Citations

Abstract Background Brain tumors represent a significant global health challenge, with rising incidence and mortality impacting individuals worldwide and contributing to cancer-related morbidity and mortality. In Africa, this burden is exacerbated by limited access to advanced diagnostics, treatment options, and multidisciplinary care, compounded by the absence of standardized cancer registration and tumor biobanking. The introduction of molecular diagnostics, as outlined in the 2021 World Health Organization central nervous system (CNS) tumor classification, adds complexity to brain tumor management, particularly in regions with scarce resources. Methods To address these issues, the Brain Tumor Consortium for Africa (BTCA) was established in 2023, bringing together experts to improve CNS tumor diagnosis, patient care, and research. The initial project, conducted via an electronic questionnaire, aimed to assess neuro-oncology capacity across Sub-Saharan Africa. Results The study revealed significant gaps, with a limited number of institutions incorporating molecular subtyping into their diagnostic algorithms. The consortium’s efforts focus on enhancing local data use, informing public policy, and promoting collaboration to advance neuro-oncology practices in Africa. By fostering a network enlisting the expertise of collaborators in the fields of neurosurgery, neurology, neuropathology, anatomic pathology, and medical and radiation oncology, the BTCA seeks to improve brain tumor management through better diagnostics, infrastructure, and policy advocacy. Future directions include expanding molecular diagnostic capabilities, standardizing brain tumor biobanking, enhancing data collection, and advocating for improved brain tumor care in national health agendas. Conclusions The BTCA represents a pioneering model of collaboration and innovation in addressing the unique challenges of brain tumor care in Africa.

Introduction/Background: Patients admitted with sepsis are at risk of developing septic cardiomyopathy (SCM), which may elevate their risk of short-term mortality. However, the effect of SCM on long-term outcomes after sepsis is poorly understood. This study explores whether patients with sepsis and SCM have worse long-term outcomes compared to those without SCM. Research Questions/Hypothesis: What are the long-term major adverse cardiovascular events, including death, stroke, and myocardial infarction (MACE) 36 months after ICU discharge for septic patients with abnormal global left ventricular strain (LV GLS)? Methods: We conducted a retrospective study of 396 sepsis patients from August 2018 to September 2022, approved by the Mayo Clinic IRB. Patient demographics, comorbidities, echo parameters, and outcomes were collected. Due to the expected non-linear relation between LV GLS and Hazard Ratio (HR) of MACE we employed Cox regression analysis with Restricted Cubic Splines. Secondly, we divided the population into 2 groups, patients with and without normal LV GLS (between -23 and -16). The effect of non-normal LV GLS on MACE was evaluated using Cox regression weight by inverse probability weighting (IPWT) analysis after propensity score assessment, adjusting for diabetes, hypertension, BMI, history of stroke or myocardial infarction, chronic kidney disease, age, and sex. Results: Demographic variables did not differ significantly based on normal versus abnormal LV GLS. In the restricted cox regression with cubic spline models, we observed that patients with normal values had HR lower than one compared with patients without normal values (Figure 1). Secondly, we found that the HR of MACE in patients with normal LV GLS was significantly lower in the crude analysis (HR 0.66 [CI 95% 0.5, 0.86]; p<0.01) and in the analysis adjusted by IPWT (HR 0.7 [CI 95% 0.53, 0.92]; p=0.01). Conclusion: Sepsis patients with abnormal global left ventricular strain (LV GLS) have a higher risk of major adverse cardiovascular events (MACE) within 36 months post-ICU discharge compared to those with normal strain. LV GLS values outside the range of -23 to -16 are associated with increased risk. Monitoring LV GLS in sepsis patients is important for identifying those at elevated risk for long-term cardiovascular complications.

