Clinical outcome of surgically treated low-grade gliomas: A retrospective analysis of a single institute

The Current State of Adult Glial Tumor Patients’ Care in Kazakhstan: Challenges in Diagnosis and Patterns in Survival Outcomes

Background: The study aimed to analyze the 5-year survival of adult patients with glial tumors and to define characteristics that are associated with the disease outcomes in Kazakhstan. Methods: Medical records of patients that were surgically treated at the National Center for Neurosurgery during the 5-year period from 2016 to 2020 were collected retrospectively. Patients with a histologically confirmed diagnosis of diffuse astrocytic or oligodendroglial tumor type were included and their survival was assessed with life tables, Kaplan–Meier plot, and Cox regression using STATA 16 statistical software. Results: Almost half of the patients had glioblastoma. The 5-year survival rate of the whole sample was 45.93%. Among Grade 4 patients, 15.6% survived the 5-year mark. Differences in survival between grades 1–3 were not significant. Grade 1 patients demonstrated worse survival rates compared to Grade 2 patients (69% vs. 74%). Worse survival rates were observed among patients of Russian ethnicity and in rural residents. Conclusions: The study described the unusual patterns in survival rates of glial tumor patients in Kazakhstan, pointing to the need for reassessment of diagnostic accuracy and resulting treatment of glial patients in Kazakhstan, and the need to introduce molecular and genetic parameters in tumor type classification. Moreover, the observed difference in survival of different ethnic groups and residents of rural and urban areas should be further investigated and addressed by healthcare professionals.

Malignant Progression of Diffuse Low-grade Gliomas: A Systematic Review and Meta-analysis on Incidence and Related Factors

Malignant progression of diffuse low-grade glioma (LGG) is a critical event affecting patient survival; however, the incidence and related factors have been inconsistent in literature. According to the PRISMA guidelines, we systematically reviewed articles from 2009, meta-analyzed the incidence of malignant progression, and clarified factors related to the transformation. Forty-one articles were included in this study (n = 7,122; n, number of patients). We identified two definitions of malignant progression: histologically proven (Htrans) and clinically defined (Ctrans). The malignant progression rate curves of Htrans and Ctrans were almost in parallel when constructed from the results of meta-regression by the mean follow-up time. The true transformation rate was supposed to lie between the two curves, approximately 40% at the 10-year mean follow-up. Risk of malignant progression was evaluated using hazard ratio (HR). Pooled HRs were significantly higher in tumors with a larger pre- and postoperative tumor volume, lower degree of resection, and notable preoperative contrast enhancement on magnetic resonance imaging than in others. Oligodendroglial histology and IDH mutation (IDHm) with 1p/19q codeletion (Codel) also significantly reduced the HRs. Using Kaplan-Meier curves from eight studies with molecular data, we extracted data and calculated the 10-year malignant progression-free survival (10yMPFS). The 10yMPFS in patients with IDHm without Codel was 30.4% (95% confidence interval [95% CI]: 22.2-39.0) in Htrans and 38.3% (95% CI: 32.3-44.3) in Ctrans, and that with IDHm with Codel was 71.7% (95% CI: 61.7-79.5) in Htrans and 62.5% (95% CI: 55.9-68.5) in Ctrans. The effect of adjuvant radiotherapy or chemotherapy could not be determined.

Malignant Tumor Purity Reveals the Driven and Prognostic Role of CD3E in Low-Grade Glioma Microenvironment

The tumor microenvironment (TME) contributes to the initiation and progression of many neoplasms. However, the impact of low-grade glioma (LGG) purity on carcinogenesis remains to be elucidated. We selected 509 LGG patients with available genomic and clinical information from the TCGA database. The percentage of tumor infiltrating immune cells and the tumor purity of LGG were evaluated using the ESTIMATE and CIBERSORT algorithms. Stromal-related genes were screened through Cox regression, and protein-protein interaction analyses and survival-related genes were selected in 487 LGG patients from GEO database. Hub genes involved in LGG purity were then identified and functionally annotated using bioinformatics analyses. Prognostic implications were validated in 100 patients from an Asian real-world cohort. Elevated tumor purity burden, immune scores, and stromal scores were significantly associated with poor outcomes and increased grade in LGG patients from the TCGA cohort. In addition, CD3E was selected with the most significant prognostic value (Hazard Ratio=1.552, P<0.001). Differentially expressed genes screened according to CD3E expression were mainly involved in stromal related activities. Additionally, significantly increased CD3E expression was found in 100 LGG samples from the validation cohort compared with adjacent normal brain tissues. High CD3E expression could serve as an independent prognostic indicator for survival of LGG patients and promotes malignant cellular biological behaviors of LGG. In conclusion, tumor purity has a considerable impact on the clinical, genomic, and biological status of LGG. CD3E, the gene for novel membrane immune biomarker deeply affecting tumor purity, may help to evaluate the prognosis and develop individual immunotherapy strategies for LGG patients. Evaluating the ratio of differential tumor purity and CD3E expression levels may provide novel insights into the complex structure of the LGG microenvironment and targeted drug development.

