Therapeutic radiation for childhood cancer drives structural aberrations of NF2 in meningiomas

Cranial radiotherapy improves survival of the most common childhood cancers, including brain tumors and leukemia. Unfortunately, long-term survivors are faced with consequences of secondary neoplasia, including radiation-induced meningiomas (RIMs). We characterized 31 RIMs with exome/NF2 intronic sequencing, RNA sequencing and methylation profiling, and found NF2 gene rearrangements in 12/31 of RIMs, an observation previously unreported in sporadic meningioma (SM). Additionally, known recurrent mutations characteristic of SM, including AKT1, KLF4, TRAF7 and SMO, were not observed in RIMs. Combined losses of chromosomes 1p and 22q were common in RIMs (16/18 cases) and overall, chromosomal aberrations were more complex than that observed in SM. Patterns of DNA methylation profiling supported similar cell of origin between RIMs and SMs. The findings indicate that the mutational landscape of RIMs is distinct from SMs, and have significant therapeutic implications for survivors of childhood cranial radiation and the elucidation of the molecular pathogenesis of meningiomas.

Radiation-induced meningiomas are often more aggressive than sporadic ones. In this study, the authors perform an exome, methylation and RNA-seq analysis of 31 cases of radiation-induced meningioma and show NF2 rearrangement, an observation previously unreported in the sporadic tumors.

Management and outcome of recurrent adult craniopharyngiomas: an analysis of 42 cases with long-term follow-up

OBJECTIVE The treatment of recurrent and residual craniopharyngiomas is challenging. In this study the authors describe their experience with these tumors and make recommendations on their management. METHODS The authors performed an observational study of adult patients (≥ 18 years) with recurrent or residual craniopharyngiomas that were managed at their tertiary center. Retrospective data were collected on demographics and clinical, imaging, and treatment characteristics from patients who had a minimum 2-year follow-up. Descriptive statistics were used and the data were analyzed. RESULTS There were 42 patients (27 male, 15 female) with a mean age of 46.3 ± 14.3 years. The average tumor size was 3.1 ± 1.1 cm. The average time to first recurrence was 3.6 ± 5.5 years (range 0.2-27 years). One in 5 patients (8/42) with residual/recurrent tumors did not require any active treatment. Of the 34 patients who underwent repeat treatment, 12 (35.3%) had surgery only (transcranial, endoscopic, or both), 9 (26.5%) underwent surgery followed by adjuvant radiation therapy (RT), and 13 (38.2%) received RT alone. Eighty-six percent (18/21) had a gross-total (n = 4) or near-total (n = 14) resection of the recurrent/residual tumors and had good local control at last follow-up. One of 5 patients (7/34) who underwent repeat treatment had further treatment for a second recurrence. The total duration of follow-up was 8.6 ± 7.1 years. The average Karnofsky Performance Scale score at last follow-up was 80 (range 40-90). There was 1 death. CONCLUSIONS Based on this experience and in the absence of guidelines, the authors recommend an individualized approach for the treatment of symptomatic or growing tumors. This study has shown that 1 in 5 patients does not require repeat treatment of their recurrent/residual disease and can be managed with a "scan and watch" approach. On the other hand, 1 in 5 patients who had repeat treatment for their recurrence in the form of surgery and/or radiation will require further additional treatment. More studies are needed to best characterize these patients and predict the natural history of this disease and response to treatment.

The genomic landscape of schwannoma

Schwannomas are common peripheral nerve sheath tumors that can cause debilitating morbidities. We performed an integrative analysis to determine genomic aberrations common to sporadic schwannomas. Exome sequence analysis with validation by targeted DNA sequencing of 125 samples uncovered, in addition to expected NF2 disruption, recurrent mutations in ARID1A, ARID1B and DDR1. RNA sequencing identified a recurrent in-frame SH3PXD2A-HTRA1 fusion in 12/125 (10%) cases, and genomic analysis demonstrated the mechanism as resulting from a balanced 19-Mb chromosomal inversion on chromosome 10q. The fusion was associated with male gender predominance, occurring in one out of every six men with schwannoma. Methylation profiling identified distinct molecular subgroups of schwannomas that were associated with anatomical location. Expression of the SH3PXD2A-HTRA1 fusion resulted in elevated phosphorylated ERK, increased proliferation, increased invasion and in vivo tumorigenesis. Targeting of the MEK-ERK pathway was effective in fusion-positive Schwann cells, suggesting a possible therapeutic approach for this subset of tumors.

