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Patients with advanced cancer undergo comprehensive genomic profiling in Japan only after treatment options have been exhausted. Patients with a very poor prognosis were not able to undergo profiling tests, resulting in a selection bias called length bias, which makes accurate survival analysis impossible. The actual impact of length bias on the overall survival of patients who have undergone profiling tests is unclear, yet appropriate methods for adjusting for length bias have not been developed. To assess the length bias in overall survival, we established a simulation-based model for length bias adjustment. This study utilized clinicogenomic data of 8813 patients with advanced cancer who underwent profiling tests at hospitals throughout Japan between June 2019 and April 2022. Length bias was estimated by the conditional Kendall τ statistics and was significantly positive for 13 of the 15 cancer subtypes, suggesting a worse prognosis for patients who underwent profiling tests in early timing. The median overall survival time in colorectal, breast, and pancreatic cancer from the initial survival-prolonging chemotherapy with adjustment for length bias was 937 (886-991), 1225 (1152-1368), and 585 (553-617) days, respectively (median; 95% credible interval). Adjusting for length bias made it possible to analyze the prognostic relevance of oncogenic mutations and treatments. In total, 12 tumor-specific oncogenic mutations correlating with poor survival were detected after adjustment. There was no difference in survival between FOLFIRINOX (leucovorin, fluorouracil, irinotecan, and oxaliplatin) or gemcitabine with nab-paclitaxel-treated groups as first-line chemotherapy for pancreatic cancer. Adjusting for length bias is an essential part of utilizing real-world clinicogenomic data.

Mismatch repair (MMR) gene deficiency is rarely observed in gliomas, a constitutional defect is associated with tumorigenesis in Lynch syndrome, and an acquired defect is associated with hypermutation after temozolomide treatment. However, the meaning of MMR gene deficiency in gliomas is unclear. Two cases of MMR-deficient glioblastomas are reported, and mutational status of oncogenes was compared between primary and recurrent tumor samples in a glioblastoma patient with Lynch syndrome. Additionally, the characteristics of MMR-deficient glioblastomas were analyzed using public glioma datasets to determine the meaning of MMR deficiency in gliomas. Case 1 was a glioblastoma patient with Lynch syndrome, and treatment with pembrolizumab for the recurrent tumor was temporarily effective for a short period. Comparison of mutational changes between primary and recurrent tumor samples showed many additional mutated genes associated with multiple signaling pathways in the recurrent tumor. Tumor recurrence and chemoresistance could be associated with intratumoral heterogeneity and accelerated tumor progression due to defects of multiple signaling pathways. Case 2 was a glioblastoma patient with acquired MMR gene deficiency, and she died of rapid progression of bone marrow metastases. This rare clinical course was considered to be associated with gene expression changes and heterogeneity that resulted from MMR gene deficiency. Two cases of MMR gene-deficient glioblastomas were presented, and their genetic characteristics suggested that their clinical courses could be associated with MMR gene deficiency.

We previously reported that there was a subgroup of IDH-mutated astrocytomas harboring only 19q-loss showing oligodendroglioma-like morphology and significantly longer overall survival (OS) compared with 19q-intact astrocytomas. The aim of this study was to further explore the biological characteristics of this possible subgroup and obtain insight into the mechanism of their relatively benign clinical behavior. We compared gene expression pattern between five 19q-loss and five 19q-intact IDH-mutated astrocytomas by microarray analysis. By comparing expression levels of genes of 19q-loss astrocytomas to those of 19q-intact astrocytomas, 102 up-regulated genes and 162 down-regulated genes were extracted. The down-regulated genes clustered heavily to 19q and 4p while the up-regulated genes clustered to 4q. It was noteworthy that fibroblast growth factor 1 associated with stem cell maintenance and multiple genes associated with glioma progression were down-regulated in 19q-loss astrocytomas, and these results were validated with the independent TCGA data set. On t-SNE analysis of the 19q-loss astrocytomas with other IDH-mutant glioma subgroups from the TCGA datasets, the expression pattern of the 19q-loss astrocytomas showed no shift toward oligodendrogliomas with 1p/19q codeletion but rather constituted a subgroup of astrocytoma. These findings suggested that 19q-loss in astrocytomas is more likely acquired event rather than an early event in oncogenesis like the 1p/19q-codeletion in oligodendrogliomas, and that the biological features of 19q-loss astrocytomas are possibly related to differentially expressed genes associated with stem cell maintenance and glioma progression.

Intratumor heterogeneity has been analyzed in brain tumors, and it has revealed that clonal evolution results in the formation of genetically diverse cell populations, which is a major factor in treatment resistance and recurrence. However, intratumoral heterogeneity has not been analyzed in routine clinical practice and remains at the research level. Here, we developed a novel tumor sampler to establish the analysis of intratumoral heterogeneity as a routine clinical procedure and to clarify its clinical significance in brain tumors. Our novel tumor sampler consists of a hollow cylinder with a lid, which enabled us to obtain a cylindrical tumor sample cross-sectionally by inserting from the tumor surface to the depth, like the geological borehole test. The obtained cylindrical sample was divided vertically into two, one for pathological analysis and one for genetic analysis, which allowed us to compare genetic findings and pathological findings in arbitrary site of the sample. The sampling procedure was simple and completed in a short time, allowing comparison of heterogeneity among a large number of cases. We collected samples from four cases of Glioblastoma and three cases of brain metastasis using the sampler, and analyzed intratumoral heterogeneity by identifying somatic mutations at multiple sites by whole exome sequencing. We evaluated genetic and morphological heterogeneity among each site, generated a phylogenetic tree of clonal evolution within the tumor, and confirmed that these data could be compared among the cases. Using our novel tumor sampler could establish the analysis of intratumoral heterogeneity as a routine clinical procedure, and it expected to have a significant impact on treatment strategies for brain tumors.

