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.

Predicting disease progression in high-grade glioma with neuropsychological parameters: the value of personalized longitudinal assessment.

PURPOSE: Progressive disease in patients with high-grade glioma may be reflected in cognitive decline. However, the cognitive functions most sensitive to progression may differ between patients. We investigated whether decline on a personalized selection of tests predicted progressive disease according to RANO criteria in high-grade glioma patients. METHODS: Starting one day before surgery, patients underwent neuropsychological assessment every three months during standard treatment and clinical follow-up. We first made a personalized selection of three tests that showed the highest Reliable Change Index (RCI) values, i.e., most positive change, at the first post-surgical assessment for each patient. In subsequent follow up, a decline of RCI ≤ - 1 on at least two of the three tests in the selection was considered cognitive decline. We performed a discrete Cox proportional hazards model including a time-dependent coefficient cognitive decline (vs. stability) and covariate age to predict progressive disease. RESULTS: Twenty five patients were included. Cognitive decline on the personalized test selection preceded or had occurred by the time progression was established in 9/15 patients with RANO confirmed progressive disease (60%). Decline was absent in 8/10 patients (80%) with stable disease during participation. The independent hazard ratio for progression in case of cognitive decline was 5.05 (p < 0.01) compared to stable performance. CONCLUSIONS: Using only three patient-specific neuropsychological tests, we found a fivefold increased chance of disease progression in case of cognitive decline as compared to stable performance. Brief, patient-tailored cognitive assessment may be a noninvasive addition to disease monitoring without overburdening patients and clinical care.

Identification of Patients with Recurrent Glioblastoma Who May Benefit from Combined Bevacizumab and CCNU Therapy: A Report from the BELOB Trial.

The results from the randomized phase II BELOB trial provided evidence for a potential benefit of bevacizumab (beva), a humanized monoclonal antibody against circulating VEGF-A, when added to CCNU chemotherapy in patients with recurrent glioblastoma (GBM). In this study, we performed gene expression profiling (DASL and RNA-seq) of formalin-fixed, paraffin-embedded tumor material from participants of the BELOB trial to identify patients with recurrent GBM who benefitted most from beva+CCNU treatment. We demonstrate that tumors assigned to the IGS-18 or "classical" subtype and treated with beva+CCNU showed a significant benefit in progression-free survival and a trend toward benefit in overall survival, whereas other subtypes did not exhibit such benefit. In particular, expression of FMO4 and OSBPL3 was associated with treatment response. Importantly, the improved outcome in the beva+CCNU treatment arm was not explained by an uneven distribution of prognostically favorable subtypes as all molecular glioma subtypes were evenly distributed along the different study arms. The RNA-seq analysis also highlighted genetic alterations, including mutations, gene fusions, and copy number changes, within this well-defined cohort of tumors that may serve as useful predictive or prognostic biomarkers of patient outcome. Further validation of the identified molecular markers may enable the future stratification of recurrent GBM patients into appropriate treatment regimens.

The impact of bevacizumab on health-related quality of life in patients treated for recurrent glioblastoma: results of the randomised controlled phase 2 BELOB trial.

BACKGROUND: The BELOB study, a randomised controlled phase 2 trial comparing lomustine, bevacizumab and combined lomustine and bevacizumab in patients with recurrent glioblastoma, showed that the 9-month overall survival rate was most promising in the combination arm. Here we report the health-related quality of life (HRQoL) results, a secondary trial end-point. METHODS: HRQoL was measured at baseline and every 6weeks until progression using the European Organisation for Research and Treatment of Cancer (EORTC) core questionnaire (QLQ-C30) and brain module (QLQ-BN20). HRQoL was assessed over time for five preselected scales (global health (GH), physical (PF) and social functioning (SF), motor dysfunction (MD) and communication deficit (CD)). Moreover, mean changes in HRQoL from baseline until progression were determined. RESULTS: 138/148 patients with at least a baseline HRQoL assessment were analysed. Over time, HRQoL remained relatively stable in all treatment arms for all five scales, at least during the first three treatment cycles. More than half (54-61%) of the patients showed stable (<10 point change) or improved (⩾10 point change) HRQoL during their progression-free time, except for SF (43%), irrespective of treatment arm. Deterioration of mean HRQoL was most profound at disease progression for all scales except SF, which deteriorated earlier in disease course. Compared to baseline, 40% of patients had clinically relevant (⩾10 points) worse GH, PF and SF, while 44% and 31% had increased MD and CD at disease progression, irrespective of treatment arm. CONCLUSIONS: Bevacizumab, whether or not in combination with lomustine, did not negatively affect HRQoL in patients treated for recurrent glioblastoma in this randomised study.

