Predictive and prognostic markers in neurooncology

Abstract Over the past few years molecular assays have been introduced to aid in typing and grading of gliomas. This is the result of improved understanding of these tumors at the molecular level. In particular, the presence or absence of combined 1p/19 loss in oligodendroglial tumors, epidermal growth factor receptor amplification, epidermal growth factor receptor vIII mutations in grade III tumors and glioblastoma multiforme, and MGMT promoter gene methylation in glioblastoma multiforme are now being used to tailor treatment decisions in patients. However, the application of these tests is far from straightforward, and certain standards are required before any test can be introduced in the daily management of patients. Some of these requirements concern inter-and intratest variability, including whether a test gives the same results if repeated in the same or in another laboratory or when different methodologies are used (e.g. loss of heterozygosity vs fluorescence in situ hybridization and a polymerase chain reaction-based test vs immunohistochemistry). The sensitivity and specificity of a test (or negative and positive predictive value) indicate the likelihood that the test results are positive if the disease is present and the likelihood that the disease is present if the test results are positive. Studies on these test characteristics usually require the presence of a gold standard to which new tests should be compared. Last but not least there is the question of what added value the test has; this criterion determines the clinical usefulness of the assay and why some recently introduced molecular assays need to be scrutinized

Liquid biopsy in central nervous system metastases: a RANO review and proposals for clinical applications

Abstract Liquid biopsies collect and analyze tumor components in body fluids, and there is an increasing interest in the investigation of liquid biopsies as a surrogate for tumor tissue in the management of both primary and secondary brain tumors. Herein we critically review available literature on spinal fluid and plasma circulating tumor cells (CTCs) and cell-free tumor (ctDNA) for diagnosis and monitoring of leptomeningeal and parenchymal brain metastases. We discuss technical issues and propose several potential applications of liquid biopsies in different clinical settings (ie, for initial diagnosis, for assessment during treatment, and for guidance of treatment decisions). Last, ongoing clinical studies on CNS metastases that include liquid biopsies are summarized, and recommendations for future clinical studies are provided

Leptomeningeal metastasis: a Response Assessment in Neuro-Oncology critical review of endpoints and response criteria of published randomized clinical trials

Purpose. To date, response criteria and optimal methods for assessment of outcome have not been standardized in patients with leptomeningeal metastasis (LM). Methods. A Response Assessment in Neuro-Oncology working group of experts in LM critically reviewed published literature regarding randomized clinical trials (RCTs) and trial design in patients with LM. Results. A literature review determined that 6 RCTs regarding the treatment of LM have been published, all of which assessed the response to intra-CSF based chemotherapy. Amongst these RCTs, only a single trial attempted to determine whether intra-CSF chemotherapy was of benefit compared with systemic therapy. Otherwise, this pragmatic question has not been formally addressed in patients with solid cancers and LM. The methodology of the 6 RCTs varied widely with respect to pretreatment evaluation, type of treatment, and response to treatment. Additionally there was little uniformity in reporting of treatment-related toxicity. One RCT suggests no advantage of combined versus single-agent intra-CSF chemotherapy in patients with LM. No specific intra-CSF regimen has shown superior efficacy in the treatment of LM, with the exception of liposomal cytarabine in patients with lymphomatous meningitis. Problematic with all RCTs is the lack of standardization with respect to response criteria. There was considerable variation in definitions of response by clinical examination, neuroimaging, and CSF analysis. Conclusion. Based upon a review of published RCTs in LM, there exists a significant unmet need for guidelines for evaluating patients with LM in clinical practice as well as for response assessment in clinical trials

Cognitive rehabilitation in patients with gliomas: a randomized, controlled trial.

Contains fulltext : 81055.pdf (publisher's version ) (Closed access)PURPOSE: Patients with gliomas often experience cognitive deficits, including problems with attention and memory. This randomized, controlled trial evaluated the effects of a multifaceted cognitive rehabilitation program (CRP) on cognitive functioning and selected quality-of-life domains in patients with gliomas. PATIENTS AND METHODS: One hundred forty adult patients with low-grade and anaplastic gliomas, favorable prognostic factors, and both subjective cognitive symptoms and objective cognitive deficits were recruited from 11 hospitals in the Netherlands. Patients were randomly assigned to an intervention group or to a waiting-list control group. The intervention incorporated both computer-based attention retraining and compensatory skills training of attention, memory, and executive functioning. Participants completed a battery of neuropsychological (NP) tests and self-report questionnaires on cognitive functioning, fatigue, mental health-related quality of life, and community integration at baseline, after completion of the CRP, and at 6-month follow-up. RESULTS: At the immediate post-treatment evaluation, statistically significant intervention effects were observed for measures of subjective cognitive functioning and its perceived burden but not for the objective NP outcomes or for any of the other self-report measures. At the 6-month follow-up, the CRP group performed significantly better than the control group on NP tests of attention and verbal memory and reported less mental fatigue. Group differences in other subjective outcomes were not significant at 6 months. CONCLUSION: The CRP has a salutary effect on short-term cognitive complaints and on longer-term cognitive performance and mental fatigue. Additional research is needed to identify which elements of the intervention are most effective

MGMT promoter methylation in malignant gliomas: ready for personalized medicine?

The DNA repair enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) antagonizes the genotoxic effects of alkylating agents. MGMT promoter methylation is the key mechanism of MGMT gene silencing and predicts a favorable outcome in patients with glioblastoma who are exposed to alkylating agent chemotherapy. This biomarker is on the verge of entering clinical decision-making and is currently used to stratify or even select glioblastoma patients for clinical trials. In other subtypes of glioma, such as anaplastic gliomas, the relevance of MGMT promoter methylation might extend beyond the prediction of chemosensitivity, and could reflect a distinct molecular profile. Here, we review the most commonly used assays for evaluation of MGMT status, outline the prerequisites for standardized tests, and evaluate reasons for difficulties in reproducibility. We critically discuss the prognostic and predictive value of MGMT silencing, reviewing trials in which patients with different types of glioma were treated with various chemotherapy schedules, either up-front or at recurrence. Standardization of MGMT testing requires comparison of different technologies across laboratories and prospectively validated cut-off values for prognostic or predictive effects. Moreover, future clinical trials will need to determine, for each subtype of glioma, the degree to which MGMT promoter methylation is predictive or prognostic, and whether testing should become routine clinical practice

Bone graft substitutes in anterior cervical discectomy and fusion

Anterior cervical discectomy with fusion is a common surgical procedure for patients suffering pain and/or neurological deficits and unresponsive to conservative management. For decades, autologous bone grafted from the iliac crest has been used as a substrate for cervical arthrodesis. However patient dissatisfaction with donor site morbidity has led to the search for alternative techniques. We present a literature review examining the progress of available grafting options as assessed in human clinical trials, considering allograft-based, synthetic, factor- and cell-based technologies