Value of long non-coding RNA HAS2-AS1 as a diagnostic and prognostic marker of glioma

BACKGROUND

Glioma presents high incidence and poor prognosis, and therefore more effective treatments are needed. Studies have confirmed that long non-coding RNAs (lncRNAs) basically regulate various human diseases including glioma. It has been theorized that HAS2-AS1 serves as an lncRNA to exert an oncogenic role in varying cancers. This study aimed to assess the value of lncRNA HAS2-AS1 as a diagnostic and prognostic marker for glioma.

METHODS

The miRNA expression data and clinical data of glioma were downloaded from the TCGA database for differential analysis and survival analysis. In addition, pathological specimens and specimens of adjacent normal tissue from 80 patients with glioma were used to observe the expression of HAS2-AS1. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic ability and prognostic value of HAS2-AS1 in glioma. Meanwhile, a Kaplan-Meier survival curve was plotted to evaluate the survival of glioma patients with different HAS2-AS1 expression levels.

RESULTS

HAS2-AS1 was significantly upregulated in glioma tissues compared with normal tissue. The survival curves showed that overexpression of HAS2-AS1 was associated with poor overall survival (OS) and progression-free survival (PFS). Several clinicopathological factors of glioma patients, including tumor size and WHO grade, were significantly correlated with HAS2-AS1 expression in tissues. The ROC curve showed an area under the curve (AUC) value of 0.863, indicating that HAS2-AS1 had good diagnostic value. The ROC curve for the predicted OS showed an AUC of 0.906, while the ROC curve for predicted PFS showed an AUC of 0.88. Both suggested that overexpression of HAS2-AS1 was associated with poor prognosis.

CONCLUSIONS

Normal tissues could be clearly distinguished from glioma tissues based on HAS2-AS1 expression. Moreover, overexpression of HAS2-AS1 indicated poor prognosis in glioma patients. Therefore, HAS2-AS1 could be used as a diagnostic and prognostic marker for glioma.

Spiking GABAergic OPC tumor cells prolong survival in IDH1 mutant glioma

Prior studies have shown that glioma cells form synapses with neurons to receive synaptic inputs. To discern if glioma cells can send outgoing electrochemical signals in the form of action potentials (APs), we employed Patch-sequencing on surgically-resected human glioma slices. Results showed that half of patched cells in IDH1 mutant (IDH1mut) tumors demonstrate select properties of both neurons and glia and fire single, short APs. To define the transcriptional profiles of these hybrid cells (HCs) and discern if they are tumor derived, we developed a computational tool, Single Cell Rule Association Mining (SCRAM), to annotate features in each cell individually. SCRAM revealed that HCs represent a heterogenous group of tumor and non-tumor cells that are uniformly defined by both GABAergic neuron and oligodendrocyte precursor cell (GABA-OPC) transcriptional signatures. We found that GABA-OPC tumor cells express requisite voltage-gated ion channels needed to fire APs. We validated our findings in human single cell and bulk RNA-seq datasets, confirming that GABA-OPCs represent 40% of IDH1mut tumor cells, correlate with survival outcomes in IDH1mut human patients and are also found in select molecular subtypes of IDH1 wild-type tumors. These studies describe a new cell type in IDH1mut glioma with unique electrophysiological and transcriptomic properties.

Association of graph-based spatial features with overall survival status of glioblastoma patients

Glioblastoma is the most common malignant brain tumor with less than 15 months median survival. To aid prognosis, there is a need for decision tools that leverage diagnostic modalities such as MRI to inform survival. In this study, we examine higher-order spatial proximity characteristics from habitats and propose two graph-based methods (minimum spanning tree and graph run-length matrix) to characterize spatial heterogeneity over tumor MRI-derived intensity habitats and assess their relationships with overall survival as well as the immune signature status of patients with glioblastoma. A data set of 74 patients was studied based on the availability of post-contrast T1-weighted and T2-weighted fluid attenuated inversion recovery (FLAIR) image data in The Cancer Image Archive (TCIA). We assessed the predictive value of MST- and GRLM-derived features from 2D images for prediction of 12-month survival status and immune signature status of patients with glioblastoma via a receiver operating characteristic curve analysis. For 12-month survival prediction using MST-based method, sensitivity and specificity were 0.82 and 0.79 respectively. For GRLM-based method, sensitivity and specificity were 0.73 and 0.77 respectively. For immune status, sensitivity and specificity were 0.91 and 0.69, respectively, for the GRLM-based method with an immune effector. Our results show that the proposed MST- and GRLM-derived features are predictive of 12-month survival status as well as the immune signature status of patients with glioblastoma. To our knowledge, this is the first application of MST- and GRLM-based proximity analyses for the study of radiologically-defined tumor habitats in glioblastoma.

Prevalence of pathogenic germline variants in adult-type diffuse glioma

Background

No consensus germline testing guidelines currently exist for glioma patients, so the prevalence of germline pathogenic variants remains unknown. This study aims to determine the prevalence and type of pathogenic germline variants in adult glioma.

Methods

A retrospective review at a single institution with paired tumor/normal sequencing from August 2018-April 2022 was performed and corresponding clinical data were collected.

Results

We identified 152 glioma patients of which 15 (9.8%) had pathogenic germline variants. Pathogenic germline variants were seen in 11/84 (13.1%) of Glioblastoma, IDH wild type; 3/42 (7.1%) of Astrocytoma, IDH mutant; and 1/26 (3.8%) of Oligodendroglioma, IDH mutant, and 1p/19q co-deleted patients. Pathogenic variants in BRCA2, MUTYH, and CHEK2 were most common (3/15, 20% each). BRCA1 variants occurred in 2/15 (13%) patients, with variants in NF1, ATM, MSH2, and MSH3 occurring in one patient (7%) each. Prior cancer diagnosis was found in 5/15 patients (33%). Second-hit somatic variants were seen in 3/15 patients (20%) in NF1, MUTYH, and MSH2. Referral to genetics was performed in 6/15 (40%) patients with pathogenic germline variants. 14/15 (93%) of patients discovered their pathogenic variant as a result of their paired glioma sequencing.

Conclusions

These findings suggest a possible overlooked opportunity for determination of hereditary cancer syndromes with impact on surveillance as well as potential broader treatment options. Further studies that can determine the role of variants in gliomagenesis and confirm the occurrence and types of pathogenic germline variants in patients with IDH wild type compared to IDH mutant tumors are necessary.

MD Anderson Phase III Randomized Preoperative Stereotactic Radiosurgery (SRS) vs. Postoperative SRS for Brain Metastases Trial

PURPOSE/OBJECTIVE(S)

Postoperative stereotactic radiation therapy/radiosurgery (SRT/SRS) is being evaluated in comparison to Preoperative SRT for brain metastases (mets) in a limited number of prospective clinical trials. Our objective is to address the significant knowledge gap concerning the logistics of preoperative SRT in comparison to postoperative SRT in a randomized controlled study.

MATERIALS/METHODS

Patients with brain mets with at least 1 surgically operable met were randomized (1:1) to Preop vs Postop SRT. In this abstract, we present non-primary endpoint data on the trial concept and logistics of treatment for this data safety monitoring board reviewed study. Patients enrolled had 1-2 lesions resected and <15 lesions treated at time of SRT to best reflect the standard population that receive SRT and surgery at our institution.