Risk Stratification in Low Grade Glioma: A Single Institutional Experience

Background

Low grade gliomas (LGG) are most often noted with the unpredictable overall survival and progression to higher grades. Objective: In the present study, we analyze the clinicopathological features influencing the prognostic outcomes and compared the features with criteria developed by EORTC.

Materials and Methods

We observed the 130 LGG clinical cases in single institute and maintained the follow-up for more than 5 years. In addition, the molecular details were confirmed with markers as IDH, 1p/19q codeletion, p53 and ATRX mutations.

Results

The mean age of patients as 37.67 years and male population contributing to 70%. We observed biased incidence among the male population with dominating occurrence at frontal and parietal lobes in the brain. 40.8% patients had oligodendroglioma, 33.8% astrocytoma, 19.2% oligoastrocytoma and 2.3% gemistocytic astrocytoma pathology. Patients who were subjected to chemotherapy and radiotherapy were noted with average survival of 29 months. Oligodendroglial tumors were found with progression free survival (PFS) of 25 months, oligoastrocytoma cases with 32 months, diffuse astrocytoma cases with 23 months while the gemistocytic astrocytoma cases had 22 months. The PFS for LGG cases was 4.7 years while the overall survival was 4.9 years. Mean survival of patients with KPS score <70 and >70 was 1.5 & 4.9 years respectively. 64 patients were observed with the tumor size >5 cm. In total, 72.3% of the patients were underwent GTR, 23.3% STR and 3.8% underwent biopsy.

Conclusion

Taken together, the clinical symptoms, expression of molecular markers and the prognosis details provided by our results can help for better management of LGG cases. We further propose to use following five factors to accurately describe the prognosis and tumor recurrence: 1) Age >50 years, 2) tumor size >5 cm, 3) MIB index >5%, 4) KPS score < 70 and 5) gemistocytic pathology.

Adult Diffuse Low-Grade Gliomas: 35-Year Experience at the Nancy France Neurooncology Unit

Background

To report survival, spontaneous prognostic factors, and treatment efficacy in a French monocentric cohort of diffuse low-grade glioma (DLGG) patients over 35 years of follow-up.

Methods

A monocentric retrospective study of 339 patients diagnosed with a new DLGG between 01/01/1982 and 01/01/2017 was created. Inclusion criteria were patient age ≥18 years at diagnosis and histological diagnosis of WHO grade II glioma (according to 1993, 2007, and 2016 WHO classifications). The survival parameters were estimated using the Kaplan-Meier method with a 95% confidence interval. Differences in survival were tested for statistical significance by the log-rank test. Factors were considered significant when p ≤ 0.1 and p ≤ 0.05 in the univariate and multivariate analyses, respectively.

Results

A total of 339 patients were included with a median follow-up of 8.7 years. The Kaplan-Meier median overall survival was 15.7 years. At the time of radiological diagnosis, Karnofsky Performance Status score and initial tumor volume were significant independent prognostic factors. Oncological prognostic factors were the extent of resection for patients who underwent surgery and the timing of radiotherapy for those concerned. In this study, patients who had delayed radiotherapy (provided remaining low grade) did not have worse survival compared with patients who had early radiotherapy. The functional capabilities of the patients were preserved enough so that they could remain independent during at least three quarters of the follow-up.

Conclusion

This large monocentric series spread over a long time clarifies the effects of different therapeutic strategies and their combination in the management of DLGG.

Genome-wide analyses of the prognosis-related mRNA alternative splicing landscape and novel splicing factors based on large-scale low grade glioma cohort

Alternative splicing (AS) changes are considered to be critical in predicting treatment response. Our study aimed to investigate differential splicing patterns and to elucidate the role of splicing factor (SF) as prognostic markers of low-grade glioma (LGG). We downloaded RNA-seq data from a cohort of 516 LGG tumors in The Cancer Genome Atlas and analyzed independent prognostic factors using LASSO regression and Cox proportional regression to build a network based on the correlation between SF-related survival AS events. We collected 100 patients from our center for immunohistochemistry and analyzed survival using χ2 test and Cox and Kaplan-Meier analyses. A total of 9,616 AS events related to LGG were screened and identified as well as established related models. Through analyzing specific splicing patterns in LGG, we screened 16 genes to construct a prognostic model to stratify the risk of LGG patients. Validation revealed that the expression level of the prognostic model in LGG tissue was increased, and patients with high expression showed worse prognosis. In summary, we demonstrated the role of SFs and AS events in the progression of LGG, which may provide insights into the clinical significance and aid the future exploration of LGG-associated AS.