We previously reported that there was a subgroup of IDH-mutated astrocytomas harboring only 19q-loss showing oligodendroglioma-like morphology and significantly longer overall survival (OS) compared with 19q-intact astrocytomas. The aim of this study was to further explore the biological characteristics of this possible subgroup and obtain insight into the mechanism of their relatively benign clinical behavior.We compared gene expression pattern between five 19q-loss and five 19q-intact IDH-mutated astrocytomas by microarray analysis.By comparing expression levels of genes of 19q-loss astrocytomas to those of 19q-intact astrocytomas, 102 up-regulated genes and 162 down-regulated genes were extracted. The down-regulated genes clustered heavily to 19q and 4p while the up-regulated genes clustered to 4q. It was noteworthy that fibroblast growth factor 1 associated with stem cell maintenance and multiple genes associated with glioma progression were down-regulated in 19q-loss astrocytomas, and these results were validated with the independent TCGA data set. On t-SNE analysis of the 19q-loss astrocytomas with other IDH-mutant glioma subgroups from the TCGA datasets, the expression pattern of the 19q-loss astrocytomas showed no shift toward oligodendrogliomas with 1p/19q codeletion but rather constituted a subgroup of astrocytoma.These findings suggested that 19q-loss in astrocytomas is more likely acquired event rather than an early event in oncogenesis like the 1p/19q-codeletion in oligodendrogliomas, and that the biological features of 19q-loss astrocytomas are possibly related to differentially expressed genes associated with stem cell maintenance and glioma progression.

Brain invasion by chronic lymphocytic leukemia (CLL) is very rare, and only a handful of cases have been reported. We here report a case of 61-year-old woman who had been treated for CLL for 14 years presenting with a progressive mental disturbance. Magnetic resonance imaging (MRI) showed discontinuous ring-enhancing lesions compatible with the "open ring" sign, which was considered a demyelinating disorder, in both the frontal lobes. However, on histological examination of the biopsied specimen, infiltration of small lymphocytes positive for CD5, CD20, and CD23, indicating brain invasion by CLL, was seen. The leukemia cells occupied the Virchow-Robin space and infiltrated into the brain parenchyma. The arterioles in the Virchow-Robin space were compressed and occluded with the tumor cells, while CD163-positive cells infiltrated the brain parenchyma. Myelin staining demonstrated myelinoclasis in the infiltrated brain tissue. The MRI findings in the present case probably reflected myelinoclasis, suggesting rare brain invasion by CLL. The possibility of lymphoma should not be eliminated based on the MRI findings.

Machine learning models for automated magnetic resonance image segmentation may be useful in aiding glioma detection. However, the image differences among facilities cause performance degradation and impede detection. This study proposes a method to solve this issue. We used the data from the Multimodal Brain Tumor Image Segmentation Benchmark (BraTS) and the Japanese cohort (JC) datasets. Three models for tumor segmentation are developed. In our methodology, the BraTS and JC models are trained on the BraTS and JC datasets, respectively, whereas the fine-tuning models are developed from the BraTS model and fine-tuned using the JC dataset. Our results show that the Dice coefficient score of the JC model for the test portion of the JC dataset was 0.779 ± 0.137, whereas that of the BraTS model was lower (0.717 ± 0.207). The mean Dice coefficient score of the fine-tuning model was 0.769 ± 0.138. There was a significant difference between the BraTS and JC models (p &lt, 0.0001) and the BraTS and fine-tuning models (p = 0.002), however, no significant difference between the JC and fine-tuning models (p = 0.673). As our fine-tuning method requires fewer than 20 cases, this method is useful even in a facility where the number of glioma cases is small.

We previously reported that there was a subgroup of IDH-mutated astrocytomas harboring only 19q-loss showing oligodendroglioma-like morphology and significantly longer overall survival (OS) compared with 19q-intact astrocytomas. To further explore the biological characteristics of this possible subgroup and obtain insight into the mechanism of their clinical behavior, we compared gene expression pattern between five 19q-loss and five 19q-intact IDH-mutated astrocytomas by microarray analysis. Comparing expression level of each genes between 19q-loss and 19q-intact astrocytomas,136 up-regulated genes and 203 down-regulated genes were extracted. Gene expression patterns of 19q-loss astrocytomas were partially different from that of 19q-intact astrocytomas. More down-regulated genes distributed on 19q and 4p, and more up-regulated genes distributed on 4q. Multiple genes associated with stem cell maintenance were down-regulated in 19q-loss astrocytomas, and genes associated with glioma progression were differentially expressed. Comparing expression patterns among 19q-loss astrocytomas and other IDH-mutant glioma subgroups using TCGA datasets by t-SNE analysis revealed that expression pattern of 19q-loss astrocytomas did not shift to that of oligodendrogliomas with 1p/19q codeletion but were a subgroup in astrocytomas. These results indicated that 19q-loss in astrocytomas was an acquired event different from 1p/19q codeletion in oligodendrogliomas, and better prognosis morphological features in 19q-loss astrocytomas were derived from differentially expressed genes associated with stem cell maintenance and glioma progression.