RESULTS

From 12/2018 to 12/2022, 99 patients with 1-2 operable brain mets were enrolled and randomized to Preop (n = 49) or Postop (n = 50) SRT. Males represented 56% of the cohort compared to females, and <25% were age 18-49 years, while 27%, 29, and 19% respectively were 50-59, 60-69, and > = 70. The most frequent histologies enrolled were lung (29%), renal cell (15%), melanoma (14%), and breast (11%) cancers. The majority of patients (83%) had 1-4 brain mets on their baseline MRI and 91% subsequently had a single lesion resected. Seventy-nine patients completed both SRT and surgery, while 9% received no therapy due to drop out before study therapy initiation. Among patients receiving both therapies in the combined cohort, 68% received a non-invasive stereotactic radiosurgery instrument to the randomized cavity lesion compared to 32% receiving LINAC based SRT. Treatment of the lesion or cavity with single fraction SRT was 51% in the Preop arm vs 31% in the Postop arm. Multi-fraction (3-5 SRT) was 67% in the Postop cohort in contrast to 47% in the Preop cohort. Time from randomization to RT was 5.6 days and 33.7 days in the Preop and Postop cohorts respectively, and for surgery was 10.2 days vs 12.9 days in the Postop vs Preop cohorts. The average time from RT to surgery was 7.3 days in the Preop arm and 23.5 days in the Postop arm (to allow for incisional healing time).

CONCLUSION

In one of the early initiated randomized prospective cohorts of Preop vs Postop SRT, we demonstrated logistical feasibility with an efficient clinical trial workflow for study treatment. Differences in Preop vs Postop logistics reflect clinical practice differences in time-to-treatment. Therapy with various modalities reflected real-world practice and possibly provider preferences in technique when addressing the nature of delineating cavities and changes in cavity volume with regard to fractionation. Independent of the primary outcomes, our data provides insights in the practical management of patients receiving these two modalities of therapy, and further data at the completion of trial will address relevant primary outcomes.

Remote neuronal activity drives glioma progression through SEMA4F

The tumour microenvironment plays an essential role in malignancy, and neurons have emerged as a key component of the tumour microenvironment that promotes tumourigenesis across a host of cancers1,2. Recent studies on glioblastoma (GBM) highlight bidirectional signalling between tumours and neurons that propagates a vicious cycle of proliferation, synaptic integration and brain hyperactivity3-8; however, the identity of neuronal subtypes and tumour subpopulations driving this phenomenon is incompletely understood. Here we show that callosal projection neurons located in the hemisphere contralateral to primary GBM tumours promote progression and widespread infiltration. Using this platform to examine GBM infiltration, we identified an activity-dependent infiltrating population present at the leading edge of mouse and human tumours that is enriched for axon guidance genes. High-throughput, in vivo screening of these genes identified SEMA4F as a key regulator of tumourigenesis and activity-dependent progression. Furthermore, SEMA4F promotes the activity-dependent infiltrating population and propagates bidirectional signalling with neurons by remodelling tumour-adjacent synapses towards brain network hyperactivity. Collectively our studies demonstrate that subsets of neurons in locations remote to primary GBM promote malignant progression, and also show new mechanisms of glioma progression that are regulated by neuronal activity.

Aspirin and immunotherapy: a Faustian bargain?

Fibrinogen-like protein 1 (FGL1) has been associated with improved survival in hepatocellular carcinoma (HCC). However, recent evidence suggests that FGL1 may bind to surface receptors on lymphocytes and induce immune senescence. In this issue of the JCI, Lin and co-authors show that FGL1 may be acetylated by aspirin and targeted for degradation, which is associated with increased antitumor immunity and improved survival. Similar findings were obtained with inhibitors of sirtuin 2 (SIRT2), a histone deacetylase. These findings expand our current understanding of the role of FGL1 in cancer and provide an impetus for the evaluation of alternative immunotherapy combinations in HCC.

Concurrent IDH1 and IDH2 mutations in glioblastoma: A case report

Isocitrate dehydrogenase (IDH) mutations are cornerstone diagnostic features in glioma classification. IDH mutations are typically characterized by mutually exclusive amino acid substitutions in the genes encoding for the IDH1 and the IDH2 enzyme isoforms. We report our institutional case of a diffuse astrocytoma with progression to secondary glioblastoma and concurrent IDH1/IDH2 mutations. A 49-year-old male underwent a subtotal resection of a lobular lesion within the right insula in 2013, revealing a WHO grade 3 anaplastic oligoastrocytoma, IDH1 mutated, 1p19q intact. Symptomatic tumor progression was suspected in 2018, leading to a surgical tumor biopsy that demonstrated WHO grade 4 IDH1 and IDH2 mutant diffuse astrocytoma. The patient subsequently underwent surgical resection followed by medical management and finally died in 2021. Although concurrent IDH1/IDH2 mutations have been rarely reported in the current literature, further study is required to better define their impact on patients’ prognoses and their response to targeted therapies.

Remote neuronal activity drives glioma infiltration via Sema4f

The tumor microenvironment (TME) plays an essential role in malignancy and neurons have emerged as a key component of the TME that promotes tumorigenesis across a host of cancers. Recent studies on glioblastoma (GBM) highlight bi-directional signaling between tumors and neurons that propagates a vicious cycle of proliferation, synaptic integration, and brain hyperactivity; however, the identity of neuronal subtypes and tumor subpopulations driving this phenomenon are incompletely understood. Here we show that callosal projection neurons located in the hemisphere contralateral to primary GBM tumors promote progression and widespread infiltration. Using this platform to examine GBM infiltration, we identified an activity dependent infiltrating population present at the leading edge of mouse and human tumors that is enriched for axon guidance genes. High-throughput, in vivo screening of these genes identified Sema4F as a key regulator of tumorigenesis and activity-dependent infiltration. Furthermore, Sema4F promotes the activity-dependent infiltrating population and propagates bi-directional signaling with neurons by remodeling tumor adjacent synapses towards brain network hyperactivity. Collectively, our studies demonstrate that subsets of neurons in locations remote to primary GBM promote malignant progression, while revealing new mechanisms of tumor infiltration that are regulated by neuronal activity.

In vivo functional characterization of EGFR variants identifies novel drivers of glioblastoma

BACKGROUND

Glioblastoma is the most common and aggressive primary brain tumor. Large-scale sequencing initiatives have cataloged its mutational landscape in hopes of elucidating mechanisms driving this deadly disease. However, a major bottleneck in harnessing this data for new therapies is deciphering "driver" and "passenger" events amongst the vast volume of information.

METHODS

We utilized an autochthonous, in vivo screening approach to identify driver, EGFR variants. RNA-Seq identified unique molecular signatures of mouse gliomas across these variants, which only differ by a single amino acid change. In particular, we identified alterations to lipid metabolism, which we further validated through an unbiased lipidomics screen.

RESULTS

Our screen identified A289I as the most potent EGFR variant, which has previously not been characterized. One of the mechanisms through which A289I promotes gliomagenesis is to alter cellular triacylglycerides through MTTP. Knockout of Mttp in mouse gliomas, reduces gliomagenesis in multiple models.

