Berberine as a potential enhancer for 5-ALA-mediated fluorescence in glioblastoma: increasing detectability of infiltrating glioma stem cells to optimize 5-ALA-guided surgery

OBJECTIVE

The prognosis of glioblastoma (GBM) correlates with residual tumor volume after surgery. In fluorescence-guided surgery, 5-aminolevulinic acid (ALA) has been used to maximize resection while avoiding neurological morbidity. However, not all tumor cells, particularly glioma stem cells (GSCs), display 5-ALA-mediated protoporphyrin IX (PpIX) fluorescence (5-ALA fluorescence). The authors searched for repositioned drugs that affect mitochondrial functions and energy metabolism, identifying berberine (BBR) as a potential enhancer of 5-ALA fluorescence. In this study, they investigated whether BBR can enhance 5-ALA fluorescence in GSCs and whether BBR can be applied to clinical practice as a 5-ALA fluorescence enhancer.

METHODS

The effects of BBR on 5-ALA fluorescence in glioma and GSCs were evaluated by flow cytometry (fluorescence-activated cell sorting [FACS]) analysis. As 5-ALA is metabolized for heme synthesis, the effects of BBR on mRNA expressions of 7 enzymes in the heme-synthesis pathway were analyzed. Enzymes showing significantly higher expression than control in all cells were identified and protein analysis was performed. To examine clinical availability, the detectability and cytotoxicity of BBR in tumor-transplanted mice were analyzed.

RESULTS

Fluorescence microscopy revealed much more intense 5-ALA fluorescence in both GSCs and non-stem cells with 5-ALA and BBR than with 5-ALA alone. FACS showed that BBR greatly enhanced 5-ALA fluorescence compared with 5-ALA alone, and enhancement was much higher for GSCs than for glioma cells. Among the 7 enzymes examined, BBR upregulated mRNA expressions of ALA synthetase 1 (ALAS1) more highly in all cells, and activated ALAS1 through deregulating ALAS1 activity inhibited by the negative feedback of heme. An in vivo study showed that 5-ALA fluorescence with 5-ALA and BBR was significantly stronger than with 5-ALA alone, and the sensitivity and specificity of BBR-enhanced fluorescence were both 100%. In addition, BBR did not show any cytotoxicity for normal brain tissue surrounding the tumor mass.

CONCLUSIONS

BBR enhanced 5-ALA-mediated PpIX fluorescence by upregulating and activating ALAS1 through deregulation of negative feedback inhibition by heme. BBR is a clinically used drug with no side effects. BBR is expected to significantly augment fluorescence-guided surgery and photodynamic therapy.

Identification of CD44 as a Reliable Biomarker for Glioblastoma Invasion: Based on Magnetic Resonance Imaging and Spectroscopic Analysis of 5-Aminolevulinic Acid Fluorescence

Recurrent glioblastoma multiforme (GBM) is largely attributed to peritumoral infiltration of tumor cells. As higher CD44 expression in the tumor periphery correlates with higher risk of GBM invasion, the present study analyzed the relationship between CD44 expression and magnetic resonance imaging (MRI)-based invasiveness of GBM on a large scale. We also quantitatively evaluated GBM invasion using 5-aminolevulinic acid (5-ALA) spectroscopy to investigate the relationship between CD44 expression and tumor invasiveness as evaluated by intraoperative 5-ALA intensity. Based on MRI, GBM was classified as high-invasive type in 28 patients and low-invasive type in 22 patients. High-invasive type expressed CD44 at a significantly higher level than low-invasive type and was associated with worse survival. To quantitatively analyze GBM invasiveness, the relationship between tumor density in the peritumoral area and the spectroscopic intensity of 5-ALA was investigated. Spectroscopy showed that the 5-ALA intensity of infiltrating tumor cells correlated with tumor density as represented by the Ki-67 staining index. No significant correlation between CD44 and degree of 5-ALA-based invasiveness of GBM was found, but invasiveness of GBM as evaluated by 5-ALA matched the classification from MRI in all except one case, indicating that CD44 expression at the GBM periphery could provide a reliable biomarker for invasiveness in GBM.

What is the Best Preoperative Quantitative Indicator to Differentiate Primary Central Nervous System Lymphoma from Glioblastoma?

BACKGROUND

The role of surgery in primary central nervous system lymphoma (PCNSL) is to allow pathological diagnosis from tumor biopsy. However, PCNSL is often difficult to distinguish from other tumors, particularly glioblastoma multiforme (GBM). Quantitative evaluations to facilitate differentiation between PCNSL and GBM would be useful. Here, we investigated the best examinations for exact differentiation of PCNSL from GBM among preoperative examinations, including imaging studies and tumor markers.

METHODS

Various examinations were performed for 68 patients with PCNSL , including serum soluble interleukin 2 receptor, β2-microglobulin (MG) in cerebrospinal fluid (CSF), diffusion-weighted imaging, ¹¹C-methionine-positron emission tomography (PET), and ¹⁸F-fluorodeoxyglucose (FDG)-PET. These results were compared with findings from 28 patients with consecutive GBM who underwent the same examinations to evaluate the utility and accuracy of different investigations.

RESULTS

CSF β2-MG ≥2.0 mg/L was relatively specific for PCNSL, offering 95.0% sensitivity and 85.7% specificity. Tumor-to-contralateral normal brain tissue ratio ≥2.4 on ¹⁸F-FDG-PET was also quite specific for PCNSL, offering 83.8% sensitivity and 95.2% specificity. No other examinations displayed any significant differences in quantitative differential markers between PCNSL and GBM.

CONCLUSIONS

Both β2-MG ≥2.0 mg/dL in CSF and tumor-to-contralateral normal brain tissue ratio ≥2.4 from ¹⁸F-FDG-PET allow quantitative differentiation of PCNSL from GBM, potentially representing clinically useful indicators. These findings could lead to innovative methods for differentiating PCNSL from GBM as well as new treatment strategies for other brain tumors.

Quantitative measurement of peritumoral concentrations of glutamate, N-acetyl aspartate, and lactate on magnetic resonance spectroscopy predicts glioblastoma-related refractory epilepsy

BACKGROUND

Increased extracellular glutamate is known to cause epileptic seizures in patients with glioblastoma (GBM). However, predicting whether the seizure will be refractory is difficult. The present study investigated whether evaluation of the levels of various metabolites, including glutamate, can predict the occurrence of refractory seizure in GBM by quantitative measurement of metabolite concentrations on magnetic resonance spectroscopy (MRS).

METHODS

Forty patients were treated according to the same treatment protocol for primary GBM at Ehime University Hospital between April 2017 and July 2021. Of these patients, 23 underwent MRS to determine concentrations of metabolites, including glutamate, N-acetylaspartate, creatine, and lactate, in the tumor periphery by applying LC-Model. The concentration of each metabolite was expressed as a ratio to creatine concentration. Patients were divided into three groups: Type A, patients with no seizures; Type B, patients with seizures that disappeared after treatment; and Type C, patients with seizures that remained unrelieved or appeared after treatment (refractory seizures). Relationships between concentrations of metabolites and seizure types were investigated.

RESULTS

In 23 GBMs, seizures were confirmed in 11 patients, including Type B in four and Type C in seven. Patients with epilepsy (Type B or C) showed significantly higher glutamate and N-acetylaspartate values than did non-epilepsy patients (Type A) (p < 0.05). No significant differences in glutamate or N-acetylaspartate levels were seen between Types B and C. Conversely, Type C showed significantly higher concentrations of lactate than did Type B (p = 0.001). Cutoff values of lactate-to-creatine, glutamate-to-creatine, and N-acetylaspartate-to-creatine ratios for refractory seizure were > 1.25, > 1.09, and > 0.88, respectively.

CONCLUSIONS

Extracellular concentrations of glutamate, N-acetylaspartate, and lactate in the tumor periphery were significantly elevated in patients with GBM with refractory seizures. Measurement of these metabolites on MRS may predict refractory epilepsy in such patients and could be an indicator for continuing the use of antiepileptic drugs.

Usefulness of intraoperative rapid immunohistochemistry in the surgical treatment of brain tumors

In the treatment of primary central nervous system lymphoma (PCNSL), intraoperative rapid pathological diagnosis can dramatically change the surgical strategy, and more accurate diagnostic methods are required. In April 2020, we adopted intraoperative rapid immunohistochemistry (IHC) in addition to conventional rapid intraoperative diagnosis based on morphological assessment, mainly for patients with PCNSL. Here, we investigate the usefulness and significance of intraoperative rapid IHC based on our initial experience. We performed intraoperative rapid IHC using antibodies for cluster of differentiation (CD)20, CD3, leukocyte common antigen (LCA) and glial fibrillary acidic protein (GFAP) using enzyme-labeled antibody methods in 25 patients, including PCNSL patients, from April 2020 to July 2022. We examined the utility of this approach in determining treatment strategies for brain tumors. Postoperative final pathological diagnoses from paraffin-embedded sections were as follows: diffuse large B-cell lymphoma, 16 cases; glioblastoma, six cases; pilocytic astrocytoma, one case; adenocarcinoma, one case; and inflammatory disorder, one case. The entire process took 32 min and staining for CD20, CD3, LCA, and GFAP was comparable to that using paraffin-embedded sections. In all cases, the results of intraoperative rapid IHC were consistent with final pathological diagnoses from paraffin-embedded sections. In addition, in two cases, the results of conventional intraoperative rapid pathological diagnosis based on morphological assessments using frozen sections were drastically changed by adding intraoperative rapid IHC. Intraoperative rapid IHC contributes to deciding appropriate treatment strategies and facilitating early initiation of chemotherapy for PCNSL. This may allow new therapeutic strategies not only for PCNSL but also for other brain tumors.

