TERTp Mutation Detection in Plasma by Droplet-Digital Polymerase Chain Reaction in Spinal Myxopapillary Ependymoma with Lung Metastases.

BACKGROUND: Spinal myxopapillary ependymoma (SP-MPE) is a subgroup of ependymomas in which after initial gross tumor resection, recurrences occur in more than half of the patients. Anaplastic transformation may also occur and contributes to intraneural and extraneural metastatic dissemination. Extraneural metastases from SP-MPE are rare and worsen the prognosis. In this situation, the noninvasive detection of recurrent somatic mutations in the circulating tumor DNA (ctDNA) from plasma is challenging. Telomerase-reverse transcriptase gene promoter (TERTp) mutation has been identified in a subset of ependymomas with aggressive behavior. CASE DESCRIPTION: We report on a patient with TERTp mutated SP-MPE presenting with an extraneural anaplastic metastatic dissemination after iterative local recurrences. From the initial SP-MPE to pleural anaplastic lesion, TERTp C228T mutation was present with allele frequency varying from 33% to 39%. Interestingly, TERTp mutation was also detected by droplet digital polymerase chain reaction in the plasma with a frequency of 2.1% at the time of pleural metastases, highlighting that ctDNA is released in plasma of patients suffering from SP-MPE with extraneural metastatic dissemination. CONCLUSIONS: Despite the rarity of this evolution, plasmatic liquid biopsy appears to be a useful diagnostic and follow-up tool in a subset of primary brain tumors.

Clinical Importance of Free Thyroxine Concentration Decline After Radiotherapy for Pediatric and Adolescent Brain Tumors.

CONTEXT: Clinical significance of a decline in free T4 (FT4) concentrations across the reference range in children with brain tumors treated with radiation therapy (RT) is uncertain. OBJECTIVES: To study trends in FT4 in children after RT and risk factors and health outcomes associated with plasma FT4 concentrations. DESIGN AND SETTING: Longitudinal, single-center retrospective cohort study. PATIENTS: Low-grade glioma or ependymoma patients (n = 267; age ≤25 years) who received RT (50.4 to 59.4 Gy) at a single institution (1996 to 2016) and followed with serial FT4 measurements. MAIN OUTCOME MEASURE: A linear mixed-effects model with a random intercept was used to investigate risk factors for longitudinal changes in FT4 concentrations. A two-stage mixed-effects model examined associations between clinical outcomes and plasma FT4 concentrations. RESULTS: FT4 concentrations declined over time after RT (P < 0.001). Females (P < 0.001) and younger patients (P < 0.001) demonstrated greater declines in FT4 concentrations over time. The rate of weight gain, but not of height loss, increased with a higher FT4 decline rate (P < 0.001). At last follow-up, patients with lower baseline FT4 concentrations had increased risk of glucose disorder (OR, 19.73; P = 0.002) or dyslipidemia (OR, 19.40; P = 0.003) but not high fat mass (P = 0.18). Lower baseline FT4 concentrations were not associated with impaired scores for intelligence, attention, memory, or psychosocial functioning. CONCLUSIONS: FT4 concentrations significantly decline in children with brain tumor after RT. Variation and trends in FT4 concentration are associated with physical health outcomes. Future studies should assess whether continuous FT4 concentrations and trends, rather than population-based cut-off values, can distinguish between euthyroid and hypothyroid states.

Translational Pharmacokinetic-Pharmacodynamic Modeling and Simulation: Optimizing 5-Fluorouracil Dosing in Children With Pediatric Ependymoma.

We previously investigated novel therapies for pediatric ependymoma and found 5-fluorouracil (5-FU) i.v. bolus increased survival in a representative mouse model. However, without a quantitative framework to derive clinical dosing recommendations, we devised a translational pharmacokinetic-pharmacodynamic (PK-PD) modeling and simulation approach. Results from our preclinical PK-PD model suggested tumor concentrations exceeded the 1-hour target exposure (in vitro IC90), leading to tumor growth delay and increased survival. Using an adult population PK model, we scaled our preclinical PK-PD model to children. To select a 5-FU dosage for our clinical trial in children with ependymoma, we simulated various 5-FU dosages for tumor exposures and tumor growth inhibition, as well as considering tolerability to bolus 5-FU administration. We developed a pediatric population PK model of bolus 5-FU and simulated tumor exposures for our patients. Simulations for tumor concentrations indicated that all patients would be above the 1-hour target exposure for antitumor effect.