CONCLUSIONS

EGFR variants that differ by a single amino acid residue differentially promote gliomagenesis. Among the identified mechanism that drives glioma growth include lipid metabolism through MTTP. Understanding triacylglyceride accumulation may present a prospective therapeutic pathway for this deadly disease.

Single-cell RNA sequencing reveals immunosuppressive myeloid cell diversity during malignant progression in a murine model of glioma

Recent studies have shown the importance of the dynamic tumor microenvironment (TME) in high-grade gliomas (HGGs). In particular, myeloid cells are known to mediate immunosuppression in glioma; however, it is still unclear if myeloid cells play a role in low-grade glioma (LGG) malignant progression. Here, we investigate the cellular heterogeneity of the TME using single-cell RNA sequencing in a murine glioma model that recapitulates the malignant progression of LGG to HGG. LGGs show increased infiltrating CD4⁺ and CD8⁺ T cells and natural killer (NK) cells in the TME, whereas HGGs abrogate this infiltration. Our study identifies distinct macrophage clusters in the TME that show an immune-activated phenotype in LGG but then evolve to an immunosuppressive state in HGG. We identify CD74 and macrophage migration inhibition factor (MIF) as potential targets for these distinct macrophage populations. Targeting these intra-tumoral macrophages in the LGG stage may attenuate their immunosuppressive properties and impair malignant progression.

Glioma epileptiform activity and progression are driven by IGSF3-mediated potassium dysregulation

Seizures are a frequent pathophysiological feature of malignant glioma. Recent studies implicate peritumoral synaptic dysregulation as a driver of brain hyperactivity and tumor progression; however, the molecular mechanisms that govern these phenomena remain elusive. Using scRNA-seq and intraoperative patient ECoG recordings, we show that tumors from seizure patients are enriched for gene signatures regulating synapse formation. Employing a human-to-mouse in vivo functionalization pipeline to screen these genes, we identify IGSF3 as a mediator of glioma progression and dysregulated neural circuitry that manifests as spreading depolarization (SD). Mechanistically, we discover that IGSF3 interacts with Kir4.1 to suppress potassium buffering and found that seizure patients exhibit reduced expression of potassium handlers in proliferating tumor cells. In vivo imaging reveals that dysregulated synaptic activity emanates from the tumor-neuron interface, which we confirm in patients. Our studies reveal that tumor progression and seizures are enabled by ion dyshomeostasis and identify SD as a driver of disease.

CXCR4 expression is associated with proneural-to-mesenchymal transition in glioblastoma

Glioblastoma (GBM) is the most common primary intracranial malignant tumor and consists of three molecular subtypes: proneural (PN), mesenchymal (MES) and classical (CL). Transition between PN to MES subtypes (PMT) is the glioma analog of the epithelial-mesenchymal transition (EMT) in carcinomas and is associated with resistance to therapy. CXCR4 signaling increases the expression of MES genes in glioma cell lines and promotes EMT in other cancers. RNA sequencing (RNAseq) data of PN GBMs in The Cancer Genome Atlas (TCGA) and secondary high-grade gliomas (HGGs) from an internal cohort were examined for correlation between CXCR4 expression and survival as well as expression of MES markers. Publicly available single-cell RNA sequencing (scRNAseq) data was analyzed for cell type specific CXCR4 expression. These results were validated in a genetic mouse model of PN GBM. Higher CXCR4 expression was associated with significantly reduced survival and increased expression of MES markers in TCGA and internal cohorts. CXCR4 was expressed in immune and tumor cells based on scRNAseq analysis. Higher CXCR4 expression within tumor cells on scRNAseq was associated with increased MES phenotype, suggesting a cell-autonomous effect. In a genetically engineered mouse model, tumors induced with CXCR4 exhibited a mesenchymal phenotype and shortened survival. These results suggest that CXCR4 signaling promotes PMT and shortens survival in GBM and highlights its inhibition as a potential therapeutic strategy.

Fibrinogen-like protein 2: Its biological function across cell types and the potential to serve as an immunotherapy target for brain tumors

Brain tumors are among the 10 leading causes of cancer-related death and present unique treatment challenges due to their critical location, genetic heterogeneity, and the blood-brain barrier. Recent advances in targeted immunotherapy and immune checkpoint blocking therapy provide alternative therapeutic strategies for brain tumors. Fibrinogen-like protein 2 (FGL2), which induces transformation from low-grade glioma to high-grade glioblastoma, is a type II membrane protein that is highly expressed in both host immune cells and tumor cells. Studies have uncovered multiple forms of FGL2 proteins with a broad range of roles in inducing immune tolerance and avoiding immune surveillance in tumor cells. Of note, presence of FGL2 transforms low grade to high grade brain tumors via promoting Treg, macrophages, and perhaps stemness. Absence (knockout) of FGL2 in tumor cells (not in host cells) induces CD103 DC cells, which triggers tumor specific CD8 +T cell activity to reject brain tumor progression. Immunotherapies targeting FGL2 have shown great promise in improving survival time in murine models. In this article, we will summarize the biological function of FGL2 in immune and tumor cells.

Characterization of recurrence patterns and outcomes of medulloblastoma in adults: The University of Texas MD Anderson Cancer Center experience

Background

Medulloblastoma in adults is rare and treatment decisions are largely driven from pediatric literature. We sought to characterize recurrent medulloblastoma in adults.

Methods

From a single-institution dataset of 200 adult patients diagnosed with medulloblastoma during 1978-2017, those with recurrence were analyzed for clinical features, treatment, and outcome.

Results

Of the 200 patients, 82 (41%) with median age of 29 years (18-59) had recurrence after a median follow-up time of 8.4 years (95% CI = 7.1, 10.3). Of these, 30 (37%) were standard-risk, 31 (38%) were high-risk, and 21 (26%) had unknown-risk diseases at the time of initial diagnosis. Forty-eight (58%) presented with recurrence outside the posterior fossa, of whom 35 (43%) had distant recurrence only. Median Progression-free survival (PFS) and OS from initial surgery were 33.5 and 62.4 months, respectively. Neither PFS nor OS from initial diagnosis differed between the standard-risk and high-risk groups in those who experience recurrence (P = .505 and .463, respectively). Median OS from first recurrence was 20.3 months, also with no difference between the standard-risk and high-risk groups (P = .518). Recurrences were treated with combinations of re-resection (20 patients; 25%), systemic chemotherapy (61 patients; 76%), radiation (29 patients; 36%), stem cell transplant (6 patients; 8%), and intrathecal chemotherapy (4 patients; 5%). Patients who received radiation at recurrence had better OS (32.9 months) than those who did not (19.2 months) (P = .034).

Conclusions

Recurrent medulloblastoma in adults has a poor prognosis irrespective of initial risk stratification. Recurrence commonly arises outside the posterior fossa years after initial diagnosis.

