External validation of the lung-molGPA to predict survival in patients treated with stereotactic radiotherapy for brain metastases of non-small cell lung cancer.

BACKGROUND: In the era of personalized medicine, individualized prognostic models with tumor characteristics are needed to inform patients about survival. Before clinical use, external validation of such models by an independent group is needed. An updated version of the graded prognostic assessment (GPA) estimates survival in patients with brain metastases (BMs) of non-small cell lung cancer (NSCLC). This is the first external validation of the updated Lung-molGPA in patients treated with stereotactic radiotherapy (SRT) for one or more BMs. MATERIALS AND METHODS: Patients treated with SRT for BMs from NSCLC adenocarcinoma were retrospectively included. GPA score was calculated for each patient based on six prognostic factors including age, Karnofsky Performance Status, number of BMs, extracranial metastases, EGFR/ALK status and PD-L1 expression. Kaplan-Meier analysis evaluated survival probability. Impact of individual prognostic factors on survival was assessed by univariate and multivariate analyses using the Cox proportional hazard model. Predictive performance was evaluated using discrimination (C-statistic) and calibration (Brier test). RESULTS: The cohort (n = 241) was divided into four prognostic groups. Overall median survival was 15 months. Predicted and observed median survival were similar between the original and validation cohorts, apart from the most favorable prognostic group. With adequate C-statistics and Brier scores, the Lung-molGPA provided accurate survival predictions. CONCLUSION: The Lung-molGPA accurately predicted survival in our European population, except for an overestimation of survival in the small most favorable prognostic group. This prognostic model was externally validated and is therefore useful for counseling of patients with BMs of NSCLC adenocarcinoma.

Impact of timing of antiseizure medication withdrawal on seizure recurrence in glioma patients: a retrospective observational study.

BACKGROUND: Withdrawal of antiseizure medication treatment (ASM) can be considered after completion of antitumour treatment in glioma patients who no longer suffer from seizures. We compared the risk for recurrent seizures after ASM withdrawal between patients with short-term, medium-term versus long-term seizure freedom after antitumour treatment. METHODS: In this retrospective observational study, the primary outcome was time to recurrent seizure, from the starting date of no ASM treatment up to 36 months follow-up. Cox proportional hazards models were used to study the effect of risk factors on time to recurrent seizure. Stratification was done with information known at baseline. Short-term seizure freedom was defined as ≥ 3 months, but < 12 months; medium-term as 12-24 months; and long-term as ≥ 24 months seizure freedom from the date of last antitumour treatment. RESULTS: This study comprised of 109 patients; 31% (34/109) were in the short-term, 29% (32/109) in the medium-term, and 39% (43/109) in the long-term group. A recurrent seizure was experienced by 47% (16/34) of the patients in the short-term, 31% (10/32) in the medium-term, and 44% (19/43) in the long-term group. Seizure recurrence risk was similar between patients in the short-term group as compared to the medium-term (cause-specific adjusted hazard ratio [aHR] = 0.65 [95%CI = 0.29-1.46]) and long-term group (cause-specific aHR = 1.04 [95%CI = 0.52-2.09]). CONCLUSIONS: Seizure recurrence risk is relatively similar between patients with short-term, medium-term, and long-term seizure freedom after completion of antitumour treatment.

Transcriptome analysis reveals tumor microenvironment changes in glioblastoma.

A better understanding of transcriptional evolution of IDH-wild-type glioblastoma may be crucial for treatment optimization. Here, we perform RNA sequencing (RNA-seq) (n = 322 test, n = 245 validation) on paired primary-recurrent glioblastoma resections of patients treated with the current standard of care. Transcriptional subtypes form an interconnected continuum in a two-dimensional space. Recurrent tumors show preferential mesenchymal progression. Over time, hallmark glioblastoma genes are not significantly altered. Instead, tumor purity decreases over time and is accompanied by co-increases in neuron and oligodendrocyte marker genes and, independently, tumor-associated macrophages. A decrease is observed in endothelial marker genes. These composition changes are confirmed by single-cell RNA-seq and immunohistochemistry. An extracellular matrix-associated gene set increases at recurrence and bulk, single-cell RNA, and immunohistochemistry indicate it is expressed mainly by pericytes. This signature is associated with significantly worse survival at recurrence. Our data demonstrate that glioblastomas evolve mainly by microenvironment (re-)organization rather than molecular evolution of tumor cells.

The EGFRvIII transcriptome in glioblastoma: A meta-omics analysis.

