circulating Ang-2 levels in GBM patients rebound after an initial decrease following cediranib (a pan-VEGFR tyrosine kinase inhibitor) administration. Here we tested whether dual inhibition of VEGFR/Ang-2 could improve survival in two orthotopic models of GBM, Gl261 and U87. Dual therapy using cediranib and MEDI3617 (an anti-Ang-2-neutralizing antibody) improved survival over each therapy alone by delaying Gl261 growth and increasing U87 necrosis, effectively reducing viable tumor burden. Consistent with their vascular-modulating function, the dual therapies enhanced morphological normalization of vessels. Dual therapy also led to changes in tumor-associated macrophages (TAMs). Inhibition of TAM recruitment using an anti-colony-stimulating factor-1 antibody compromised the survival benefit of dual therapy. Thus, dual inhibition of VEGFR/Ang-2 prolongs survival in preclinical GBM models by reducing tumor burden, improving normalization, and altering TAMs. This approach may represent a potential therapeutic strategy to overcome the limitations of anti-VEGFR monotherapy in GBM patients by integrating the complementary effects of anti-Ang2 treatment on vessels and immune cells.