TERT promoter mutations are commonly associated with 1p/19q codeletion in IDH-mutated gliomas. However, whether these mutations have an impact on patient survival independent of 1p/19q codeletion is unknown. In this study, we investigated the impact of TERT promoter mutations on survival in IDH-mutated glioma cases. Detailed clinical information and molecular status data were collected for a cohort of 560 adult patients with IDH-mutated gliomas. Among these patients, 279 had both TERT promoter mutation and 1p/19q codeletion, while 30 had either TERT promoter mutation (n = 24) or 1p/19q codeletion (n = 6) alone. A univariable Cox proportional hazard analysis for survival using clinical and genetic factors indicated that a Karnofsky performance status score (KPS) of 90 or 100, WHO grade II or III, TERT promoter mutation, 1p/19q codeletion, radiation therapy, and extent of resection (90–100%) were associated with favorable prognosis (p TERT promoter mutation had a significantly favorable prognostic impact (hazard ratio = 0.421, p = 0.049), while 1p/19q codeletion did not have a significant impact (hazard ratio = 0.648, p = 0.349). Analyses incorporating patient clinical and genetic information were further conducted to identify subgroups showing the favorable prognostic impact of TERT promoter mutation. Among the grade II-III glioma patients with a KPS score of 90 or 100, those with IDH-TERT co-mutation and intact 1p/19q (n = 17) showed significantly longer survival than those with IDH mutation, wild-type TERT, and intact 1p/19q (n = 185) (5-year overall survival, 94% and 77%, respectively; p = 0.032). Our results demonstrate that TERT promoter mutation predicts favorable prognosis independent of 1p/19q codeletion in IDH-mutated gliomas. Combined with its adverse effect on survival among IDH-wild glioma cases, the bivalent prognostic impact of TERT promoter mutation may help further refine the molecular diagnosis and prognostication of diffuse gliomas.

Intravascular lymphoma (IVL) has been characterized in many case reports by multiple white matter lesions reflecting ischemic changes. In contrast, there are very few case reports of cerebral or cerebellar hemorrhage resulting from IVL. A 56-year-old woman was referred to our department with two-week history of headache, nausea, and poor appetite. Gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) showed dilated veins on the cerebellar surface. No ischemic lesions were detected on diffusion-weighted images. Three days after admission, the patient had a large cerebellar hemorrhage, prompting emergency surgery. Unfortunately, the patient died on the 11th postoperative day. Massive CD20-positive lymphoma cells were recognized in the cerebellar veins, but not in the arteries or the parenchyma of the brain. This is the rare case report of a cerebellar hemorrhage complication from IVL that might have been caused by venous congestion. The dilated veins on the cerebellar surface recognized from the Gd-enhanced T1-weighted images were specific clues in this case.

BACKGROUND Manual segmentation of brain tumor images from a large volume of MR images generated in clinical routines is difficult and time-consuming. Hence, it is imperative to develop a machine learning model for automated segmentation of brain tumor images. PURPOSE Machine learning models for automated MR image segmentation of gliomas may be useful. However, the image differences among facilities cause performance degradation and impede successful automatic segmentation. In this study, we proposed a method to solve this issue. METHODS We used the data from the Multimodal Brain Tumor Image Segmentation Benchmark (BraTS) and the Japanese cohort (JC) datasets collected from 10 facilities. Three models for tumor segmentation were developed. The BraTS model was trained on the BraTS dataset, and the JC model was trained on the JC dataset; whereas, the Fine-tuning model was a fine-tuned BraTS model using the JC dataset. RESULTS MR images of 544 patients were obtained for the JC dataset. Half of the JC dataset was used for independent testing. The Dice coefficient score of the JC model for the JC dataset was 0.779± 0.137, whereas that of the BraTS model was remarkably lower (0.717 ± 0.207). The mean of the Fine-tuning models for the JC dataset was 0.769 ± 0.138. There was a significant difference between the BraTS and JC models (P < 0.0001) and the BraTS and Fine-tuning models (P = 0.002); however, no significant difference was observed between the JC and Fine-tuning models (P = 0.673). CONCLUSIONS Application of the BraTS model to heterogeneous datasets can significantly reduce its performance; however, fine-tuning can solve this issue. Since our fine-tuning method only requires less than 20 cases, this methodology is particularly useful for a facility where there are a few glioma cases.

