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Sphingolipid metabolism is dysregulated in many cancers, allowing cells to evade apoptosis through increased sphingosine-1-phosphate (S1P) and decreased ceramides. Ceramidases hydrolyze ceramides to sphingosine, which is phosphorylated by sphingosine kinases to generate S1P. The S1P allows cells to evade apoptosis by shifting the equilibrium away from ceramides, which favor cell death. One tumor type that exhibits a shift in the sphingolipid balance towards S1P is glioblastoma (GBM), a highly aggressive brain tumor. GBMs almost always recur despite surgical resection, radiotherapy, and chemotherapy with temozolomide (TMZ). Understanding sphingolipid metabolism in GBM is still limited, and currently, there are no approved treatments to target dysregulation of sphingolipid metabolism in GBM. Carmofur, a derivative of 5-fluorouracil, inhibits acid ceramidase (ASAH1), a key enzyme in the production of S1P, and is in use outside the USA to treat colorectal cancer. We find that the mRNA for ASAH1, but not other ceramidases, is elevated in recurrent GBM. When TMZ-resistant GBM cells were treated with carmofur, decreased cell growth and increased apoptosis were observed along with cell cycle perturbations. RNA-sequencing identified decreases in cell cycle control pathways that were specific to TMZ-resistant cells. Furthermore, the transcription factor and G1 to S phase regulator, E2F8, was upregulated in TMZ-resistant versus parental GBM cells and inhibited by carmofur treatment in TMZ-resistant GBM cells, specifically. These data suggest a possible role for E2F8 as a mediator of carmofur effects in the context of TMZ resistance. These data suggest the potential utility of normalizing the sphingolipid balance in the context of recurrent GBM.
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Glioblastoma multiforme (GBM) is a malignant adult brain tumor that is visualized as an enhancing lesion on post-contrast magnetic resonance imaging (MRI). In this study, we present a rare case of non-enhancing GBM that required histopathological examination for a definitive diagnosis. Our findings emphasize the critical role of biopsy in the diagnosis and treatment of GBMs, particularly in cases of non-enhancing lesions on MRI.
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Background: Treatment-resistant glioblastoma (trGBM) is an aggressive brain tumor with a dismal prognosis, underscoring the need for better treatment options. Emerging data indicate that trGBM iron metabolism is an attractive therapeutic target. The novel iron mimetic, gallium maltolate (GaM), inhibits mitochondrial function via iron-dependent and -independent pathways. Methods: In vitro irradiated adult GBM U-87 MG cells were tested for cell viability and allowed to reach confluence prior to stereotactic implantation into the right striatum of male and female athymic rats. Advanced MRI at 9.4T was carried out weekly starting two weeks after implantation. Daily oral GaM (50mg/kg) or vehicle were provided on tumor confirmation. Longitudinal MRI parameters were processed for enhancing tumor ROIs in OsiriX 8.5.1 (lite) with Imaging Biometrics Software (Imaging Biometrics LLC). Statistical analyses included Cox proportional hazards regression models, Kaplan-Meier survival plots, linear mixed model comparisons, and t-statistic for slopes comparison as indicator of tumor growth rate. Results: In this study we demonstrate non-invasively, using longitudinal MRI surveillance, the potent antineoplastic effects of GaM in a novel rat xenograft model of trGBM, as evidenced by extended suppression of tumor growth (23.56 mm3/week untreated, 5.76 mm3/week treated, P < 0.001), a blunting of tumor perfusion, and a significant survival benefit (median overall survival: 30 days untreated, 56 days treated; P < 0.001). The therapeutic effect was confirmed histologically by the presence of abundant cytotoxic cellular swelling, a significant reduction in proliferation markers (P < 0.01), and vessel normalization characterized by prominent vessel pruning, loss of branching, and uniformity of vessel lumina. Xenograft tumors in the treatment group were further characterized by an absence of an invasive edge and a significant reduction in both, MIB-1% and mitotic index (P < 0.01 each). Transferrin receptor and ferroportin expression in GaM-treated tumors illustrated cellular iron deprivation. Additionally, treatment with GaM decreased the expression of pro-angiogenic markers (von Willebrand Factor and VEGF) and increased the expression of anti-angiogenic markers, such as Angiopoietin-2. Conclusion: Monotherapy with the iron-mimetic GaM profoundly inhibits trGBM growth and significantly extends disease-specific survival in vivo.