BACKGROUND: EGFR is among the genes most frequently altered in glioblastoma, with exons 2-7 deletions (EGFRvIII) being among its most common genomic mutations. There are conflicting reports about its prognostic role and it remains unclear whether and how it differs in signaling compared with wildtype EGFR. METHODS: To better understand the oncogenic role of EGFRvIII, we leveraged 4 large datasets into 1 large glioblastoma transcriptome dataset (n = 741) alongside 81 whole-genome samples from 2 datasets. RESULTS: The EGFRvIII/EGFR expression ratios differ strongly between tumors and range from 1% to 95%. Interestingly, the slope of relative EGFRvIII expression is near-linear, which argues against a more positive selection pressure than EGFR wildtype. An absence of selection pressure is also suggested by the similar survival between EGFRvIII-positive and -negative glioblastoma patients. EGFRvIII levels are inversely correlated with pan-EGFR (all wildtype and mutant variants) expression, which indicates that EGFRvIII has a higher potency in downstream pathway activation. EGFRvIII-positive glioblastomas have a lower CDK4 or MDM2 amplification incidence than EGFRvIII-negative (P = .007), which may point toward crosstalk between these pathways. EGFRvIII-expressing tumors have an upregulation of "classical" subtype genes compared to those with EGFR-amplification only (P = 3.873e-6). Genomic breakpoints of the EGFRvIII deletions have a preference toward the 3'-end of the large intron-1. These preferred breakpoints preserve a cryptic exon resulting in a novel EGFRvIII variant and preserve an intronic enhancer. CONCLUSIONS: These data provide deeper insights into the complex EGFRvIII biology and provide new insights for targeting EGFRvIII mutated tumors.

Molecular Evolution of IDH Wild-Type Glioblastomas Treated With Standard of Care Affects Survival and Design of Precision Medicine Trials: A Report From the EORTC 1542 Study.

PURPOSE: Precision medicine trials in glioblastoma (GBM) are often conducted at tumor recurrence. However, second surgeries for recurrent GBM are not routinely performed, and therefore, molecular data for trial inclusion are predominantly derived from the primary sample. This study aims to establish whether molecular targets change during tumor progression and, if so, whether this affects precision medicine trial design. MATERIALS AND METHODS: We collected 186 pairs of primary-recurrent GBM samples from patients receiving chemoradiotherapy with temozolomide and sequenced approximately 300 cancer genes. MGMT, TERT, and EGFRvIII status was individually determined. RESULTS: The molecular profile of our cohort was identical to that of other GBM cohorts (IDH wild-type [WT], 95%; EGFR amplified, approximately 50%), indicating that patients amenable to second surgery do not represent a specific molecular subtype. Molecular events in IDH WT GBMs were stable in approximately 80% of events, but changes in mutation status were observed for all examined genes (range, approximately 90% and 60% for TERT and EGFR mutations, respectively), and such changes strongly affected targeted trial size and design. A similar pattern of GBM driver instability was observed within MGMT promoter-methylated tumors. MGMT promoter methylation status remained prognostic at tumor recurrence. The observation that hypermutation at GBM recurrence was rare (8%) and not correlated with outcome was relevant for immunotherapy-based treatments. CONCLUSION: This large cohort of matched primary and recurrent IDH WT tumors establishes the frequency of GBM driver instability after chemoradiotherapy with temozolomide. This allows per gene or pathway calculation of trial size at tumor recurrence, using molecular data of the primary tumor only. We also identify genes for which repeat surgery is necessary because of low mutation retention rate.

Visual inspection of MR relative cerebral blood volume maps has limited value for distinguishing progression from pseudoprogression in glioblastoma multiforme patients.

AIM: We examined whether visual interpretation of relative cerebral blood volume (rCBV) color maps made with dynamic susceptibility-weighted perfusion MRI can reliably distinguish progressive disease (PD) from pseudoprogression (PsPD) in glioblastoma patients during treatment with temozolomide chemoradiation. MATERIALS & METHODS: Magnetic resonance (MR) perfusion-weighted images were evaluated based on visual inspection of rCBV maps. Sensitivity and specificity were calculated to assess if rCBV can reliably differentiate between PD and PsPD, during standard chemoradiation therapy. RESULTS: Evaluation of dynamic susceptibility-weighted contrast-enhanced perfusion MRI by visual interpretation of rCBV maps did not differentiate PD from PsPD (sensitivity = 72%; specificity = 23%). Furthermore, the interpretation of the rCBV maps had no prognostic value regarding survival. CONCLUSION: Qualitative rCBV-based dynamic susceptibility-weighted contrast-enhanced perfusion MRI does not reliably differentiate PD from PsPD, and is not prognostic for survival in glioblastoma multiforme patients during treatment with temozolomide chemoradiation.