Recent studies have demonstrated that tumor-driving alterations are often different among gliomas that originated from different brain regions and have underscored the importance of analyzing molecular characteristics of gliomas stratified by brain region. Therefore, to elucidate molecular characteristics of diffuse cerebellar gliomas (DCGs), 27 adult, mostly glioblastoma cases were analyzed. Comprehensive analysis using whole-exome sequencing, RNA sequencing, and Infinium methylation array (n = 17) demonstrated their distinct molecular profile compared to gliomas in other brain regions. Frequent mutations in chromatin-modifier genes were identified including, noticeably, a truncating mutation in SETD2 (n = 4), which resulted in loss of H3K36 trimethylation and was mutually exclusive with H3F3A K27M mutation (n = 3), suggesting that epigenetic dysregulation may lead to DCG tumorigenesis. Alterations that cause loss of p53 function including TP53 mutation (n = 9), PPM1D mutation (n = 2), and a novel type of PPM1D fusion (n = 1), were also frequent. On the other hand, mutations and copy number changes commonly observed in cerebral gliomas were infrequent. DNA methylation profile analysis demonstrated that all DCGs except for those with H3F3A mutations were categorized in the “RTK I (PDGFRA)” group, and those DCGs had a gene expression signature that was highly associated with PDGFRA. Furthermore, compared with the data of 315 gliomas derived from different brain regions, promoter methylation of transcription factors genes associated with glial development showed a characteristic pattern presumably reflecting their tumor origin. Notably, SOX10, a key transcription factor associated with oligodendroglial differentiation and PDGFRA regulation, was up-regulated in both DCG and H3 K27M-mutant diffuse midline glioma, suggesting their developmental and biological commonality. In contrast, SOX10 was silenced by promoter methylation in most cerebral gliomas. These findings may suggest potential tailored targeted therapy for gliomas according to their brain region, in addition to providing molecular clues to identify the region-related cellular origin of DCGs. Electronic supplementary material The online version of this article (doi:10.1007/s00401-017-1771-1) contains supplementary material, which is available to authorized users.

Classification of gliomas, first established by Cushing and Bailey in early 20th century, has been based on histological features that were associated with clinical behavior of the tumor fairly well. However, inter-observer variation in the diagnosis and heterogeneous clinical outcome within a single entity have been problematic in some cases. Accumulation of molecular information of gliomas over the past two to three decades gradually elucidated the mechanism of oncogenesis and progression of gliomas at the molecular level, and it now appears to be possible to classify gliomas by the molecular markers, especially in adult diffuse gliomas that constitute ~25-30% of the primary intracranial tumors. Most powerful molecular markers to classify those tumors are those that appear to be involved in the early phases of oncogenesis, including IDH1/2, TP53, TERT, ATRX and 1p/19q co-deletion. Interesting tight negative and positive correlations among those molecular genetic alterations enable clearer definition of entities and better prognosis prediction in adult diffuse gliomas.

Hemangioblastoma is usually amenable to total surgical resection, but indication for surgery can be hampered by its location, multiplicity, or repeated recurrences frequently observed in patients with von Hippel Lindau disease (VHLD). Stereotactic radiosurgery (SRS) has been administered for such cases as an alternative therapeutic option with generally favorable clinical response, but the effect of SRS has not been underscored by histological examination of the treated hemangioblastoma. Here we present histology of VHLD-associated hemangioblastoma tissue resected three months after SRS because of cyst enlargement. It confirmed that hemangioblastoma cells totally disappeared after SRS with a marginal dose of 20 Gy. Furthermore, Electron microscope revealed that endothelial cells of the vascular structure disappeared while maintaining the basement membranes, and leakage of intraluminal contents was observed around the structure. We showed the SRS was effective for hemangioblastoma pathologically at least with the marginal dose of 20 Gy. Leakage of intraluminal contents from the damaged vascular structure losing the endothelial cells is one possible mechanism for the cyst enlargement, and it may be a reason of poor control rate of SRS for the cystic hemangioblastoma.

To elucidate the mechanisms of malignant progression of lower-grade glioma, molecular profiling using methylation array, whole-exome sequencing, and RNA sequencing was performed for 122, 36 and 31 gliomas, respectively. This cohort included 24 matched pairs of initial lower-grade gliomas and recurrent tumors, most of which showed malignant progression. Nearly half of IDH-mutant glioblastomas that had progressed from lower-grade gliomas exhibited characteristic partial DNA demethylation in previously methylated genomic regions of their corresponding initial tumors, which had the glioma CpG island methylator phenotype (G-CIMP). In these glioblastomas, cell cycle-related genes, RB and PI3K-AKT pathway genes were frequently altered. Notably, late-replicating domain was significantly enriched in the demethylated regions that were mostly located in non-regulatory regions, suggesting that the loss of DNA methylation during malignant transformation may involve mainly passive demethylation due to a delay in maintenance of methylation during accelerated cell division. Nonetheless, a limited number of genes including IGF2BP3, which potentially drives cell proliferation, were presumed to be upregulated due to demethylation of their promoter. Our data indicated that demethylation of the G-CIMP profile found in a subset of recurrent gliomas reflects accelerated cell divisions accompanied by malignant transformation. Oncogenic genes activated by such epigenetic change represent potential therapeutic targets.