Clinical utility of new bone imaging using zero-echo-time sequence in neurosurgical procedures: Can zero-echo-time be used in clinical practice in neurosurgery?

Purpose

The purpose of this study was to evaluate the clinical usefulness of zero-echo-time (ZTE)–based magnetic resonance imaging (MRI) in planning the optimum surgical approach and applying ZTE for anatomical guidance during transcranial surgery.

Methods

Eleven of 26 patients who underwent transcranial surgery and carotid endarterectomy and in whom ZTE-based MRI and magnetic resonance angiography (MRA) data were obtained were analyzed by creating ZTE/MRA fusion images and 3D ZTE-based MRI models. We examined whether these images and models can be substituted for computed tomography imaging for neurosurgical procedures. Furthermore, the clinical usability of the 3D ZTE-based MRI models was evaluated by comparing them with actual surgical views.

Results

Zero-echo-time/MRA fusion images and 3D ZTE-based MRI models clearly illustrated the cranial and intracranial morphology without radiation exposure or the use of iodinated contrast medium. The models allowed determination of the optimum surgical approach to cerebral aneurysms, brain tumors near the brain surface, and cervical internal carotid artery stenosis by visualizing the relationship of lesions with adjacent bone structures. However, ZTE-based MRI did not provide useful information for surgery for skull base lesions such as vestibular schwannoma because bone structures of the skull base often include air components, which cause signal disturbance in MRI.

Conclusions

Zero-echo-time sequences on MRI allowed distinct visualization of not only bone but also vital structures around the lesion. This technology has low invasiveness for patients and was useful for preoperative planning and guidance of the optimum approach during surgery in a subset of neurosurgical diseases.

A case of radical resection for brain metastases of pancreatic cancer after curative chemotherapy for para-aortic lymph node metastases

Background

The incidence of brain metastasis of pancreatic cancer has been reported to be approximately 0.3%. The blood–brain barrier of the central nervous system restricts the transfer of substances, including chemotherapeutic agents, from the bloodstream. It is hypothesized that brain metastasis may occur despite successful chemotherapy for the primary tumor. Herein, we report a case of brain metastases of pancreatic cancer that occurred after chemotherapy and discuss relevant literature.

Case presentation

A 64-year-old man underwent distal pancreatectomy with D2 lymph node dissection for resectable pancreatic tail cancer. Invasive ductal carcinoma of pancreas, pT3N2M0 pStageIII (TNM Classification of Malignant Tumors, UICC 8th edition) was diagnosed. S-1 adjuvant chemotherapy was initiated. Three months postoperatively, CA19-9 had increased to 619 U/mL. Additionally, contrast-enhanced computed tomography (CT) and fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT revealed local recurrence in the para-aortic lymph nodes. Chemotherapy was revised to a combined regimen of gemcitabine and nab-paclitaxel. After 4 cycles, tumor markers were normalized. After 5 cycles, recurrence could not be identified on contrast-enhanced CT; therefore, the patient was adjudged to be in complete remission. However, after 29 cycles of chemotherapy, the patient had symptoms of raised intracranial pressure. Magnetic resonance imaging showed two metastatic lesions of 20 mm and 32 mm in the left frontal lobe and cerebellum, respectively. Quasi-emergency resection of the metastatic brain tumors was performed. Pathological examination revealed that the resected specimens originated from primary pancreatic cancer. The patient was discharged on postoperative day 12, without any complications. Postoperatively, a total of 53 Gy of local brain radiation therapy was added. On postoperative day 30, blood carcinoembryonic antigen level had decreased to 5.4 ng/dl and all other tumor markers were negative. Additionally, tumor markers of the cerebrospinal fluid were markedly reduced and the cytology was negative for tumor cells. These results suggested complete resection of the metastatic brain tumors.

Conclusions

Aggressive resection and salvage stereotactic radiotherapy for metastatic brain tumors may lead to complete cure and a good long-term prognosis.

COT-3 Exosomal microRNA expression signature in blood and cerebrospinal fluid of glioblastoma patients

Analysis of exosomes derived from plasma or cerebrospinal fluid (CSF) has emerged as a promising biomarker platform for therapeutic monitoring in glioblastoma patients. However, the contents of the various subpopulations of exosomes in these clinical specimens remain poorly defined. Here we characterize the relative abundance of miRNA species in exosomes derived from the plasma and CSF of glioblastoma patients. To this end, we first employed miRNA arrays to measure the expression of exosomal miRNAs in the plasma from glioblastoma patients (n = 24) and healthy volunteers (n = 7) as control. In addition, we performed global miRNA profiling of exosomal miRNAs in the CSF from glioblastoma patients (n = 5) and non-tumoral patients (n = 3; hydrocephalus patients) as control. In plasma derived exosomes, 80 miRNAs were altered by >2-fold in glioblastoma patients compared to controls. In CSF, 92 miRNAs were altered by >2-fold in glioblastoma patients compared to controls. Combined analysis of plasma and CSF revealed a similar fold difference in eight miRNAs. Next, we measured these eight miRNAs expression in in the plasma from pre- and post-operative glioblastoma patients (n = 9). Among these eight miRNAs, we identified only one miRNA (miR-34b-3p) that was upregulated in exosomes from pre-operative glioblastoma patients. Our results suggest that miR-34b-3p might have a potential as a novel diagnostic marker or a therapeutic tool for glioblastoma patients.

Efficacy and safety of nivolumab in Japanese patients with first recurrence of glioblastoma: an open-label, non-comparative study

BACKGROUND

An open-label, non-comparative study assessed the efficacy and safety of nivolumab in Japanese patients with first recurrence glioblastoma.

METHODS

Patients with first recurrence of histologically confirmed World Health Organization Grade IV glioma, after treatment with temozolomide and radiotherapy, received nivolumab 3 mg/kg every 2 weeks until confirmed disease progression (Response Assessment in Neuro-Oncology criteria) or toxicity. Primary endpoint was 1-year overall survival rate assessed by Bayesian approach. The prespecified efficacy criterion was that the Bayesian posterior probability threshold for exceeding the 1-year overall survival of bevacizumab (34.5%) from the Japanese phase 2 study (JO22506) would be 93%.

RESULTS

Of the 50 enrolled patients, 44 (88.0%) had recurrent malignant glioma (glioblastoma, gliosarcoma), and of these, 26 (59.1%) had at least one measurable lesion at baseline. The Bayesian posterior mean 1-year overall survival (90% Bayesian credible intervals) with nivolumab was 54.4% (42.27-66.21), and the Bayesian posterior probability of exceeding the threshold of the 1-year overall survival rate of bevacizumab (34.5%) was 99.7%. Median (90% confidence interval) overall and progression-free survival was 13.1 (10.4-17.7) and 1.5 (1.4-1.5) months, respectively. One partial response was observed (objective response rate 1/26 evaluable patients [3.8%]). Treatment-related adverse event rates were 14.0% for Grade 3-4 and 2.0% for Grade 5; most adverse events resolved and were manageable.

CONCLUSIONS

The 1-year overall survival with nivolumab monotherapy in Japanese patients with glioblastoma met the prespecified efficacy criterion. The safety profile of nivolumab was consistent with that observed in other tumor types.

CLINICAL TRIAL REGISTRATION

JapicCTI-152967.

Comparison of the Signal Intensity of Vestibular Schwannoma Between Growing and Nongrowing Tumors

OBJECTIVES/HYPOTHESIS

To determine the relationship between signal intensity on gadolinium (Gd)-enhanced magnetic resonance images and growth of vestibular schwannomas (VSs).

STUDY DESIGN

Cross-sectional study.

METHODS

In this cross-sectional study, we retrospectively reviewed the data of 31 patients with VSs who underwent magnetic resonance imaging (MRI). The mean signal intensities within the regions of interest in the tumor, pons, and temporal muscles were measured on Gd-enhanced T1-weighted MRI. Relative intensity ratios were calculated as follows: T/N pons ratio (T/Np) is the tumor signal intensity/pons signal intensity and T/N muscle ratio (T/Nm) is the tumor signal intensity/temporal muscle signal intensity. Volume measurements were used to assess the tumor size. Growth rate was determined by assessing previous imaging studies. Growing VS was defined as a tumor with a growth rate >100 mm³ /year.

RESULTS

The mean (standard deviation) T/Np and T/Nm were 1.47 (0.27) and 1.50 (0.24), respectively, in nongrowing tumors and 1.78 (0.17) and 1.90 (0.12), respectively, in growing tumors. The T/Np and T/Nm differed significantly between the two groups (T/Np, P < .001; T/Nm, P < .001). Receiver operating characteristic curve analysis showed that cutoffs of 1.56 and 1.76 for T/Np (93.33% sensitivity, 75.00% specificity) and T/Nm (100.00% sensitivity, 93.75% specificity), respectively, could be used to diagnose a growth rate of >100 mm³ /year. The area under the curve was 0.85 (95% confidence interval, 0.70-1.00) for T/Np and 0.94 (0.82-1.00) for T/Nm.

CONCLUSION

Growing VSs show higher signal intensities on Gd-enhanced MRI. Thus, measuring the signal intensity of VS on Gd-enhanced MRI may aid in predicting VS growth.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Chloride intracellular channel protein 2 is secreted and inhibits MMP14 activity, while preventing tumor cell invasion and metastasis

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CLIC2 is highly expressed in benign, less invasive and less metastatic tumors.