Awake Craniotomy with Noninvasive Brain Mapping by 3-Tesla Functional Magnetic Resonance Imaging for Excision of Low-grade Glioma: A Case of a Young Patient from Pakistan

The past few years have seen increasing support for gross total resection in the management of low-grade gliomas (LGGs), with a greater extent of resection correlated with better overall survival, progression-free survival, and time to malignant transformation. There is consistent evidence in literature supporting extent of safe resection as a good prognostic indicator as well as positively affecting seizure control, symptomatic relief in pressure symptoms, and longer progression-free and total survival. The operative goal in most LGG cases is to maximize the extent of resection for these benefits while avoiding postoperative neurologic deficits. Several advanced invasive and noninvasive surgical techniques such as intraoperative magnetic resonance imaging (MRI), fluorescence-guided surgery, intraoperative functional pathway mapping, and neuronavigation have been developed in an attempt to better achieve maximal safe resection. We present a case of LGG in a young patient with a 5-year history of refractory seizures and gradual onset walking difficulty. Serial MRI brain scans revealed a progressive increase in right frontal tumor size with substantial edema and parafalcine herniation. Noninvasive brain mapping by functional MRI (fMRI) and sleep-awake-sleep type of anesthesia with endotracheal tube insertion was utilized during an awake craniotomy. Histopathology confirmed a Grade II oligodendroglioma, and genetic analysis revealed no codeletion at 1p/19q. Neurological improvement was remarkable in terms of immediate motor improvement, and the patient remained completely seizure free on a single antiepileptic drug. There is no radiologic or clinical evidence of recurrence 6 months postoperatively. This is the first published report of an awake craniotomy for LGG in Pakistan. The contemporary concept of supratotal resection in LGGs advocates generous functional resection even beyond MRI findings rather than mere excision of oncological boundaries. This relatively aggressive approach is only possible with an awake craniotomy, which ensures preservation of functional status and thus less postoperative morbidity and better outcomes. Noninvasive mapping for intracranial space-occupying lesions, including fMRI and blood-oxygen-level dependent (BOLD) imaging modality, is an essential tool in a resource-limited setting such as Pakistan.

Prognosis of older patients with low-grade glioma: A retrospective study

Introduction

Clinical behavior, treatment parameters, and prognostic factors are less well defined in older adults with low-grade gliomas (LGG). We conducted a two-institution retrospective review of older patients with LGG to better understand disease characteristics and prognosis in this population.

Methods

Northwestern University (NU) and The University of Washington (UW) clinical research databases were queried for patients ≥ 50 years of age with a diagnosis of WHO grade II glioma between January 1, 2000 and December 2012 (UW). Medical records were reviewed and data relevant to diagnosis, treatment and outcomes were collected. PFS and OS with respect to prognostic factors were calculated. Log-rank test and multivariate proportional hazards models were calculated for multiple tumor characteristics.

Results

Thirty-five patients with a diagnosis of LGG (WHO grade II) were identified; 15 women and 20 men had a median age of 55 (range 50-78). Fourteen had astrocytomas, fourteen had oligodendrogliomas and seven had oligoastrocytomas. Eight patients had contrast enhancement on neuroimaging, 9 of 21 tested had 1p19q co-deletion and 5 of 14 tested had an IDH1 mutation. Five year PFS was 21% with median PFS of 17 months; 20 patients had died (5 year OS=43%, median OS=48 months). On univariate analysis There was a statistically significant improvement in OS for patients with mixed histology (p=0.001), no midline shift at diagnosis (p=0.002) and with IDH1 mutation (p=0.003).

Conclusion

LGG appear more aggressive in older patients. Treatment following surgical resection should be considered; ongoing studies may clarify the most appropriate treatments for this age group.