Introduction/Background: Patients with heart failure and those waiting for a heart transplant often experience a significant decrease in their ability to perform daily activities and exercise, leading to a lower quality of life. Although exercise-based cardiac rehabilitation (EBCR) is a possible treatment option, its effectiveness has not been well measured, resulting in limited adoption. Research Questions/Hypothesis: Could physical rehabilitation before receiving a heart transplant improve functional status and better outcomes? Goals/Aims: Our objective is to evaluate the effect of pre-transplant physical therapy on the standardized improvement of AM-PAC scores, measured from the earliest pre-transplant assessment to the most recent pre-transplant evaluation. Our second objective is to assess the impact of the latest Pre-Transplant AM-PAC Score on the number of hospital-free days following transplantation. Methods: We conducted a retrospective study on 91 heart transplant patients who received Impella support from January 2019 to April 2023, approved by the Mayo Clinic Institutional Review Board. We collected data on demographics, AMPAC scores, and outcomes at three time points. Continuous variables were compared using the T-test or Mann-Whitney test, and categorical variables using the Chi-square or Fisher's exact test. We used a linear regression model to investigate the relationship between rehabilitation duration and AMPAC scores. Quantile regression was preferred due to the non-normal distribution of the outcome, hospital-free days. Results: We conducted a linear regression analysis and found a statistically significant association between increased hours spent in PT and greater improvement. After one hour of physical therapy, there was an average increase of 1.07 (95% CI 0.1, 2; p=0.03) in AMPAC scoore. We also compared the change in the AMPAC score with hospital-free days, and it was statistically significant in quantile regression analysis, indicating an increase of 0.28 (95% CI 0.2, 0.55; P=0.03) points in the AMPAC Score, corresponding to an additional hospital-free day. Conclusion: Increased hours spent in physical therapy show a significant positive association with greater improvement in standardized AM-PAC Mobility scores and hospital-free days. These findings encourage increasing uptake and support of cardiac rehabilitation programs.

INTRODUCTION: There is a significant shortage of specialized Adult Congenital Heart Disease (ACHD) cardiologists despite a rising prevalence of adults with this condition. AIM: Our study explores the specific motivations and deterrents that influence adult and pediatric cardiologists’ ACHD career decisions, which could serve as the basis for future solutions to overcome this shortage in each specific region. METHODS: An anonymous global survey was distributed to adult and pediatric cardiologists and trainees via email, social media, and medical society newsletters. The survey included demographics, ACHD exposure, career considerations, Likert scale ratings, and open-ended inquiries on ACHD career recommendations. Respondents included non-ACHD and ACHD cardiologists (defined as those caring for ACHD with or without formal training). The analysis covered regional variations across continents. Responses with less than 75% completion were excluded. RESULTS: A total of 811 valid responses were collected (53.5% female, 48.3% aged 31-40, and 43.3% White). ACHD cardiologists were 21%, mostly practicing in North America (44.1%) and Europe (32.9%). Almost all ACHD cardiologists (94.7%) recommended it as a career. Among the 641 non-ACHD cardiologists, 85.7% had been exposed to ACHD, however, only 35.1% considered pursuing it themselves. For ACHD cardiologists the top global motivators for pursuing an ACHD career were awareness of the field and its significance, mentor's influence, and sufficient clinical exposure during residency (Figure 1A). Factors that deterred non-ACHD cardiologists included a lack of compensation compared to other cardiology subspecialties, limited job opportunities, and the longer duration of training (Figure 1B). Absence of specialized training and educational programs emerged as a major deterrent in all continents except North America. The lack of mentorship or role models in ACHD was particularly pronounced in Africa and Central and South America. Limited exposure to ACHD during training was a significant issue in Europe and Africa. CONCLUSION: Most ACHD cardiologists recommend a career in ACHD. However, only a few non-ACHD cardiologists recommend it. Influential mentors, clinical exposure motivate; low compensation, lengthy training deter. Regional disparities require targeted interventions for better ACHD cardiologist recruitment.

