Giannini, Caterina

Abstract Background Methylation class pleomorphic xanthoastrocytoma (mcPXA) comprises tumors with the DNA methylation signature of classical PXA but with a wider histologic spectrum, including overlap with glioblastoma (GBM). Methods To clarify the histologic and molecular scope of mcPXA and characterize its clinical behavior, a cohort of 469 tumor samples from 458 patients matching to mcPXA by the DKFZ classifier (v12.6 score ≥0.85) was interrogated. Results Patient median age was 23 years (range 1-73 years) with a female predominance (259 female/199 male). CDKN2A/B homozygous deletion was observed in 406 of 469 (87%) samples. In samples tested for BRAF p.V600E mutations (n = 279), 240 (86%) harbored the mutation. A chr7+/chr10− pattern was observed in 103 of 469 (22%) samples. Among samples tested for TERT promoter mutations (n = 143), 32 (22%) harbored the mutation. Progression-free and overall survival of patients with mcPXA were comparable to patients with methylation class IDH-mutant astrocytoma, low grade, but a GBM-like subset (ie, cases with a pre-methylation working diagnosis of GBM) showed shorter survival. Histologic features of high grade, including palisading necrosis and microvascular proliferation, were prognostic in mcPXA. Compared to patients with BRAF p.V600E-altered GBM, patients with mcPXA were younger and had a lower frequency of TERT promoter mutations. Conclusion Tumors in mcPXA share molecular characteristics with histologically defined PXA, and high-grade histologic features can help predict their clinical behavior. The use of an epigenetic classification of PXA reveals that this group of tumors is more common than previously appreciated and warrants in-depth study to identify efficacious therapeutic options.

BACKGROUND: Spinal cord involvement is infrequently reported in primary central nervous system vasculitis (PCNSV). This study describes the clinical findings, therapeutic responses, and outcomes of spinal cord involvement in a large cohort of patients with PCNSV. METHODS: We retrospectively studied 216 consecutive patients with PCNSV evaluated at the Mayo Clinic from 1983 to 2023. Spinal cord involvement was documented by histological examination or imaging. The clinical, laboratory, radiological, and pathological findings, along with management and outcomes, were compared between patients with and without spinal cord involvement. RESULTS: Of 216 patients, 10 (4.6%) had spinal cord involvement, with cerebral involvement in 9 cases. One patient (0.5%) had isolated spinal cord vasculitis. Histological evidence of vasculitis was found in all 10, with necrotizing vasculitis in 5 (50%). Magnetic resonance imaging showed thoracic abnormalities in 8 patients, cervical spine involvement in 2, conus medullaris involvement in 3, and cauda equina enhancement in 4. Compared with the 206 patients without spinal cord involvement, those with spinal cord vasculitis were more likely to present with paraparesis/tetraparesis ( P <0.001) and necrotizing vasculitis ( P =0.01) and less likely with hemiparesis ( P =0.006) and granulomatous vasculitis ( P =0.03). Patients with spinal cord involvement were more likely to have at least 1 relapse ( P <0.001) or more ( P <0.001). No differences between the 2 groups were observed regarding long-term remission, therapy response, and high disability scores (modified Rankin Scale score, 4–6) or death at last follow-up. Spinal cord involvement was associated with meningeal enhancement on brain imaging (odds ratio, 10.50) and the presence of lymphoma (odds ratio, 6.49), specifically Hodgkin lymphoma diagnosed simultaneously with PCNSV. Spinal involvement was negatively associated with increasing age (odds ratio, 0.64) and cerebral infarction on imaging (odds ratio, 0.08). CONCLUSIONS: Spinal cord involvement defines a distinct subset of patients with PCNSV.

Abstract Genome-wide DNA methylation signatures correlate with and distinguish central nervous system (CNS) tumor types. Since the publication of the initial CNS tumor DNA methylation classifier in 2018, this platform has been increasingly used as a diagnostic tool for CNS tumors, with multiple studies showing the value and utility of DNA methylation-based classification of CNS tumors. A Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT-NOW) Working Group was therefore convened to describe the current state of the field and to provide advice based on lessons learned to date. Here, we provide recommendations for the use of DNA methylation-based classification in CNS tumor diagnostics, emphasizing the attributes and limitations of the modality. We emphasize that the methylation classifier is one diagnostic tool to be used alongside previously established diagnostic tools in a fully integrated fashion. In addition, we provide examples of the inclusion of DNA methylation data within the layered diagnostic reporting format endorsed by the World Health Organization (WHO) and the International Collaboration on Cancer Reporting. We emphasize the need for backward compatibility of future platforms to enable accumulated data to be compatible with new versions of the array. Finally, we outline the specific connections between methylation classes and CNS WHO tumor types to aid in the interpretation of classifier results. It is hoped that this update will assist the neuro-oncology community in the interpretation of DNA methylation classifier results to facilitate the accurate diagnosis of CNS tumors and thereby help guide patient management.