The role of 5-aminolevulinic acid in enhancing surgery for high-grade glioma, its current boundaries, and future perspectives: A systematic review

5-Aminolevulinic acid (5-ALA) has been approved as an intraoperative adjunct in glioma surgery in Europe, but not North America. A systematic review was conducted to assess the evidence regarding 5-ALA as a surgical adjunct. The MEDLINE, EMBASE, and CENTRAL databases were searched, using terms relevant to "5-ALA" and "high-grade gliomas." Included studies were based on adults aged ≥18 years who underwent surgical resection/biopsy. No language or date limitations were used. Forty-three studies (1830 patients) were identified. Thirty-six were coordinated by European countries, 2 were in the United States, and none were in Canada. One was randomized, 28 were prospective, and 14 were retrospective. Twenty-six studies assessed the utility of 5-ALA as a diagnostic tool, 24 assessed its influence on the extent of resection (EOR), 9 assessed survival, and 22 reported adverse events. 5-ALA had high sensitivity and positive predictive value, whereas its specificity increased with additional adjuncts. The EOR increased with 5-ALA, but only progression-free survival was significantly influenced. Reporting of adverse events was not systematic. The use of 5-ALA improved tumor visualization and thus enabled a greater EOR and perhaps increased survival. However, additional adjuncts may be necessary for maximizing the specificity of resection and patient safety. Additional parameters, such as patient quality of life and health economic analyses, would be informative. Thus, additional systematic collection of prospective evidence may be necessary for the global incorporation of this potentially valuable surgical adjunct into routine practice. Cancer 2016;122:2469-78. © 2016 American Cancer Society.

Surgically resected skull base meningiomas demonstrate a divergent postoperative recurrence pattern compared with non-skull base meningiomas

OBJECTIVE The objective of this study was to identify the natural history and clinical predictors of postoperative recurrence of skull base and non-skull base meningiomas. METHODS The authors performed a retrospective hospital-based study of all patients with meningioma referred to their institution from September 1993 to January 2014. The cohort constituted both patients with a first-time presentation and those with evidence of recurrence. Kaplan-Meier curves were constructed for analysis of recurrence and differences were assessed using the log-rank test. Cox proportional hazard regression was used to identify potential predictors of recurrence. RESULTS Overall, 398 intracranial meningiomas were reviewed, including 269 (68%) non-skull base and 129 (32%) skull base meningiomas (median follow-up 30.2 months, interquartile range [IQR] 8.5-76 months). The 10-year recurrence-free survival rates for patients with gross-total resection (GTR) and subtotal resection (STR) were 90% and 43%, respectively. Skull base tumors were associated with a lower proliferation index (0.041 vs 0.062, p = 0.001), higher likelihood of WHO Grade I (85.3% vs 69.1%, p = 0.003), and younger patient age (55.2 vs 58.3 years, p = 0.01). Meningiomas in all locations demonstrated an average recurrence rate of 30% at 100 months of follow-up. Subsequently, the recurrence of skull base meningiomas plateaued whereas non-skull base lesions had an 80% recurrence rate at 230 months follow-up (p = 0.02). On univariate analysis, a prior history of recurrence (p < 0.001), initial WHO grade following resection (p < 0.001), and the inability to obtain GTR (p < 0.001) were predictors of future recurrence. On multivariate analysis a prior history of recurrence (p = 0.02) and an STR (p < 0.01) were independent predictors of a recurrence. Assessing only patients with primary presentations, STR and WHO Grades II and III were independent predictors of recurrence (p < 0.001 for both). CONCLUSIONS Patients with skull base meningiomas present at a younger age and have less aggressive lesions overall. Extent of resection is a key predictor of recurrence and long-term follow-up of meningiomas is necessary, especially for non-skull base tumors. In skull base meningiomas, recurrence risk plateaus approximately 100 months after surgery, suggesting that for this specific cohort, follow-up after 100 months can be less frequent.

Predictors of response to Gamma Knife radiosurgery for intracranial meningiomas

OBJECT

In this paper, the authors’ aim was to determine short-term volumetric and diametric tumor growth and identify clinical, radiological, and dosimetric predictors of adverse radiation events (AREs) following stereotactic radiosurgery (SRS) for intracranial WHO Grade I meningiomas.

METHODS

This is a retrospective review of all WHO Grade I meningiomas that were treated with SRS (primary or adjuvant) between December 2005 and June 2012 at the University Health Network. Seventy-five patients had at least 24 months of both clinical and radiological follow-up and were, therefore, included in this study. Tumor growth was defined as any volumetric or diametric change greater than 10% per year. Any variation less than +10% was considered growth stability. Volumetric measurements were made using T1-weighted gadolinium-enhanced 3-T MRI scans and ITK-SNAP software. Tumor growth rates were calculated using the specific growth rate (SGR). Univariate statistics were used to identify predictors of post-SRS AREs. All statistical analyses were performed using IBM SPSS.

