Citations

Abstract Background: Glioma diagnosed during pregnancy and pregnancy following glioma treatment present complex management challenges. The safety of glioma treatment during pregnancy is not well established. The ability to counsel patients on timing of conception after treatment remains limited. The aim of this study was to review our institution’s experience with glioma during and before pregnancy. Methods: In this single-institution study, we retrospectively identified patients diagnosed with glioma during or prior to pregnancy and reviewed treatment course and maternal and neonatal outcomes. Results: Twenty-one female patients were included in our study. Glioma diagnoses included 12 high-grade tumors and 9 low-grade tumors. Cohort A consisted of 8 patients who presented with glioma during pregnancy, of which, 7 underwent glioma treatment during pregnancy. All pregnancies in cohort A were without significant maternal complications and resulted in delivery of a healthy neonate. Cohort B consisted of 13 patients who experienced pregnancy after a prior diagnosis of glioma, totaling 23 pregnancies. Antepartum course was complicated by seizure in three pregnancies. Functionally inconsequential anatomic abnormalities in childhood offspring of cohort B occurred in 5 (27.8%) of the pregnancies. Four of the offspring with anatomic abnormalities had exposure to TMZ prior to conception. Conclusions: In this retrospective series, diagnosis of glioma before or during pregnancy was associated with generally favorable maternal, fetal and childhood outcomes. We observed a higher-than-expected rate of anatomic abnormalities in the post-diagnosis cohort, though none carried meaningful functional consequences. These findings add to the limited literature exploring maternal and fetal outcomes in patients with glioma.

Abstract Introduction Glioblastoma (GBM), the most aggressive primary brain tumor in adults, is marked by profound immune suppression. Tumor-derived extracellular vesicles (TEVs) are increasingly recognized as key mediators of this immunosuppressive environment. Methods In this study, we examined the tumor-immune microenvironment using ultrasonic aspirate samples from GBM patients (n = 14). Results Several immune checkpoint molecules, including PDL1, B7-H3, and VISTA, were notably elevated. TIGIT, a receptor typically associated with T cells, was widely expressed across multiple myeloid subsets, including monocytic myeloid-derived suppressor cells (mMDSCs; 64.27±7.99%) and non-classical monocytes (NCM; 39.8±4.37%). Co-culture of healthy donor CD11b+ cells (n = 10) with TEVs replicated similar effects (mMDSCs; control 11.691.87 vs EV treated 23.322.0). We found CD155, a primary TIGIT ligand, to be heavily enriched in TEVs and co-localized with TIGIT in co-culture, suggesting the TIGIT/CD155 axis may be involved in promoting immune suppression. induced MDSCs markedly suppressed T cell proliferation (30.65 ± 5.97% vs. control 86.47 ± 2.94, p = 0.0001), accompanied by elevated Th2 cytokine production and increased NLRP3 and IL-1β expression. Interestingly, TIGIT knockdown did not affect NLRP3 expression, but did restore T cell proliferation (64.13±1.33%; p = 0.02) and pro-inflammatory cytokine production. However, this effect was lost upon NLRP3 knockdown, indicating its essential role in mediating immune rescue. Furthermore, IL-13 (a Th2 cytokine) blockade, in this model, enhanced pro-inflammatory response by suppressing phosphorylation of STAT-6 protein. Conclusion Overall, our findings highlight a crucial role for the TIGIT/CD155 axis in driving myeloid-mediated immune suppression in GBM. Furthermore, TIGIT inhibition may unmask NLRP3 function, potentially contributing to immune rescue. Funding Source Neurosurgery Research & Education Foundation through the B*CURED & NREF Young Clinician Investigator Award, as well as intramural K12 funding through the Institute for Clinical and Translational Research and the NCI Paul Calabresi Career Development Award (1K12CA279871). Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Abstract Background Glioblastoma (GB) exhibits marked tumor microenvironmental heterogeneity, contributing to both therapy resistance and poor survival outcomes. Intercellular adhesion molecule 1 (ICAM1) is an inflammation-associated adhesion molecule implicated in immune-stromal interactions, but its clinical and biological significance in GB remains incompletely defined. Methods We performed ICAM1 immunohistochemistry, bulk RNA sequencing, DNA methylation analysis, single-nucleus RNA sequencing, and preoperative MRI-derived morphologic feature analysis across multi-institutional cohorts of treatment-naïve IDH-wildtype GB. Results High ICAM1 expression at both transcript and protein levels is associated with shorter overall survival, particularly within the mesenchymal transcriptional subtype. ICAM1 expression is inversely associated with promoter methylation. Single-nucleus RNA-sequencing analysis shows that ICAM1-high tumors are enriched for mesenchymal, hypoxia, stress-associated, and immunosuppressive myeloid programs, suggesting that ICAM1 reflects a multicompartment inflammatory tumor ecosystem. ICAM1 expression, tumor surface irregularity, and patient age are independently prognostic and minimally correlated, capturing complementary clinical, imaging, and molecular features of GB biology. When combined, our Clinical-Imaging-Molecular (CIM) framework refines outcome prediction across independent GB cohorts using routinely available clinical data, conventional imaging, and standard immunohistochemistry. Conclusions ICAM1 characterizes an immune-remodeled, stress-adapted GB ecosystem associated with poor clinical outcomes. Integrating patient age, surface irregularity, and ICAM1 expression yields a scalable and clinically accessible prognostic framework for GB, supporting tailored outcome prediction, particularly in low- and middle-resource settings without routine access to advanced molecular profiling.