Abstract BACKGROUND Both radiation and temozolomide (TMZ) have meaningful single-modality anti-tumor activity against low-grade gliomas. ECOG-ACRIN E3F05 tested whether combined therapy with radiation and temozolomide is more effective than radiation alone in patients with grade II gliomas. METHODS Patients with grade II gliomas (central pathology review performed post hoc), no prior radiation/chemotherapy, and either age &gt; 40, uncontrolled symptoms/seizures, or progression after initial observation were randomized 1:1 to radiation 50.4 Gy alone in 28 fractions (Arm A) versus radiation 50.4 Gy with concomitant and 12 four-week cycles of post-radiation TMZ (Arm B). Randomization was stratified by 1p/19q codeletion status, age, KPS, pre-operative tumor diameter, and contrast enhancement. The primary endpoint was progression-free survival (PFS); overall survival (OS), quality of life, cognition, severe toxicities, and impact of codeletion status were secondary objectives. RESULTS The trial opened 1/09. Accrual was stopped in 1/14 after RTOG 9802 reported benefit from the addition of PCV chemotherapy to radiation in grade II gliomas. A total of 172 subjects were enrolled. Median age was 44 (range 19-78) and 54% male. 1p/19q codeletion was present in 44%. NCI CTCAE (version 4) grade 3+ toxicity was more common in participants treated with TMZ: thrombocytopenia (11%) and neutropenia (5%) versus none in the radiation alone arm. With a median follow-up of 117 months, OS was superior in Arm B (HR 0.54, 95% CI 0.31-0.95, stratified log-rank p value 0.03). OS HRs were 0.56 and 0.53 for subjects with and without 1p/19q codeleted tumors, respectively. PFS did not differ between Arms A and B (HR 0.76, 95% CI 0.44-1.28, p = 0.30). Five and ten-year OS were 78% and 70% in Arm B versus 70% and 47% in Arm A. CONCLUSION The addition of temozolomide to radiation improves overall survival in both co-deleted and non-co-deleted grade II gliomas.

Background: Glioblastoma IDH-wildtype (GBM IDH-wt) is the most aggressive brain tumor in adults and is characterized by an immunosuppressive microenvironment. Different factors shaping its tumor microenvironment (TME) regulate tumor progression and treatment response. The aim of this study was to characterize the main immunosuppressive elements of the GBM IDH-wt TME. Methods: Immunohistochemistry for CD3, CD4, CD8, CD163, programmed death ligand 1 (PD-L1) and programmed death 1 (PD1) was performed on surgical tumor specimens from patients diagnosed with GBM IDH-wt, according to the CNS WHO 2021 criteria. The impact of categorical variables on time-dependent outcomes such as overall survival (OS) and progression-free survival (PFS) has been estimated through the Kaplan–Meier method. Results: We included 30 patients (19 males and 11 females), median age of 59.8 years (range 40.2–69.1 years). All patients underwent surgery followed by temozolomide concurrent with and adjuvant to radiotherapy. MGMT was methylated in 14 patients (47%) and unmethylated in 16 patients (53%). The overall absolute percentages of CD4+ lymphocytes, both intratumoral and perivascular, were significantly more represented than CD8+ lymphocytes in the TME (p = 0.02). A low density of CD4+ lymphocytes (≤10%) was found to be a favorable prognostic factor for GBM outcome (p = 0.02). Patients with MGMT methylated and unmethylated tumors exhibited a distinct TME composition, with a significant higher number of perivascular CD8+ lymphocytes (p = 0.002), intratumoral CD8+ lymphocytes (p = 0.0024) and perivascular CD4+ lymphocytes (p = 0.014) in MGMT unmethylated tumors. PD-L1 expression in tumor cell surface was observed in four tumors (13.3%), and PD1 expression in infiltrating T lymphocytes was observed in nine (30%) tumors, with predominantly perivascular distribution. Conclusions: MGMT methylated and unmethylated tumors exhibit different immune profiles, likely reflecting the different biology of these tumors. The expression of PD-L1 in GBM IDH-wt patients is confined to a small subpopulation. While we found a significant association between low CD4+ lymphocyte density (≤10%) and survival, given the small numbers of our cohort, the prognostic value of CD4+ lymphocyte density will need to be validated in large-scale studies.