Spinal myxopapillary ependymomas: a retrospective clinical and immunohistochemical study.

BACKGROUND: Myxopapillary ependymoma (MPE) is a rare subtype of ependymoma that develops almost exclusively within the spinal cord. Despite its benign biological nature, MPE has a propensity to recur locally or distantly. Although variables influencing the prognosis, such as age, the extent of surgery and radiotherapy, have been widely discussed, no definitive standard has been established. Compared to other spinal tumors, many fewer histological markers have been elucidated to assist the determination of the prognosis. METHODS: Twenty-seven patients who underwent resection of MPE were enrolled. We determined their demographic features, imaging characteristics, clinical presentations and outcomes, surgical procedures and histological properties by chart review, telephone contact, reviewing of surgical notes, pre-/postoperative imaging and immunohistological staining. RESULTS: GTR (gross total resection) was achieved in 18 patients (66.7 %) and STR (subtotal resection) in 9 (33.3 %). Although GTR rendered a better disease control rate, the difference was not significant. Pediatric patients suffered from a greater risk of recurrence as well as a shorter period to disease relapse. In the majority of cases, we observed the overexpression of platelet-derived growth factor receptor α (PDGFRα), matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-14 (MMP14). Epidermal growth factor receptor (EGFR) was observed in the tumors of 7 of 23 nonrecurrent patients, but not in any recurrent tumors. CONCLUSIONS: The results of the present study indicate that the extent of resection and age are major factors related to tumor recurrence. Therefore, gross total resection is recommended whenever possible unless following neurological dysfunction is predictable. Moreover, pediatric patients need considerable attention after surgery, particularly in the early stages. PDGFRα, MMP2 and MMP14 may be new diagnostic and therapeutic targets and EGFR a potential predictor of improved prognosis for MPE.

Exosomal levels of miRNA-21 from cerebrospinal fluids associated with poor prognosis and tumor recurrence of glioma patients.

Glioma is a most common type of primary brain tumors. Extracellular vesicles, in the form of exosomes, are known to mediate cell-cell communication by transporting cell-derived proteins and nucleic acids, including various microRNAs (miRNAs). Here we examined the cerebrospinal fluid (CSF) from patients with recurrent glioma for the levels of cancer-related miRNAs, and evaluated the values for prognosis by comparing the measures of CSF-, serum-, and exosome-contained miR-21 levels. Samples from seventy glioma patients following surgery were compared with those from brain trauma patients as a non-tumor control group. Exosomal miR-21 levels in the CSF of glioma patients were found significantly higher than in the controls; whereas no difference was detected in serum-derived exosomal miR-21 expression. The CSF-derived exosomal miR-21 levels correlated with tumor spinal/ventricle metastasis and the recurrence with anatomical site preference. From additional 198 glioma tissue samples, we verified that miR-21 levels associated with tumor grade of diagnosis and negatively correlated with the median values of patient overall survival time. We further used a lentiviral inhibitor to suppress miR-21 expression in U251 cells. The results showed that the levels of miR-21 target genes of PTEN, RECK and PDCD4 were up-regulated at protein levels. Therefore, we concluded that the exosomal miR-21 levels could be demonstrated as a promising indicator for glioma diagnosis and prognosis, particularly with values to predict tumor recurrence or metastasis.

Preclinical examination of clofarabine in pediatric ependymoma: intratumoral concentrations insufficient to warrant further study.