OBJECTIVE Maximal safe resection of intra-axial brain tumors near the motor cortex is aided by intraoperative motor mapping. Here, the authors compared outcomes in patients undergoing either low-frequency bipolar stimulation (LFBS) or high-frequency monopolar stimulation (HFMS) for cortical and/or subcortical motor mapping during brain tumor resection. METHODS A retrospective analysis of patients undergoing an asleep craniotomy with motor mapping or an awake craniotomy with motor and speech mapping with a single surgeon was performed. Three cohorts were compared: 1) asleep LFBS (AsLFBS), 2) awake LFBS (AwLFBS; motor + speech mapping), and 3) asleep HFMS. HFMS mapping was not used for awake craniotomies. RESULTS A total of 284 patients who underwent 300 craniotomies with motor mapping were identified. No significant differences in permanent neurological deficits (p = 0.377) or extent of resection (EOR) of nonenhancing tumors (p = 0.453) were identified between LFBS or HFMS motor mapping cases. Both EOR (92.7% vs 83.5%, p = 0.035) and permanent neurological deficits (7.6% vs 3.3%) occurred more frequently in enhancing tumors with LFBS, although the latter was not statistically significant. HFMS was associated with higher rates of subcortical motor pathway identification (p = 0.001) and fewer total intraoperative seizures (p = 0.003) compared with LFBS. Previous resection (HR 0.46, p = 0.003) and a higher cortical threshold (HR 0.95, p = 0.023) were significantly associated with longer survival, while preoperative aphasia (HR 2.24, p = 0.022), hospital length of stay (HR 1.1, p = 0.005), an insular-based tumor (HR 3.5, p = 0.021), and a histological diagnosis of glioblastoma (HR 2.9, p = 0.001) were negative predictors. Interestingly, overall FLAIR EOR was significantly associated with a marginally decreased overall survival (HR 1.01, p = 0.011). CONCLUSIONS No significant differences in postoperative neurological deficits were found between LFBS and HFMS paradigms. HFMS may identify subcortical motor fibers more reliably while resulting in significantly fewer intraoperative seizures. Although LFBS was associated with greater EOR of contrast-enhancing tumors, it may also be associated with higher rates of postoperative deficits, perhaps reflecting less reliable identification of subcortical motor fibers.

Abstract Background Isocitrate dehydrogenase (IDH)-mutant gliomas are infiltrative tumors with limited treatment options at recurrence. Early studies suggest IDH inhibition has therapeutic activity. We evaluated clinical outcomes associated with IDH-1 inhibitor ivosidenib in recurrent IDH-1-mutant gliomas and molecular predictors of response. Methods We retrospectively analyzed adults treated with ivosidenib from January 2021 to August 2025 with predominantly recurrent, pretreated CNS WHO grade 2-4 astrocytoma IDH-mutant or grade 2-3 oligodendroglioma, IDH-mutant and 1p/19q codeleted. Prior anticancer treatments, toxicities, enhancement status at ivosidenib initiation, and genomic alterations were collected. The primary endpoint was progression-free survival (PFS); secondary analyses evaluated associations between PFS, genomic complexity, and CDKN2A/B homozygous deletion. Results Ninety-two adults, median age 43, were included: 61 astrocytomas and 31 oligodendrogliomas, mostly grade 2. Before ivosidenib, 69 had surgery, 64 chemotherapy, and 64 radiation. Median time from diagnosis to ivosidenib was 4.8 years, with median of two prior progressions. Median treatment duration was 5.8 months. Median PFS was 15.2, 4.6, and 2.1 months for astrocytoma grades 2-4, 14.0 and 6.9 months for oligodendroglioma grades 2-3. Increasing genomic complexity was associated with shorter PFS in univariate analysis. Patients without CDKN2A/B homozygous deletion had median PFS of 19.2 months. Two patients with homozygous deletion had median PFS of 0.6 months. Conclusions In this retrospective analysis of predominantly recurrent IDH-1-mutant glioma, ivosidenib was associated with longer PFS in lower-grade, non-enhancing tumors that received little or no prior anticancer treatment and less complex genomic profiles. These findings support a context-dependent benefit of IDH inhibition in recurrent disease.