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Glioblastoma (GBM) remains one of the most aggressive cancers, partially due to its ability to migrate into the surrounding brain. The sphingolipid balance, or the balance between ceramides and sphingosine-1-phosphate, contributes to the ability of GBM cells to migrate or invade. Of the ceramidases which hydrolyze ceramides, acid ceramidase (ASAH1) is highly expressed in GBM samples compared to non-tumor brain. ASAH1 expression also correlates with genes associated with migration and focal adhesion. To understand the role of ASAH1 in GBM migration, we utilized shRNA knockdown and observed decreased migration that did not depend upon changes in growth. Next, we inhibited ASAH1 using carmofur, a clinically utilized small molecule inhibitor. Inhibition of ASAH1 by carmofur blocks in vitro migration of U251 (GBM cell line) and GBM cells derived from patient-derived xenografts (PDXs). RNA-sequencing suggested roles for carmofur in MAPK and AKT signaling. We found that carmofur treatment decreases phosphorylation of AKT, but not of MAPK. The decrease in AKT phosphorylation was confirmed by shRNA knockdown of ASAH1. Our findings substantiate ASAH1 inhibition using carmofur as a potential clinically relevant treatment to advance GBM therapeutics, particularly due to its impact on migration.
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Ceramidase Ácida , Glioblastoma , Ceramidase Ácida/genética , Ceramidase Ácida/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Ceramidas/metabolismo , Fluoruracila , Glioblastoma/metabolismo , Humanos , Proteínas Proto-Oncogênicas c-akt , RNA Interferente PequenoRESUMO
Intracerebral hemorrhage (ICH), accounting for 9-27% of all strokes, carries substantial rates of morbidity and mortality that have not shown much improvement in the past decades. The poor outcomes of ICH can be attributed to the primary and secondary brain injuries caused by mass effects and inflammatory mechanisms, respectively. Early ICH evacuation is a critical component of treatment, as it mitigates the effect of both the primary and secondary mechanisms of brain injury and is associated with significant improvement in patient outcomes. However, no standardized evacuation technique exists. This technical report introduces a novel stereotactic vacuum-assisted minimally invasive (MIS) aspiration of a hemorrhagic stroke with its effectiveness evidenced by excellent patient recovery.
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Brain abscesses are difficult to manage clinically and often result in a poor outcome. Although surgical and medical therapeutics have progressed, there are still challenges that make treating intracranial abscesses problematic. One of these treatment barriers is the poor penetration of intravenous antibiotics to the infection source through the blood-brain barrier. In this case report, we will discuss the use of a surgical drain as a conduit for direct antibiotic administration for a rare, recurrent Streptococcus intermedius infection. This technique allows us to bypass the blood-brain barrier while also reducing the systemic effects of antibiotics. When used in conjunction with craniotomy and resection, direct antibiotic administration via a surgical drain proved to be effective at treating our patient's abscess and preventing recurrence.
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Olfactory groove meningiomas are slow-growing tumors that manifest with headaches, changes in vision, and personality changes. The anatomic location of these tumors makes psychiatric disturbances more common early in the stage of tumors than focal neurological deficits. The case study here describes a unique instance of an undiagnosed giant olfactory groove meningioma in a young mother who was charged with a felony of aggravated child abuse for the death of her toddler daughter. The patient underwent gross tumor resection and radiation therapy, which halted the visual decline, resolved the frontal headaches, and the patient showed improved mood. In this patient, the insidious onset of personality changes without obvious focal neurologic deficits until late as well as a history of depression likely contributed to the delayed diagnosis. Failure to notice these initial behavioral manifestations in these patients allows for further psychiatric and cognitive decline, which can result in devastating social consequences.