Clofarabine, a deoxyadenosine analog, was an active anticancer drug in our in vitro high-throughput screening against mouse ependymoma neurospheres. To characterize the clofarabine disposition in mice for further preclinical efficacy studies, we evaluated the plasma and central nervous system disposition in a mouse model of ependymoma. A plasma pharmacokinetic study of clofarabine (45 mg/kg, IP) was performed in CD1 nude mice bearing ependymoma to obtain initial plasma pharmacokinetic parameters. These estimates were used to derive D-optimal plasma sampling time points for cerebral microdialysis studies. A simulation of clofarabine pharmacokinetics in mice and pediatric patients suggested that a dosage of 30 mg/kg IP in mice would give exposures comparable to that in children at a dosage of 148 mg/m(2). Cerebral microdialysis was performed to study the tumor extracellular fluid (ECF) disposition of clofarabine (30 mg/kg, IP) in the ependymoma cortical allografts. Plasma and tumor ECF concentration-time data were analyzed using a nonlinear mixed effects modeling approach. The median unbound fraction of clofarabine in mouse plasma was 0.79. The unbound tumor to plasma partition coefficient (K pt,uu: ratio of tumor to plasma AUCu,0-inf) of clofarabine was 0.12 ± 0.05. The model-predicted mean tumor ECF clofarabine concentrations were below the in vitro 1-h IC50 (407 ng/mL) for ependymoma neurospheres. Thus, our results show the clofarabine exposure reached in the tumor ECF was below that associated with an antitumor effect in our in vitro washout study. Therefore, clofarabine was de-prioritized as an agent to treat ependymoma, and further preclinical studies were not pursued.

High plasma-GFAP levels in metastatic myxopapillary ependymoma.

Myxopapillary ependymoma (MPE) is a rare tumor of the distal spinal cord. Despite benign histopathology, local recurrences occur in ~30 % of patients and distant metastases have been described in few cases. MPE tumor cells typically express glial fibrillary acidic protein (GFAP), which could be released to the circulation. In this current report, we investigated circulating plasma-GFAP in a series of MPE patients. We analyzed circulating plasma-GFAP using a commercially available ELISA kit in 3 patients with completely resected MPE, 1 patient with locally advanced MPE and 2 patients with pleuropulmonary metastases of MPE. As controls we used blood samples of age and gender-matched healthy volunteers (n = 3), 6 glioblastoma patients with known plasma-GFAP status (positive for 3 and negative for 3 patients) and 3 brain metastases patients with known plasma-GFAP negativity. We found very high concentrations of plasma-GFAP in two MPE patients with pleuropulmonary metastases, while in none of the other MPE patients circulating plasma-GFAP was detectable. Circulating GFAP could be useful as marker for early detection or follow-up of distant metastases in MPE patients.

Various components of the insulin-like growth factor system in tumor tissue, cerebrospinal fluid and peripheral blood of pediatric medulloblastoma and ependymoma patients.

The insulin-like growth factor (IGF) system plays an important role in neuronal development and may contribute to the development of brain tumors. In this study, we studied mRNA expression levels of IGFs, insulin-like growth factor binding proteins (IGFBPs) and insulin-like growth factor receptors (IGFRs) in 27 pediatric medulloblastomas, 13 pediatric ependymomas and 5 control cerebella. Compared to normal cerebellum, mRNA levels of IGFBP-2 and IGFBP-3 were significantly increased in medulloblastomas and ependymomas. IGFBP-2 expression was indicative of poor prognosis in medulloblastomas, whereas IGFBP-3 mRNA levels were especially high in anaplastic ependymomas. IGFBP-5 and IGF-II mRNA levels were significantly increased in ependymomas compared to control cerebellum. Protein expression levels of IGFs and IGFBPs were analyzed in the cerebrospinal fluid (CSF) of 16 medulloblastoma, 4 ependymoma and 23 control patients by radioimmuno assay to determine whether they could be used as markers for residual disease after surgery. No aberrant CSF protein expression levels were found for ependymoma patients. In medulloblastoma patients, the IGFBP-3 protein levels were significantly higher than in ependymoma patients and controls. Moreover, enhanced levels of proteolytic fragments of IGFBP-3 were found in the CSF of medulloblastoma patients, being in concordance with a significantly increased IGFBP-3 proteolytic activity in the CSF of these patients. In conclusion, our data suggest that the IGF system is of importance in pediatric medulloblastomas and ependymomas. Larger studies should be conducted to validate the predictive values of the levels of intact IGFBP-3 and proteolytic fragments in CSF in the follow-up of medulloblastomas.