Varied histomorphology and clinical outcomes of FGFR3-TACC3 fusion gliomas

Targeted therapies for driver gene fusions in cancers have yielded substantial improvements in care. Here, the authors outline a case series of 6 patients with FGFR3-TACC3 fusion in primary brain tumors ranging from polymorphous low-grade neuroepithelial tumor of the young to papillary glioneuronal tumors and glioblastoma (GBM). Previous studies indicated the FGFR3-TACC3 fusion provides survival benefit to GBM patients. Consistent with this, 2 patients with GBM had unexpectedly good outcomes and survived for 5 and 7 years, respectively. In contrast, 2 patients with initially lower graded tumors survived only 3 years and 1 year, respectively. One patient received erdafitinib, a targeted FGFR inhibitor, for 3 months at late disease recurrence and no response was seen. There were varied histomorphological features, including many cases that lacked the characteristic FGFR3-TACC3 pathology. The findings of this cohort suggest that molecular testing is justified, even for glioma cases lacking classic histopathological signatures. Currently, FGFR3-TACC3 fusion gliomas are often classified on the basis of histopathological features. However, further research is needed to examine whether IDH1/2-wild-type tumors with FGFR3-TACC3 fusion should be classified as a subtype on the basis of this molecular fusion. Because patients with IDH1/2-wild-type GBM with FGFR3-TACC3 fusion have improved survival, routine molecular testing for this mutation in patients enrolled in clinical trials and subsequent stratification may be warranted.

Human Dectin-1 deficiency impairs macrophage-mediated defense against phaeohyphomycosis

Subcutaneous phaeohyphomycosis typically affects immunocompetent individuals following traumatic inoculation. Severe or disseminated infection can occur in CARD9 deficiency or after transplantation, but the mechanisms protecting against phaeohyphomycosis remain unclear. We evaluated a patient with progressive, refractory Corynespora cassiicola phaeohyphomycosis and found that he carried biallelic deleterious mutations in CLEC7A encoding the CARD9-coupled, β-glucan-binding receptor, Dectin-1. The patient's PBMCs failed to produce TNF-α and IL-1β in response to β-glucan and/or C. cassiicola. To confirm the cellular and molecular requirements for immunity against C. cassiicola, we developed a mouse model of this infection. Mouse macrophages required Dectin-1 and CARD9 for IL-1β and TNF-α production, which enhanced fungal killing in an interdependent manner. Deficiency of either Dectin-1 or CARD9 was associated with more severe fungal disease, recapitulating the human observation. Because these data implicated impaired Dectin-1 responses in susceptibility to phaeohyphomycosis, we evaluated 17 additional unrelated patients with severe forms of the infection. We found that 12 out of 17 carried deleterious CLEC7A mutations associated with an altered Dectin-1 extracellular C-terminal domain and impaired Dectin-1-dependent cytokine production. Thus, we show that Dectin-1 and CARD9 promote protective TNF-α- and IL-1β-mediated macrophage defense against C. cassiicola. More broadly, we demonstrate that human Dectin-1 deficiency may contribute to susceptibility to severe phaeohyphomycosis by certain dematiaceous fungi.

SURG-23. EFFICACY OF LASER INTERSTITIAL THERMAL THERAPY (LITT) FOR NEWLY DIAGNOSED AND RECURRENT IDH WILD-TYPE GLIOBLASTOMA

Treatment options for glioblastoma remain limited, particularly for those who are not eligible for traditional resection, whether due to lesion location or inability to tolerate open craniotomy. Maximal-safe resection followed by radiation with concurrent and adjuvant temozolomide offers the best outcomes for patients. Unfortunately, not all tumors are amenable to conventional surgical resection at the time of diagnosis with only about 1/3 of patients able to receive a gross-total resection and 15-25% of patients receiving biopsy only, thus reducing their projected overall survival to 9 months. Laser interstitial thermal therapy (LITT) is a minimally invasive, cytoreductive tool, that has demonstrated safety as a surgical approach to treat primary brain tumors.

METHODS

Data from LAANTERN prospective multicenter registry (NCT02392078) was analyzed to determine clinical outcomes for patients with new and recurrent IDH wild-type glioblastoma (N=89). Demographics, intraprocedural data, adverse events, KPS, health-economics, and survival data were prospectively collected then analyzed separately for newly diagnosed GBM (N=29) and recurrent GBM (N=60).

RESULTS

Median overall-survival was 9.73 months (95% CI: 5.16, 15.91) for newly diagnosed patients and median post-procedure survival was 8.97 (6.94, 12.36) months for recurrent patients. Median overall-survival for newly diagnosed patients receiving post-LITT chemoradiotherapy was 16.14 months (6.11, not reached). The median length of hospital stay was 50 hours and 80% of patients were discharged to home.

CONCLUSIONS

LITT offers an effective cytoreductive approach for patients with newly diagnosed and recurrent IDH wild-type glioblastoma. Importantly, its use in newly diagnosed patients who receive post-LITT chemoradiotherapy leads to a median OS similar to that of patients treated with conventional surgical resection. LITT remains an important alternative for patients with inoperable tumors or those not amenable to resection. Enrollment in LAANTERN is ongoing and these cohorts will be revisited as data continues to mature. Benefits beyond cytoreduction are also being actively explored.

EPID-03. PATHOGENIC GERMLINE MUTATIONS IN GLIOMA PATIENTS

BACKGROUND

No consensus germline testing guidelines currently exist for glioma patients. Hence such testing is not routinely performed. The prevalence and type of germline pathogenic variants in these brain tumors remains unknown. DESIGN/

METHODS

A retrospective review of patients treated at Baylor College of Medicine with paired tumor/normal sequencing using the Tempus xT tumor/normal matched approach from August 2018- April 2022 was performed. Corresponding clinical data was collected for these patients.

RESULTS

We identified 152 glioma patients of which 15 (9.8%) had pathogenic germline variants. Pathogenic germline variants were seen in 11/84 (13.1%) of Glioblastoma, IDH wildtype, 3/42 (7.1%) of Astrocytoma, IDH mutant and 1/26 (3.8%) of Oligodendroglioma, IDH mutant and 1p/19q co-deleted patients. Pathogenic variants in BRCA2, MUTYH and CHEK2 were seen more commonly (3/15 or 20% each). BRCA1 variants were seen in 2/15 (13%) patients, with variants in NF1, ATM, MSH2, and MSH3 occurring in one patient (7%) each. Second hit somatic variants were seen in 3/15 patients (20%). A second somatic hit was seen in NF1, MUTYH and MSH2 in one patient (7%) each. Referral to genetics was performed in 6/15 (40%) patients with pathogenic germline variants. Median overall survival was 1.6 years for glioblastoma, IDH wildtype patients with a pathogenic germline variant compared to 1.79 years for glioblastoma, IDH wildtype patients without it (p = 0.67).

CONCLUSIONS

Although not routinely performed in glioma patients, pathogenic germline variants occurred in ~10% of our patients. Only 40% of these patients were referred to genetics. These findings suggest a possible overlooked opportunity for determination of hereditary cancer syndromes with impact on surveillance as well as potential broader treatment options. Further research to confirm the occurrence and types of pathogenic germline variants in patients with IDH wildtype compared to IDH mutant tumors is necessary.

