Publications by authors named "Warren P Mason"

Background: The diagnosis of leptomeningeal metastatic disease has major prognostic and therapeutic implications. We report 13 patients with a radiologically distinct kind of focal, enhancing leptomeningeal lesion on brain MRI that mimics leptomeningeal metastatic disease.

Methods: These patients were assessed at University Health Network (Toronto, Canada) between January 2001 and December 2023.

View Article and Find Full Text PDF

Background: Patients with glioblastoma (GBM) have a median overall survival (OS) of approximately 16 months. However, approximately 5% of patients survive >5 years. This study examines the differences in methylation profiles between long-term survivors (>5 years, LTS) and short-term survivors (<1 year, STS) with isocitrate dehydrogenase (IDH)-wild-type GBMs.

View Article and Find Full Text PDF

Isocitrate dehydrogenase (IDH) enzymes catalyze the decarboxylation of isocitrate to alpha-ketoglutarate (αKG). IDH1/2 mutations preferentially convert αKG to R-2-hydroxyglutarate (R2HG), resulting in R2HG accumulation in tumor tissues. We investigated circulating 2-hydroxyglutate (2HG) as potential biomarkers for patients with IDH-mutant (IDHmt) cholangiocarcinoma (CCA).

View Article and Find Full Text PDF

Glioblastoma is the most common malignant primary brain tumor in adults. The prognosis is extremely poor even with standard treatment of maximal safe resection, radiotherapy, and chemotherapy. Recurrence is inevitable within months, and treatment options are very limited.

View Article and Find Full Text PDF

Background: For multiply recurrent glioma, options are few and choices are very limited. Etoposide in combination with carboplatin and/or bevacizumab has been evaluated in recurrent glioma with modest efficacy. This retrospective study describes the efficacy of etoposide monotherapy in adults with multiply recurrent diffuse glioma.

View Article and Find Full Text PDF
Article Synopsis
  • Isocitrate dehydrogenase (IDH)-mutant grade 2 gliomas are aggressive brain tumors, and vorasidenib is a promising oral treatment that targets these mutations and showed preliminary effectiveness.
  • A randomized phase 3 trial involved 331 patients with untreated residual or recurrent gliomas, comparing vorasidenib to a placebo over 28-day cycles, focusing on progression-free survival as the main outcome.
  • Results indicated that patients taking vorasidenib had significantly longer progression-free survival (27.7 months) compared to those on placebo (11.1 months) and experienced better outcomes before needing further treatment, although adverse effects were more common in the vorasidenib group.
View Article and Find Full Text PDF

Gliomas are a heterogeneous group of brain tumors with limited therapeutic options. However, identification of BRAF V600E mutations in a subset of gliomas has provided a genomic-targeted approach for management of these diseases. In this review, we aimed to review the role of BRAF V600E in gliomagenesis, to characterize concurrent genomic alterations and their potential prognostic implications, and to review comprehensively the efficacy data of BRAF inhibitors (combined or not with MEK inhibitors) for the treatment of low- and high-grade gliomas.

View Article and Find Full Text PDF

Immune-mediated anti-tumoral responses, elicited by oncolytic viruses and augmented with checkpoint inhibition, may be an effective treatment approach for glioblastoma. Here in this multicenter phase 1/2 study we evaluated the combination of intratumoral delivery of oncolytic virus DNX-2401 followed by intravenous anti-PD-1 antibody pembrolizumab in recurrent glioblastoma, first in a dose-escalation and then in a dose-expansion phase, in 49 patients. The primary endpoints were overall safety and objective response rate.

View Article and Find Full Text PDF

Background: The historic standard of care for adult medulloblastoma has been considered surgery and radiation, while chemotherapy is increasingly being prescribed. This study reviewed 20-year chemotherapy trends at a high-volume center, as well as overall and progression free-survival.

Methods: Adults with medulloblastoma treated at an academic center from January 1, 1999 to -December 31, 2020 were reviewed.

View Article and Find Full Text PDF

Background: In addition to poor survival rates, individuals with glioblastoma (GBM) are at risk of neurocognitive impairment due to multiple factors. This study aimed to characterize neurocognitive impairment, neurobehavioral symptoms, fatigue, sleep disturbance, and depressive symptoms in newly diagnosed GBM patients; and to examine whether neurobehavioral symptoms, fatigue, sleep, and depressive symptoms influence neurocognitive performance.

Methods: This study was part of a prospective, inception cohort, single-arm exercise intervention in which GBM patients underwent a neuropsychological assessment shortly after diagnosis (median 4 weeks; ie, baseline) and 3, 6, 12, and 18 months later, or until tumor progression.

View Article and Find Full Text PDF

Diffuse infiltrating gliomas are the most common malignant brain tumors in adults. The 2021 World Health Organization classification for CNS tumors (CNS5 WHO) has significantly altered the rules for classification and grading of diffuse gliomas. Clinicians, including neurology residents and neurologists, will have to consider the changes that include the introduction of new tumor types, allotting established tumor types to other groups and substituting previously essential morphological features for additional molecular markers.