Phase I trial of intrathecal spartaject busulfan in children with neoplastic meningitis: a Pediatric Brain Tumor Consortium Study (PBTC-004).

PURPOSE: A phase I trial of intrathecal Spartaject Busulfan (SuperGen, Inc., San Ramon, CA) was conducted in children with neoplastic meningitis following recurrent primary brain tumors to describe toxicities, estimate the maximum tolerated dose (MTD), and document evidence of responses to this agent. EXPERIMENTAL DESIGN: The continuous reassessment method was used to assign cohorts of patients to doses of intrathecal Spartaject Busulfan via an Ommaya reservoir and/or lumbar puncture twice weekly for 2 weeks followed by an assessment of toxicity and response. Patients with stable disease or an objective response continued to receive intrathecal Spartaject Busulfan plus systemic chemotherapy at regular intervals. Cerebrospinal fluid and blood were obtained for pharmacokinetic studies in patients with Ommaya reservoirs after the first dose of intrathecal Spartaject Busulfan. Seven evaluable patients were assigned to the starting dose of 5 mg, two patients to 7.5 mg, three patients to 10 mg, seven patients to 13 mg, and four patients to 17 mg. RESULTS: Between September 2000 and May 2003, 28 patients were enrolled in this study. Twenty-three patients (median age, 8.8 years; range, 2.5-19.5 years) were evaluable for estimating the MTD, and dose-limiting toxicities were observed in three and included grade 3 vomiting (n = 1 at 5 mg), grade 3 headache (n = 1 at 17 mg), and grade 3 arachnoiditis (n = 1 at 17 mg). Pharmacokinetic data showed that post-infusion concentrations of busulfan ranged from 50 to 150 microg/mL and declined to <1 microg/mL within 5 hours. CONCLUSIONS: Intrathecal Spartaject Busulfan was well tolerated in children with neoplastic meningitis from brain tumors, and the recommended dose for future phase II studies is 13 mg.

Radiation dose-volume effects on growth hormone secretion.

PURPOSE: Growth hormone (GH) deficiency is a known consequence of central nervous system irradiation. The relationship between the dose to the hypothalamus and the time to onset of clinically significant GH deficiency is unknown. Conformal radiotherapy (CRT) techniques allow for a more accurate determination of hypothalamic dosimetry. We correlated the dosimetry of the hypothalamus and the peak GH value after CRT in children with localized primary brain tumors. METHODS AND MATERIALS: The arginine tolerance/L-dopa test was performed before (baseline) and repeated 6 and 12 months after CRT in 25 children (median age 4.8 years) with ependymoma (n = 15) or low-grade (n = 8) or high-grade (n = 2) astrocytoma. None had evidence of GH deficiency (arginine tolerance/L-dopa peak GH level >10 ng/mL [10 microg/L]) at baseline. Peak GH levels were modeled as a function of time after CRT and volume of the hypothalamus receiving a dose within the specified intervals of 0-20 Gy, 20-40 Gy, and 40-60 Gy. The model was used to predict the change in the peak GH levels over time (0-12 months) and fit under the assumption that the integral effect of irradiation was a linear sum of the products of the volume receiving a particular dose and the impact of that dose. RESULTS: The peak GH level declined during the 0-12 months after CRT (p < 0.0001). GH deficiency was observed in 11 children at 6 months and a total of 20 children at 12 months. As expected, the effect of the dose interval 0-20 Gy was smaller than the 20-40-Gy dose interval; the largest effect was noted with the dose interval 40-60 Gy. The peak GH level may be predicted using the following estimating equation within the time limit of 0-12 months: GH(t)=Exp[ln(bGH)-(0.00058V(0-20 Gy)+0.00106V(20-40 Gy)+0.00156V(40-60 Gy))x t], where bGH is the baseline peak GH level, V(0-20 Gy), V(20-40 Gy), and V(40-60 Gy) is the percent-volume of the hypothalamus irradiated from 0 to 20 Gy, 20 to 40 Gy, and 40 to 60 Gy, respectively, and t is time after irradiation. When included in the model, the rate of decline in the peak GH response also was influenced by hydrocephalus and tumor location. CONCLUSION: The peak GH response within 12 months after CRT depends on hypothalamic dose-volume effects and may be predicted on the basis of a linear model that sums the effects of the entire distribution of dose. The modeled effects may be used to optimize radiotherapy and minimize and treat GH deficiency.