Malignant transformation of low-grade gliomas in patients undergoing adjuvant therapy

Low-grade gliomas (LGG) comprise nearly 15-20 % of all central nervous system glial tumors. Several factors have been recognized as playing role in LGG malignant transformation (MT). A breakthrough analysis of a multidisciplinary group pointed that temozolomide may play a role in MT of LGGs. We analyzed the prevalence of MT in LGG patients submitted to adjuvant therapy (AT). We analyzed the medical charts of 43 patients with LGG submitted to surgery or biopsy and attending at Hospital do Servidor Público Estadual de São Paulo (São Paulo, Brazil), consecutively diagnosed from 1995 to 2013. 43 patients (24 women and 19 men) were evaluated, with mean age of 45.3 years. According to histology, 30 were astrocytomas (70 %), 12 (27 %) were oligodendrogliomas, and 1 (3 %) were mixed glioma. Mean follow-up time was 4.2 years with the standard deviation of 2.1. Twenty-eight patients did not receive adjuvant therapy and 15 received adjuvant therapy. From 43 patients with complete follow-up, 21 (48 %) experienced malignant transformation. Among such patients, nine were users of AT. Forty-eight percent of patients presented MT, being 60 % in the AT group and 42.8 % without AT. Our analysis revealed a high prevalence of MT in patients undergoing AT, higher than in patients without AT.

Oligodendrogliomas in Children: Clinical Experiences With 20 Patients

Oligodendrogliomas occurring rarely in children are incompletely characterized. The purpose of this study was to identify prognostic factors affecting the local control and survival in the management of children with oligodendrogliomas. We retrospectively analyzed clinical data on 20 pediatric patients with oligodendrogliomas treated at Chang Gung Children's Hospital between 1994 and 2014. There were 12 males and 8 females with a median age of 9.2 years at diagnosis (range, 3 mo to 18 y). Eighteen (90%) tumors were located in the cerebral hemispheres, 10 cases were located on the right, 8 on the left. One was located in the third ventricle and 1 in the thoracic spine. Presenting symptoms included seizures (n=7), headache (n=5), visual field defects (n=3), limb weakness (n=2), vomiting (n =1), back pain (n=1), and increased head circumference (n=1). All patients underwent craniotomy: 8 gross total resections, 8 subtotal resections, and 4 biopsies. Nine of the patients had pure oligodendroglioma and 11 had anaplastic oligodendroglioma (WHO grade III or IV). Ten children had adjuvant therapy including radiation (n=7), chemotherapy (n=1) or both (n=2). With the median follow-up of 5.3 years (range, 1.2 to 14.7 y), the 5-year overall survival and disease-free survival rates were 78.9% with 65.0%, respectively. Total tumor resection offers better overall survival regardless of the histologic grading. Our data demonstrate that patients with less than gross total resections are at increased risk for progression and may benefit from more aggressive therapy.

Whole Chromosome 7 Gain Predicts Higher Risk of Recurrence in Pediatric Pilocytic Astrocytomas Independently From KIAA1549-BRAF Fusion Status

The most frequent genetic alteration identified in pediatric pilocytic astrocytomas and pilomyxoid variant is the KIAA1549-BRAF fusion, which typically results from a 2.0 Mb tandem duplication in chromosome band 7q34. Less frequent abnormalities include fusion genes,BRAF, FGFR, KRAS, and NF1 point mutations, and whole chromosome gains. To correlate genetic alterations with clinical course data, we retrospectively analyzed the tumors with pilocytic and pilomyxoid histology of a cohort of 116 pediatric patients, aged 5 months to 23 years. Gross total resection was associated with a decreased risk of recurrence (p = 0.001), supporting previous findings that complete tumor excision correlates with long-term and disease-free survival. We found no significant association between recurrence rate and the presence of the KIAA1549-BRAF fusion or BRAF mutation (p = 0.167). Interestingly, gain of whole chromosome 7 (WC7) was associated with a 4.7-fold increased risk of tumor recurrence, even after adjusting for surgical status (p = 0.025), and other genetic alterations. Using fluorescence in situ hybridization, we demonstrated that when WC7 gain accompanies the KIAA1549-BRAF fusion, the fusion likely arises first. This study highlights the utility of genetic studies for risk assessment of pilocytic and pilomyxoid astrocytomas, which may impact treatment selections.

Second chances

An 81-year-old woman presented with light perception vision in her left eye and had pallid swelling of the left optic disk. Temporal artery biopsy was normal. Magnetic resonance imaging revealed enlargement and enhancement of the left orbital optic nerve. There were vitreous cells, but a vitrectomy specimen showed only a benign lymphocytic population. Her vision deteriorated to no light perception in the left eye, and an optic nerve biopsy revealed a diffuse astrocytoma of World Health Organization grade II.