Seizures in oligodendroglial tumors.

Epilepsy develops in more than 70-90% of oligodendroglial tumors and represents a favorable indicator for long-term survival if present as the first clinical sign. Presence of IDH1 mutation is frequently associated with seizures in oligodendrogliomas, next to alterations of glutamate and GABA metabolism in the origin of glioma-associated epilepsy. Treatment by surgery or radiotherapy results in seizure freedom in about two-thirds of patients, and chemotherapy to a seizure reduction in about 50%. Symptomatic anticonvulsive therapy with levetiracetam and valproic acid as monotherapy are both evidence-based drugs for the partial epilepsies, and their effective use in brain tumors is supported by a large amount of additional data. Pharmacoresistance against anticonvulsants is more prevalent among oligodendrogliomas, occurring in about 40% despite polytherapy with two anticonvulsants or more. Toxic signs of anticonvulsants in brain tumors involve cognition, bone marrow and skin. Previous neurosurgery, radiation therapy or chemotherapy add to the risks of cognitive dysfunction.

Seizure outcome after radiotherapy and chemotherapy in low-grade glioma patients: a systematic review.

There is growing evidence that antitumor treatment contributes to better seizure control in low-grade glioma patients. We performed a systematic review of the current literature on seizure outcome after radiotherapy and chemotherapy and evaluated the association between seizure outcome and radiological response. Twenty-four studies were available, of which 10 described seizure outcome after radiotherapy and 14 after chemotherapy. All studies demonstrated improvements in seizure outcome after antitumor treatment. Eight studies reporting on imaging response in relation to seizure outcome showed a seizure reduction in a substantial part of patients with stable disease on MRI. Seizure reduction may therefore be the only noticeable effect of antitumor treatment. Our findings demonstrate the clinical relevance of monitoring seizure outcome after radiotherapy and chemotherapy, as well as the potential role of seizure reduction as a complementary marker of tumor response in low-grade glioma patients.

Changes in the EGFR amplification and EGFRvIII expression between paired primary and recurrent glioblastomas.

BACKGROUND: The efficacy of novel targeted therapies is often tested at the time of tumor recurrence. However, for glioblastoma (GBM) patients, surgical resections at recurrence are performed only in a minority of patients; therefore, molecular data are predominantly derived from the initial tumor. Molecular data of the initial tumor for patient selection into personalized medicine trials can therefore be used only when the specific genetic change is retained in the recurrent tumor. METHODS: In this study we determined whether EGFR amplification and expression of the most common mutation in GBMs (EGFRvIII) is retained at tumor recurrence. Because retention of genetic changes may be dependent on the initial treatment, we only used a cohort of GBM samples that were uniformly treated according to the current standard of care (ie, chemo-irradiation with temozolomide). RESULTS: Our data show that, in spite of some quantitative differences, the EGFR amplification status remains stable in the majority (84%) of tumors evaluated. EGFRvIII expression remained similar in 79% of GBMs. However, within the tumors expressing EGFRvIII at initial diagnosis, approximately one-half lose their EGFRvIII expression at tumor recurrence. CONCLUSIONS: The relative stability of EGFR amplification indicates that molecular data obtained in the primary tumor can be used to predict the EGFR status of the recurrent tumor, but care should be taken in extrapolating EGFRvIII expression from the primary tumor, particularly when expressed at first diagnosis.

Withdrawal of antiepileptic drugs in glioma patients after long-term seizure freedom: design of a prospective observational study.

BACKGROUND: Epilepsy is common in patients with a glioma. Antiepileptic drugs (AEDs) are the mainstay of epilepsy treatment, but may cause side effects and may negatively impact neurocognitive functioning and quality of life. Besides antiepileptic drugs, anti-tumour treatment, which currently consists of surgery, radiotherapy and/or chemotherapy, may contribute to seizure control as well. In glioma patients with seizure freedom after anti-tumour therapy the question emerges whether AEDs should be continued, particularly in the case where anti-tumour treatment has been successful. We propose to explore the possibility of AED withdrawal in glioma patients with long-term seizure freedom after anti-tumour therapy and without signs of tumour progression. METHODS/DESIGN: We initiate a prospective, observational study exploring the decision-making process on the withdrawal or continuation of AEDs in low-grade and anaplastic glioma patients with stable disease and prolonged seizure freedom after anti-tumour treatment, and the effects of AED withdrawal or continuation on seizure freedom. We recruit participants through the outpatient clinics of three tertiary referral centers for brain tumour patients in The Netherlands. The patient and the treating physician make a shared decision to either withdraw or continue AED treatment. Over a one-year period, we aim to include 100 glioma patients. We expect approximately half of the participants to be willing to withdraw AEDs. The primary outcome measures are: 1) the outcome of the shared-decision making on AED withdrawal or continuation, and decision related arguments, and 2) seizure freedom at 12 months and 24 months of follow-up. We will also evaluate seizure type and frequency in case of seizure recurrence, as well as neurological symptoms, adverse effects related to AED treatment or withdrawal, other anti-tumour treatments and tumour progression. DISCUSSION: This study addresses two issues that are currently unexplored. First, it will explore the willingness to withdraw AEDs in glioma patients, and second, it will assess the risk of seizure recurrence in case AEDs are withdrawn in this specific patient population. This study aims to contribute to a more tailored AED treatment, and prevent unnecessary and potentially harmful use of AEDs in glioma patients.