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Forced expression of CLIC2 prevents metastasis and invasion in animal tumor models.

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CLIC2 is associated with decreased vascular permeability in tumor masses.

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CLIC2, a secretable soluble protein, can bind to and inhibit MMP14.

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Extracellular CLIC2 can suppress malignant cell invasion.

The abilities to invade surrounding tissues and metastasize to distant organs are the most outstanding features that distinguish malignant from benign tumors. However, the mechanisms preventing the invasion and metastasis of benign tumor cells remain unclear. By using our own rat distant metastasis model, gene expression of cells in primary tumors was compared with that in metastasized tumors. Among many distinct gene expressions, we have focused on chloride intracellular channel protein 2 (CLIC2), an ion channel protein of as-yet unknown function, which was predominantly expressed in the primary tumors. We created CLIC2 overexpressing rat glioma cell line and utilized benign human meningioma cells with naturally high CLIC2 expression. CLIC2 was expressed at higher levels in benign human brain tumors than in their malignant counterparts. Moreover, its high expression was associated with prolonged survival in the rat metastasis and brain tumor models as well as with progression-free survival in patients with brain tumors. CLIC2 was also correlated with the decreased blood vessel permeability likely by increased contents of cell adhesion molecules. We found that CLIC2 was secreted extracellularly, and bound to matrix metalloproteinase (MMP) 14. Furthermore, CLIC2 prevented the localization of MMP14 in the plasma membrane, and inhibited its enzymatic activity. Indeed, overexpressing CLIC2 and recombinant CLIC2 protein effectively suppressed malignant cell invasion, whereas CLIC2 knockdown reversed these effects. Thus, CLIC2 suppress invasion and metastasis of benign tumors at least partly by inhibiting MMP14 activity.

Hypoxia-induced phenotypic transition from highly invasive to less invasive tumors in glioma stem-like cells: Significance of CD44 and osteopontin as therapeutic targets in glioblastoma

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CD44, upregulated by HIF-1α under 1%O₂, induces highly invasive phenotype GSCs.

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HIF-2α-activated OPN under 5%O₂ promotes less-invasive/proliferative type GSCs.

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CD44 and OPN knockdowns inhibit in vitro/vivo GSCs invasion and proliferation.

The poor prognosis of glioblastoma multiforme (GBM) is primarily due to highly invasive glioma stem-like cells (GSCs) in tumors. Upon GBM recurrence, GSCs with highly invasive and highly migratory activities must assume a less-motile state and proliferate to regenerate tumor mass. Elucidating the molecular mechanism underlying this transition from a highly invasive phenotype to a less-invasive, proliferative tumor could facilitate the identification of effective molecular targets for treating GBM. Here, we demonstrate that severe hypoxia (1% O₂) upregulates CD44 expression via activation of hypoxia-inducible factor (HIF-1α), inducing GSCs to assume a highly invasive tumor. In contrast, moderate hypoxia (5% O₂) upregulates osteopontin expression via activation of HIF-2α. The upregulated osteopontin inhibits CD44-promoted GSC migration and invasion and stimulates GSC proliferation, inducing GSCs to assume a less-invasive, highly proliferative tumor. These data indicate that the GSC phenotype is determined by interaction between CD44 and osteopontin. The expression of both CD44 and osteopontin is regulated by differential hypoxia levels. We found that CD44 knockdown significantly inhibited GSC migration and invasion both in vitro and in vivo. Mouse brain tumors generated from CD44-knockdown GSCs exhibited diminished invasiveness, and the mice survived significantly longer than control mice. In contrast, siRNA-mediated silencing of the osteopontin gene decreased GSC proliferation. These results suggest that interaction between CD44 and osteopontin plays a key role in tumor progression in GBM; inhibition of both CD44 and osteopontin may represent an effective therapeutic approach for suppressing tumor progression, thus resulting in a better prognosis for patients with GBM.

CD44 expression in the tumor periphery predicts the responsiveness to bevacizumab in the treatment of recurrent glioblastoma

Antiangiogenic therapy with bevacizumab (Bev), a monoclonal antibody targeting vascular endothelial growth factor (VEGF), is a common treatment for recurrent glioblastoma (GBM), but its survival benefit is limited. Resistance to Bev is thought to be a major cause of ineffectiveness on Bev therapy. To optimize Bev therapy, identification of a predictive biomarker for responsiveness to Bev is required. Based on our previous study, we focused on the expression and functions of CD44 and VEGF in the Bev therapy. Here, we analyze a relationship between CD44 expression and responsiveness to Bev and elucidate the role of CD44 in anti‐VEGF therapy. CD44 and VEGF expression in the tumor core and periphery of 22 GBMs was examined, and the relationship between expression of these molecules and progression‐free time on Bev therapy was analyzed. The degree of CD44 expression in the tumor periphery was evaluated by the ratio of the mRNA expression in the tumor periphery to that in the tumor core (P/C ratio). VEGF expression was evaluated by the amount of the mRNA expression in the tumor periphery. To elucidate the roles of CD44 in the Bev therapy, in vitro and in vivo studies were performed using glioma stem‐like cells (GSCs) and a GSC‐transplanted mouse xenograft model, respectively. GBMs expressing high P/C ratio of CD44 were much more refractory to Bev than those expressing low P/C ratio of CD44, and the survival time of the former was much shorter than that of the latter. In vitro inhibition of VEGF with siRNA or Bev‐activated CD44 expression and increased invasion of GSCs. Bev showed no antitumor effects in mice transplanted with CD44‐overexpressing GSCs. The P/C ratio of CD44 expression may become a useful biomarker predicting responsiveness to Bev in GBM. CD44 reduces the antitumor effect of Bev, resulting in much more highly invasive tumors.

CBMS-01 Mechanism of brain tumor malignancy caused by aging and social isolation

The rise in population aging worldwide is causing an unparalleled increase in death from many cancers, including glioblastoma (GBM). In advanced countries, the number of elderly people living alone is increasing due to the rapid aging of the population and the socialization of nuclear families. Here, we explored the impact of aging and social isolation on GBM tumorigenesis. In normal brain tissue, aging promoted pathways related to cytokines and inflammation, which were further promoted by social isolation. In tumor tissues, the expression of neuron/synapse-related genes was significantly reduced in aged mice, and their expression was further reduced by social isolation. In addition, the survival period of aged mice was significantly shorter than that of young mice, and the survival period was further shortened by social isolation, which was characteristic of males. This phenomenon was the same in humans, and the survival period in the young group was significantly longer than that in the elderly group, and in the elderly group, the survival period was shortened in the male elderly group living alone. Our data indicate that social isolation contributes to the highly aggressive GBM by the shift to neuro-inflammation in the elderly brain.

QOLP-07. HEALTH-RELATED QUALITY OF LIFE AND SYMPTOM BURDEN IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA TREATED WITH BEVACIZUMAB BEYOND PROGRESSION: A PROSPECTIVE TRIAL

BACKGROUND

In BIOMARK trial, patients with newly diagnosed glioblastoma were treated with standard chemoradiotherapy combined with first-line bevacizumab; a subset of patients continued bevacizumab beyond progression (BBP). Neurocognitive function (NCF), symptom burden, and health-related quality of life (HRQoL) were examined as secondary endpoints.

PATIENTS AND METHODS

In the primary protocol, newly diagnosed glioblastoma patients aged 20-75 received standard 6-week radiotherapy combined with temozolomide and bevacizumab followed by 4-week cycles of temozolomide plus bevacizumab, and then 2-3-week cycles of bevacizumab monotherapy. Upon recurrence, patients were subjected to the secondary protocol with 2-3-week cycles of bevacizumab monotherapy with or without other chemotherapeutic agents. NCF tests (Hopkins verbal learning test-revised, trail making test, and controlled oral word association), EORTC QLQ-C30/BN20, and MDASI-BT were completed by the patients. Time to deterioration (TTD) was defined as the time from randomization until a pre-specified change from baseline without further improvement or death. The Kaplan-Meier method and the log-rank test were used to assess TTD for each subscale of the above tests.

RESULTS

Overall, 94 patients were enrolled in the study. Analyses were based on the full analysis set cohort (N=90), excluding non-glioblastoma diagnosis by central review. The median overall survival (OS) and progression-free survival (PFS) were 25.0 and 14.9 months, respectively. Baseline HRQoL and symptom burden subscales (emotional functioning, symptom severity score, affective factor, and focal factor) were significantly associated with PFS. The median TTD was 8.7, 7.5, 8.1 months for global health status/QoL, symptom severity score, interference score, respectively. Among patients who experienced recurrence, disease progression was apparently preceded by deterioration in terms of symptom burden.

CONCLUSIONS

Detailed analysis of HRQoL and symptom burden may aid care of glioblastoma patients throughout the disease trajectory.

TAMI-39. AGE-DEPENDENT PHENOTYPIC CONVERSION FROM NEURONAL ACTIVITY TO NEURO-INFLAMMATION IN GLIOBLASTOMA PROGRESSION

The rise in population aging worldwide is causing an unparalleled increase in death from many cancers, including glioblastoma (GBM). Here, we have explored the impact of aging and rejuvenation on GBM tumorigenesis. Compared with neuro-inflammatory old GBM, young GBM displayed elevated neuronal/synaptic signaling via brain-derived neurotrophic factor (BDNF) and SLIT and NTRK like-family member 6 (SLITRK6), promoting favorable survival rates. These effects were attributed to the rise in nicotinamide adenine dinucleotide (NAD+) levels, as brain rejuvenation by parabiosis or administration of nicotinamide mononucleotide (NMN) in mice elicited a younger phenotype with activated neuronal/synaptic signaling and improved outcomes. Our data indicate that age-associated NAD+ loss contributes to the highly aggressive GBM by the shift from neuronal/synaptic activity to neuro-inflammation in the elderly brain. These findings have therapeutic and preventive implications in GBM and provide mechanistic insights into the exacerbation of GBM tumorigenesis by aging.

