The utility of DNA methylation analysis in elderly patients with pilocytic astrocytoma morphology.

INTRODUCTION Pilocytic astrocytoma (PA) is a circumscribed low-grade astrocytic glioma, generally considered to be associated with a good prognosis. However, some PA patients experience unfavorable outcomes; advanced age was known as an independent poor prognostic factor. This study retrospectively reviewed PA patients and conducted molecular analyses for elderly patients. METHODS We analyzed data from 29 histologically confirmed PA patients treated at a single center from 2002 to 2021 and conducted integrated molecular analyses including DNA methylation profiling for elderly PA patients. RESULTS The median age at diagnosis was 14 years (range 3-82 years), with 4 patients (14%) being elderly (patients≥60years old). Elderly patients had significantly worse progression-free survival and overall survival. DNA methylation analysis was performed on 2 of the 4 elderly patients. Despite histological diagnoses of PA, methylation profiling classified one case as high-grade astrocytoma with piloid features (methylation class scores below 0.3 in both v11b4 and v12.5) and the other as glioblastoma, IDH-wildtype (score over 0.5 in both v11b4 and v12.5), using classifiers from the German Cancer Research Center and t-SNE analysis. CONCLUSION Elderly patients with PA morphology showed unfavorable outcomes in this cohort. In those patients, DNA methylation profiling revealed the possibility of high-grade astrocytic tumors, including newly defined entities.

Polyarteritis nodosa and Churg-Strauss angiitis: characteristics and outcome in 38 patients over 65 years.

Differences in Supratentorial Damage of White Matter in Pediatric Survivors of Posterior Fossa Tumors With and Without Adjuvant Treatment as Detected by Magnetic Resonance Diffusion Tensor Imaging

How old is old: the beginning of a new era for therapeutic challenges for elderly patients with AML.

BACKGROUND: Genome-wide methylation profiling reliably classifies pediatric central nervous system (CNS) tumors. Extracellular vesicles (EVs) are released by pediatric CNS tumor cells (pCC) and contain high molecular weight tumor DNA, rendering EVs a potential biomarker source to identify tumor subgroups, stratify patients and monitor therapy by liquid biopsy. We investigated, whether the DNA in pCC-derived EVs reflects genome-wide tumor methylation profiles and allows tumor subtype classification. Currently, the tests are being expanded to include blood samples (n=80 patients). METHODS: DNA was isolated from EVs secreted by pediatric CNS tumor cells (pCC) as well as from the shortly cultured tumor cells and from the original tumor samples (n=4 patients). Pediatric Fibroblasts and EVs derived thereof were used as a non-tumorous control. EVs were classified by nanoparticle analysis (NTA), immunoblotting, imaging flow cytometry (IFCM and electron microscopy. Genome-wide DNA methylation profiling was performed using an 850k Illumina EPIC array and results were classified according to the DKFZ brain tumor classifier and further analysed by t-SNE and Copy number alteration analysis (CNA). RESULTS: The size range of pCC-derived EVs was 120-150 nm, as measured by NTA. The majority of secreted EVs exhibited high expression of common EV markers (i.e. CD9, CD63 and CD81), as characterized by IFCM. Genome-wide DNA methylation profiling of pCC-derived EVs correctly identified the methylation class of the original tumor (i.e. pilocytic astrocytoma, medulloblastoma). In addition, t-SNE analysis and copy number alterations matched the pattern of the parental pCC and original tumor samples. CONCLUSION: EV DNA faithfully reflects the tumor methylation class and copy number alterations present in the parental cells and the original tumor. Methylation profiling of circulating tumor EV DNA could become a useful tool to detect and classify pediatric CNS tumors.