Abstract Clinical management of IDH wildtype glioblastoma (GBM) and tumefactive multiple sclerosis (tMS) is drastically different. GBM requires maximal safe resection followed by chemoradiation, while tMS outcome is worsened by surgery and radiotherapy. Noninvasive methods are needed to help with accurate diagnosis of tumor and non-tumor etiologies. To develop an MRI-based classification model, tMS subjects diagnosed prior to January 1, 2020, were matched to tMS by age at diagnosis, sex, index MRI date, and 2D/3D acquisition. Inclusion criteria included one cm minimal lesion size and pre-operative post-contrast T1 and T2 images available for analysis. A 3D-DenseNet121 was used to develop a classification model using prespecified parameters: 650 epochs, batch size 16, learning rate 10-3, cross-entropy loss, and AdamW optimizer. The stopping rule was defined as three sequential differences in epoch cross-entropy loss &lt;0.02. Models were developed using both T1gd and T2, as well as from only T1gd and only T2. Training included 220 subjects (110 GBM, 110 tMS). A 2-stage validation design was used, which included both retrospective and prospective cohorts. Stage 1 consisted of 272 retrospective GBM (diagnosed prior to January 1, 2020). Stage 2 consisted of 69 and 34 prospective (diagnosed after January 1, 2020) GBM and tMS, respectively. External validation on the 272 retrospective GBM demonstrated accuracy of 91%, 84%, and 78% for T1gd+T2, T1gd only, and T2 only, respectively. External validation on the 69 prospective GBM demonstrated an accuracy of 87%, 64%, and 67% for T1gd+T2, T1gd only, and T2 only, respectively. The 34 prospective tMS demonstrated accuracy of 76%, 76%, and 82% for T1gd+T2, T1gd only, and T2 only, respectively. This shows the feasibility of deep learning to aid in differential diagnosis of brain lesions. Future work entails the integration of germline variants into the classification model, including variants associated with the risk of glioma or MS.

Abstract Brain tumors constitute significant morbidity and mortality in sub-Saharan Africa (SSA). There is no previous large-scale effort focusing on brain tumor genetics in SSA. This project aims to map out the current neuro-oncology capacity in terms of workforce and available services in SSA. This is an ongoing online survey among a cross section of neuro-oncology practitioners spread across SSA countries to capture information on the distribution, number of available neuro-oncology care practitioners, capacity for neuropathology and molecular diagnosis, management of brain tumors, cancer registration, and tumor biobanking. The survey was disseminated by the Society for Neuro-oncology in SSA (SNOSSA). There were 83 respondents representing 15 countries and 52 health institutions: 46 tertiary, 4 secondary, 1 private and 1 other. Here, we present data on the 52 institutions. The prevalence of specialties was 87% neurosurgery, 75% anatomic pathology, 69% medical oncology, 64% neurology, 60% radiation oncology, and 39% neuropathology. For radiologic evaluation, 81% of institutions were reported to have both CT and MRI, 17% CT only, and one institution neither. For molecular testing, 46% have access to IHC or NGS testing, whereas 52% were reported to have neither. A neuro-oncology tumor board was reported at 58% of institutions. A general cancer registry is available in 64% of institutions, 31% have a brain tumor specific registry and 10% have a brain tumor biorepository. This study shows that SSA has substantial potential in neuro-oncology care practice capacity and facilities. Most significant gaps remain in areas such as neuropathology and molecular testing, which makes widespread implementation of the WHO 2021 diagnosis challenging. Understanding the prevalence of CNS tumor subtypes is also difficult due to low number of brain tumor registries and biobanks in SSA. The present findings reveal strategic opportunities, especially in neuropathology, tumor registries, biobanks, and infrastructure for IHC and NGS in SSA.