DDEL-06. HEAT-ACTIVATED DOXORUBICIN UPTAKE FACILITATED BY LASER INTERSTITIAL THERMAL THERAPY

Although surgery has been shown to provide a survival benefit in patients with glioblastoma multiforme (GBM), tumor location and geometry may restrict maximal resection. Additionally, the margin of resection cavity contains infiltrating tumor cells that result in recurrence and therapy resistance. Laser interstitial thermal therapy (LITT) is a treatment modality that uses thermal energy to destroy tumor cells. LITT is useful for tumors that are not appropriate for conventional surgical resection. Our laboratory has developed a LITT model to study LITT in a genetically engineered mouse model of GBM. The combination of heat activated nanoparticles and LITT represents an opportunity to target the infiltrating tumor margin, extending the treatment penumbra. We hypothesized that heat-activated liposomes containing doxorubicin (ThermoDox, Celsion) would demonstrate infiltration into the brain parenchyma after treatment with LITT. We treated tumor-bearing mice with LITT or sham (laser fiber implanted but not activated) after either ThermoDox (5mg/kg) or PBS infusion, 30 minutes before performing LITT or sham treatment. We euthanized these mice 1 hour after LITT or sham treatment, harvested brains, and performed immunofluorescence to identify doxorubicin in parenchymal cells. Doxorubicin was identified in 100% of mice treated with LITT following ThermoDox administration which is in contrast with groups treated with LITT and PBS, sham and ThermoDox, and sham and PBS. Here, we show that heat-activated nanoparticles are disrupted through hyperthermia followed by the release of doxorubicin only in the presence of hyperthermia, which paves way for the clinical use of ThermoDox as adjunct chemotherapy following LITT in treatment-resistant GBM treatment.

The impact of a night float system on operative experience in neurosurgery residency

OBJECTIVE

Since the Accreditation Council for Graduate Medical Education (ACGME) implemented duty-hour restrictions in 2003, many residency programs have adopted a night float system to comply with time constraints. However, some surgical subspecialities have been concerned that use of a night float system deprives residents of operative experience. In this study, the authors describe their training program's transition to a night float system and its impact on resident operative experience.

METHODS

The authors conducted a single-program study of resident surgical case volume before and after implementing the night float system at 3 of their 5 hospitals from 2014 to 2020. The authors obtained surgical case numbers from the ACGME case log database.

RESULTS

Junior residents received a concentrated educational experience, whereas senior residents saw a significant decrease from 112 calls/year to 17. Logged cases significantly increased after implementation of the night float system (8846 vs 10,547, p = 0.04), whereas cases at non-night float hospitals remained the same. This increase was concurrent with an increase in hospital cases. This difference was mainly driven by senior resident cases (p = 0.010), as junior and chief residents did not show significant differences in logged cases (p > 0.40). Lead resident cases increased significantly after implementation of the night float system (6852 vs 8860, p = 0.04). When normalized for increased hospital cases, resident case increases were not statistically significant.

CONCLUSIONS

Transitioning to a night float call system at the authors' institution increased overall resident operative cases, particularly for lead resident surgeons. Based on the results of this study, the authors recommend the use of a night float call system to consolidate night calls, which increases junior resident-level educational opportunities and senior resident cases.

Investigating Useful Features for Overall Survival Prediction in Patients with Low-Grade Glioma Using Histology Slides

Glioma, characterized by neoplastic growth in the brain, is a life-threatening condition that, in most cases, ultimately leads to death. Typical analysis of glioma development involves observation of brain tissue in the form of a histology slide under a microscope. Although brain histology images have much potential for predicting patient outcomes such as overall survival (OS), they are rarely used as the sole predictors due challenges presented by unique characteristics of brain tissue histology. However, utilizing histology in predicting overall survival can be useful for treatment and quality-of-life for patients with early-stage glioma. In this study, we investigate the use of deep learning models on histology slides combined with simple descriptor data (age and glioma subtype) as a predictor of (OS) in patients with low-grade glioma (LGG). Using novel clinical data, we show that models which are more attentive to discriminative features of the image will confer better predictions than generic models (82.7 and 65.3 AUC RFD-Net and Baseline VGG16 model, respectively). Additionally, we show that adding age and subtype information to a histology image-based model may provide greater robustness in the model than using the image alone (3.8 and 4.3 stds for RFD-Net and Baseline VGG16 model with 3-fold CV, respectively), while a model based on image and age but not subtype may confer the best predictive results (83.7 and 82.0 AUC for RFD-Net + age and RFD-Net + age + subtype, respectively). Clinical relevance- This study establishes important criteria for deep learning models which predict OS using histology and basic clinical data from LGG patients.

Hypertrophic Olivary Degeneration Postoperatively Following Pilocytic Astrocytoma Resection

A 25-year-old male presented with headaches 3 weeks after a car accident. His MRI images showed a hemorrhagic vermis mass with 4^th ventricle effacement. One month later, he underwent suboccipital craniotomy for removal of a pilocytic astrocytoma. A 3-month postoperative scan demonstrated a new area of medullary hyperintensity in the inferior olive also present 7-months postoperatively consistent with hypertrophic olivary degeneration (HOD). This condition is caused by disruption to the dento-rubro-olivary pathway with MRI enlargement of the inferior olivary nucleus and increased T2 signal. HOD should be considered after cerebellar surgery and should not be mistaken for tumor recurrence.

Abstract 2548: The central nervous system immune cell interactome is a function of cancer lineage, tumor microenvironment and STAT3 expression

Introduction: Deconstructive immune cell profiling of central nervous system (CNS) tumors has focused on the tumor, excluding interrogation of the tumor microenvironment (TME). Integrated spatial analysis can ascertain the cell interactome and may be a key biomarker for effective anti-tumor immune responses.

Methods: En bloc resections of glioma (n=10) and lung metastasis (n=10) to preserve the tissue architecture, underwent tissue segmentation and high dimension opal 7-color multiplex imaging. Bioinformatic analysis of scRNA was used to infer immune cell functionality.

Results: CD3+ T cell frequency was equivalent between CNS cancer lineages. Within gliomas T cells were confined to the perivascular space and the infiltrating edge. In lung metastasis, T cells are confined to the tumor stroma. CD163+ macrophages predominate in brain metastasis throughout the TME (p&lt;0.05), while CD68+ monocytes (CD68+, CD11c+CD68+, and CD11+CD68+CD163+) are more common in gliomas (p&lt;0.05). T cell dyad and cluster immune interactions were more common in the absence of nuclear STAT3 expression. T cells usually interact with CD163+ macrophages as dyads in metastasis at the brain interface (p=0.031) and within tumor (p=0.0009); in clusters throughout the TME (interface: p=0.024; tumor: p=0.01; necrosis: p=0.045), and as STAT3+ dyads and cluster interactions in the tumor (p&lt;0.05). Immune suppressed CD11c+CD163+ dendritic cells (tumor: p=0.036; and necrosis p=0.020) predominate in metastasis. In contrast, gliomas typically lacked dyad and cluster interactions except for T cell and CD68+ dyads in the tumor (p=0.023). Bioinformatic analysis of CD45+ scRNA seq data revealed that the majority of innate immune populations express both pro-inflammatory and immune suppressive genes and that subsets of CD68+ and CD11c+CD68+ cells expressed markers such as TMEM119, P2YR13 and CX3CR1 that identify microglia.

