Search PubMedSearch

Biomedical subjects

David Capper

Publications and source records attributed to David Capper.

3 recordsLinked to original sources

Primary mismatch repair deficient glioma, IDH-wildtype and H3-wildtype: A giant cell tumor with potential for long-term survival occurring at all ages.

BACKGROUND: Replication repair deficiency is associated with increased risk of developing malignant gliomas. The aim of this study was to investigate primary mismatch repair deficient gliomas (PMMRDGs), a group of IDH-wildtype and H3-wildtype gliomas that is enriched among patients with CMMRD and Lynch syndrome. METHODS: We investigated how PMMRDGs differ from other gliomas with respect to DNA methylation profile, genomic alterations, histopathology, and clinical outcomes. RESULTS: PMMRDGs occur in pediatric, adolescents and the elderly, falling in two related methylation clusters and are characterized by a high frequency of replication repair deficiency. Histology showed multinucleated giant cells, and immunohistochemistry demonstrated loss of MMR protein expression. Survival analysis revealed long-term survival in patients with high mutational burden (>50 mut/Mb) and an intact chromosome 9p region, which was validated in an independent reference cohort. CONCLUSIONS: Overall, our findings indicate that PMMRDGs represent a distinct type of IDH-wildtype gliomas with potential for long-term survival likely driven by immune activation.

Humans

Age-associated epigenomic heterogeneity in papillary tumors of the pineal region: a multicenter YoungNOA investigation.

BACKGROUND: Papillary tumors of the pineal region (PTPR) are rare CNS neoplasms with adult and pediatric presentations, but whether age defines distinct molecular biology is unclear. METHODS: We assembled a multicenter retrospective cohort of 86 histologically confirmed PTPR with genome-wide DNA methylation data, comprising 62 adult and 24 pediatric tumors. Molecular subgroup, array platform, sex, and tumor purity were incorporated into multivariable models. Analyses included DNA methylation class assignment, differential methylation, copy-number variation (CNV), epigenetic mitotic-clock scores, methylation-based tumor microenvironment deconvolution, and descriptive survival evaluation. RESULTS: Adult and pediatric tumors mapped within the established PTPR-A and PTPR-B methylation framework rather than forming age-defined methylation classes. Pediatric tumors were enriched for PTPR-B (22 of 24 tumors [91.7%]) compared with adult tumors (39 of 62 [62.9%]). After adjustment for methylation-based subgroup as well as technical and biological covariates, 2,923 CpG probes were associated with age at a false discovery rate (FDR) threshold below 0.05, and 530 also met the prespecified effect-size threshold. Global methylation summaries were similar between age groups. CNV patterns were dominated by molecular subgroup; adjusted genomic CNV load was not independently associated with pediatric age. In contrast, epiTOC2 intrinsic rate score and the methylation signature represented by the first principal component (PC1) showed age-associated effects independent of molecular subgroup. Methylation-based deconvolution suggested a limited microenvironmental signal, with neutrophil fraction showing the most consistent adjusted association. CONCLUSIONS: Adult and pediatric PTPR share the established PTPR-A/PTPR-B framework. Pediatric tumors, particularly within PTPR-B, showed age-associated DNA methylation differences and higher epigenetic mitotic-clock (epiTOC2) scores in this retrospective cohort. These tissue-level associations do not establish clinical risk or treatment implications and require prospective clinical annotation and orthogonal validation.

Humans

The effect of TERT promoter mutation on predicting meningioma outcomes: a multi-institutional cohort analysis.

BACKGROUND: Molecular aberrations have been incorporated into tumour classification guidelines of meningioma. TERT-promoter (TERTp) mutation is associated with worse prognosis and is designated a WHO grade 3 biomarker. However, it remains unclear whether TERTp mutation is context-dependent, with other co-occurring genetic alterations potentially driving its association with prognosis. We sought to characterise the role of TERTp mutation in meningioma and guide TERTp sequencing. METHODS: We identified 1492 patients of all ages who had previously received surgery for meningioma across 14 medical centres in the USA, Canada, and Germany. Patients were eligible if they had post-surgical clinical or radiographical assessment of the resection site, and TERTp status evaluated by Nov 1, 2024. Multi-modal profiling was used to assess TERTp mutation, focal gene alterations-including CDKN2A/B loss-and copy number alterations. An adjusted WHO grade was calculated for TERTp-mutant meningiomas, incorporating all WHO criteria except TERTp status. Kaplan-Meier curves and multivariable Cox proportional hazards models were used to quantify the effect of TERTp mutation on the endpoints of overall survival and recurrence-free survival across adjusted WHO grade and co-occurring molecular alterations. FINDINGS: 64 (4&#xb7;3%) of 1492 meningiomas were TERTp-mutant and 1428 (95&#xb7;7%) were TERTp-wildtype. Of the TERTp-mutant meningiomas, 33 (51&#xb7;6%) were from female patients and 31 (48&#xb7;4%) were from male patients, and the overall median age was 67 years (IQR 60-75). Of the wildtype meningiomas, 965 (67&#xb7;6%) were from female patients and 463 (32&#xb7;4%) were from male patients, and the overall median age of the patients was 59 years (IQR 48-70). Data on race was inconsistently reported and thus excluded. The TERTp-mutant patients had a 5-year overall survival (49&#xb7;4% [95% CI 33&#xb7;7-72&#xb7;4]) and 5-year recurrence-free survival (27&#xb7;6% [95% CI 16&#xb7;8-45&#xb7;5]) resembling that of patients with WHO grade 3 TERTp-wildtype tumours (5-year overall survival 32&#xb7;3% [95% CI 17&#xb7;2-60&#xb7;5], p=0&#xb7;28, 5-year recurrence-free survival 14&#xb7;3% [5&#xb7;8-35&#xb7;2], p=0&#xb7;28). However, the TERTp-mutant group had heterogenous histological grading and was enriched for aggressive molecular features, with 1p loss present in 44 (77&#xb7;2%) of 57 profiled tumours and CDKN2A/B loss in 24 (41&#xb7;4%) of the 58 profiled tumours. Adjusting tumour grade revealed a subset of TERTp-mutant meningiomas that were more molecularly and clinically benign. Among TERTp-mutant tumours, CDKN2A/B loss played a defining role in stratifying tumour behaviour. Multivariable analysis confirmed this, with CDKN2A/B loss being significantly associated with shorter overall survival (HR 3&#xb7;04 [95% CI 1&#xb7;67-5&#xb7;52], p=0&#xb7;00026) and faster time to recurrence (HR 5&#xb7;22 [95% CI 3&#xb7;10-8&#xb7;79], p<0&#xb7;0001), while TERTp-mutation did not independently affect overall survival (HR 1&#xb7;00 [95% CI 0&#xb7;53-1&#xb7;87], p=0&#xb7;99) or recurrence-free survival (1&#xb7;17 [95% CI 0&#xb7;75-1&#xb7;83], p=0&#xb7;49). Sequencing for TERTp-mutation demonstrated clinical impact only among histologically WHO grade 2 meningiomas. INTERPRETATION: The indolent behaviour of certain TERTp-mutant meningiomas suggests that TERTp mutation is not sufficient to assign the most aggressive meningioma grade. Instead, TERT sequencing might offer prognostic utility in identifying high-risk cases among WHO grade 2 meningiomas. FUNDING: National Institutes of Health, National Institute of Neurological Disorders and Stroke, Friedberg Charitable Foundation, Courtney Meningioma Research Fund, Fleming Meningioma Research Fund, and the Gray Family Foundation.

Humans