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OBJECTIVE: Endometrial cancer is the most common gynecologic cancer and yet much is still unknown about this disease. Our goal was to identify unique biomarkers of disease by performing a comprehensive proteomic analysis of early stage, low-grade endometrial cancer through analysis of serum collected from patients pre- and post-definitive surgery. METHODS: We used mass spectrometry (MS)-based proteomics to identify serum proteins from these patients. Serum samples from women undergoing hysterectomy with bilateral salpingo-oophorectomy for benign reasons served as control samples for the correlative studies. We then correlated our findings with The Cancer Genome Atlas (TCGA) database for additional confirmation. RESULTS: The Ingenuity Pathway Analysis of proteins that were differentially expressed in endometrial cancer showed increased cell survival and decreased organismal death, the most common hallmarks of cancer. We identified over expression of FAM83D (family with sequence similarity 83, member D) in the serum of patients with early stage low-grade endometrial cancer and verified the same in the endometrial cancer cell lines and patient tumors. We also confirmed our hypothesis that FAM83D may serve as a biomarker for endometrial cancer in a cohort of patients with endometrial cancer from The Cancer Genome Atlas (TCGA) project. CONCLUSION: Comprehensive proteomic analysis is a feasible strategy for potential biomarker identification. Using this technique, FAM83D was identified as a candidate biomarker in early endometrial cancer in our patient samples and was not present in benign control samples. FAM83D has been associated with poor clinical outcomes in several human malignancies. SIGNIFICANCE: Our manuscript describes an alternative approach to comprehensive protein analysis in a model pre and post tumor removal for a sample of patients with early endometrial cancer. The model is innovative and the findings of over expression FAM83D in this population of early cancer may be useful in the study of a disease where there are few biomarkers or targetable therapies.
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Neoplasias do Endométrio , Proteômica , Proteínas de Ciclo Celular , Endométrio , Feminino , Humanos , Proteínas Associadas aos MicrotúbulosRESUMO
A 53-year-old female admitted to the hospital for generalized weakness, fever, and cough, tested positive for coronavirus disease 2019 (COVID-19). She experienced cardiac arrest and then developed a deep-venous thrombosis and pneumonia. She then developed new-onset paraplegia due to an epidural abscess found on thoracic-spine imaging. After surgical removal of the epidural abscess, the patient improved clinically. This is a unique case report of a patient developing paraplegia secondary to an epidural abscess as a serious complication of COVID-19 infection.
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Atypical central neurocytoma with extracranial metastases is a rare variant of benign central neurocytoma (CN). No definitive course of treatment exists for atypical CN. We report a unique case of atypical CN with concomitant pituitary macroadenoma and subsequent metastases to the spine. The patient received craniospinal radiation therapy. Close-follow up post tumor-resection may be advised to monitor for drop metastases. To the best of our knowledge, this is the only case reported of atypical CN with drop metastases to the spine concomitant with pathological-proven pituitary macroadenoma.
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BACKGROUND: For gliomas, metropolitan status has not been heavily explored in the context of short-term mortality or long-term observed survival. Larger populations are associated with proximity to academic universities/high-volume hospitals. METHODS: The SEER-18 registry was queried for patients with gliomas. The patients were further classified into two population groups based on rural-urban continuum codes: metropolitan or non-metropolitan. Demographics and clinical factors were compared between both groups. For observed survival, univariate and multivariate analyses occurred with Cox proportional hazards model. RESULTS: The non-metropolitan group constituted approximately 10.8% of all patients. Age at diagnosis of glioma was older for the non-metropolitan group compared to metropolitan group (51.60 years vs. 49.06 years). Relative to the metropolitan group, the non-metropolitan group exhibited a larger proportion of Caucasian, married, grade I and IV gliomas, no surgery, no GTR (for those who had surgery), and temporal/parietal/occipital locations. Other covariates (sex, tumor size, laterality, and radiation status) did not exhibit significant differences in proportions. From analysis of observed survival, independent predictors include population group, as well as age, gender, marital status, tumor location, tumor grade, laterality, GTR, and receipt of radiation. Short-term mortality was 11.68% and 13.04% for Metropolitan and non-metropolitan groups, respectively. Median survival was 15 months and 12 months for Metropolitan and non-metropolitan groups, respectively. CONCLUSIONS: About one-tenth of gliomas are treated at non-metropolitan sites. Key differences exist among patient/glioma characteristics based on metropolitan status. Overall, metropolitan status appears to influence short-term mortality and long-term observed survival for gliomas.