Conclusion: Current therapies are targeted to cell populations and singular pathways. Immunosuppressive macrophages dominate within the TME and targeting this population may create an environment that favors T cell activation and effective immune responses. Furthermore, the immune interactome, an important event for anti-tumor immune response, is a function of cancer lineage, TME, and STAT3 expression, which will gain relevance for future therapeutics directed to modulating these interactions.

Citation Format: Hinda Najem, Martina Ott, Cynthia Kassab, Arvind Rao, Ganesh Rao, Anantha Marisetty, Adam M. Sonabend, Craig Horbinski, Roel Verhaak, Anand Shakar, Santhoshi Krishnan, Frederick S. Varn, Victor A. Arietta, Pravesh Gupta, Sherise D. Ferguson, Jason Huse, Gregory N. Fuller, James Long, Dan Winskowski, Ben Freiberg, C. David James, Leonidas C. Platanias, Maciej S. Lesniak, Jared K. Burks, Amy B. Heimberger. The central nervous system immune cell interactome is a function of cancer lineage, tumor microenvironment and STAT3 expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2548.

Abstract 2534: Neural control of glioma infiltration

Adult glioblastoma multiforme (GBM) is the most common and deadly form of malignant brain cancer. A broad relationship between tumor progression and neuronal stimulation in the microenvironment is known in peripheral tumors, but only a few interactions between neuronal cues and GBM cells have been characterized. By combining in utero electroporation (IUE) with CRISPR/Cas9 and piggyBac transposase genetics, we have developed an endogenous, immunocompetent, in vivo model with which to study these interactions in a native tumor context. Combining this model with Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) we interrogated tumor-neuron interactions. We assessed molecular and physiological changes in tumors during neural stimulation through tumor development with single cell sequencing and spatial transcriptomics. We examined expression data in populations present under stimulation that did not appear or appeared later in control tumors. These data showed axon guidance genes, a family of genes associated with directed cell motility, were upregulated in these populations. To functionally test these findings, we performed a barcoded screen of axon guidance genes in the IUE model followed by individual confirmation with gain and loss of function of individual genes. We found Sema4F affects infiltration of tumors as well as overall survival. Currently we wish to study the abrogation of this infiltration with Sema4F knockout in the context of DREADD stimulation. Completion of this study will provide new insights into neuronal interactions driving tumor progression in GBM.

Citation Format: Emmet J. Huang-Hobbs, Yi-Ting Cheng, Yeungjun Ko, Junsung Woo, Akdes Harmanci, Ganesh Rao, Benjamin Deneen. Neural control of glioma infiltration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2534.

Comparison of landing kinematics and kinetics between experienced and novice volleyball players during block and spike jumps

BACKGROUND

The practice of volleyball requires many jumps. During landing, anterior cruciate ligament injuries may occur with high-risk lower limb kinematics and kinetics. Differences in landing strategies between experienced and novice volleyball players have not been fully explored. The purpose of the study was to compare lower limb kinematics and kinetics in experienced and novice volleyball players when performing volleyball specific jumps.

METHODS

A total of 30 healthy males, 15 experienced and 15 novice volleyball players, participated in the study. Participants performed block and spike jumps at a controlled jump height. Hip, knee and ankle joints angles at initial ground contact and ranges of motion in the sagittal plane, knee joint angles and moments in the frontal plane, vertical ground reaction force peak and loading rate were analyzed to investigate the expertise effect.

RESULTS

Experienced volleyball players landed with larger ankle dorsiflexion range of motion compared to novices. For the spike jump, experienced players landed with larger ankle plantarflexion angles at initial contact and larger ankle dorsiflexion ranges of motion, and for the block jump, they landed with larger knee flexion ranges of motion. Experienced players jumped significantly higher than novices. No difference was found in vertical ground reaction force peaks and loading rates.

CONCLUSIONS

Although the experienced group jumped higher than the novice group, no difference was found in ground reaction force parameters. These findings highlight that the experience of volleyball players acquired during regular trainings and competitions may play an important role in landing kinematics and kinetics to reduce the injury risk.

LGG-47. Single-cell RNA Sequencing Reveals Immunosuppressive Myeloid Cell Diversity During Malignant Progression in Glioma

Myeloid cells and macrophages have been shown to promote immunosuppression in high-grade gliomas (HGG), however their roles in malignant progression of low-grade glioma (LGG) are poorly understood. Here, we investigated the heterogeneity of the immune microenvironment during glioma progression using a murine model that recapitulates the malignant progression of low to high-grade glioma. To that end, we performed single-cell RNA sequencing on CD45+ immune cells isolated from animals bearing no tumor (NT), LGG, and HGG. We observed an increased infiltration of CD4+ T cells, CD8+ T cells, B cells, and natural killer cells in the tumor microenvironment of LGG, whereas this infiltration was abrogated in HGG. Our study identified two distinct macrophage clusters across all 3 samples, with signatures of bone marrow derived and resident macrophages, respectively. These macrophages showed an immune-activated phenotype (Stat1, Tnf, Cxcl9 and Cxcl10) in LGG, but then evolved to a more immunosuppressive state (Lgals3, Apoc1 and Id2) in HGG, restricting T cell recruitment and activation. In addition, we identified CD74 and macrophage migration inhibition factor (MIF) as potential targets for both these distinct macrophage populations, based on their increased expression in LGG and HGG compared to NT. Targeting these factors during the LGG therapeutic window may inhibit myeloid cells and intra-tumoral macrophages and attenuate their immunosuppressive properties and impair malignant progression.

A first-in-human Phase I trial of the oral p-STAT3 inhibitor WP1066 in patients with recurrent malignant glioma

Aim: To ascertain the maximum tolerated dose (MTD)/maximum feasible dose (MFD) of WP1066 and p-STAT3 target engagement within recurrent glioblastoma (GBM) patients. Patients & methods: In a first-in-human open-label, single-center, single-arm 3 + 3 design Phase I clinical trial, eight patients were treated with WP1066 until disease progression or unacceptable toxicities. Results: In the absence of significant toxicity, the MFD was identified to be 8 mg/kg. The most common adverse event was grade 1 nausea and diarrhea in 50% of patients. No treatment-related deaths occurred; 6 of 8 patients died from disease progression and one was lost to follow-up. Of 8 patients with radiographic follow-up, all had progressive disease. The longest response duration exceeded 3.25 months. The median progression-free survival (PFS) time was 2.3 months (95% CI: 1.7 months-NA months), and 6-month PFS (PFS6) rate was 0%. The median overall survival (OS) rate was 25 months (95% CI: 22.5 months-NA months), with an estimated 1-year OS rate of 100%. Pharmacokinetic (PK) data demonstrated that at 8 mg/kg, the T1/2 was 2-3 h with a dose dependent increase in the Cmax. Immune monitoring of the peripheral blood demonstrated that there was p-STAT3 suppression starting at a dose of 1 mg/kg. Conclusion: Immune analyses indicated that WP1066 inhibited systemic immune p-STAT3. WP1066 had an MFD identified at 8 mg/kg which is the target allometric dose based on prior preclinical modeling in combination with radiation therapy and a Phase II study is being planned for newly diagnosed MGMT promoter unmethylated glioblastoma patients.