Primary central nervous system lymphoma (PCNSL) is a rare subtype of non-Hodgkin’s lymphoma, and its prognosis is still very poor despite the conventional therapy of high-dose methotrexate (HD-MTX) followed by whole-brain radiation therapy (WBRT). The purpose of the present study was to evaluate the survival benefit of continuous intrathecal injection therapy of methotrexate (CIT-MTX) combined with the conventional therapy. A total of 26 PCNSL patients treated with CIT-MTX were analyzed. Ten mg of methotrexate were continuously injected into the lateral ventricle via a subcutaneous port over 5 days biweekly for 5 cycles. CIT-MTX was performed with WBRT in addition to HD-MTX in 15 cases, and 11 cases with high risk for HD-MTX were treated with CIT-MTX and WBRT. The response rate of all patients was 92.3%, and median progression-free survival and median overall survival (mOS) were 59.4 months and 93.8 months, respectively. Median OS of patients treated with CIT-MTX in addition to HD-MTX and WBRT was longer than the previously reported mOS with HD-MTX and WBRT (95 vs 33 months). In cases that could not tolerate HD-MTX, mOS of patients treated with CIT-MTX and WBRT was longer than the previously reported mOS with WBRT alone (36.7 vs 18 months). There was no difference in OS between patients with cerebrospinal fluid dissemination and patients without (p = 0.83). Better prognosis in patients treated with CIT-MTX may be derived from stable concentration of methotrexate in the cerebrospinal fluid. CIT-MTX was an effective additional therapeutic option for PCNSL.

We previously reported that there was a subgroup of IDH-mutated astrocytomas harboring only 19q-loss showing oligodendroglioma-like morphology and significantly longer overall survival (OS) compared with 19q-intact astrocytomas. To further explore the biological characteristics of this possible subgroup and obtain insight into the mechanism of their relatively benign clinical behavior, we compared gene expression pattern between five 19q-loss and five 19q-intact IDH-mutated astrocytomas by microarray analysis. By comparing expression levels of genes of 19q-loss astrocytomas to those of 19q-intact astrocytomas,136 up-regulated genes and 203 down-regulated genes were extracted. Down-regulated genes in the 19q-loss astrocytomas were heavily clustered to 19q and 4p, and up-regulated genes to 4q. It was noted that fibroblast growth factor 1 associated with stem cell maintenance was down-regulated in 19q-loss astrocytomas and genes associated with glioma progression were differentially expressed, these results were validated with the independent TCGA data set. On t-SNE analysis of the 19q-loss astrocytomas with other IDH-mutant glioma subgroups from the TCGA datasets, 19q-loss astrocytomas did not shift to oligodendrogliomas with 1p/19q codeletion but were a subgroup in astrocytomas. These results indicated that 19q-loss in astrocytomas is more likely to be an acquired event rather than early event in oncogenesis like 1p/19q codeletion in oligodendrogliomas, and the biological and morphological features of 19q-loss astrocytomas were possibly related to differentially expressed genes associated with stem cell maintenance and glioma progression.

We previously reported that there was a subgroup of IDH-mutated astrocytomas harboring only 19q-loss showing oligodendroglioma-like morphology and significantly longer overall survival (OS) compared with 19q-intact astrocytomas (Otani et al. Cancer Sci 2018). The purpose of the present study was to reveal how 19q-loss contributed to better prognosis and the morphology in the subgroup. We compared expression pattern between five 19q-loss and five 19q-intact IDH-mutated astrocytomas by microarray analysis. 136 up-regulated genes and 203 down regulated genes were extracted in 19q-loss astrocytomas compared with 19q-intact astrocytomas. Significantly changed genes distributed throughout all chromosomes, but more down-regulated genes were on 19q and 4p, and more up-regulated genes were on 4q. Genes associated with apoptosis, cell adhesion, and antigen presentation were up-regulated, and genes associated with Ras signaling pathway were down-regulated. These changes could result in better prognosis. By contrast, there was few expression changed gene associated with oligodendroglioma-like morphology although up-regulation of genes associated with axon guidance and down-regulation of genes associated with cell shape might result in the morphology or neuronal differentiation. Expression pattern of 19q-loss astrocytomas indicated no tendency of oligodendroglial differentiation. Better prognosis of 19q-loss astrocytomas was derived from expression changes associated with tumor proliferation and tumor immunity.

The introduction of systemic chemotherapy for advanced hepatocellular carcinoma in recent years has led to the prediction that cases of brain metastases from hepatocellular carcinoma will increase. However, because brain metastases from hepatocellular carcinoma are relatively rare, the characteristics of this pathology are poorly understood. We carried out a multicenter retrospective study to verify the characteristics of brain metastases from hepatocellular carcinoma in Japan. A total of 38 patients were enrolled and patient characteristics were poor general condition in many patients due to the progression of primary cancers. Stereotactic radiosurgery/stereotactic radiotherapy alone was the most common treatment (39.5%), with best supportive care provided for 10.5%. Median survival was 6 months, the neurological death rate was 28%, and the rate of brain hemorrhage was high (39.5%). Overall survival was analyzed for correlations with age, etiology of chronic liver disease, albumin–bilirubin (ALBI) grade, RPA classification, control of the primary tumor, number of brain metastases, brain hemorrhage, surgical resection, and radiotherapy. In multivariate analysis, ALBI grade, number of brain metastases and brain hemorrhage showed statistically significant correlation. A multivariate analysis extracted three items—ALBI grade, number of brain metastases, and brain hemorrhage—as prognostic factors for survival of brain metastases from hepatocellular carcinoma.