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Neoplasias Encefálicas/mortalidade , Glioma/mortalidade , Adulto , Idoso , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , População Rural , Programa de SEER , População UrbanaRESUMO
BACKGROUND: Glioblastoma (GB) and its variants portend a poor prognosis. The predominant cause of death (COD) is related to the cancer diagnosis, but a significant subset is related to other causes. As GB is a systemic disease requiring systemic treatment, focus regarding all COD provides a comprehensive illustration of the disease. METHODS: The SEER-18 was queried for patients with cranial GB and its variants. Age, gender, race, marital status, tumor characteristics, treatment details, and follow-up data were acquired. The patients were classified into group A (death attributed to this cancer diagnosis) or group B (death attributed to causes other than this cancer diagnosis). RESULTS: From 1973 to 2013, 36,632 deaths (94%) constituted group A, and 2,324 deaths (5.9%) constituted group B. The latter significantly exhibited lower proportions of age <60, Caucasians, married status, frontal/brain stem/ventricle tumor locations, and receipt of radiation. From logistic regression, age >60, male gender, race, not married, tumor location, and no radiation were significant independent predictors for group B. The top known CODs in group B are diseases of heart, pneumonia and influenza, cerebrovascular diseases, accidents and adverse effects, and infections. CONCLUSIONS: CODs not attributed to GB remains a significant subset of all CODs. Many of these, particularly diseases of heart, are frequent comorbidities. Moreover, infection-related CODs after GB diagnosis appear more salient compared to CODs in the general population. Consideration of these CODs, and vigilant treatment aimed at these CODs, may improve overall care for GB patients.
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Neoplasias Encefálicas/epidemiologia , Causas de Morte , Glioblastoma/epidemiologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Programa de SEERRESUMO
Human acid ceramidase (AC) is a lysosomal cysteine amidase, which has received a great deal of interest in recent years as a potential target for the development of new therapeutics against melanoma and glioblastoma tumors. Despite the strong interest in obtaining structural information, only the structures of the apo-AC enzyme in its zymogen and activated conformations are available. In this work, the crystal structure of AC in complex with the covalent carmofur inhibitor is presented. Carmofur is an antineoplastic drug containing an electrophilic carbonyl reactive group that targets the catalytic cysteine. This novel structural data explains the basis of the AC inhibition, provides insights into the enzymatic properties of the protein, and is a great aid toward the structure-based drug design of potent inhibitors for AC, providing the detailed mechanism, which has eluded the scientific community for more than 30 years, of carmofur's mysterious 5-fluorouracil-independent antitumor activity.
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Ceramidase Ácida/antagonistas & inibidores , Antineoplásicos/química , Fluoruracila/análogos & derivados , Simulação de Dinâmica Molecular , Ceramidase Ácida/genética , Ceramidase Ácida/metabolismo , Antineoplásicos/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Fluoruracila/química , Fluoruracila/metabolismo , Humanos , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificaçãoRESUMO
INTRODUCTION: The impact of multiple primary tumors, in the setting of malignant glioma (MG), has not been heavily explored. METHODS: We extracted demographics and clinical data from the SEER-18 registry for adult patients with MGs. The cases were separated based on the sequence of MG diagnosis relative to the other primary tumors: Group (A) One primary only or first primary of multiple primaries and Group (B) second primary or subsequent primary tumor. Incidences, frequencies, and glioma-related survivals were analyzed. RESULTS: Group B constituted 12.8% of new MG. The incidences of group B, relative to those of all new MG, range from 0.14 to 0.18. Compared to group A, group B exhibited an older age. Moreover, group B exhibited a higher proportion of females, Caucasians, smaller tumors, non-operative cases, and those receiving radiation (p < 0.05); the proportion with GTR remained comparable. Multiple groupings (oral cavity, digestive system, respiratory system, skin, breast, genital systems, urinary system, lymphoma) exhibited lower glioma-related observed survival (p < 0.05) compared to Group A. An active diagnosis of "leukemia" appears to confer longer glioma-related survival while a history of "breast" or "digestive system" malignancies portends a shorter glioma-related survival. CONCLUSION: For newly diagnosed MG, a high proportion does have history of extra-CNS primary tumors. Generally, these patients appear to have worse glioma-related observed survival compare to those with malignant glioma as the only primary or the first of multiple primary tumors. Knowledge regarding epidemiology, clinical factors, and observed survival can help guide clinical management/consultation for this subset of patients.