Pilocytic astrocytoma (PA) is classified as a Grade I benign neuroglial tumor. The extent of surgical resection is a critical factor influencing the prognosis for patients with PA. In prior researches of PA, the extent of surgical resection is generally categorized into GTR, STR and biopsy. In some researches on brain tumor surgeries, the extent of resection also includes GTL. There is no existing research specifically comparing the efficacy of GTR versus GTL in PA treatment. In this study, the data we used are from the SEER database. We categorized the extent of resection into GTL, GTR, STL, STR, biopsy, and no surgery based on SEER classification of surgical procedures, to investigate the impact of extent of resection on PA patient survival. A multivariate logistic regression model was utilized to acquire odds ratios (OR) for different extent of resection. Survival outcomes across different extent of resection (GTL, GTR, STL, STR, biopsy, no surgery) were assessed using Kaplan–Meier survival curve analysis, with curve comparisons conducted via log-rank tests. The impact of various risk factors on survival was assessed using the Cox proportional hazards model. The hazard ratio (HR) was employed to quantify the influence of one or more factors on overall survival throughout the follow-up period. Multivariate Cox analysis revealed that age, tumor location, extent of resection, as well as the application of radiotherapy and chemotherapy, all significantly impacted prognosis. Compared to GTL, GTR did not significantly increase the risk of mortality (HR 1.17; 95% CI 0.73–1.86, p = 0.5). Furthermore, there was no statistically significant difference between the Kaplan–Meier survival curves of the two groups (p = 0.18). We employed propensity score matching (PSM) to balance the differences in baseline characteristics of patients receiving chemotherapy or radiotherapy. A total of 4429 patients were included in this study. Age, diagnosis period, race, tumor size, and tumor location as influential on the extent of resection. Age, tumor location, extent of resection, and application of radiotherapy and chemotherapy influenced the survival of PA patients. The Kaplan–Meier survival curves revealed that the long-term survival rate for GTR is slightly higher than that for GTL. The PSM analysis revealed that the application of radiotherapy and chemotherapy was associated with the reduction of overall survival in PA patients. In conclusion, there was no significant difference in survival between GTR and GTL, so GTR with less damage was preferred. The application of radiotherapy and chemotherapy can reduce overall survival of patients with PA.

Motor and cognitive function losses resemble handicaps in pediatric posterior fossa tumor survivors. Several factors determine type and extent of impairment. We quantified loss of fine motor function and its association with ataxia and intelligence in patients with and without adjuvant treatment. Fine motor function, extent of ataxia and cognitive function were assessed in 25 medulloblastoma (MB) and 16 cerebellar pilocytic astrocytoma (PA) patients at least 1 year after completion of therapy. Kinematic parameters (speed, automation, variability, and pressure) of different movement complexity levels were investigated employing a digitizing graphic tablet. Degree of ataxia was quantified using the International Cooperative Ataxia Rating Scale and cognition was determined using the Wechsler Intelligence Scale. Kinematic parameters of low and high complexity tasks as well as ataxia of MB patients were strongly impaired. Fine motor impairment was weaker in PA patients, but still evident in the complex task of writing. Ataxia was significantly more pronounced in medulloblastoma patients. Young age and short recovery time correlated significantly with impaired kinematic parameters. Ataxia was strongly associated with inferior fine motor function. Cognition, especially performance IQ, was associated with dysfunctional kinematic parameters. The digitizing tablet detected extent of fine motor function loss at varying levels of complexity of pediatric cerebellar tumor survivors. This tool promises to be a potentially effective method for measuring fine motor function in clinical trials and may be helpful in studying mechanisms of neurotoxicity in posterior fossa tumor patients as well as success of rehabilitation.

69P Novel urinary methylated DNA biomarkers for kidney cancer detection and prognosis

Clinicopathological features and global genomic copy number alterations of pilomyxoid astrocytoma in the hypothalamus/optic pathway: comparative analysis with pilocytic astrocytoma using array-based comparative genomic hybridization

2013 Background: Glioblastomas in elderly patients are associated with particularly poor outcome, with only few patients demonstrating long-term survival (LTS). Methods: To better characterize clinical and molecular correlates of LTS in elderly glioblastoma patients, we searched the German Glioma Network (GGN) database for patients aged 71 years or more with histological confirmation of glioblastoma and survival of at least two years after diagnosis. Results: Of 2071 glioblastoma patients enrolled in the GGN from 2004-2012, 425 patients were aged 71 years or more; of these, 27 patients (6.4%) survived for 2 years or more (median survival: 37.1 months, 95% confidence interval: 30.0-44.2 months). A comparison of these 27 patients with the 398 patients who survived shorter than 2 years (median survival: 6.2, 95% confidence interval: 5.2-7.2 months) revealed more intensive up-front treatment and a trend towards higher initial Karnofsky performance score as distinguishing clinical factors. Molecular analyses additionally showed more frequent O6-methylguanine-DNA methyltransferase ( MGMT) promoter methylation in the LTS patients. Isocitrate dehydrogenase (IDH) mutation was restricted to single patients and the frequency of telomerase reverse transcriptase ( TERT) promoter mutation did not differ between groups. Genome-wide DNA copy number and methylation profiling using 450k microarray analysis performed for 16 LTS patients and 40 control patients revealed limited differential DNA methylation and no specific copy number profiles linked to LTS. Conclusions: Collectively, our findings confirm that LTS is rare in elderly patients with glioblastoma and that clinical and tumor-associated molecular factors linked to LTS resemble those in standard age patients, except for less common IDH mutation.