Background Tumors extending into the optic canal can cause progressive visual impairment because of optic nerve compression. Prompt surgical resection is often necessary. When the tumor is located medially in the optic canal, endoscopic transnasal surgery provides a safer, less invasive alternative to a transcranial approach. Case Description We recently encountered a case of small solitary fibrous tumor in the optic canal causing rapid visual deterioration. The radiographic findings of preoperative imaging studies were compatible with those of meningioma; however, unlike meningioma, bleeding from the tumor was profuse during the operation. The endoscopic transnasal approach was effective for handling the highly vascularized tumor in this delicate region, and gross total removal was achieved with postoperative gradual improvement in his visual function. Nevertheless, the tumor recurred after 6 months, and re-resection was performed using the same surgical corridor, followed by adjuvant radiotherapy. Conclusions Endoscopic transnasal surgery is a valuable option for aggressive lesions in the optic canal. Although the efficacy of radiotherapy for solitary fibrous tumor remains controversial, it should be considered when the tumor shows progressive features.

We report an extremely rare case of pial arteriovenous fistula (AVF) caused by trauma. A 61-year-old man suffered from brain contusion by a traffic accident. He was neurologically normal on admission. However, his headache gradually worsened, and partial seizures occurred thereafter. He presented with general tonic seizure 7 days after the head injury. Magnetic resonance imaging demonstrated the exacerbation of brain edema and an abnormal vein near the contusion. Subsequent angiography showed a pial AVF, which was considered to be responsible for the brain edema. After treatment of the AVF by direct surgery, the brain edema was ameliorated. We should take into consideration the formation of vascular disease in cases with unexpected worsening of edema after brain injury.

OBJECTIVEChordoma is a slow-growing but clinically malignant tumor, and the prognosis remains poor in many cases. There is a strong impetus to develop more effective targeted molecular therapies. On this basis, the authors investigated the potential of Brachyury, a transcription factor involved in notochord development, as a candidate molecular target for the treatment of chordoma.METHODSBrachyury gene copy number and expression levels were evaluated by quantitative polymerase chain reaction in 27 chordoma samples, and the transcriptomes of Brachyury high-expression tumors (n = 4) and Brachyury low-expression tumors (n = 4) were analyzed. A chordoma cell line (U-CH2) was used to investigate the signaling pathways that regulate Brachyury expression.RESULTSAll chordoma specimens expressed Brachyury, and expression levels varied widely. Patients with higher Brachyury expression had significantly shorter progression-free survival (5 months, n = 11) than those with lower expression (13 months, n = 16) (p = 0.03). Somatic copy number gain was confirmed in 12 of 27 (44%) cases, and copy number was positively correlated with Brachyury expression (R = 0.61, p < 0.001). Expression of PI3K/Akt pathway genes was upregulated in Brachyury high-expression tumors, and suppression of PI3K signaling led to reduced Brachyury expression and inhibition of cell growth in the U-CH2 chordoma cell line.CONCLUSIONSActivation of the PI3K/Akt pathway and Brachyury copy number gain are strongly associated with Brachyury overexpression, which appears to be a key event in chordoma growth regulation. These findings suggest that targeting Brachyury and PI3K/Akt signaling may be an effective new approach for treating chordoma.

Among diffuse gliomas, oligodendrogliomas show relatively better prognosis, respond well to radiotherapy and chemotherapy, and seldom progress to very aggressive tumors. To elucidate the genetic and epigenetic background for such behavior and tumor evolution during tumor relapse, we comparatively analyzed 12 pairs of primary and recurrent oligodendrogliomas with 1p/19q-codeletion. Initial treatment for these patients was mostly chemotherapy alone. Temozolomide was used for 3, and procarbazine, nimustine and vincristine (PAV chemotherapy) were used for 7 patients. World Health Organization histological grade at recurrence was mostly stable; it was increased in 2, the same in 9, and decreased in 1 cases. Whole-exome sequencing demonstrated that the rate of shared mutation between the primary and recurrent tumors was relatively low, ranging from 3.2-57.9% (average, 33.3%), indicating a branched evolutionary pattern. The trunk alterations that existed throughout the course were restricted to IDH1 mutation, 1p/19q-codeletion, and TERT promoter mutation, and mutation of the known candidate tumor suppressor genes CIC and FUBP1 were not consistently observed between primary and recurrent tumors. Multiple sampling from different regions within a tumor showed marked intratumoral heterogeneity. Notably, in general, the number of mutations was not significantly different after recurrence, remaining under 100, and no hypermutator phenotype was observed. FUBP1 mutation, loss of chr. 9p21, and TCF12 mutation were among a few recurrent de novo alterations that were found at recurrence, indicating that these events were clonally selected at recurrence but were not enough to enhance malignancy. Genome-wide methylation status, measured by Illumina 450 K arrays, was stable between recurrence and the primary tumor. In summary, although oligodendroglioma displays marked mutational heterogeneity, histological malignant transformation accompanying events such as considerable increase in mutation number and epigenetic profile change were not observed at recurrence, indicating that noticeable temporal and spatial genetic heterogeneity in oligodendrogliomas does not result in rapid tumor progression. Electronic supplementary material The online version of this article (doi:10.1186/s40478-017-0422-z) contains supplementary material, which is available to authorized users.