Recurrent HGNET-MN1 altered (astroblastoma MN1-altered) of the foramen magnum: Case report and molecular classification

Background:

Astroblastoma is a rare primary brain tumor of unclear origin, often occurring in young patients less than 30-years-old. It typically arises supratentorially and is diagnosed based on histological features including vascular hyalinization and perivascular pseudorosettes. Recent molecular characterization of primary CNS high-grade neuroepithelial tumors with meningioma I alteration (HGNET-MN1) found that HGNET-MN1 and tumors with morphological signatures of astroblastoma clustered together. Further analysis revealed such astroblastomas have MN1 alteration and the 2021 WHO classification of tumors of the CNS now recognizes astroblastoma MN1-altered as a new entity.

Case Description:

Here, we present the case of a 36-year-old right-handed woman with recurrent low-grade astroblastoma in the cervicomedullary junction. The patient presented with worsening motor and sensory deficits of her upper extremities, pain, ataxia, visual disturbance, and nausea. Due to extensive recurrence and neurological symptoms, the patient underwent reoperation.

Conclusion:

We review a rare case of recurrent astroblastoma in the foramen magnum in light of new relevant literature about tumor biology and prognostic significance of the new classification of astroblastoma MN1-altered.

Efficacy of Laser Interstitial Thermal Therapy (LITT) for Newly Diagnosed and Recurrent IDH Wild-type Glioblastoma

Background

Treatment options for unresectable new and recurrent glioblastoma remain limited. Laser ablation has demonstrated safety as a surgical approach to treat primary brain tumors. The LAANTERN prospective multicenter registry (NCT02392078) data was analyzed to determine clinical outcomes for patients with new and recurrent IDH wild-type glioblastoma.

Methods

Demographics, intraprocedural data, adverse events, KPS, health-economics, and survival data were prospectively collected then analyzed on IDH wild-type newly diagnosed and recurrent glioblastoma patients who were treated with laser ablation at 14 US centers between January 2016 and May 2019. Data was monitored for accuracy. Statistical analysis included individual variable summaries, multivariable differences in survival, and median survival numbers.

Results

A total of 29 new and 60 recurrent IDH wild-type WHO grade 4 glioblastoma patients were treated. Positive MGMT promoter methylation status was present in 5/29 of new and 23/60 of recurrent patients. Median physician-estimated extent of ablation was 91-99%. Median overall-survival was 9.73 months (95% confidence interval: 5.16, 15.91) for newly diagnosed patients and median post-procedure survival was 8.97 (6.94, 12.36) months for recurrent patients. Median overall-survival for newly diagnosed patients receiving post-LITT chemo/radiation was 16.14 months (6.11, not reached). Factors associated with improved survival were MGMT promoter methylation, adjuvant chemotherapy within 12 weeks, and tumor volume &lt;3cc.

Conclusions

Laser ablation is a viable option for patients with new and recurrent glioblastoma. Median overall survival for IDH wild type newly diagnosed glioblastoma is comparable to outcomes observed in other tumor resection studies when those patients undergo radiation and chemotherapy following LITT.

Central nervous system immune interactome is function of cancer lineage, tumor microenvironment and STAT3 expression

BACKGROUND

Immune cell profiling of primary and metastatic CNS tumors has been focused on the tumor, not the tumor microenvironment (TME), or has been analyzed via biopsies.

METHODS

En bloc resections of gliomas (n = 10) and lung metastases (n = 10) were analyzed via tissue segmentation and high-dimension Opal 7-color multiplex imaging. Single-cell RNA analyses were used to infer immune cell functionality.

RESULTS

Within gliomas, T cells were localized in the infiltrating edge and perivascular space of tumors, while residing mostly in the stroma of metastatic tumors. CD163⁺ macrophages were evident throughout the TME of metastatic tumors, whereas in gliomas, CD68⁺, CD11c⁺CD68⁺, and CD11c⁺CD68⁺CD163⁺ cell subtypes were commonly observed. In lung metastases, T cells interacted with CD163⁺ macrophages as dyads and clusters at the brain-tumor interface and within the tumor itself and as clusters within the necrotic core. In contrast, gliomas typically lacked dyad and cluster interactions, except for T cell CD68⁺ cell dyads within the tumor. Analysis of transcriptomic data in glioblastomas revealed that innate immune cells expressed both proinflammatory and immunosuppressive gene signatures.

CONCLUSION

Our results show that immunosuppressive macrophages are abundant within the TME and that the immune cell interactome between cancer lineages is distinct. Further, these data provide information for evaluating the role of different immune cell populations in brain tumor growth and therapeutic responses.

FUNDING

This study was supported by the NIH (NS120547), a Developmental research project award (P50CA221747), ReMission Alliance, institutional funding from Northwestern University and the Lurie Comprehensive Cancer Center, and gifts from the Mosky family and Perry McKay. Performed in the Flow Cytometry & Cellular Imaging Core Facility at MD Anderson Cancer Center, this study received support in part from the NIH (CA016672) and the National Cancer Institute (NCI) Research Specialist award 1 (R50 CA243707). Additional support was provided by CCSG Bioinformatics Shared Resource 5 (P30 CA046592), a gift from Agilent Technologies, a Research Scholar Grant from the American Cancer Society (RSG-16-005-01), a Precision Health Investigator Award from University of Michigan (U-M) Precision Health, the NCI (R37-CA214955), startup institutional research funds from U-M, and a Biomedical Informatics & Data Science Training Grant (T32GM141746).

Racial and Socioeconomic Disparities in Patients With Meningioma: A Retrospective Cohort Study

BACKGROUND

Meningiomas are the most common intracranial neoplasms. Although genomic analysis has helped elucidate differences in survival, there is evidence that racial disparities may influence outcomes. African Americans have a higher incidence of meningiomas and poorer survival outcomes. The etiology of these disparities remains unclear, but may include a combination of pathophysiology and other factors.

OBJECTIVE

To determine factors that contribute to different clinical outcomes in racial populations.

METHODS

We retrospectively reviewed 305 patients who underwent resection for meningiomas at a single tertiary care facility. We used descriptive statistics and univariate, multivariable, and Kaplan-Meier analyses to study clinical, radiographical, and histopathological differences.

RESULTS

Minority patients were more likely to present through the emergency department than an outpatient clinic (P < .0001). They were more likely to present with more advanced clinical symptoms with lower Karnofsky Performance scores, more frequently had peritumoral edema (P = .0031), and experienced longer postoperative stays in the hospital (P = .0053), and African-American patients had higher hospitalization costs (P = .046) and were more likely to be publicly insured. Extent of resection was an independent predictor of recurrence freedom (P = .039). Presentation in clinic setting trended toward an association with recurrence-free survival (P = .055). We observed no significant difference in gross total resection rates, postoperative recurrence, or recurrence-free survival.

CONCLUSION

Minority patients are more likely to present with severe symptoms, require longer perioperative hospitalization, and generate higher hospitalization costs. This may be due to socioeconomic factors that affect access to health care. Targeting barriers to access, especially to subspecialty care, may facilitate more appropriate and timely diagnosis, thereby improving patient care and outcomes.