Single-agent bevacizumab or lomustine versus a combination of bevacizumab plus lomustine in patients with recurrent glioblastoma (BELOB trial): a randomised controlled phase 2 trial.

BACKGROUND: Treatment options for recurrent glioblastoma are scarce, with second-line chemotherapy showing only modest activity against the tumour. Despite the absence of well controlled trials, bevacizumab is widely used in the treatment of recurrent glioblastoma. Nonetheless, whether the high response rates reported after treatment with this drug translate into an overall survival benefit remains unclear. We report the results of the first randomised controlled phase 2 trial of bevacizumab in recurrent glioblastoma. METHODS: The BELOB trial was an open-label, three-group, multicentre phase 2 study undertaken in 14 hospitals in the Netherlands. Adult patients (≥18 years of age) with a first recurrence of a glioblastoma after temozolomide chemoradiotherapy were randomly allocated by a web-based program to treatment with oral lomustine 110 mg/m(2) once every 6 weeks, intravenous bevacizumab 10 mg/kg once every 2 weeks, or combination treatment with lomustine 110 mg/m(2) every 6 weeks and bevacizumab 10 mg/kg every 2 weeks. Randomisation of patients was stratified with a minimisation procedure, in which the stratification factors were centre, Eastern Cooperative Oncology Group performance status, and age. The primary outcome was overall survival at 9 months, analysed by intention to treat. A safety analysis was planned after the first ten patients completed two cycles of 6 weeks in the combination treatment group. This trial is registered with the Nederlands Trial Register (www.trialregister.nl, number NTR1929). FINDINGS: Between Dec 11, 2009, and Nov 10, 2011, 153 patients were enrolled. The preplanned safety analysis was done after eight patients had been treated, because of haematological adverse events (three patients had grade 3 thrombocytopenia and two had grade 4 thrombocytopenia) which reduced bevacizumab dose intensity; the lomustine dose in the combination treatment group was thereafter reduced to 90 mg/m(2). Thus, in addition to the eight patients who were randomly assigned to receive bevacizumab plus lomustine 110 mg/m(2), 51 patients were assigned to receive bevacizumab alone, 47 to receive lomustine alone, and 47 to receive bevacizumab plus lomustine 90 mg/m(2). Of these patients, 50 in the bevacizumab alone group, 46 in the lomustine alone group, and 44 in the bevacizumab and lomustine 90 mg/m(2) group were eligible for analyses. 9-month overall survival was 43% (95% CI 29-57) in the lomustine group, 38% (25-51) in the bevacizumab group, 59% (43-72) in the bevacizumab and lomustine 90 mg/m(2) group, 87% (39-98) in the bevacizumab and lomustine 110 mg/m(2) group, and 63% (49-75) for the combined bevacizumab and lomustine groups. After the reduction in lomustine dose in the combination group, the combined treatment was well tolerated. The most frequent grade 3 or worse toxicities were hypertension (13 [26%] of 50 patients in the bevacizumab group, three [7%] of 46 in the lomustine group, and 11 [25%] of 44 in the bevacizumab and lomustine 90 mg/m(2) group), fatigue (two [4%], four [9%], and eight [18%]), and infections (three [6%], two [4%], and five [11%]). At the time of this analysis, 144/148 (97%) of patients had died and three (2%) were still on treatment. INTERPRETATION: The combination of bevacizumab and lomustine met prespecified criteria for assessment of this treatment in further phase 3 studies. However, the results in the bevacizumab alone group do not justify further studies of this treatment. FUNDING: Roche Nederland and KWF Kankerbestrijding.