Glycosphingolipids are major components of the membrane raft, and several kinds of viruses and bacterial toxins are known to bind to glycosphingolipids in the membrane raft. Since the viral genes and pathogenic proteins that are taken into cells are directly delivered to their target organelles, caveolae/raft-mediated endocytosis represents a promising pathway for specific delivery. In the present study, we demonstrated the ability of an artificial pentadecapeptide, which binds to ganglioside GM3, to deliver protein into cells by caveolae/raft-mediated endocytosis. The cellular uptake of a biotinylated GM3-binding peptide (GM3BP)-avidin complex into HeLa cells was observed, and the cellular uptake of this complex was inhibited by an incubation with sialic acid or endocytic inhibitors such as methyl-ß-cyclodextrin, and also by an incubation at 4 °C. These results indicate that the GM3BP-avidin complex bind to GM3 in membrane raft, and are taken into cell through caveolae/raft-mediated endocytosis. The GM3BP-avidin complex was transported into cells and localized around the nucleus more slowly than a human immunodeficiency virus type 1 TAT peptide. Furthermore, the uptake of a green fluorescent protein (GFP) linked with GM3BP into HeLa cells was similar to that of the GM3BP-avidin complex, and the localization of the GM3BP-GFP fusion protein was markedly different with that of the TAT-GFP fusion protein. The uptake and trafficking of GM3BP were distinguished from conventional cell-penetrating peptides. GM3BP has potential as a novel peptide for the selective delivery of therapeutic proteins and materials into cells in addition to being a cell-penetrating peptide.

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The prognostic impact of TERT mutations has been controversial in IDH-wild tumors, particularly in glioblastomas (GBM). The controversy may be attributable to presence of potential confounding factors such as MGMT methylation status or patients’ treatment. This study aimed to evaluate the impact of TERT status on patient outcome in association with various factors in a large series of adult diffuse gliomas. We analyzed a total of 951 adult diffuse gliomas from two cohorts (Cohort 1, n = 758; Cohort 2, n = 193) for IDH1/2, 1p/19q, and TERT promoter status. The combined IDH/TERT classification divided Cohort 1 into four molecular groups with distinct outcomes. The overall survival (OS) was the shortest in IDH wild-type/TERT mutated groups, which mostly consisted of GBMs (P

Objective: Some patients with temporal lobe brain tumours show aggressive or escape behaviour during awake surgery. As the amygdala plays a critical role in coping with stress, we evaluated whether the left or right amygdala was involved in aggressive or escape behaviour in six patients undergoing awake surgery for temporal lobe brain tumours.Methods: Brain tumours were located in the left temporal lobe in cases 1–3 and in the right temporal lobe in cases 4–6. In cases 1, 2, 4 and 5, the tumours invaded the amygdala.Results: In case 1, the patient showed aggressive behaviour before partial removal of the left amygdala during awake surgery; just after partial removal of left amygdala, the patient was calm and cooperative. In case 2, the patient showed aggressive behaviour when the tumour near the left amygdala was removed. In case 3, the patient showed aggressive behaviour when awakening during awake surgery. In case 4, the patient showed escape behaviour when removal of the tumour near the right amygdala was initiated. In cases 5 and 6, patients showed escape behaviour upon awakening and upon initiation of tumour removal from the temporal lobe.Conclusion: In conclusion, these results suggest that left or right temporal lesions might induce aggressive or escape behaviour during awake surgery, respectively, and that the amygdala on the respective side may play a role in these behaviours.

Nowadays, young neurosurgeons need to brush up their skills with lower surgical case volume compared with what senior neurosurgeons have experienced before due to the increasing number of endovascular treatments as well as the trend toward less invasive treatment. To overcome such difficulties, under the instruction of the senior author (KT), the first author underwent suturing training using 10-0 nylon under desktype microscope, accumulating up to 80,000 stitches over the past 8 years. In addition, the junior author (NK, AK, RO) underwent the same training, accumulating up to 10,000-40,000 stitches. The training resulted in the surgeons being able to achieve stable STA-MCA anastomosis under supervision after 10,000 stitches, STA-MCA anastomosis within 20 minutes occlusion time and mastery of aneurysmal clipping of anterior circulation (normal size) after 30,000 stitches, deep anastomosis and clipping of large aneurysm under supervision after 50,000 stitches. After 80,000 stitches, it was possible to manage 280 surgical cases/year institution (clipping, 50; bypass, 30; ICH removal, 30) as a chief. Although there are various factors to improve surgical skills, this simple, daily and long-term training could help overcome the steep learning curve of cerebrovascular surgical skills by improving dexiterity and maneuverability under high magnification.