Endoscopic transpapillary gallbladder drainage for acute cholecystitis is feasible for patients receiving antithrombotic therapy

OBJECTIVES

Patients with acute cholecystitis receiving antithrombotic therapy (ATT) have an increased risk of bleeding complications during surgery and percutaneous drainage. Endoscopic transpapillary gallbladder drainage (ETGBD) is recommended for such cases; however, evidence is limited. To investigate this issue further, we performed a retrospective multicenter study.

METHODS

One hundred thirty patients with acute cholecystitis who underwent ETGBD were enrolled. They were divided into an ATT group (continuation of ATT on the day of the procedure and/or heparin substitution) and a Non-ATT group (discontinuation or no use of ATT). The primary outcome was bleeding complication rate, and the secondary outcomes were technical success rate, clinical success rate and total complication rate.

RESULTS

Eighty-three patients were enrolled in the ATT group, and 47 were enrolled in the Non-ATT group. In the ATT group, 42.2% continued multi-agent ATT. No bleeding complications occurred in either group. There were no significant differences between the ATT and Non-ATT groups in the technical success rate (84.3% vs 89.4%, P = 0.426 respectively) or the clinical success rate (97.1% vs 100%, P = 0.259, respectively). The overall early complication rate was 3.1% (4/130): mild pancreatitis (n = 3) and cholangitis (n = 1). Stent dysfunction was found in 10.9% of patients (at 196 days on average), and the 12-month stent patency rate was 69.0%.

CONCLUSIONS

No significant difference was found in the bleeding complication rate between ETGBD with and without ATT. ETGBD may be an ideal drainage method for patients with acute cholecystitis receiving ATT.

Tricks and traps of ICG endoscopy for effectively applying endoscopic transsphenoidal surgery to pituitary adenoma

Differentiating tumor from normal pituitary gland is very important for achieving complete resection without complications in endoscopic endonasal transsphenoidal surgery (ETSS) for pituitary adenoma. To facilitate such surgery, we investigated the utility of indocyanine green (ICG) fluorescence endoscopy as a tool in ETSS. Twenty-four patients with pituitary adenoma were enrolled in the study and underwent ETSS using ICG endoscopy. After administering 12.5 mg of ICG twice an operation with an interval > 30 min, times from ICG administration to appearance of fluorescence on vital structures besides the tumor were measured. ICG endoscopy identified vital structures by the phasic appearance of fluorescent signals emitted at specific consecutive elapsed times. Elapsed times for internal carotid arteries did not differ according to tumor size. Conversely, as tumor size increased, elapsed times for normal pituitary gland were prolonged but those for the tumor were reduced. ICG endoscopy revealed a clear boundary between tumors and normal pituitary gland and enabled confirmation of no more tumor. ICG endoscopy could provide a useful tool for differentiating tumor from normal pituitary gland by evaluating elapsed times to fluorescence in each structure. This method enabled identification of the boundary between tumor and normal pituitary gland under conditions of a low-fluorescence background, resulting in complete tumor resection with ETSS. ICG endoscopy will contribute to improve the resection rate while preserving endocrinological functions in ETSS for pituitary adenoma.

Intracranial anaplastic solitary fibrous tumor/hemangiopericytoma: immunohistochemical markers for definitive diagnosis

Intracranial anaplastic hemangiopericytoma (AHPC) is a rare and malignant subset of solitary fibrous tumor/hemangiopericytoma (SFT/HPC) as per the WHO 2016 Classification of Tumors of the Central Nervous System. AHPC portends a poor prognosis and is associated with higher rates of recurrence/metastasis in comparison with SFT/HPC. Accordingly, it is critical to continue to define the clinical course of patients with AHPC and in so doing further refine clinicopathologic/immunohistochemical (IHC) criteria needed for definitive diagnosis. Herein, we describe clinical/histological characteristics of six patients with AHPC. In addition, we reviewed and analyzed the expression of various IHC markers reported within the literature (i.e., a total of 354 intracranial SFT/HPCs and 460 meningiomas). Histologically, tumors from our six patients were characterized by a staghorn-like vascular pattern, mitotic cells, and strong nuclear atypia. Immunohistochemically, all tumors displayed positive nuclear staining for STAT6; other markers, including CD34 and Bcl-2, were expressed only in three patients. Analysis of IHC expression patterns for SFT/HPC and meningioma within the literature revealed that nuclear expression of STAT6 had the highest specificity (100%) for SFT/HPC, followed by ALDH1 (97.2%) and CD34 (93.6%). Of note, SSTR2A (95.2%) and EMA (85%) displayed a high specificity for meningioma. Anaplastic SFT/HPC is a tumor with poor prognosis that is associated with higher rates of recurrence and metastasis in comparison with SFT/HPC. Given that anaplastic SFT/HPC requires more aggressive treatment than meningioma despite of a similar presentation on imaging, it is crucial to be able to distinguish between these tumors.

Clinical features and endoscopic findings of granular cell tumor of the sellar region: A case report and review of the literature

Background:

Granular cell tumor (GCT) of the sellar region is a rare tumor of the sellar and suprasellar regions that originate from the neurohypophysis. This tumor is very difficult to differentiate from other pituitary neoplasms, such as pituitary adenoma, pituicytoma, and spindle cell oncocytoma. We report a rare case of GCT arising from the posterior pituitary of the sellar region and suggest a useful indicator for accurate diagnosis and pitfalls for surgical procedures.

Case Description:

A 42-year-old woman was admitted to our hospital with bitemporal hemianopsia. Neuroimaging showed a large pituitary tumor in the sellar and suprasellar regions with a hypointense part on T2-weighted magnetic resonance imaging, and the enhanced anterior pituitary gland was displaced anteriorly. Laboratory findings showed mild hyperprolactinemia. Subtotal resection of the tumor was achieved using an endoscopic endonasal transsphenoidal approach. Histological findings showed round or polygonal cells with abundant granular eosinophilic cytoplasm staining strongly for thyroid transcription factor 1. The tumor was, therefore, diagnosed as a GCT of the sellar region, belonging to tumors of the posterior pituitary. After surgery, visual impairment and anterior pituitary function were improved. Follow-up neuroimaging after 1 year showed no signs of recurrence.

Conclusion:

GCT of the sellar region is difficult to diagnose on routine neuroimaging. Therefore, accurate diagnosis requires careful identification of clinical signs, magnetic resonance imaging including hypointensity on T2-weighted imaging, and analysis of combined morphological and immunohistochemical studies.

Met-PET uptake index for total tumor resection: identification of 11C-methionine uptake index as a goal for total tumor resection including infiltrating tumor cells in glioblastoma

Glioblastoma multiforme (GBM) is largely due to glioma stem cells (GSCs) that escape from total resection of gadolinium (Gd)-enhanced tumor on MRI. The aim of this study is to identify the imaging requirements for maximum resection of GBM with infiltrating GSCs. We investigated the relationship of tumor imaging volume between MRI and ¹¹C-methionine (Met)-PET and also the relationship between Met uptake index and tumor activity. In ten patients, tumor-to-contralateral normal brain tissue ratio (TNR) was calculated to evaluate metabolic activity of Met uptake areas which were divided into five subareas by the degrees of TNR. In each GBM, tumor tissue was obtained from subareas showing the positive Met uptake. Immunohistochemistry was performed to examine the tumor proliferative activity and existence of GSCs. In all patients, the volume of Met uptake area at TNR ≦ 1.4 was larger than that of the Gd-enhanced area. The Met uptake area at TNR 1.4 beyond the Gd-enhanced tumor was much wider in high invasiveness-type GBMs than in those of low invasiveness type, and survival was much shorter in the former than the latter types. Immunohistochemistry revealed the existence of GSCs in the area showing Met uptake at TNR 1.4 and no Gd enhancement. Areas at TNR > 1.4 included active tumor cells with relatively high Ki-67 labeling index. In addition, it was demonstrated that GSCs could exist beyond the border of Gd-enhanced tumor. Therefore, to obtain maximum resection of GBMs, including infiltrating GSCs, aggressive surgical excision that includes the Met-positive area at TNR 1.4 should be considered.

Epithelioid glioblastoma presenting as multicentric glioma: A case report and review of the literature

Background:

Epithelioid glioblastoma is a rare aggressive variant of glioblastoma multiforme (GBM), which was formally recognized by the World Health Organization classification of the central nervous system in 2016. Clinically, epithelioid GBMs are characterized by aggressive features, such as metastases and cerebrospinal fluid dissemination, and an extremely poor prognosis. A rare case of epithelioid GBM that was discovered as a multicentric glioma with different histopathology is reported.

Case Description:

A 78-year-old man was admitted to our hospital with mild motor weakness of the right leg. Neuroimaging showed small masses in the left frontal and parietal lobes on magnetic resonance imaging. The abnormal lesion had been increasing rapidly for 3 weeks, and a new lesion appeared in the frontal lobe. 11C-methionine positron emission tomography (PET) showed abnormal uptake corresponding to the lesion. To reach a definitive diagnosis, surgical excision of the right frontal mass lesion was performed. Histological findings showed diffuse astrocytoma. Only radiotherapy was planned, but the left frontal and parietal tumors progressed further within a short period. Therefore, it was thought that these tumors were GBM, and a biopsy of the left parietal tumor was performed. The histological diagnosis was epithelioid GBM. Immunohistochemistry showed that most tumor cells were negatively stained for p53 and isocitrate dehydrogenase 1. BRAF V600E mutations were not identified, but TERT promoter mutations were identified. Immediately after surgery, the patient was given chemotherapy using temozolomide, extended local radiotherapy and then bevacizumab. After 6 months, he showed no signs of recurrence.