RESULTS

Women accounted for 69.3% of patients, and the mean treatment age was 58.6 years. Median follow-up was 36.2 months. Twenty-one (28%) patients had undergone prior resection. Two (3%) patients required salvage surgical intervention following SRS. The majority of the lesions (56%) were skull base tumors. Median tumor volume and diameter were 5.2 cm3 and 27.5 mm, respectively. The absence of tumor growth was observed in 39 cases (52%) based on the volumetric measurements, while the absence of tumor growth was observed in 69 cases (92%) based on the diametric measurements. Twenty-six patients (34.6%) experienced new-onset AREs, including headache (17.3%), cranial neuropathy (10.6%), speech impairment (2.7%), tremors (2.7%), and ataxia (1.3%). Fourteen patients (18.7%) experienced new-onset edema, and 4 of these patients were symptomatic. A lower conformity index (1.24 vs 1.4) was significantly associated with the development of edema (p < 0.001 power > 0.8). Patients with meningiomas that had growth rates of more than 10% per year were more likely to experience long-term headaches after SRS (p = 0.022).

CONCLUSIONS

Volume-based reporting of SRS outcomes for meningiomas may be a more accurate method given the complex morphology of some lesions. The conformity index was identified as a predictor of edema following radiosurgery.

Stereotactic radiosurgery for intracranial meningiomas: current concepts and future perspectives

Meningiomas are among the most common adult brain tumors. Although the optimal management of meningiomas would provide complete elimination of the lesion, this cannot always be accomplished safely through resection. Therefore, other therapeutic modalities, such as stereotactic radiosurgery (as primary or adjunctive therapy), have emerged. In the current review, we have provided an overview of the historical outcomes of various radiosurgical modalities applied in the management of meningiomas. Furthermore, we provide a discussion on key factors (eg World Health Organization grade, lesion size, and lesion location) that affect tumor control and adverse event rates. We discuss recent changes in our understanding of meningiomas, based on molecular and genetic markers, and how these will change our perspective on the management of meningiomas. We conclude by outlining the areas in which knowledge gaps persist and provide suggestions as to how these can be addressed.

Pure endoscopic expanded endonasal approach for olfactory groove and tuberculum sellae meningiomas

The expanded endoscopic endonasal (EEE) approach for the removal of olfactory groove (OGM) and tuberculum sellae (TSM) meningiomas is currently becoming an acceptable surgical approach in neurosurgical practice, although it is still controversial with respect to its outcomes, indications and limitations. Here we provide a review of the available literature reporting results with use of the EEE approach for these lesions together with our experience with the use of the endoscope as the sole means of visualization in a series of patients with no prior surgical biopsy or resection. Surgical cases between May 2006 and January 2013 were retrospectively reviewed. Twenty-three patients (OGM n=6; TSM n=17) were identified. In our series gross total resection (GTR) was achieved in 4/6 OGM (66.7%) and 11/17 (64.7%) TSM patients. Vision improved in the OGM group (2/2) and 8/11 improved in the TSM group with no change in visual status in the remaining three patients. Post-operative cerebrospinal fluid (CSF) leak occurred in 2/6 (33%) OGM and 2/17 (11.8%) TSM patients. The literature review revealed a total of 19 OGM and 174 TSM cases which were reviewed. GTR rate was 73% for OGM and 56.3% for TSM. Post-operative CSF leak was 30% for OGM and 14% for TSM. With careful patient selection and a clear understanding of its limitations, the EEE technique is both feasible and safe. However, longer follow-ups are necessary to better define the appropriate indications and ideal patient population that will benefit from the use of these newer techniques.

Salvage stereotactic radiosurgery for brain metastases

Recurrent or progressive brain metastases after initial treatment represent a common clinical entity mainly due to increased survival of cancer patients. From the various available treatment modalities, salvage stereotactic radiosurgery seems to be the most commonly used. Many clinical studies of class of evidence III have demonstrated satisfied results concerning the local brain control and survival of patients with relapsing brain disease. Also stereotactic radiosurgery is considered a relatively safe modality with low incidence of brain toxicity side effects. It is obvious that well-designed, randomized, prospective studies are necessary for the evaluation of the stereotactic radiosurgery as salvage treatment and for the establishment of guidelines for the selection of patients most suitable for this treatment option. The increasing number of patients with relapsing brain metastatic disease will act as a pressure to this direction.

Cerebellar hemorrhage after supratentorial burr hole drainage of a chronic subdural hematoma

Cerebellar hemorrhage is an unusual, but increasingly recognized complication after supratentorial surgery. Even rarer are the cases of cerebellar hemorrhage after supratentorial burr-hole drainage of a chronic subdural hematoma (CSDH). The pathophysiology of this rare complication still remains unclear. Hypertension and overdrainage of cerebrospinal fluid seem to be causative factors of postoperative cerebellar hemorrhage. The most important key to minimize this hazardous sequel is to be aware of this potential complication and its pathogenetic mechanisms. We report our case of a 43-year old man who developed cerebellar hemorrhage after burr hole trephination for supratentorial CSDH.