Abstract Background Immunotherapy has yet to make significant gains in glioblastoma (GBM) treatment, due in part to GBM-mediated immune suppression. Increasing evidence points to critical roles for tumor-derived extracellular vesicles (EVs) and immunosuppressive myeloid cells as key factors in this process. Methods Immunophenotyping of the tumor-immune microenvironment was performed using ultrasonic aspirate collected during GBM resection by high-dimensional flow cytometry. EVs collected from patient-derived GBM cell lines were used to condition myeloid cells collected from healthy donors to generate immunosuppressive myeloid cells. siRNA was used to knockdown TIGIT and/or NLRP3 expression prior to EV conditioning. T cell co-culture studies were performed with donor-matched T cells. Results Immune phenotyping of the tumor microenvironment and EV-conditioned myeloid cells revealed similar immunomodulatory protein expression across myeloid cell populations, with particularly elevated TIGIT expression. Knockdown of TIGIT reduced the immunosuppressive polarization of myeloid cells, resulting in improved T cell function. This finding proceeded in an NLRP3-dependent manner, with substantial co-expression of TIGIT and NLRP3 expression prior to knockdown, and concomitant knockdown of NLRP3 abrogating the effect of TIGIT knockdown. TIGIT expression correlated with increased IL-13 expression, and IL-13 blockade unmasked a pro-inflammatory myeloid cell phenotype. Conclusion TIGIT expression in myeloid cells in the GBM microenvironment is a functional marker of immunosuppressive activity, with TIGIT knockdown reducing IL-13 expression and unmasking the pro-inflammatory activity of NLRP3. This study bolsters our understanding of the immunosuppressive complexities of the GBM microenvironment and supports attenuation of immunosuppressive myeloid cell activity as a strategy to restore immune function in GBM.

Abstract Background Current literature suggestsisocitrate dehydrogenase (IDH)-mutant astrocytoma contains several molecular subgroups. In this study, we are interested in determining the connection between different molecular subgroups with grade and/or survival. Methods A cohort of 470 Mayo Clinic adult patients (≥18 years, 56.2% male) with primary IDH-mutant astrocytoma diagnosed by World Health Organization (WHO) 2021 criteria were examined. Results were validated in an independent cohort of 614 Mayo Clinic Neuropathology consult patients and 235 The Cancer Genome Atlas (TCGA) patients. Results The Mayo Clinic Practice cohort confirmed the association of CDKN2A/B deletion with overall survival (OS, homozygous vs hemizygous vs intact, 2.7 vs 9.6 vs 17.2 years, P < .001). Phosphatase and tensin homolog (PTEN) deletion was also associated with poor OS (7.3 vs 17.4 years, P < .001). Increased number of copy number alterations was associated with OS (continuous variable, HR = 1.027, P < .001). Carrying one or more copies of the germline risk allele at rs55705857 was associated with earlier age of onset (median age 33 vs 35 years, P = .01), and a shorter OS after adjusting for age, grade, sex and treatment (HR = 1.81, P = .007). The Mayo Clinic Neuropathology Consult cohort and TCGA were utilized to validate age of onset and survival, respectively. Unsupervised clustering of the copy number alterations identified several clinically significant groups that may define pathways to disease progression. Losses of chromosomes 11p, 13q, 1p, and 10q were all associated with reduced overall survival in the Mayo Clinic cohort. Conclusions Patients with hemizygous loss of CDKN2A/B, loss of PTEN, increased number of copy number alterations, specific chromosomal arm losses or rs55705857 germline risk allele have reduced overall survival.