Abstract Low-grade gliomas (LGG) are slowly growing brain cancers that ultimately undergo a malignant progression to lethal secondary glioblastomas with a dismal prognosis. Despite intensive research, very little progress has been made in our understanding of this transformation. Hence, outside of known alternations in well-characterized driver genes CDKN2A, PTEN and PDGFRA, genetic drivers that underlie LGG transformation are largely unknown. Contrary to other types of cancer, LGGs exhibit very few driver mutations (30-40 mutations) as they progress. Interestingly, LGGs also exhibit a highly prevalent and heterogenous pattern of copy-number-alterations (CNAs) suggesting that they might be driven by changes in gene dosages that result from widespread chromosomal instability observed within these tumors. Through analysis of the human Mayo Clinic and TCGA LGG datasets (~1500 patients), we have identified eleven highly recurrent CNAs affecting LGG patients, many of which correlate with patient survival. We hypothesized that these CNAs contain driver genes that confer a growth advantage resulting in the highly recurrent CNA pattern and prognostic associations. To investigate the tumor suppressive potential of the ~1800 genes located in recurrently deleted regions and the oncogenic potential of the ~1200 genes located in recurrently amplified regions, our lab developed a novel in vivo ‘CRISPR-Knock Out and Activation Linked Assay’ (CRISPR-KOALA). Stereotaxic delivery of arm-level CNA lentiviral gRNA libraries targeting the mouse orthologs of genes in CNAs into the brain of our animal model (rs557mut;IDHmut;P53KO;AtrxKO;Cas9GFP: Yanchus et. al Science 2022) resulted in rapid formation of tumors compared to animals injected with control libraries. Deconvoluting the screen revealed enrichment of immune modulators such as Them6 as well as a modulator of NMDA receptors (Grina) implicating immune system and glutamate dysregulation in LGG malignant transformation. Taken together, our study provides insights into mechanisms underlying LGG progression which may serve to inform intervention strategies for this lethal disease.

Abstract Most TERT promoter (TERTp) clinically relevant sequence variants in CNS tumors are the canonical C228T and C250T mutations. Non-canonical TERTp mutations have been reported mainly in non-CNS tumors. We describe 12 CNS tumors with non-canonical TERTp variants interpreted as clinically relevant. Using clinical targeted NGS panels (2020-2024), we detected c.-100_-79dup (n=2), c.-92_-91insGGCGGCCCCGCCCCTTCCTTTC (n=1), c.-118_-117insTCCCCGGCCCAGCCCCTTCCGGG (n=1), c.-123_-76dup (n=1), c.-110_-89dup (n=2), and c.-57A&gt;C (n=5). Most cases had chromosomal microarray (n=11) and/or methylation array data analyzed using the NCI/Bethesda v.2 classifier (n=9). All non-canonical TERTp variants occurred at a variant allele frequency suggestive of somatic clonal origin (mean, 34%; range, 18-46), and in adults (mean age, 60 years; range, 36-88). Except for the c.-57A&gt;C variant, all non-canonical TERTp variants occurred in tumors with histological and/or molecular diagnostic features of glioblastoma, IDH-wildtype (GBM), often epigenetically aligning to this tumor type. All five tested cases matched to superfamily glioblastoma (score ≥ 0.9), with three to class GBM_RTK_I (&gt;0.9 in 2, 0.86 in 1) and two to GBM_RTK_II (&gt;0.9). The size and sequence of such variants suggest that these may be functionally equivalent to canonical mutations or generate favorable TERTp activation motif conformations like previously reported activating duplications. The c.-57A&gt;C variant is a well-established oncogenic mutation observed in other cancer types but has not been reported in CNS tumors. We describe five cases with the c.-57A&gt;C variant: one GBM matching to methylation class GBM_MES_TYP (0.99); two oligodendroglioma, IDH-mutant and 1p/19q-codeleted, one of which had methylation data matching to class O_IDH (0.99); one diffuse glioma, IDH-mutant, which was partially 1p/19q-codeleted and matched to class O_IDH (0.99); and one anaplastic meningioma, aligning to superfamily meningioma (0.99)/MNG_MAL (0.79). Our findings show that non-canonical TERTp variants typically occur in tumor types that often harbor TERTp canonical mutations, expanding the spectrum of TERTp clinically relevant variants that are molecular biomarkers in CNS tumors.