Conclusion:

Epithelioid GBM is one of the rarest morphologic subtypes of GBM and has a strongly infiltrative and aggressive nature. Therefore, careful identification of preoperative imaging studies and detailed evaluation of genetic studies are necessary to select the appropriate treatment for epithelioid GBM.

ML-04 PROGNOSTIC SIGNIFICANCE OF IMMUNOHISTOCHEMICAL SUBTYPES BASED ON THE STAGE OF B-CELL DIFFERENTIATION IN PRIMARY CNS LYMPHOMA

PURPOSE

Primary central nervous system lymphoma (PCNSL) has been immunohistochemically classified into two subtypes, germinal center (GC) B-cell and non-GC B-cell, but prognostic impact of these subtypes remains debated. We investigated clinical features and prognostic significance of newly defined immunohistochemical subtypes that were identified by expression patterns of three B-cell differentiation markers in PCNSL. In addition, we analyzed a factor related to responsiveness to high-dose methotrexate (HD-MTX) chemotherapy.

METHODS

Tumors from 32 PCNSL patients were immunohistochemically evaluated regarding expression of CD10, BCL-6, and MUM-1 and classified into subtypes according to the expression patterns of these markers. Clinical features and prognostic outcome of these subtypes were investigated.

RESULTS

Twenty-three patients were treated with HD-MTX-based chemotherapy followed by whole-brain radiation therapy (WBRT), and nine were treated with WBRT alone. Three immunohistochemical subtypes were identified, including A-type expressing CD10, BCL-6, and MUM-1 (12 patients), B-type expressing BCL-6 and MUM-1 (12 patients) and C-type expressing MUM-1 only (8 patients). Response rate in the HD-MTX therapy group was 57.1% (4/7) in A-type, 87.5% (7/8) in B-type, and 75% (6/8) in C-type. C-type with the lowest metabolic activity showed significantly longer overall survival than A-type with the higher uptake of methionine (71.6 versus 39.6 months).

CONCLUSIONS

Immunohistochemical identification of PCNSL based on the B-cell differentiation stage revealed three types of tumors, showing different metabolic activity and survival time. Refined immunohistochemical classification of PCNSL subtypes may become a useful tool for predicting more accurate prognosis and accessing the sensitivity to HD-MTX therapy.

BOT-04 POSSIBLE INVOLVEMENT OF CHLORIDE INTRACELLULAR CHANNEL PROTEIN 2 (CLIC2) IN THE SUPPRESSION OF INVASIVE ACTIVITY OF BRAIN TUMORS

Chloride intracellular channel protein 2 (CLIC2) belongs to the CLIC family of conserved metazoan proteins. However, CLIC2 is the least studied among its family members, and its function remains to be elucidated. Recently, we have shown that CLIC2 is correlated with the development and/or maintenance of tight junctions in blood vessel endothelial cells in human non-cancer tissues. CLIC2-expressing endothelial cells supposedly prevent hematogenous spread of cancer cells. In this study, we investigated CLIC2 expression in human brain tumor tissues and also addressed its function by employing human meningioma cells, rat glioma cells and rat malignant brain tumor model. Thirty-one meningioma cases, six SFT/HPC cases, twelve pituitary adenoma cases and twenty-three glioblastoma cases who underwent surgery at Ehime University Hospital were included. CLIC2 mRNA expression levels were investigated with immunoblotting and quantitative RT-PCR. Cells from the meningiomas were cultured and their CLIC2 expression was knockdown. Filter-based invasion assays and gelatin zymography were performed using the knocked-down meningioma cells. Rat C6 glioma cells stably expressing rat CLIC2 were established and transplanted into the right striatum of neonatal Wistar rats. Effects of CLIC2 on the survival periods of the animals were investigated. CLIC2 expression levels were high in the low-grade cases but low in the high-grade cases and highly invasive cases. Meningioma cells, of which CLIC2 expression was knocked-down, showed higher invasive activity than control cells. The CLIC2-knock down cells displayed increased activities of MMP-2 and MMP-9. Rat brain tumor models revealed that high expression of CLIC2 was correlated with smaller and less invasive brain tumors compared with those consisted of control cells. The rats transplanted with CLIC2-expressing cells survived longer periods than the rats with control C6 cells. These results suggest that CLIC2 plays a role in suppression of invasive activities of tumor cells.

CBMS-04 SIGNIFICANT ROLE OF HYPOXIA IN THE EXPRESSION AND FUNCTION OF OSTEOPONTIN IN CD44-HIGHLY EXPRESSED GLIOMA STEM-LIKE CELLS IN TUMOR PROGRESSION OF GLIOBLASTOMA

The poor prognosis of glioblastoma multiforme (GBM) may be due to the surviving glioma stem-like cells (GSCs) in the tumor periphery after tumor resection. We demonstrated that CD44-expressed GSCs existed much more in the tumor periphery of high invasive (HI) type GBM than low invasive (LI) type GBM. The HI type was significantly associated with worse outcome, but how GSCs with high CD44 expression relate to tumor progression remains unknown. In this study, we investigated effects of hypoxia on CD44-directed signal pathways, leading to tumor invasion and proliferation in GBM. We focused on the CD44 ligand osteopontin (OPN) because it is known hypoxia affects the interaction of CD44 and OPN which promotes stemness and proliferation of cancer stem cells. We examined mRNA expressions of hypoxia inducible factor (HIF)-1a, HIF-2a, CD44 and OPN in tumor tissues of GBM and investigated effects of hypoxia (1%O2:severe or 5%O2:moderate) on the expression of these molecules using cultured GSCs that were established from tumor tissues showing high CD44 expression in the periphery of GBMs. In addition, we analyzed the effects of OPN on invasive, migratory and proliferative activities of GSCs under the hypoxic conditions. OPN was much higher expressed in the tumor periphery of LI type GBM than HI type GBM. Severe hypoxia significantly increased the expressions of HIF-1a and CD44 but did not OPN. On the other hands, moderate hypoxia promoted the expressions of HIF-2a and OPN. Knockdown of HIF-2a significantly inhibited OPN expression. In addition, the more OPN was expressed in the cultured GSCs under moderate hypoxia, the more the GSCs proliferated and decreased their invasive and migratory activities. In conclusion, GSCs existing in the tumor periphery of GBM can migrate or proliferate by changing CD44-directed signal pathways. Moderate hypoxia promoted HIF-2a/OPN/CD44 pathway, resulting in phenotypic transition to high proliferative tumors.

CBMS-01 AGE-DEPENDENT GLIOBLASTOMA PROGRESSION SUPPRESSED BY NAD+

The rise in population aging worldwide is causing an unparalleled increase in death from many cancers, including glioblastoma (GBM). Here, we have explored the impact of aging and rejuvenation on GBM tumorigenesis. Compared with old GBM, young GBM displayed elevated neuronal/synaptic signaling via brain-derived neurotrophic factor (BDNF) and SLIT and NTRK like-family member 6 (SLITRK6), promoting favorable survival rates. These effects were attributed to the rise in nicotinamide adenine dinucleotide (NAD+) levels, as brain rejuvenation by parabiosis or administration of nicotinamide mononucleotide (NMN) in mice elicited a younger phenotype with activated neuronal/synaptic signaling and improved outcomes. Our data indicate that age-associated NAD+ loss contributes to the highly aggressive GBM in the elderly. These findings have therapeutic implications in GBM and provide mechanistic insights into the exacerbation of GBM tumorigenesis with age.

EXTH-70. ENHANCEMENT OF ANTITUMOR ACTIVITY BY USING 5-ALA–MEDIATED SONODYNAMIC THERAPY TO INDUCE APOPTOSIS AND NECROSIS IN A MOUSE GLIOMA MODEL

OBJECTIVE

High invasiveness of malignant gliomas frequently causes local tumor recurrence. To control such recurrence, novel therapies targeted toward infiltrating glioma cells are required. Here, we examined cytotoxic effects of sonodynamic therapy (SDT) combined with a sonosensitizer, 5-aminolevulinic acid (5-ALA), on malignant gliomas both in vitro and in vivo.

METHODS

In vitro cytotoxicity of 5-ALA-SDT was evaluated in U87 and U251 glioma cells and in U251Oct-3/4 glioma stemlike cells. Treatment-related apoptosis was analyzed using flow cytometry. Intracellular reactive oxygen species (ROS) were measured and the role of ROS in treatment-related cytotoxicity was examined. Effects of 5-ALA-SDT with high-intensity focused ultrasound (HIFU) on tumor growth, survival of glioma-transplanted mice, and histological features of the mouse brains were investigated.

RESULTS

The 5-ALA-SDT inhibited cell growth and changed cell morphology. Flow cytometric analysis indicated that 5-ALA-SDT induced apoptotic cell death. The 5-ALA-SDT generated higher ROS than in the control group, and inhibition of ROS generation completely eliminated the cytotoxic effects of 5-ALA-SDT. In the in vivo study, 5-ALA-SDT with HIFU greatly prolonged survival of the tumor-bearing mice compared with that of the control group (p < 0.05). Histologically, 5-ALA-SDT produced mainly necrosis of the tumor tissue in the focus area and induced apoptosis of the tumor cells in the perifocus area around the target of the HIFU-irradiated field. Normal brain tissues around the ultrasonic irradiation field of HIFU remained intact.