Abstract Background Glioblastoma IDH-wildtype (GBM) may be diagnosed histologically (hGBM) or based on molecular features when microvascular proliferation and histologic necrosis are absent (mGBM). Clinical and radiographic distinction between hGBM and mGBM remains unclear. Methods 101 hGBM cases were matched to 109 mGBM cases by age, sex, year of diagnosis, and TERT promoter mutation (TERTp) status. Clinical outcome, radiographic, and molecular features were compared across mGBM and hGBM. Results Median time from first MRI to diagnosis was longer for mGBM versus hGBM (34 vs 7 days, p < .001). mGBM more often presented with seizures (51% vs 26%, p < .001), gliomatosis pattern (12% vs 2%, p = .005), basal ganglia involvement (17% vs 0%, p < .001). Contrast enhancement appeared on MRI for 98% (96/98) of hGBM and 50% (54/107) of mGBM (p < .001). mGBM with non-enhancing MRI were rarely multifocal (2% vs 30%, p < .001). mGBM harbored fewer total copy number alterations (median 20 vs 16.5, p = .029), less often had EGFRamp (34% vs 48%, p = .051), isolated chromosome 10 loss (84% vs 96%, p = .013), and CDKN2A/B homozygous deletion (56% vs 77%, p = .005). Median overall survival was longer for mGBM (2.16 vs 1.44 years, p < .001), and for mGBM without MRI contrast enhancement versus hGBM with enhancement (3.11 vs 1.62 years, adjusted p = .003). mGBM without +7/−10 or without CDKN2A/B homozygous deletion had longer survival and time-to-progression versus hGBM with these alterations. Conclusion mGBM with MRI enhancement may represent undersampled or early/evolving hGBM. mGBM that are non-enhancing, present with seizures, prolonged time to diagnosis, absent CDKN2A/B alteration or +7/−10 may represent other IDH-wildtype entities.

Glioblastoma (GBM), the most common primary malignant brain tumor in adults, has a median survival of 14–15 months despite aggressive treatment. Monitoring relies on MRI, but differentiating tumor progression from pseudo-progression or radiation necrosis remains difficult. Plasma extracellular vesicles (EVs) are emerging as promising non-invasive biomarkers due to their molecular cargos and accessibility. This review evaluates studies that specifically isolated plasma EVs for molecular profiling in GBM diagnosis and monitoring. Biomarkers (miRNA, RNA, DNA, proteins), EV characterization methods, and advancements in enriching tumor-derived EV subpopulations and assessing their diagnostic and prognostic potential are highlighted. Plasma EVs carry diverse cargos, including miRNAs (e.g., miR-21, miR-15b-3p), mRNAs (e.g., EGFRvIII), circRNAs, and proteins (e.g., CD44, GFAP). Composite molecular signatures have achieved sensitivities of 87–100% and specificities of 73–100% for GBM diagnosis. Tumor-derived EVs, enriched using techniques like SEC-CD44 immunoprecipitation, microfluidic platforms, or 5-ALA-induced PpIX fluorescence, enhance biomarker detection. Non-tumor-derived EVs may also reflect GBM’s systemic effects. Challenges include EV heterogeneity, non-EV contamination, and variable biomarker expression across studies. Plasma-EV-based liquid biopsies offer significant potential for GBM monitoring, with advanced enrichment methods improving tumor-specific biomarker detection. Standardizing isolation protocols and validating biomarkers in larger cohorts are critical for clinical translation.

Abstract Description Glioblastoma (GBM), the most common and malignant primary brain tumor, exhibits profound immune suppression, hindering immunotherapy efficacy. GBM-derived extracellular vesicles (EVs) play a major role through the immunosuppressive polarization of myeloid cells. Inhibition of EV-myeloid cell interactions thus represents a novel target to mitigate GBM-mediated immune suppression. However, there are multiple mechanisms of EV-target interaction, and downstream pathways of GBM-EV signaling are poorly understood. We explored two pharmacological agents targeting different mechanisms of EV uptake: Methyl-B-cyclodextrin (MBCD), which disrupts lipid rafts, and cytochalasin D, which inhibits actin polymerization. Our results showed immunosuppressive myeloid cell (CD11b+/ CD15-/ HLA-DRlow/ CD14high) populations increased upon GBM-EV treatment. Following cytochalasin D treatment, fewer immunosuppressive myeloid cells were observed (7.40%±1.01 vs. untreated 9.66%±2.86), with rescuing T cell proliferation. Conversely, MBCD treatment increased immunosuppressive myeloid cell levels (10.42%±2.38 vs. untreated 8.87%±3.97) without impacting T cell proliferation. This study demonstrates the feasibility of pharmacologically targeting EV-myeloid cell interactions to rescue tumor mediated immune suppression by inhibiting actin-dependent endocytosis with cytochalasin D. The converse results using MBCD treatment indicate differential importance of different EV uptake pathways in monocyte regulation. Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)