Combined immunotherapy with controlled Interleukin-12 gene therapy and immune checkpoint blockade in recurrent glioblastoma: an open-label, multi-institutional phase 1 trial

BACKGROUND

Veledimex (VDX)-regulatable interleukin-12 (IL-12) gene therapy in recurrent glioblastoma (rGBM) was reported to show tumor infiltration of CD8 + T cells, encouraging survival, but also up-regulation of immune checkpoint signaling, providing the rationale for a combination trial with immune checkpoint inhibition.

METHODS

An open-label, multi-institutional, dose-escalation phase 1 trial in rGBM subjects (NCT03636477) accrued 21 subjects in 3 dose-escalating cohorts: 1- neo-adjuvant then ongoing nivolumab (1mg/kg) and VDX (10 mg) (n= 3); 2- neo-adjuvant then ongoing nivolumab (3 mg/kg) and VDX (10 mg) (n=3); and 3- neo-adjuvant then ongoing nivolumab (3 mg/kg) and VDX (20 mg) (n=15). Nivolumab was administered 7 (+/- 3) days before resection of the rGBM followed by peritumoral injection of IL-12 gene therapy. VDX was administered 3 hours before and then for 14 days after surgery. Nivolumab was administered every two weeks after surgery.

RESULTS

Toxicities of the combination were comparable to IL-12 gene monotherapy and were predictable, dose-related and reversible upon withholding doses of VDX and/or nivolumab. VDX plasma pharmacokinetics demonstrate a dose-response relationship with effective brain tumor tissue VDX penetration and production of IL-12. IL-12 levels in serum peaked in all subjects at about Day 3 after surgery. Tumor IFNγ increased in post treatment biopsies. Median overall survival (mOS) for VDX 10 mg with nivolumab was 16.9 months and for all subjects was 9.8 months.

CONCLUSION

The safety of this combination immunotherapy was established and has led to an ongoing phase 2 clinical trial of immune checkpoint blockade with controlled IL-12 gene therapy (NCT04006119).

CNTM-04. Alterations in structural connectomic properties associated with neurocognitive changes following glioma resection

BACKGROUND

Patients with brain tumors often experience decline in neurocognitive functioning (NCF) following surgical tumor resection. Connectomic studies have begun to uncover how abnormalities to underlying cerebral networks contribute to NCF deficits; however, few studies have investigated relationships between pre- to postoperative changes in structural connectomics and NCF.

METHODS

Fifteen right-handed adults with left perisylvian tumors underwent MRI of the brain with diffusion tensor imaging (DTI) and neuropsychological assessment before and after awake tumor resection. Graph theoretical analysis was applied to DTI-derived connectivity matrices to calculate structural network properties. Structural network properties and NCF measures were compared across the pre- to postoperative periods with matched pairs Wilcoxon signed-rank tests. Associations between pre- to postoperative change in network properties and change in NCF were determined with Spearman rank-order correlations (ρ).

RESULTS

Nearly 90% of the sample showed postoperative decline on 1 or more NCF measures. Significant postoperative NCF decline was found across measures of verbal memory, processing speed, executive functioning, receptive language, and the Clinical Trial Battery Composite (CTB COMP) index. Regarding connectomic properties, significant postoperative changes were observed in global and local efficiency, characteristic path length, clustering coefficient, betweenness centrality, and assortativity, with medium effect sizes. Significant associations (ρ = .59 to .62, all p &lt; .05) were observed between changes in aspects of NCF and connectomic properties.

CONCLUSIONS

Decline in NCF was common following resection and some postoperative outcomes were associated with changes in structural connectomic properties following surgery.

Laser interstitial thermal therapy for newly diagnosed glioblastoma

Gliomas are the most frequent primary brain tumor in adults. Patients with glioblastoma (GBM) tumors deemed inoperable with open surgical techniques and treated only with chemo/radiation have a median overall survival of less than 9 months. Laser interstitial thermal therapy (LITT) has emerged as a cytoreductive alternative to surgery for these patients. The present study describes the outcomes of twenty patients with newly diagnosed, IDH wild-type glioblastoma treated with LITT. We retrospectively reviewed patients with newly diagnosed, unresectable GBM who underwent LITT at our institution. Progression-free survival (PFS) was the primary endpoint measured in our study, defined as time from LITT to disease progression. Results Twenty patients were identified with newly diagnosed, inoperable GBM lesions who underwent LITT. The overall median PFS was 4 months (95% CI = 2 - N/A, upper limit not reached). The median progression-free survival (PFS) for patients with less than 1 cm 3 residual tumor (gross total ablation, GTA) was 7 months (95% CI = 6 - N/A, upper limit not reached), compared to 2 months (95% CI = 1 - upper limit not reached) for patients with a lower GTA (p = .0019). The median overall survival was 11 months (95% CI = 6 - upper limit not reached). Preoperative Karnofsky performance score (KPS) less than or equal to 80 and deep-seated tumor location were significantly associated with decreased PFS (HR, .18, p = .03; HR, .08, p = .03, respectively). At the end of 1 month, only 4 patients (20%) experienced persistent motor deficits. LITT is a safe and effective treatment for patients with unresectable, untreated GBM with rates of survival and local recurrence comparable to patients with surgically accessible lesions treated with conventional resection. Careful patient selection is needed to determine if GTA is attainable.

Prolonged survival after laser interstitial thermal therapy in glioblastoma

Background:

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Management includes surgical resection followed by chemoradiation, and prognosis remains poor. Surgical resection is not possible for some deep-seated or eloquent tumors. Laser interstitial thermal therapy (LITT) has emerged as a new, minimally invasive surgical option for deep-seated GBM.

Case Description:

We report a case of newly diagnosed thalamic GBM managed with LITT followed by radiation and chemotherapy.

Conclusion:

The patient remains well at 50-month post-LITT, indicating a potentially unique durability of LITT treatment in GBM.

Autism-Associated Vigilin Depletion Impairs DNA Damage Repair

Vigilin (Vgl1) is essential for heterochromatin formation, chromosome segregation, and mRNA stability and is associated with autism spectrum disorders and cancer: vigilin, for example, can suppress proto-oncogene c-fms expression in breast cancer. Conserved from yeast to humans, vigilin is an RNA-binding protein with 14 tandemly arranged nonidentical hnRNP K-type homology (KH) domains. Here, we report that vigilin depletion increased cell sensitivity to cisplatin- or ionizing radiation (IR)-induced cell death and genomic instability due to defective DNA repair. Vigilin depletion delayed dephosphorylation of IR-induced γ-H2AX and elevated levels of residual 53BP1 and RIF1 foci, while reducing Rad51 and BRCA1 focus formation, DNA end resection, and double-strand break (DSB) repair. We show that vigilin interacts with the DNA damage response (DDR) proteins RAD51 and BRCA1, and vigilin depletion impairs their recruitment to DSB sites. Transient hydroxyurea (HU)-induced replicative stress in vigilin-depleted cells increased replication fork stalling and blocked restart of DNA synthesis. Furthermore, histone acetylation promoted vigilin recruitment to DSBs preferentially in the transcriptionally active genome. These findings uncover a novel vigilin role in DNA damage repair with implications for autism and cancer-related disorders.