To determine whether the chemical shift of residual N-acetylaspartate (NAA) signal in pilocytic astrocytomas (PA) is consistent with the position of the NAA peak in controls. MR spectra from 27 pediatric World Health Organization (WHO) grade I pilocytic astrocytoma patients, fifteen patients with WHO grade II and high-grade (III-IV) astrocytomas, and 36 controls were analyzed. All spectra were acquired with a short echo time (35 ms), single voxel point-resolved spectroscopy sequence on clinical 3 tesla scanners. Fully automated LCModel software was used for processing, which included the fitting of peak positions for NAA and creatine (Cr). The chemical shift difference between the NAA and Cr peaks was significantly smaller (by 0.016 ± 0.005 parts per million, P < 1e-10) in PAs than in controls and was also smaller than what was observed in infiltrative astrocytomas. The chemical shift position of the residual NAA peak in PAs is not consistent with NAA. The signal likely originates from an N-acetyl group of one or more other chemicals such as N-acetylated sugars. Magn Reson Med 78:452-456, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

To elucidate the relationship between DNA methylation profiling (DMP) and pathological diagnosis (PD) in pediatric glial and glioneuronal tumors with B-Raf proto-oncogene, serine/threonine kinase (BRAF) mutations, addressing their diagnostic challenges. This retrospective study, conducted in Saudi Arabia, analyzed 47 cases from the Children's Brain Tumor Network online database using scanned images, next-generation sequencing data, and methylation profiles processed using the Heidelberg methylation brain tumor classifiers v12.5 and v12.8. The data was last access on 10 November 2023. The highest prevalence of BRAF mutations was observed in pilocytic astrocytoma and ganglioglioma. The DMP was consistent with PD in 23 cases, but discrepancies emerged in others, including diagnostic changes in diffuse leptomeningeal glioneuronal tumor and polymorphous low-grade neuroepithelial tumor of the young. A key inconsistency appeared between a pilocytic astrocytoma MC and a glioneuronal tumor PD. Two high-grade astrocytomas were misclassified as pleomorphic xanthoastrocytomas. Additionally, low variant allelic frequency in gangliogliomas likely contributed to misclassifications as control in 5 cases. This study emphasized the importance of integrating DMP with PD in diagnosing pediatric glial and glioneuronal tumors with BRAF mutations. Although DMP offers significant diagnostic insights, its limitations, particularly in cases with low tumor content, necessitate cautious interpretation, as well as its use as a complementary diagnostic tool, rather than a definitive method.

Low-grade gliomas (LGGs) account for about a third of all brain tumours in children. We conducted a detailed study of DNA methylation and gene expression to improve our understanding of the biology of pilocytic and diffuse astrocytomas. Pilocytic astrocytomas were found to have a distinctive signature at 315 CpG sites, of which 312 were hypomethylated and 3 were hypermethylated. Genomic analysis revealed that 182 of these sites are within annotated enhancers. The signature was not present in diffuse astrocytomas, or in published profiles of other brain tumours and normal brain tissue. The AP-1 transcription factor was predicted to bind within 200 bp of a subset of the 315 differentially methylated CpG sites; the AP-1 factors, FOS and FOSL1 were found to be up-regulated in pilocytic astrocytomas. We also analysed splice variants of the AP-1 target gene, CCND1, which encodes cell cycle regulator cyclin D1. CCND1a was found to be highly expressed in both pilocytic and diffuse astrocytomas, but diffuse astrocytomas have far higher expression of the oncogenic variant, CCND1b. These findings highlight novel genetic and epigenetic differences between pilocytic and diffuse astrocytoma, in addition to well-described alterations involving BRAF, MYB and FGFR1.Electronic supplementary materialThe online version of this article (doi:10.1186/s40478-016-0323-6) contains supplementary material, which is available to authorized users.