View Article and Find Full Text PDF

Introduction: The treatment of glioma with temozolomide chemoradiotherapy predisposes patients to pneumocystis pneumonia (PCP). Because PCP is a rare outcome, very little is known about specific clinical risk factors for its development in patients with glioma.

Methods: We performed a population-based retrospective cohort study of glioma patients undergoing temozolomide chemoradiotherapy 2005 to 2019 in Ontario, Canada.

View Article and Find Full Text PDF

Purpose: Pseudoprogression (PsP) remains an elusive and clinically important, yet ill-defined, phenomena that, generally, involves a period of early radiographic progression (enhancement) followed by a period of radiographic stability or regression. In the current study, we utilized data from the control arm of a phase III clinical trial in newly-diagnosed glioblastoma to explore imaging characteristics of "clinically-defined PsP", or early radiographic progression (PFS < 6 months from chemoradiation) followed by a long post-progression residual overall survival (ROS > 12 months).

Methods: One hundred sixty-nine patients with newly-diagnosed GBM from the control arm of the AVAglio trial (NCT00943826) who presented with early radiographic progressive disease (PD) (< 6 months) were included.

View Article and Find Full Text PDF

Background: Cerebral radionecrosis, a subacute or late effect of radiotherapy, can be debilitating and difficult to treat. Steroids can reduce symptoms, but have significant long-term side effects. Bevacizumab has been shown to reduce edema and other radiologic features associated with radionecrosis and improve patient symptoms.

View Article and Find Full Text PDF

Background: Malignant gliomas are treated with temozolomide chemoradiotherapy. Because pneumocystis pneumonia (PCP) can occur in patients receiving temozolomide, the product monograph recommends PCP prophylaxis during temozolomide chemoradiotherapy. Not all neuro-oncologists follow these recommendations, though.

View Article and Find Full Text PDF

Purpose: In a post hoc analysis of the CATNON trial (NCT00626990), we explored whether adding temozolomide to radiotherapy improves outcome in patients with IDH1/2 wildtype (wt) anaplastic astrocytomas with molecular features of glioblastoma [redesignated as glioblastoma, isocitrate dehydrogenase-wildtype (IDH-wt) in the 2021 World Health Organization (WHO) classification of central nervous system tumors].

Patients And Methods: From the randomized phase III CATNON study examining the addition of adjuvant and concurrent temozolomide to radiotherapy in anaplastic astrocytomas, we selected a subgroup of IDH1/2wt and H3F3Awt tumors with presence of TERT promoter mutations and/or EGFR amplifications and/or combined gain of chromosome 7 and loss of chromosome 10. Molecular abnormalities including MGMT promoter methylation status were determined by next-generation sequencing, DNA methylation profiling, and SNaPshot analysis.

View Article and Find Full Text PDF

Background: Effective treatments are needed to improve outcomes for high-grade glioma and low-grade glioma. The activity and safety of dabrafenib plus trametinib were evaluated in adult patients with recurrent or progressive BRAF mutation-positive high-grade glioma and low-grade glioma.

Methods: This study is part of an ongoing open-label, single-arm, phase 2 Rare Oncology Agnostic Research (ROAR) basket trial at 27 community and academic cancer centres in 13 countries (Austria, Belgium, Canada, France, Germany, Italy, Japan, the Netherlands, Norway, South Korea, Spain, Sweden, and the USA).

View Article and Find Full Text PDF

Background: Lymphopenia may lead to worse outcomes for glioblastoma patients. This study is a secondary analysis of the CCTG CE.6 trial evaluating the impact of chemotherapy and radiation on lymphopenia, and effects of lymphopenia on overall survival (OS).

View Article and Find Full Text PDF

Background: Medical assistance in dying (MAiD), also known as physician-assisted death, is currently legal in several locations across the globe. Brain cancer or its treatments can lead to cognitive impairment, which can impact decision-making capacity for MAiD.

Objective: We sought to explore neuro-oncology clinicians' attitudes and perspectives on MAiD, including interpretation of decision-making capacity for patient MAiD eligibility.

View Article and Find Full Text PDF

Background: The CATNON trial investigated the addition of concurrent, adjuvant, and both current and adjuvant temozolomide to radiotherapy in adults with newly diagnosed 1p/19q non-co-deleted anaplastic gliomas. The benefit of concurrent temozolomide chemotherapy and relevance of mutations in the IDH1 and IDH2 genes remain unclear.

Methods: This randomised, open-label, phase 3 study done in 137 institutions across Australia, Europe, and North America included patients aged 18 years or older with newly diagnosed 1p/19q non-co-deleted anaplastic gliomas and a WHO performance status of 0-2.

View Article and Find Full Text PDF