Abstract Acquired tumor alterations are part of the WHO diagnosis of glioma. However, germline predisposition to these alterations is unknown. GWAS in European and Asian populations identified germline variants in 30 regions, many in or near genes that also acquire alterations, suggesting that interactions between inherited and acquired genetics are involved in glioma development. To evaluate such interactions, we used 3686 glioma cases and 1889 controls. A case-control design and multinomial logistic regression were used to identify germline variants associated with development of TERT-promoter mutant gliomas, generating two interesting observations. First, TERT germline variants were associated with predisposition to IDHwt glioma that have a TERT promoter mutation, but not with IDH-mutant codeleted gliomas that have a TERT promoter mutation. Second, two novel regions were observed in this more homogeneous subgroup of TERT mutated tumors: variants in TXNDC11 (OR=2.66, p=5.7x10-8) and RUVBL2 (OR=3.1, p=5.8x10-8). High tumor expression of TXNDC11 is associated with poor prognosis in glioma and RUVBL2 interacts with TERT to affect telomerase activity. Similar analyses are being performed on additional clinically relevant acquired alterations. In parallel, case-case GWAS analyses were performed to evaluate germline variants associated with other tumor alterations. Comparing IDH-mutant versus IDHwt stratified by rs55705857 genotype, the most significant variants were PHLDB1 (p=1.2x10-13) and D2HGDH (p=2.1x10-10), highlighting the importance of these two variants independent of CCDC26 for the development of IDH-mutant glioma. As a parallel approach, we utilized recursive partitioning and regression trees (rpart) to classify IDH mutation status using the 30 known variants. The top four branches of the regression tree included CCDC26, D2HGDH, PHLDB1, and MAML2, as well as two Asian variants (RAB27A, CYP4F12). This highlights the importance of utilizing variants discovered in non-European populations in analyses. Overall, understanding these interactions are necessary to develop therapeutics, stratify clinical trials, and to develop relevant tumor models.

Abstract BACKGROUND The prognostic factors impacting the survival of grade 4 IDH-mutant astrocytoma treated with standard radiation/temozolomide are not well-described. METHODS A retrospective cohort was generated of all patients diagnosed at Mayo Clinic with grade 4 IDH-mutant astrocytoma (2021 WHO Classification) on initial diagnosis between 2002-2023, and who received standard radiation/temozolomide. The impact of patient, tumor and molecular variables on overall survival (OS) and progression-free survival (PFS) was evaluated using survival analyses and Cox regression models. RESULTS Fifty-eight patients were identified. The median age was 36 years, 64% were male and 93% were white. The median follow up was 3.3 years. The median OS and PFS were 6.9 years and 2.4 years, respectively. CDKN2A/B homozygous deletion significantly reduced both OS (2.5 years vs NR, HR=3.9, p=0.0168) and PFS (1.4 vs 4.5 years, HR=4.2, p=0.0005). Midline involvement (brainstem, basal ganglia, thalamus, cerebellum or corpus callosum) also significantly reduced both OS (2.4 vs 12.8 years, HR=7.0, p=0.0014) and PFS (1.4 vs 4.5 years, HR=4.8, p=0.0002). MGMT promoter hypermethylation showed a trend toward significance for PFS (p=0.082) but did not impact OS. Age, sex, tumor size, ATRX immunohistochemistry and tumor-treating field therapy did not impact survival outcomes. Multivariable analyses revealed that PFS remained significantly impacted by both CDKN2A/B homozygous deletion (HR=3.5, p=0.0051) and midline involvement (HR=3.1, p=0.0125). A significant association between CDKN2A/B homozygous deletion and midline involvement was unexpectedly observed (53% if midline, 24% if non-midline; χ2=4.3, p=0.037). Exploratory analyses revealed that 15/15 (100%) of patients with midline involvement demonstrated aberration in RB1 signaling (CDKN2A/B homozygous deletion, n=8; CDKN2A/B hemizygous deletion or loss of heterozygosity, n=6; CDK4 amplification, n=1). CONCLUSION CDKN2A/B homozygous deletion and midline involvement independently impact PFS in patients with grade 4 IDH-mutant astrocytoma treated with standard radiation/temozolomide. Furthermore, midline involvement may be associated with aberrant RB1 signaling.