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Neoplasias Encefálicas/epidemiologia , Neoplasias Encefálicas/terapia , Glioma/epidemiologia , Glioma/terapia , Neoplasias Primárias Múltiplas/epidemiologia , Neoplasias Primárias Múltiplas/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/complicações , Criança , Pré-Escolar , Feminino , Glioma/complicações , Humanos , Lactente , Recém-Nascido , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Neoplasias Primárias Múltiplas/complicações , Sistema de Registros , Adulto JovemRESUMO
INTRODUCTION: Secondary glioblastomas (GBs) constitute a small subset of all GBs and tend to arise after a lower grade glioma. Though knowledge regarding this subset has gained traction in recent years, its definition continues to evolve, complicating its clinical management. Investigation of epidemiology and survival patterns may help provide needed insights. RESULTS: The age at GB diagnosis is significantly lower (46.22 vs 60.25 years) for group B. The distribution among type of GB (glioblastoma, giant cell glioblastoma, or gliosarcoma) was significantly different, with no diagnosis of giant cell GB in Group B. Compared to Group A, Group B exhibited a higher proportion of females, not married, smaller tumors, no GTR, and no radiation (all p < 0.05). GB-related observed survivals were comparable. Cox regression with inclusion of co-variates reveal no significant influence of GB group on observed survival. Regarding group B, mean age was 40.197 for diagnosis of initial lower grade glioma. The most common initial ICD-O-3 pathology was oligodendroglioma, NOS; astrocytoma, NOS; astrocytoma, anaplastic; and mixed glioma. METHODS: The SEER-18 registry was queried for patients with GBs. Patients were further classified into two GB groups: Group A - those with GB as the only primary tumor, and Group B - those with GB as a 2nd primary or subsequent tumor and with history of lower grade gliomas. Demographics and clinical factors were compared between group A and B. Appropriate statistics were employed to calculate incidences and differences among factors and GB-related survivals between the groups. CONCLUSIONS: Overall, Group B develops GBs at an earlier age, but observed survival remains similar to those with GBs as the only primary. Moreover, this subset also exhibit different proportions of the types of GBs, and well as differences in other key clinical factors (namely, gender and tumor size at presentation). Prior treatments for lower grade gliomas likely explain some of the differences noted regarding management course after diagnosis of GB.
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Methotrexate (MTX) is a common antimetabolite agent that is widely used today in treating leukemia, lymphoma, and osteosarcoma. Its use has been associated with leukoencephalopathy causing seizures, paralysis, and even coma. To achieve the best possible outcome, it is important to be able to make a prompt diagnosis. Studies reported restricted diffusion on diffusion-weighted imaging (DWI) which is a reliable early sign of acute MTX-induced leukoencephalopathy. However, we report here the first case of MTX-induced leukoencephalopathy without typical restricted diffusion on DWI and the utility magnetic resonance spectroscopy to support this diagnosis in the difficult case such as the one being presented here.
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Pediatric glioblastoma (GBM) is a relatively rare brain tumor in children that has a dismal prognosis. Surgery followed by radiotherapy is the main treatment protocol used for older patients. The benefit of adjuvant chemotherapy is still limited due to a poor understanding of the underlying molecular and genetic changes that occur with irradiation of the tumor. In this study, we performed total RNA sequencing on an established stable radioresistant pediatric GBM cell line to identify mRNA expression changes following radiation. The expression of many genes was altered in the radioresistant pediatric GBM model. These genes have never before been reported to be associated with the development of radioresistant GBM. In addition to exhibiting an accelerated growth rate, radioresistant GBM cells also have overexpression of the DNA synthesis-rate-limiting enzyme ribonucleotide reductase, and pro-cathepsin B. These newly identified genes should be concertedly studied to better understand their role in pediatric GBM recurrence and progression after radiation. It was observed that the changes in multiple biological pathways protected GBM cells against radiation and transformed them to a more malignant form. These changes emphasize the importance of developing a treatment regimen that consists of a multiple-agent cocktail that acts on multiple implicated pathways to effectively target irradiated pediatric GBM. An alternative to radiation or a novel therapy that targets differentially expressed genes, such as metalloproteases, growth factors, and oncogenes and aim to minimize oncogenic changes following radiation is necessary to improve recurrent GBM survival.