CONCLUSIONS

The 5-ALA-SDT was cytotoxic toward malignant gliomas. Generation of ROS by the SDT was thought to promote apoptosis of glioma cells. The 5-ALA-SDT with HIFU induced tumor necrosis in the focus area and apoptosis in the perifocus area of the HIFU-irradiated field. These results suggest that 5-ALA-SDT with HIFU may present a less invasive and tumor-specific therapy, not only for a tumor mass but also for infiltrating tumor cells in malignant gliomas.

ACTR-04. BIOMARK: A PHASE II STUDY OF BEVACIZUMAB BEYOND PROGRESSION FOR NEWLY DIAGNOSED GLIOBLASTOMA: SAFETY, EFFICACY AND PROSPECTIVE BIOMARKER ANALYSIS

BACKGROUND

Clinical benefit of continuing bevacizumab beyond progression is unknown in glioblastomas. A biomarker analysis of the AVAglio trial suggested that proneural subtype of IDH-wildtype glioblastoma patients may receive an OS benefit from a first-line bevacizumab. This study explored biomarkers that may predict survival of glioblastoma patients treated with concurrent irradiation, temozolomide (TMZ) and bevacizumab (BEV) followed by BEV beyond progression (BBP).

METHODS

In the primary protocol, newly diagnosed GBM patients aged 20–75 received concurrent TMZ (75 mg/m2, D1-42), irradiation (2 Gy x 5 QW x6) and BEV (10 mg/kg Q2W x 3) followed by ≤12 4-week cycles of TMZ (150–200 mg/m2, D1-5) plus BEV (10 mg/kg, D1 and 15) and then 2 or 3-week cycles of BEV monotherapy (15 or 10 mg/kg). Upon PD/recurrence during the primary protocol, the patients were subjected to the secondary protocol with 2-3-week cycles of BEV monotherapy with or without other chemotherapeutic agents (BBP). The primary endpoint was 2-year survival rate in patients receiving BBP. Fresh-frozen tumor specimen were subjected to genome-wide methylation, copy number, expression and mutation analysis. A subset of the control cohort of the AVAglio study was used as BEV-negative control.

RESULTS

A total of 94 GBM patients were enrolled at 39 centers between June 2015 and January 2017. Efficacy analyses were based on the full analysis set (FAS) cohort (N=90), excluding non-GBM diagnosis by central review. The median time to PD/recurrence was 453 days in the FAS and 348 days in patients receiving BBP (N=27). The 2-year survival rate (90% CI) was 52.4% (43.3–60.8%) and 28.8% (15.4–43.7%), respectively. The 2-year survival rate in GBM patients receiving BBP was lower than expected (50%). That of proneural and mesenchymal IDH-wt GBM in the biomarker cohort (n=83) were 52.9% (31.7–70.3%) and 56.6% (41.6–69.1%), respectively. A full biomarker analysis will be presented.

A New Technique of Endoscopic Transpapillary Gallbladder Drainage Combined with Intraductal Ultrasonography for the Treatment of Acute Cholecystitis

Background/Aims:

Endoscopic transpapillary gallbladder drainage (ETGBD) is useful for the treatment of acute cholecystitis; however, the technique is difficult to perform. When intraductal ultrasonography (IDUS) is combined with ETGBD, the orifice of the cystic duct in the common bile duct may be more easily detected in the cannulation procedure. The aim of this study was to evaluate the efficacy of ETGBD with IDUS compared with that of ETGBD alone.

Methods:

A total of 100 consecutive patients with acute cholecystitis requiring ETGBD were retrospectively recruited. The first 50 consecutive patients were treated using ETGBD without IDUS, and the next 50 patients were treated using ETGBD with IDUS. Through propensity score matching analysis, we compared the clinical outcomes between the groups. The primary outcome was the technical success rate.

Results:

The technical success rate of ETGBD with IDUS was significantly higher than that of ETGBD without IDUS (92.0% vs. 76.0%, p=0.044). There was no significant difference in procedure length between the two groups (74.0 min vs. 66.7 min, p=0.310). The complication rate of ETGBD with IDUS was significantly higher than that of ETGBD without IDUS (6.0% vs. 0%, p<0.001); however, only one case showed an IDUS technique-related complication (pancreatitis).

Conclusions:

The assistance of IDUS may be useful in ETGBD.

Relationship between Barrett's esophagus and colonic diseases: a role for colonoscopy in Barrett's surveillance

BACKGROUND

Given that risk factors for Barrett's carcinogenesis are predictive, appropriate management and surveillance of Barrett's esophagus (BE) may be provided. The presence of colorectal neoplasms (CRNs) is a possible predictor of the development of BE and the progression to esophageal adenocarcinoma (EAC). We evaluated the relationship between BE or EAC and colonic diseases, including neoplasms and diverticulosis.

METHODS

Patients (N = 5606) who underwent both colonoscopy and esophagogastroduodenoscopy between January 2016 and December 2017 at three institutions were enrolled. The relationships between the presence of colonic diseases and BE or EAC and other clinical or endoscopic predictors of the presence of BE were investigated retrospectively.

RESULTS

The prevalence of BE ≥ 1 cm and ≥ 3 cm in length was 13.0% and 0.52%, respectively. BE was closely related with the presence of colorectal adenoma (48.4% vs. 37.2% in non-BE; P < 0.001), adenocarcinoma (16.6% vs. 8.4%, P < 0.001) and colonic diverticulosis (CD) (34.1% vs. 29.3%, P < 0.001). In patients with long-segment BE, CRNs (79.3%, P < 0.001) and CD (48.2%, P = 0.038) were more common. EAC patients also had a statistically significantly higher incidence of CRNs than non-BE patients (87.5% vs. 45.6%, P = 0.027). Diverticulosis at the distal colon correlated significantly with EAC and BE (50.0%, P = 0.010 and 15.4%, P = 0.024, vs. 12.0% in non-BE). Multivariate analysis showed that CRNs (t = 8.55, P < 0.001), reflux esophagitis (t = 5.26, P < 0.001) and hiatal hernia (t = 11.68, P < 0.001) were predictors of BE.

CONCLUSIONS

The presence of CRNs was strongly associated with BE and EAC. Therefore, colonoscopy may be useful for establishing a strategy for the surveillance of BE.

Enhancement of antitumor activity by using 5-ALA-mediated sonodynamic therapy to induce apoptosis in malignant gliomas: significance of high-intensity focused ultrasound on 5-ALA-SDT in a mouse glioma model

OBJECTIVEHigh invasiveness of malignant gliomas frequently causes early local recurrence of the tumor, resulting in extremely poor outcome. To control such recurrence, novel therapies targeted toward infiltrating glioma cells around the tumor border are required. Here, the authors investigated the antitumor activity of sonodynamic therapy (SDT) combined with a sonosensitizer, 5-aminolevulinic acid (5-ALA), on malignant gliomas to explore the possibility for clinical use of 5-ALA-mediated SDT (5-ALA-SDT).METHODSIn vitro cytotoxicity of 5-ALA-SDT was evaluated in U87 and U251 glioma cells and in U251Oct-3/4 glioma stemlike cells. Treatment-related apoptosis was analyzed using flow cytometry and TUNEL staining. Intracellular reactive oxygen species (ROS) were measured and the role of ROS in treatment-related cytotoxicity was examined by analysis of the effect of pretreatment with the radical scavenger edaravone. Effects of 5-ALA-SDT with high-intensity focused ultrasound (HIFU) on tumor growth, survival of glioma-transplanted mice, and histological features of the mouse brains were investigated.RESULTSThe 5-ALA-SDT inhibited cell growth and changed cell morphology, inducing cell shrinkage, vacuolization, and swelling. Flow cytometric analysis and TUNEL staining indicated that 5-ALA-SDT induced apoptotic cell death in all gliomas. The 5-ALA-SDT generated significantly higher ROS than in the control group, and inhibition of ROS generation by edaravone completely eliminated the cytotoxic effects of 5-ALA-SDT. In the in vivo study, 5-ALA-SDT with HIFU greatly prolonged survival of the tumor-bearing mice compared with that of the control group (p < 0.05). Histologically, 5-ALA-SDT produced mainly necrosis of the tumor tissue in the focus area and induced apoptosis of the tumor cells in the perifocus area around the target of the HIFU-irradiated field. The proliferative activity of the entire tumor was markedly decreased. Normal brain tissues around the ultrasonic irradiation field of HIFU remained intact.CONCLUSIONSThe 5-ALA-SDT was cytotoxic toward malignant gliomas. Generation of ROS by the SDT was thought to promote apoptosis of glioma cells. The 5-ALA-SDT with HIFU induced tumor necrosis in the focus area and apoptosis in the perifocus area of the HIFU-irradiated field, whereas the surrounding brain tissue remained normal, resulting in longer survival of the HIFU-treated mice compared with that of untreated mice. These results suggest that 5-ALA-SDT with HIFU may present a less invasive and tumor-specific therapy, not only for a tumor mass but also for infiltrating tumor cells in malignant gliomas.

The effect of anticoagulants on delayed bleeding after colorectal endoscopic submucosal dissection

BACKGROUND AND AIMS

The withdrawal of antithrombotic therapy from patients at high risk of thromboembolism is controversial. Previously, treatment with anticoagulants, such as warfarin and dabigatran, was recommended for heparin bridge therapy (HBT) during endoscopic submucosal dissection (ESD). However, HBT is associated with a high risk of bleeding during and after ESD. This study aimed to investigate the clinical outcomes of colorectal ESD in patients treated with warfarin and direct oral anticoagulants (DOAC).