BACKGROUND Genome-wide methylation profiling reliably classifies pediatric central nervous system (CNS) tumors. Extracellular vesicles (EVs) are released by pediatric CNS tumor cells (pCC) and contain high molecular weight tumor DNA, rendering EVs a potential biomarker source to identify tumor subgroups, stratify patients and monitor therapy by liquid biopsy. We investigated whether the DNA in pCC-derived EVs reflects genome-wide tumor methylation profiles and allows tumor subtype classification. METHODS DNA was isolated from EVs secreted by pediatric CNS tumor cells (pCC) as well as from the shortly cultured tumor cells and from the original tumor samples (n=4 patients). Pediatric Fibroblasts and EVs derived thereof were used as a non-tumorous control. EVs were classified by nanoparticle analysis (NTA), immunoblotting, imaging flow cytometry (IFCM and electron microscopy. Genome-wide DNA methylation profiling was performed using an 850k Illumina EPIC array and results were classified according to the DKFZ brain tumor classifier and further analysed by t-SNE and Copy number alteration analysis (CNA). RESULTS The size range of pCC-derived EVs was 120–150 nm, as measured by NTA. The majority of secreted EVs exhibited high expression of common EV markers (i.e. CD9, CD63 and CD81), as characterized by IFCM. Genome-wide DNA methylation profiling of pCC-derived EVs correctly identified the methylation class of the original tumor (i.e. pilocytic astrocytoma, medulloblastoma). In addition, t-SNE analysis and copy number alterations matched the pattern of the parental pCC and original tumor samples. CONCLUSION EV DNA faithfully reflects the tumor methylation class and copy number alterations present in the parental cells and the original tumor. Methylation profiling of circulating tumor EV DNA could become a useful tool to detect and classify pediatric CNS tumors.

Surgical resection for elderly patients with gastric cancer is controversial. This study aims to evaluate the preoperative features and postoperative short- and long-term outcomes of elderly patients following surgical resection for gastric adenocarcinoma. Between January 2000 and May 2018, a total of 177 consecutive patients underwent curative gastrectomy for gastric adenocarcinoma was retrospectively reviewed. Propensity score matching (PSM) analysis was used to balance confounding covariates between the elderly and non-elderly groups. Clinicopathological characteristics, intraoperative characteristics, postoperative complicationsand long-term survival outcomes including overall survival (OS) and Disease Specific Survival (DSS) were compared and analysed using the Kaplan-Meier log-rank test. Multivariate cox proportional hazards regression analysis of clinicopathological factors influencing survival wereevaluated. There were 50 patients in the elderly group (age ≥ 75years) and 127 patients in the non-elderly group (age < 75years). Elderly patients had more comorbid conditions (p < 0.001), lower albumin concentration (p = 0.034), lower haemoglobin levels (p = 0.001), and poorer renal function (p = 0.043). TNM stage was similar between both groups (p = 0.174); however, lymphatic invasion (p = 0.006) and lymph node metastasis (p = 0.029) were higher in the elderly group. Elderly patients were much less likely to receive any chemo- (p < 0.001) or radiotherapy treatment (p = 0.007) with surgical treatment. After PSM, there were 50 patients in each group. Elderly patients were more likely to develop complications (Clavien Dindo ≥ 2: 50% vs. 26%, p = 0.003). The most common postoperative complications were pneumonia (12% vs. 6%, p = 0.498) and delirium (10% vs. 0%, p = 0.066). Elderly patients had a longer median length of hospital stay (median (IQR): 15.6(9.5) vs. 11.3 (9.9), p = 0.030). There were no differences in 30-day mortality (elderly vs. non-elderly: 1% vs. 1%, p = 0.988). Before and after PSM,age remains an independent predictor of postoperative complications. Before PSM,the estimated mean OS for the elderly and non-elderly patients were 108months (95%CI, 72.5-143.5) and 143months (95%CI, 123.0-163.8), respectively (p = 0.264). After PSM, the estimated mean OS for the elderly and non-elderly patients were 108 months (95%CI, 72.5-143.5) and 140 months (95%CI, 112.1-168.2), respectively, (p = 0.360). Before PSM,the estimatedmean DSS for the elderly and non-elderly patients were 94months (95%CI, 61.9-127.5) and 121months (95%CI, 100.9-141.0), respectively (p = 0.405). After PSM, the estimated mean DSS for the elderly and non-elderly patients were 94months (95%CI, 61.9-127.5) and 115 months (95%CI, 87.3-143.3), respectively (p = 0.721). Age was not an independent predictor of mortality following gastrectomy for gastric cancer in both PSM matched and unmatched cohort. Chronological age alone is not a contraindication to curative resection of gastric adenocarcinoma in elderly patients with acceptable risk. Whilst age affects perioperative complications, the incidence of postoperative mortality and overall survival were not significantly different between elderly and non-elderly gastric cancer patients treated with curative surgery. Gastrectomy with D2 lymphadenectomy can also be performed in carefully selected elderly patients by surgeons with expertise in gastric resection along with appropriate perioperative management.