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BACKGROUND: Subependymal giant cell astrocytoma (SEGA) is a rare, benign neoplasm predominantly associated with tuberous sclerosis complex. Clinical outcomes have largely been conveyed via small- and medium-sized case series. METHODS: With the Surveillance, Epidemiology, and End Results Program (SEER)-18 registry database, information from all patients diagnosed with SEGA from 2004 to 2013 was obtained (age, sex, race, marital status, tumor size, tumor location, occurrence of surgery, receipt of radiation, and follow-up data). Age-adjusted incidence rates and overall survival (OS) were determined. Cox proportional hazards model was used for both univariate and multivariate analyses. RESULTS: The overall incidence of SEGA within the SEER-18 database is 0.027 per 100,000 person-years (95% confidence interval, 0.024-0.031). A total of 226 cases were identified. For OS, univariate analysis revealed age younger than 18 years (hazard ratio [HR], 0.214; P = 0.004) and occurrence of surgery (HR, 0.328; P = 0.039) were significant positive prognostic factors. Sex, marital status, race, tumor size, tumor location, and receipt of radiation did not exhibit significant relationships. Interestingly, subanalysis for extent of resection to gross total resection did not show benefit. Multivariate analysis revealed that both age younger than 18 years (HR, 0.193; P = 0.002) and occurrence of surgery (HR, 0.286; P = 0.021) remained significant. CONCLUSIONS: Based on our analysis, younger age and occurrence of surgery are significant independent factors associated with better OS. There was no support for radiation.
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Astrocitoma/epidemiologia , Astrocitoma/terapia , Vigilância da População , Programa de SEER/tendências , Esclerose Tuberosa/epidemiologia , Esclerose Tuberosa/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Vigilância da População/métodos , Sistema de Registros , Adulto JovemRESUMO
INTRODUCTION: Intracranial hemangioblastoma (HB) is a rare pathology. Limited data exist regarding its epidemiology. METHODS: With the SEER-18 registry database, information from all patients diagnosed with intracranial HB from 2004 to 2013 were extracted, including age, gender, race, marital status, presence of surgery, extent of surgery, receipt of radiation, tumor size, tumor location, and follow-up data. Age-adjusted incidence rates and overall survival (OS). Cox proportional hazards model was employed for both univariate and multivariate analyses. RESULTS: A total of 1307 cases were identified. The overall incidence of intracranial hemangioblastoma is 0.153 per 100,000 person-years [95% confidence interval (CI)=0.145-0.162]. Through univariate analysis, age < 40 [hazard ratio (HR)=0.277, p<0.001], no radiation [HR=0.56, p=0.047], and presence of surgery [HR=0.576, p=0.012] are significant positive prognostic factors. Caucasian race [HR=1.42, p=0.071] and female gender [HR=0.744, p=0.087] exhibit noticeable trends towards positive prognosis. Through multivariate analysis, younger age [HR=1.053, p < 0.01], race [HR=1.916, p<0.01], and presence of surgery [HR=0.463, p<0.01 were significant independent prognostic factors. CONCLUSION: Clinical factors such as younger age, Caucasian race, and presence of surgery are significant independent factors for overall survival in patients with HBs. Though analysis regarding extent of surgery did not produce a meaningful relationship, this may be related to surgical bias / expertise. Moreover, no validation for radiation therapy was identified, but this may be related to short follow up intervals and the variable growth patterns of HBs.
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Glioblastoma (GBM) is the most common primary malignant tumor of the central nervous system. With its overall dismal prognosis (the median survival is 14 months), GBMs demonstrate a resounding resilience against all current treatment modalities. The absence of a major progress in the treatment of GBM maybe a result of our poor understanding of both GBM tumor biology and the mechanisms underlying the acquirement of treatment resistance in recurrent GBMs. A comprehensive understanding of these markers is mandatory for the development of treatments against therapy-resistant GBMs. This review also provides an overview of a novel marker called acid ceramidase and its implication in the development of radioresistant GBMs. Multiple signaling pathways were found altered in radioresistant GBMs. Given these global alterations of multiple signaling pathways found in radioresistant GBMs, an effective treatment for radioresistant GBMs may require a cocktail containing multiple agents targeting multiple cancer-inducing pathways in order to have a chance to make a substantial impact on improving the overall GBM survival.