Uptake and retention of estramustine and the presence of estramustine binding protein in malignant brain tumours in humans.

Estraumustine phosphate (EMP), a cytotoxic drug used in the treatment of prostatic carcinoma, has been shown to exert cytotoxic effects on glioma cells in vitro. The drug uptake is assumed to depend on a specific estramustine binding protein (EMBP). One of the main difficulties in achieving cytotoxic effect in malignant brain tumours is believed to be due to the poor penetration of cytotoxic drugs into tumour tissue. In patients with malignant supratentorial brain tumours we have analysed the uptake of EMP metabolites in tumour tissue after oral administration and demonstrated EMBP in the same tissue specimens. Sixteen patients were given 280 mg EMP orally 14 h prior to surgery. Specimens from brain tumour tissue, cystic fluid, and serum were collected during surgery. Using gas chromatography the metabolites of EMP, estramustine (EaM) and estromustine (EoM), were quantified, EMBP was demonstrated by immunohistochemistry. The mean concentrations of EaM and EoM, expressed in ng g-1, were 60.3 and 38.4 in tumour tissue and 3.5 and 56.3 in serum, respectively. An accumulation of EaM in tumour tissue was found with a mean concentration gradient of 16.1 versus serum, while the gradient for EoM was 0.76. EMBP was demonstrated with a high degree of staining in all but one tumour. The high concentrations of EaM and EoM found in malignant brain tumour tissue correspond to potentially cytotoxic levels. The present results as well as the earlier in vitro demonstrated cytotoxic effects on glioma cells strengthen the possibility of a therapeutic effect of EMP in the treatment of malignant brain tumours.

Cytogenetic and loss of heterozygosity studies in ependymomas, pilocytic astrocytomas, and oligodendrogliomas.

Cytogenetic and/or loss of heterozygosity studies were performed on 13 ependymomas, 11 pilocytic astrocytomas, and 18 oligodendrogliomas. Loss of chromosome 22 was the most frequent genetic abnormality among the ependymomas. We found no consistent genetic abnormality in pilocytic astrocytomas. The most common genetic abnormality in oligodendrogliomas was loss of a portion of chromosome 19. Each informative oligodendroglioma had loss of alleles mapped to the long arm (q) of chromosome 19. One oligodendroglioma had an apparent homozygous deletion of the D19S8 locus. Our results, when combined with those in the literature, indicate that chromosomes 9, 11, and 22 may harbor genes important for the pathogenesis of ependymomas and that 19q probably harbors a gene important for the pathogenesis of oligodendrogliomas.

Characteristics of cisternal cerebrospinal fluid associated with primary brain tumors in the dog: a retrospective study.

Results of cisternal CSF analyses of 77 dogs with primary brain tumors (1970 to 1984) were examined retrospectively. The types of primary brain tumors were astrocytomas, choroid plexus papillomas, ependymomas, meningiomas, and oligodendrogliomas. Fifty-three dogs had complete CSF analyses performed (total WBC count, total protein content, and pressure). Of these 53 CSF, 39.6% had a pattern of change consistent with current descriptions of CSF associated with brain neoplasia. Results of the remaining 60.4% of the 53 CSF were normal (9.4%) or had an atypical pattern of abnormality (50.9%). The CSF associated with meningiomas was unique in having CSF with a WBC count greater than 50 cells/microliter and a WBC differential count greater than 50% polymorphonuclear (PMN) cells. Within the meningioma group, a predominance of PMN cells in the CSF correlated with necrosis or PMN cell infiltration of the tumors. Additional correlations between specific CSF characteristics and histologic features of the tumors could not be made. Statistical analysis of the 77 CSF revealed that the mean CSF total WBC count of the oligodendroglioma group was significantly less than the mean WBC count of the choroid plexus papilloma group and the meningioma group. The mean CSF total protein contents of the astrocytoma group and the meningioma group were significantly less than the mean protein of the choroid plexus papilloma group. The mean CSF pressure of the tumor groups was not significantly different. For all 77 tumors, the most common abnormality was an increased total protein content (69.4%); the least common abnormality was an increased total WBC count (41.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Immunoenzyme method of determining brain-specific alpha 1-globulin in glial tumors]. / Immunofermentnyi metod opredeleniia spetsificheskogo al'fa 1-globulina mozga pri glial'nykh opukholiakh.