Seizure prognosis in brain tumors: new insights and evidence-based management.

Brain tumor-related epilepsy (BTE) is common in low- and high-grade gliomas. The risk of seizures varies between 60% and 100% among low-grade gliomas and between 40% and 60% in glioblastomas. The presence of seizures in patients with brain tumors implies favorable and unfavorable factors. New-onset seizures represent an early warning sign for the presence of a brain tumor and count as a good prognostic factor for survival. Recurrence or worsening of seizures during the course of disease may signal tumor progression. Each of the modalities for tumor control (i.e., surgery, radiotherapy, chemotherapy) contributes to seizure control. Nevertheless, one third of BTE shows pharmacoresistance to antiepileptic drugs (AEDs) and may severely impair the burden of living with a brain tumor. For symptomatic therapy of BTE, seizure type and individual patient factors determine the appropriate AED. Randomized controlled trials in partial epilepsy in adults to which type BTE belongs and additional studies in gliomas indicate that levetiracetam is the agent of choice, followed by valproic acid (VPA). In the case of recurring seizures, combining these two drugs (polytherapy) seems effective and possibly synergistic. If either one is not effective or not well tolerated, lacosamide, lamotrigine, or zonisamide are additional options. A new and exciting insight is the potential contribution of VPA to prolonged survival, particularly in glioblastomas. A practice guideline on symptomatic medical management including dose schedules of AEDs is supplied.

Seizure characteristics and prognostic factors of gliomas.

Epilepsy in neuroepithelial tumors is highly prevalent. Neurogliomas (dysembryoplastic neuroepitheliomas [DNETs] and gangliogliomas) have a seizure incidence of 80-100%, low-grade gliomas of 60-85%, and glioblastoma of 30-60%. With each type, the appearance of seizures is usually the presenting clinical symptom, and with neuroglial tumors often the only clinical sign. Tumor locations in the temporal and insular cortex are associated with a higher risk of developing epilepsy in both neuroglial tumors and low-grade gliomas. Focal seizures with or without alteration of consciousness and/or secondary generalization are common. Focal seizures with altered consciousness are present in 50-70% of neuroglial tumors, and secondarily generalized seizures in 70% of low-grade gliomas. Surgical treatment, particularly gross tumor resection, contributes strongly to seizure freedom, especially in neuroglial tumors. Refractory epilepsy is more common in low-grade gliomas, occurring in 30-35%. Recurrence or worsening of seizures is often associated with tumor recurrence in glioblastomas. Translational studies have revealed a strong prevalence of IDH1 enzyme mutation together with the presence of seizures and long-term survival in low-grade gliomas. Disturbances of glutamate metabolism occur both in low-grade tumors and glioblastomas, and provide insight into mutual cellular pathway abnormalities contributing to both seizure development and tumor growth. Likewise, the recent clinical observations on antitumor activity of the anticonvulsant valproic acid in glioblastoma now provide promising outlooks on single therapies that target both seizures and gliomas.

Effect of valproic acid on seizure control and on survival in patients with glioblastoma multiforme.