METHODS

This study included 412 patients with superficial colorectal neoplasms that were resected by ESD between June 2010 and June 2018. The patients were classified into two groups: without antithrombotics (n = 286) and with anticoagulants (n = 51). The anticoagulants group was further divided into two groups: warfarin (n = 26) and DOAC (n = 25).

RESULTS

Among all patients, delayed bleeding occurred in 35 (8.5% [35/412]) patients. The bleeding rate in the anticoagulants group (11.8% [6/51]) was higher than that in the group without antithrombotics (6.6% [19/286]), but the difference was not statistically significant (P = 0.240). The bleeding rate in the DOAC group (16.0% [4/25]) was higher than that in the warfarin group (7.7% [2/26]), but the difference was not statistically significant (P = 0.419). All delayed bleeding was successfully managed with endoscopic hemostasis. Thromboembolic events were not observed in any patients.

CONCLUSIONS

The bleeding rate with anticoagulants was relatively high. However, all bleeding events with anticoagulants were minor and clinically controllable. Colorectal ESD with DOAC and warfarin may be feasible and acceptable.

Saline-pocket endoscopic submucosal dissection for superficial colorectal neoplasms: a randomized controlled trial (with video)

BACKGROUND AND AIMS

Colorectal endoscopic submucosal dissection (ESD) is a time-consuming procedure because of the technical difficulty. The newly developed saline-pocket ESD (SP-ESD) provides a clearer view and better traction of the submucosal layer compared with the standard ESD with gas insufflation (S-ESD). This study aimed to prospectively compare the efficacy and safety between S-ESD and SP-ESD in patients with superficial colorectal neoplasms (SCNs).

METHODS

From April 2017 to November 2018, 95 patients with SCNs ≥20 mm in diameter were prospectively and randomly enrolled. Four patients were excluded because of an incomplete ESD procedure. Patients were finally allocated to 2 groups, S-ESD with 45 patients and SP-ESD with 46 patients. The primary outcome was dissection speed. Secondary outcomes were ESD procedure time, en bloc and complete resection rates, perforation rate, and adverse effects.

RESULTS

Median dissection speed was significantly faster in the SP-ESD than the S-ESD group (20.1 mm²/min [range, 17.3-28.1] vs 16.3 mm²/min [range, 11.4-19.8]; P < .001). Median procedure time was significantly shorter in the SP-ESD than the S-ESD group (29.5 minutes [range, 22.3-44] vs 41 minutes [range, 31-55]; P < .001). The en bloc and complete resection rates were 100% in both groups. No perforations occurred among patients. The volume of saline solution used in the SP-ESD group was significantly greater than that in the S-ESD group (200 mL [range, 120-250] vs 150 mL [range, 100-200]; P = .016).

CONCLUSIONS

SP-ESD improved dissection speed and procedure time compared with S-ESD. SP-ESD may be an alternative method for resection of SCNs. (Clinical trial registration number: UMIN 000026317.).

Serum bilirubin level is a strong predictor for disability in activities in daily living (ADL) in Japanese elderly patients with diabetes

Elderly patients with diabetes are at increased risk of frailty and disability in activities of daily living (ADL). Recent evidence has shown that oxidative stress is associated with these conditions. In this cross-sectional study, we aimed to assess whether serum level of bilirubin, a strong endogenous antioxidant, can predict ADL disability in elderly patients with diabetes. Forty elderly patients aged 70 years and older with diabetes and ADL disability and 158 elderly patients with diabetes and without ADL disability were continuously recruited. Multivariate logistic regression models showed that serum bilirubin level was a significant predictor for ADL disability. Receiver operating characteristic analysis showed that the area under the curve (AUC) of serum bilirubin level alone for ADL disability was 0.887 (95% CI 0.837–0.936, P < 0.001) and the cut-off value was 0.4 mg/dL (sensitivity = 88.0% and specificity = 65.0%). The predictive ability was further increased by the addition of age (AUC = 0.921) or addition of age, body mass index, red blood cell count, cerebrovascular disease and chronic renal failure (AUC = 0.953). In conclusion, low serum bilirubin level is a strong predictive biomarker for ADL disability in elderly patients with diabetes, and its clinical utility is suggested.

Electrospray Deposition of {200} Oriented Regular-Assembly BaTiO3 Nanocrystal Films under an Electric Field

Highly oriented, regularly assembled nanocrystalline films have recently emerged as attractive new functional materials. In this study, we deposited a BaTiO₃ (BT) nanocube dispersion on a Si substrate by electrospraying, resulting in a dense, regularly assembled BT nanocrystalline film. X-ray diffraction analysis revealed that applying a voltage between the electrospray nozzle and the Si substrate during electrospraying caused the BT nanocubes to form a regular array in the 200 plane aligned perpendicularly to the substrate. The volume fraction of BT nanocubes in the 200 plane in the assembly was estimated by the orientation distribution function analysis to be about 50%. The formation of this regularly assembled layer was determined to be linked to the interaction between the vaporized solvent and the substrate, enabled by the enhanced wettability under the electric field. Electrospray deposition has potential applications in the manufacture of nanocrystalline assembled films for nanofunctional devices.

Prognostic significance of immunohistochemical subtypes based on the stage of B-cell differentiation in primary CNS lymphoma

Primary central nervous system lymphoma (PCNSL) has been immunohistochemically classified into two subtypes, germinal center (GC) B-cell and non-GC B-cell, but the prognostic impact of these subtypes remains debated. We investigated clinical features and prognostic significance of immunohistochemical subtypes that were identified by expression patterns of three B-cell differentiation markers in PCNSL. We also analyzed a factor related to responsiveness to high-dose methotrexate (HD-MTX) chemotherapy. Tumors from 32 PCNSL patients were immunohistochemically evaluated for expression of cluster of differentiation (CD) 10, B-cell lymphoma-6 (BCL-6), and multiple myeloma oncogene-1 (MUM-1) and classified into subtypes according to the expression patterns of these markers. Clinical features and prognostic outcome of these subtypes were investigated. Twenty-three patients were treated with HD-MTX-based chemotherapy followed by whole-brain radiation therapy (WBRT), and nine were treated with WBRT alone. Three immunohistochemical subtypes were identified, including A-type expressing CD10, BCL-6, and MUM-1 (12 patients), B-type expressing BCL-6 and MUM-1 (12 patients) and C-type expressing MUM-1 only (8 patients). Response rate in the HD-MTX therapy group was 57.1% (4/7) in A-type, 87.5% (7/8) in B-type, and 75% (6/8) in C-type. C-type with the lowest metabolic activity showed significantly longer overall survival than A-type with the higher uptake of methionine (71.6 versus 39.6 months) (P<0.05). Immunohistochemical identification of PCNSL based on the B-cell differentiation stage revealed three types of tumors, showing different metabolic activity and survival time. Refined immunohistochemical classification of PCNSL subtypes may become a useful tool for predicting more accurate prognosis and accessing sensitivity to HD-MTX therapy.

Feasibility of gastric endoscopic submucosal dissection with continuous low-dose aspirin for patients receiving dual antiplatelet therapy

BACKGROUND

Endoscopic submucosal dissection (ESD) for gastric neoplasms during continuous low-dose aspirin (LDA) administration is generally acceptable according to recent guidelines. This retrospective study aimed to investigate the effect of continuous LDA on the postoperative bleeding after gastric ESD in patients receiving dual antiplatelet therapy (DAPT).

AIM

To investigate the feasibility of gastric ESD with continuous LDA in patients with DAPT.

METHODS

A total of 597 patients with gastric neoplasms treated with ESD between January 2010 and June 2017 were enrolled. The patients were categorized according to type of antiplatelet therapy (APT).

RESULTS

The postoperative bleeding rate was 6.9% (41/597) in all patients. Patients were divided into the following two groups: no APT (n = 443) and APT (n = 154). APT included single-LDA (n = 95) and DAPT (LDA plus clopidogrel, n = 59) subgroups. In the single-LDA and DAPT subgroups, 56 and 39 patients were received continuous LDA, respectively. The bleeding rate with continuous single-LDA (10.7%) was similar to that with discontinuous single-LDA (10.3%) (P > 0.99). Although the bleeding rate with continuous LDA in patients receiving DAPT (23.1%) was higher than that with discontinuous LDA in patients receiving DAPT (5.0%), no significant difference was observed (P = 0.141).

CONCLUSION

The bleeding rate with continuous LDA in patients receiving DAPT was not statistically different from that with discontinuous LDA in patients receiving DAPT. Therefore, continuous LDA administration may be acceptable for ESD in patients receiving DAPT, although patients should be carefully monitored for possible bleeding.

Usefulness of neuroimaging and immunohistochemical study for accurate diagnosis of chordoid glioma of the third ventricle: A case report and review of the literature

Background:

Chordoid glioma of the third ventricle is a rare neuroepithelial tumor characterized by a unique histomorphology within the third ventricular region, but with radiological and histopathological features mimicking benign lesions such as meningioma. We report a case of chordoid glioma of the third ventricle and suggest a useful indicator for accurate diagnosis.