Low-grade gliomas often undergo malignant progression, and these transformations are a leading cause of death in patients with low-grade gliomas. However, the molecular mechanisms underlying malignant tumor progression are still not well understood. Recent evidence indicates that epigenetic deregulation is an important cause of gliomagenesis; therefore, we examined the impact of epigenetic changes during malignant progression of low-grade gliomas. Specifically, we used the Illumina Infinium Human Methylation 450K BeadChip to perform genome-wide DNA methylation analysis of 120 gliomas and four normal brains. This study sample included 25 matched-pairs of initial low-grade gliomas and recurrent tumors (temporal heterogeneity) and 20 of the 25 recurring tumors recurred as malignant progressions, and one matched-pair of newly emerging malignant lesions and pre-existing lesions (spatial heterogeneity). Analyses of methylation profiles demonstrated that most low-grade gliomas in our sample (43/51; 84%) had a CpG island methylator phenotype (G-CIMP). Remarkably, approximately 50% of secondary glioblastomas that had progressed from low-grade tumors with the G-CIMP status exhibited a characteristic partial demethylation of genomic DNA during malignant progression, but other recurrent gliomas showed no apparent change in DNA methylation pattern. Interestingly, we found that most loci that were demethylated during malignant progression were located outside of CpG islands. The information of histone modifications patterns in normal human astrocytes and embryonal stem cells also showed that the ratio of active marks at the site corresponding to DNA demethylated loci in G-CIMP-demethylated tumors was significantly lower; this finding indicated that most demethylated loci in G-CIMP-demethylated tumors were likely transcriptionally inactive. A small number of the genes that were upregulated and had demethylated CpG islands were associated with cell cycle-related pathway. In summary, we demonstrated that characteristic DNA demethylation occurred during malignant progression of a subset of low-grade gliomas. The mechanisms underlying and consequences of such DNA demethylation should be studied further.

The usefulness of rapid growth hormone (GH) measurement was retrospectively evaluated as an indicator of total tumor removal during surgery and compared with several reported criteria in 252 acromegalic patients who underwent transsphenoidal surgery at Toranomon Hospital between 2006 and 2008. GH levels were measured in blood samples obtained before surgery, at the start of tumor removal, and every 20 minutes thereafter until 20 minutes after total tumor removal as judged by the operator. Intraoperative GH dynamics were compared between 201 patients fulfilling the Cortina consensus criteria (successful group) and 37 patients who did not (unsuccessful group). Among several criteria indicating total tumor removal, only the ratio of serum GH level 20 minutes after the end of tumor removal to GH level at the end of tumor excision was significantly different between the groups; a reduction ratio of 65% was the most appropriate cut-off value based on sensitivity (59.2%) and specificity (59.5%). The ratio of GH level 20 minutes after the end of tumor removal/GH level at the end of tumor excision was the most reliable index to judge tumor removal during surgery, but this index is neither necessary nor sufficient and should be used as one of the indicators to judge complete tumor removal during surgery.

Brain imaging studies suggest that panic disorder (PD) is mediated by several brain regions, including the anterior cingulate cortex (ACC). In the present report we describe a patient who experienced a panic attack during awake surgery (case 1) and another patient who developed PD after surgery and radiotherapy (case 2). In case 1, the patient experienced repeated panic attacks when the tumor at the upper border of right dorsal ACC was removed during awake surgery. In case 2, the patient developed PD at six months after surgery and Cyberknife radiotherapy. MRI examination revealed that the dorsal ACC size was reduced at six months after surgery and that the dorsal ACC was absent at two years after surgery, possibly due to radiotherapy-induced damage by radiotherapy. Profile of mood states (POMS) testing characterized the presence of tension-anxiety as the common abnormal symptom in cases 1 and 2. In conclusion, these results suggest that damage to the right dorsal ACC can induce PD and that this structure likely plays a pathophysiologic role in PD.

Low-grade glioma, especially astrocytomas often undergo malignant progression, and these transformations are a leading cause of death in patients with low-grade gliomas. However, the mechanisms underlying malignant tumor transformation are still not well understood. Recent evidence indicates that epigenetic deregulation is an important cause of gliomagenesis; therefore, we examined the epigenetic changes during malignant progression of gliomas. We used the Illumina Infinium Human Methylation 450K BeadChip to perform genome-wide DNA methylation analysis of 124 gliomas and four normal brains. These tumors comprised 37 grade IV gliomas, 32 grade III gliomas, and 55 grade II gliomas. This study sample included 26 matched-pairs of initial lower grade gliomas and recurrent tumors and 21 of the 26 recurring tumors recurred as malignant progressions. Analyses of methylation profiles demonstrated that most low-grade gliomas in our sample (84%) had a CpG island methylator phenotype (G-CIMP). Remarkably, approximately 25% of recurrent malignant gliomas that had progressed from low-grade tumors with the G-CIMP status exhibited a characteristic partial demethylation of genomic DNA during malignant progression, but other recurrent gliomas showed no apparent change in DNA methylation pattern. Interestingly, we found that most loci that were demethylated during malignant progression were located outside of CpG islands. The information of histone modifications patterns in normal human astrocytes and embryonal stem cells also showed that the ratio of active marks at the site corresponding to DNA demethylated loci in G-CIMP-demethylated tumors was significantly lower; this finding indicated that most demethylated loci in G-CIMP-demethylated tumors were likely transcriptionally inactive. A small number of the genes that were upregulated and had demethylated CpG islands were associated with cell cycle-related pathway. Here, we demonstrated that partial DNA demethylation occurred during malignant transfomrmation of a subset of lower grade gliomas. Citation Format: Mukasa Akitake, Kuniaki Saito, Koki Aihara, Genta Nagae, Mayu Omata, Ryohei Otani, Shunsaku Takayangi, Shota Tanaka, Yoshitaka Narita, Keisuke Ueki, Ryo Nishikawa, Motoo Nagane, Hiroyuki Aburatani, Nobuhito Saito. DNA methylation profile analysis of gliomas revealed a change in methylation status during malignant progression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1072. doi:10.1158/1538-7445.AM2015-1072