BACKGROUND: To examine the efficacy of valproic acid (VPA) given either with or without levetiracetam (LEV) on seizure control and on survival in patients with glioblastoma multiforme (GBM) treated with chemoradiation. METHODS: A retrospective analysis was performed on 291 patients with GBM. The efficacies of VPA and LEV alone and as polytherapy were analyzed in 181 (62%) patients with seizures with a minimum follow-up of 6 months. Cox-regression survival analysis was performed on 165 patients receiving chemoradiation with temozolomide of whom 108 receiving this in combination with VPA for at least 3 months. RESULTS: Monotherapy with either VPA or LEV was instituted in 137/143 (95.8%) and in 59/86 (68.6%) on VPA/LEV polytherapy as the next regimen. Initial freedom from seizure was achieved in 41/100 (41%) on VPA, in 16/37 (43.3%) on LEV, and in 89/116 (76.7%) on subsequent VPA/LEV polytherapy. At the end of follow-up, seizure freedom was achieved in 77.8% (28/36) on VPA alone, in 25/36 (69.5%) on LEV alone, and in 38/63 (60.3%) on VPA/LEV polytherapy with ongoing seizures on monotherapy. Patients using VPA in combination with temozolomide showed a longer median survival of 69 weeks (95% confidence interval [CI]: 61.7-67.3) compared with 61 weeks (95% CI: 52.5-69.5) in the group without VPA (hazard ratio, 0.63; 95% CI: 0.43-0.92; P = .016), adjusting for age, extent of resection, and O(6)-DNA methylguanine-methyltransferase promoter methylation status. CONCLUSIONS: Polytherapy with VPA and LEV more strongly contributes to seizure control than does either as monotherapy. Use of VPA together with chemoradiation with temozolomide results in a 2-months' longer survival of patients with GBM.

Effect of the correction for noncompliance and contamination on the estimated reduction of metastatic prostate cancer within a randomized screening trial (ERSPC section Rotterdam).

The European Randomized study of Screening for Prostate Cancer (ERSPC) has recently reported a 20% reduction in death from prostate cancer in a population-based prostate cancer screening (core age group: 55-69 years of age). The effect of screening may be diluted by noncompliance in the screening arm and contamination by PSA testing in the control arm. The purpose is to analyze the effect of prostate cancer screening on the incidence of metastatic prostate cancer, both with and without adjustment for noncompliance and contamination. We analyzed the occurrence of metastases in 42,376 men aged 55-75 years who were randomized in the Rotterdam section of the ERSPC between 1993 and 1999. Contamination adjustment was based on follow-up findings and questionnaire data from all men in the control group who developed prostate cancer and from a random sample of 291 men without cancer who had a PSA test. Prostate cancer screening significantly reduced the occurrence of metastatic prostate cancer in the intention-to-screen analysis [RR 0.75, 95% CI 0.59-0.95, p = 0.02] and more so in adjusted analyses; contamination adjusted RR 0.73, 95% CI 0.56-0.96; noncompliance adjusted RR 0.72, 95% CI 0.55-0.95 and fully adjusted analysis RR 0.68, 95% CI 0.49-0.94, p = 0.02. In the population of ERSPC Rotterdam (N = 42,376 men), screening reduces the risk to be diagnosed with metastatic prostate cancer considerably on population level, an effect which is even more pronounced in men who are in fact screened.

Prostate cancer mortality reduction by prostate-specific antigen-based screening adjusted for nonattendance and contamination in the European Randomised Study of Screening for Prostate Cancer (ERSPC).

BACKGROUND: Prostate-specific antigen (PSA) based screening for prostate cancer (PCa) has been shown to reduce prostate specific mortality by 20% in an intention to screen (ITS) analysis in a randomised trial (European Randomised Study of Screening for Prostate Cancer [ERSPC]). This effect may be diluted by nonattendance in men randomised to the screening arm and contamination in men randomised to the control arm. OBJECTIVE: To assess the magnitude of the PCa-specific mortality reduction after adjustment for nonattendance and contamination. DESIGN, SETTING, AND PARTICIPANTS: We analysed the occurrence of PCa deaths during an average follow-up of 9 yr in 162,243 men 55-69 yr of age randomised in seven participating centres of the ERSPC. Centres were also grouped according to the type of randomisation (ie, before or after informed written consent). INTERVENTION: Nonattendance was defined as nonattending the initial screening round in ERSPC. The estimate of contamination was based on PSA use in controls in ERSPC Rotterdam. MEASUREMENTS: Relative risks (RRs) with 95% confidence intervals (CIs) were compared between an ITS analysis and analyses adjusting for nonattendance and contamination using a statistical method developed for this purpose. RESULTS AND LIMITATIONS: In the ITS analysis, the RR of PCa death in men allocated to the intervention arm relative to the control arm was 0.80 (95% CI, 0.68-0.96). Adjustment for nonattendance resulted in a RR of 0.73 (95% CI, 0.58-0.93), and additional adjustment for contamination using two different estimates led to estimated reductions of 0.69 (95% CI, 0.51-0.92) to 0.71 (95% CI, 0.55-0.93), respectively. Contamination data were obtained through extrapolation of single-centre data. No heterogeneity was found between the groups of centres. CONCLUSIONS: PSA screening reduces the risk of dying of PCa by up to 31% in men actually screened. This benefit should be weighed against a degree of overdiagnosis and overtreatment inherent in PCa screening.