Specific alpha 1-globulin of the brain was assayed by an immunoenzyme technique in blood sera from cases of various brain pathologies and healthy donors. Relative elevation in brain specific alpha 1-globulin level, as compared with that in healthy subjects, was more frequent in patients with malignant glial tumors of the brain, less frequent in cases of benign glial tumors and in very few patients suffering from other brain diseases. Raised level of specific alpha 1-globulin may be caused by disorders in the blood-brain barrier or lesions in brain or tumor tissues which is peculiar to glial malignancies of the brain. The said test offers much advantage in diagnosis of glial tumors.

Serum ceruloplasmin and copper levels in patients with primary brain tumors.

Serum copper and ceruloplasmin levels are known to increase in several malignancies such as osteosarcomas, some gastrointestinal tumors, and lung cancer. In this study serum copper and ceruloplasmin levels in 40 patients with primary brain tumors were studied. Both parameters were increased in sera of patients with tumors in comparison with healthy subjects or patients with non-tumorous neurological diseases. It is concluded that copper and ceruloplasmin represent a good complement to some other nonspecific parameters in evaluating the activity of malignancy and the therapeutic results.

[An infant autopsy case of ependymoblastoma with high serum alpha fetoprotein (author's transl)].

This report is concerned with a 55-day-old female hospitalized because of intraventricular hemorrhage from a tumor in the pineal region. Examination of serum alpha fetoprotein showed 7400 ng/ml. The patient expired because of frequent intraventricular hemorrhage and progressive hydrocephalus. Autopsy demonstrated the tumor was ependymoblastoma. No teratomatous component was noticed in the histological examination. High serum alpha fetoprotein in relation to tumor histology was briefly discussed.

Carcinoembryonic antigen (CEA) levels in patients with brain tumours.

Plasma and cerebrospinal fluid CEA determination was done in 97 patients with neurosurgical disorders. Elevated titres were found in 14 of 64 patients with brain tumours. CEA levels were elevated significantly in patients with metastatic brain tumours. Following treatment, the values fell in three patients with ependymoma, medulloblastoma, and unverified brain tumour. This study suggests that CEA levels may be of value in the differential diagnosis of primary and metastatic brain tumours, and useful in the evaluation of patients with brain tumours after treatment. CEA in the cerebrospinal fluid was absent in eight patients with brain tumours.

Lymphopenia caused by cranial irradiation in children receiving craniospinal radiotherapy.

The peripheral blood changes were studied in 67 children who received craniospinal irradiation for posterior fossa tumors. At the completion of a cranial dose of about 3500 rad to the whole brain port, the lymphocytes were reduced to 858/mm3 rom 3084/mm3 preoperatively. The counts of the remaining leukocytes stayed at a level somewhat higher than preoperatively; the eosinophils rose to 288/mm3 from 125/mm3. With the initiation of the spinal field irradiation, which included a large proportion of the total bone marrow, the numbers of all the leukocytes decreased rapidly; the observed leukopenia was mainly secondary to neutropenia. A mechanism that was operating to restore the number of leukocytes became manifest immediately after the completion of radiotherapy, though the number of lymphocytes had not been totally restored to the preoperative level 6 years later. Irradiation of the lymphocytes that circulate through the vascular bed can explain the lymphopenia observed during cranial radiotherapy. Mild leukopenia observed in patients receiving radiotherapy through a relatively small port may be secondary to lymphopenia, and this does not necessarily indicate impaired bone marrow reserves.