Loss of inhibitor of growth (ING-4) is implicated in the pathogenesis and progression of human astrocytomas

Inhibitor of growth 4 (ING-4) is a tumor suppressor gene that interacts with nuclear factor-kappaB (NF-kappaB) and represses its transcriptional activity. Several lines of evidence suggest that the tumor suppressor gene ING-4, the transcription factor NF-kappaB and its target genes matrix metalloproteases MMP-2, MMP-9 and urokinase plasminogen activator (u-PA) are critically involved in tumor invasion. The aim of the present study was to investigate immunohistochemically the expression pattern of ING-4, NF-kappaB and the NF-kappaB downstream targets MMP-2, MMP-9 and u-PA in human astrocytomas from 101 patients. We found that ING-4 expression was significantly decreased in astrocytomas, and ING-4 loss was associated with tumor grade progression. Expression of p65, a NF-kappaB subunit, was significantly higher in grade IV than in grade III and grade I/II tumors, and a statistical significant negative correlation between expression of ING-4 and expression of nuclear p65 was noticed. MMP-9, MMP-2 and u-PA were overexpressed in human astrocytomas. Of note, astrocytomas of advanced histologic grades (grade III, IV) displayed significantly higher expression levels of these proteins compared to tumors of lower grades (grade I, II). Collectively, our data suggest an essential role for ING-4 in human astrocytoma development and progression possibly through regulation of the NF-kappaB-dependent expression of genes involved in tumor invasion.

ILK over-expression in human colon cancer progression correlates with activation of beta-catenin, down-regulation of E-cadherin and activation of the Akt-FKHR pathway

Integrin-linked kinase (ILK) has been implicated in the development and progression of several human malignancies. However, the role of ILK in human colon cancer progression is not well established, neither have its possible in vivo downstream effectors in the disease been identified. We studied, by immunohistochemistry, ILK, beta-catenin, E-cadherin, p-Akt and p-FKHR protein expression in 125 primary colon carcinomas and 45 corresponding lymph node metastases. ILK was expressed in 98.4% of the primary tumours and in 100% of metastatic lesions. The levels of ILK expression correlated strongly with tumour invasion, tumour grade and stage and were significantly higher in metastatic tumours. Activation of beta-catenin, down-regulation of E-cadherin and activation of the Akt-FKHR pathway correlated significantly with both ILK expression and tumour progression parameters. In conclusion, our results suggest that ILK may have an important role in progression of human colon cancer, possibly through in vivo regulation of beta-catenin, E-cadherin and Akt pathways. Our study also provides some evidence implicating p-FKHR in human colon carcinogenesis and ILK signalling.

Determination of trans-resveratrol in human plasma by high-performance liquid chromatography

The first method using high-performance liquid chromatography (HPLC) has been developed for the determination of trans-resveratrol in human plasma. The method involves a liquid--liquid extraction followed by reversed-phase HPLC with UV detection. The detection limit of trans-resveratrol in human plasma was 5.0 ng/ml. Standard curves are linear over the concentration range of 5.0-5000.0 ng/ml. Intra-assay variability ranged from 1.9 to 3.7% and inter-assay variability ranged from 2.5 to 4.0% at the concentration range of 15.0-4000.0 ng/ml.

Comparison of an intercalating dye and an intercalant-enzyme conjugate for DNA detection in a microtiter-based assay

Two methods have been developed for the detection of DNA immobilized on the surface of microtiter wells. An intercalating dye, 3,6-diaminoacridine, is used in stain and rinse solutions, so that measured absorbance values (450 nm) reflect the sum of DNA-bound and free dye. With diaminoacridine, signal increases of 0.056 +/- 0.010 were achieved on immobilizing double-stranded calf thymus DNA. An intercalant-enzyme conjugate, consisting of an average of four daunomycin moieties covalently bound to each glucose oxidase, was shown to provide a 10-fold signal enhancement (optimum 0.25 microM, with rinsing and peroxidase-o-dianisidine detection) compared to diaminoacridine, due to catalytic amplification; signals of 0.50 +/- 0.05 were obtained. This conjugate possesses 56% of the activity of native glucose oxidase and was prepared using water-soluble carbodiimide and N-hydroxysuccinimide reagents. Single-stranded DNA was immobilized onto avidin-coated polystyrene plates and commercially available (Covalink) plates possessing secondary amine groups. Following hybridization with complementary DNA, detection was performed with the daunomycin-glucose oxidase conjugate. Both immobilization methods showed optimum DNA concentrations of 0.10 microgram/mL, and maximum signal intensities were obtained when > 0.5 microgram/mL complementary DNA was present in the hybridization solution. Some nonspecific binding of the intercalant-enzyme conjugate was suggested by results obtained with avidin-coated polystyrene plates, but not with Covalink plates.