Case Description:

A previously healthy 46-year-old woman was admitted to our hospital with mild headache. Neuroimaging revealed a large tumor measuring approximately 18 mm in the suprasellar region, and perifocal edema in the optic tract and internal capsule on magnetic resonance imaging. Laboratory findings revealed no pituitary dysfunction including diabetes insipidus. Gross total resection of the tumor was performed by the interhemispheric translamina terminalis approach. Histological findings revealed nests of regular epithelioid cells with large nuclei and abundant eosinophilic cytoplasm within myxoid stroma. Immunohistochemical studies demonstrated diffuse cytoplasmic expression of glial fibrillary acidic protein (GFAP) and CD34, and strong nuclear staining for thyroid transcription factor 1 (TTF-1). We, therefore, histologically classified the tumor as chordoid glioma of the third ventricle. Headache improved immediately postoperatively, and follow-up neuroimaging after 12 months showed no signs of recurrence.

Conclusions:

Chordoid glioma of the third ventricle is a very rare tumor that is difficult to diagnose on routine neuroimaging. Accurate diagnosis requires detailed analysis of neuroimaging and immunohistochemical studies using CD34 and TTF-1 staining.

Clinical impact of prophylactic clip closure of mucosal defects after colorectal endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

 Endoscopic submucosal dissection (ESD) is useful for en bloc resection of superficial colorectal neoplasms to ensure accurate histologic diagnoses. However, colorectal ESD is associated with a high frequency of adverse events (AEs). We aimed to investigate the effectiveness of prophylactic clip closure (PCC) of mucosal defects for AEs after colorectal ESD.

PATIENTS AND METHODS

 This study included 197 patients with 211 lesions who underwent colorectal ESD between June 2010 and August 2016. Patients who had delayed perforation, delayed bleeding, abdominal pain, or fever were defined as AEs after colorectal ESD. Complete PCC was defined as completely sutured mucosal defect using endoclips following colorectal ESD, whereas incomplete PCC was defined as the mucosal defects that did not enable PCC or were partially sutured. Clinical records were retrospectively reviewed and clinical outcomes evaluated.

RESULTS

AEs occurred in 29 lesions (13.7 %), including 12 with delayed bleeding, 12 with fever, 2 with abdominal pain, 2 with fever and abdominal pain, and 1 with delayed bleeding and fever. Delayed perforation was not observed in any patient. The frequency of AEs was significantly lower in the group with complete PCC than in the group with incomplete PCC (7.3 % [9/123] vs. 22.7 % [20/88]; P  < 0.001). Multivariate analysis revealed that AEs after colorectal ESD were significantly associated with tumor size and submucosal fibrosis. Subgroup analysis among the resected specimen size of < 40 mm revealed that there was no significant difference in AEs between the 2 groups (5.6 % [6/107] vs. 17.8 % [8/45]; P  = 0.069). However, the frequency of fever with complete PCC was significantly lower than that with incomplete PCC (2.8 % [3/107] vs. 13.3 % [6/45]; P  = 0.020).

CONCLUSIONS

Tumor size and submucosal fibrosis were independent risk factors for AEs after colorectal ESD. PCC may be effective in minimizing AEs after colorectal ESD, especially the frequency of fever.

Is it possible to perform gastric endoscopic submucosal dissection without discontinuation of a single antiplatelet of thienopyridine derivatives?

BACKGROUND AND STUDY AIMS

Combined use of thienopyridine derivatives and other antithrombotic agents is reported to be a risk factor for postoperative bleeding after gastric endoscopic submucosal dissection (ESD). However, risk associated with a single thienopyridine derivative has not been evaluated. In this study, we aimed to evaluate bleeding risks of gastric ESD without discontinuation of a single thienopyridine derivative agent.

PATIENTS AND METHODS

 This multicenter, prospective, observational cohort study included patients who had undergone implantation of a coronary artery stent and who were taking a combination of aspirin antiplatelet therapy and a thienopyridine derivative agent. Enrolled patients discontinued aspirin and underwent gastric ESD without the discontinuation of a single thienopyridine derivative agent. The primary endpoint was the major bleeding complication rate after gastric ESD.

RESULTS

 Eleven patients were enrolled in this study from April 2015 to November 2016 after written informed consent was obtained. Among them, 1 patient, who had undergone surgery for a primary cardiac tumor before ESD, was excluded from the study. Ten patients underwent gastric ESD for neoplasms. En-bloc resections were achieved in all cases without intraoperative bleeding complications. Two patients experienced postoperative bleeding although neither case required a blood transfusion (95 % CI 2.5 - 55.6 %).

CONCLUSION

 En-bloc resections were possible although the postoperative bleeding rate tended to be higher in gastric ESD without discontinuation of a single thienopyridine derivative agent. Additional preventive measures are mandatory to carry out safe gastric ESD in such settings.

Continuous use of low-dose warfarin for gastric endoscopic submucosal dissection: a prospective study

Background and study aims Patients who receive warfarin usually require heparin bridge therapy (HBT) to prevent thromboembolic events during endoscopic submucosal dissection (ESD); however, clinical evidence demonstrating the safety and efficacy of HBT during gastric ESD is limited. Conversely, warfarin can be continuously used as a substitute for HBT to endoscopic procedures which have a low risk of bleeding. This study aimed to clarify the safety and efficacy of continuous low-dose warfarin (LDW) for gastric ESD. Patients and methods This was a prospective observational study at a single institution. A total of 22 patients who received warfarin between December 2014 and January 2016 were enrolled. The patients were treated with gastric ESD with a low dose of warfarin ( ≤ 4 mg) at approximately 1.6 - 2.6 of the international normalized ratio (INR) levels. Furthermore, we analyzed a total of 23 patients with HBT who underwent gastric ESD between January 2011 and November 2014. Results The average of warfarin dose and the INR level on the day of gastric ESD in the continuous LDW group were 2.3 mg/day (range 0.5 - 4.0) and 1.87 (range 1.41 - 2.75), respectively. Two of the 22 patients (9.1 %) in the continuous LDW group and 5 of the 23 patients (21.7 %) in the HBT group had postoperative bleeding after gastric ESD. Although the postoperative bleeding rate in the continuous LDW group was lower than that in the HBT group, no significant difference was observed between the 2 groups (P = 0.414). Conclusions Gastric ESD with continuous LDW as a substitute for HBT was feasible and may be acceptable.

Endoscopic submucosal dissection for small submucosal tumors of the rectum compared with endoscopic submucosal resection with a ligation device

AIM

To evaluate the efficacy and safety of endoscopic submucosal dissection (ESD) for small rectal submucosal tumors (SMTs).

METHODS

Between August 2008 and March 2016, 39 patients were treated with endoscopic submucosal resection with a ligation device (ESMR-L) (n = 21) or ESD (n = 18) for small rectal SMTs in this study. Twenty-five lesions were confirmed by histological evaluation of endoscopic biopsy prior to the procedure, and 14 lesions were not evaluated by endoscopic biopsy. The results for the ESMR-L group and the ESD group were retrospectively compared, including baseline characteristics and therapeutic outcomes.

RESULTS

The rate of en bloc resection was 100% in both groups. Although the rate of complete endoscopic resection was higher in the ESD group than in the ESMR-L group (100% vs 95.2%), there were no significant differences between the two groups (P = 0.462). In one patient in the ESMR-L group with a previously biopsied tumor, histological complete resection with a vertical margin involvement of carcinoid tumor could not be achieved, whereas there was no incomplete resection in the ESD group. The mean length of the procedure was significantly greater in the ESD group than in the ESMR-L group (14.7 ± 6.4 min vs 5.4 ± 1.7 min, P < 0.05). The mean period of the hospitalization was also significantly longer in the ESD group than in the ESMR-L group (3.7 ± 0.9 d vs 2.8 ± 1.5 d, P < 0.05). Postoperative bleeding was occurred in one patient in the ESMR-L group.

CONCLUSION

Both ESMR-L and ESD were effective for treatment of small rectal SMTs. ESMR-L was simpler to perform than ESD and took less time.

Synthesis of highly c-axis-oriented ZnO thin films using novel laser-enhanced electrospray CVD under atmospheric pressure

Novel process for synthesizing c-axis-oriented ZnO films by novel laser enhanced electrospray CVD.

Valproic acid reduces hair loss and improves survival in patients receiving temozolomide-based radiation therapy for high-grade glioma

PURPOSE

Valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, is also used to manage seizures in glioblastoma patients. HDAC inhibitors can protect normal cells and tissues from the deleterious effects of radiotherapy, and VPA is reported to improve the survival of glioblastoma patients receiving chemoradiation therapy. VPA also promotes hair growth, and thus has the potential to reduce the radiotherapy side effect of hair loss while improving the survival of patients with glioblastoma. The purpose of this study was to determine whether VPA use during radiotherapy for high-grade glioma is associated with decreased side effects of radiotherapy and an improvement in overall survival (OS) and progression-free survival (PFS).

METHODS

Medical records of 112 patients with high-grade glioma were retrospectively reviewed. We grouped patients by VPA use or non-use during radiotherapy, and evaluated hair loss, OS, and PFS.

RESULTS

The radiation dose and fractionation at the onset of hair loss were 4 Gy and two fractions higher, respectively, in the VPA group compared with the VPA non-use group (P < 0.01). Median OS was 42.2 and 20.3 months in the VPA use and non-use groups, respectively (P < 0.01; hazard ratio [HR], 0.36; 95% confidence interval [CI], 0.18-0.74). Median PFS was 22.7 and 11.0 months in the VPA use and non-use groups, respectively (P = 0.099; HR, 0.62; 95% CI, 0.36-1.09).

CONCLUSIONS

VPA use during radiotherapy for glioma is associated with delayed hair loss and improvement in survival. Hair loss prevention benefits patients suffering from the deleterious effects of radiation.