Randomized trial on the efficacy of radiotherapy for cerebral low-grade glioma in the adult: European Organization for Research and Treatment of Cancer Study 22845 with the Medical Research Council study BRO4: an interim analysis

SEOM-GEINO clinical guidelines for grade 2 gliomas (2023)

The 2021 World Health Organization (WHO) classification has updated the definition of grade 2 gliomas and the presence of isocitrate dehydrogenase (IDH) mutation has been deemed the cornerstone of diagnosis. Though slow-growing and having a low proliferative index, grade 2 gliomas are incurable by surgery and complementary treatments are vital to improving prognosis. This guideline provides recommendations on the multidisciplinary treatment of grade 2 astrocytomas and oligodendrogliomas based on the best evidence available.

Adjuvant Chemoradiation Therapy Versus Chemotherapy Alone for Resected Oligodendroglioma: A Surveillance, Epidemiology and End Results (SEER) Analysis

OBJECTIVE

The benefit of postoperative adjuvant therapy for survival of oligodendrocyte glioma remains unclear. In this study, we compared the effect of chemoradiation therapy (CRT) and chemotherapy (CT) alone in patients who underwent resection. We aim to identify which adjuvant therapy provides more survival benefits.

METHODS

We identified patients who underwent oligodendroglioma resection in the Surveillance, Epidemiology and End Results (SEER) database. A multivariate Cox regression analysis was used to evaluate the factors affecting survival rates. We used a propensity matching analysis to minimize selection bias in each group. We performed subgroup analyses based on patients' clinical characteristics.

RESULTS

This study identified 1826 patients who received adjuvant CT (n = 503) or adjuvant CRT (n = 1323). On multivariate analysis, elderly, white and other race, and temporal lobe and parietal lobe tumor site were independent risk factors for improved overall survival (OS). After 1:1 propensity match, we included 501 patients who received CT and 501 with CRT. Patients in the CT group showed improved overall survival rate compared with those who received CRT (median OS: 146 months vs. 111 months). Subgroup analysis showed that improved overall survival in CT group was more significant in patients who were younger or older, male or female, white race, frontal lobe and parietal lobe tumor site, smaller tumor size (≤4 cm), and with gross total resection (GTR) (P < 0.05).

CONCLUSIONS

In patients with resected oligodendroglioma, adjuvant CT is associated with better survival compared to adjuvant CRT. The benefit was more significant in patients who were younger and older, male and female, white race, frontal lobe and parietal lobe tumor site, smaller tumor size (≤4 cm), and with GTR.

Resection of Low-Grade Gliomas in the Face Area of the Primary Motor Cortex and Neurological Outcome

OBJECTIVE

During surgery on low-grade gliomas (LGG), reliable data relevant to the primary motor cortex (M1) for the face area are lacking. We analyzed the impact of tumor removal within the M1 face area on neurological deficits.

METHODS

We included LGG patients with resection within the M1 face area between May 2012 and November 2019. The primary endpoint was postoperative facial motor function. Secondary endpoints were postoperative aphasia, dysarthria, and dysphagia. Surgery was performed either with the awake protocol or under anesthesia with continuous dynamic mapping. The alarm criteria were speech arrest or a mapping threshold of 3 mA or less. Resection was completed in five patients. The resection was stopped due to the alarm criteria in three patients and for other reasons (vascular supply, patient performance) in four patients. A total of 66.7% (n = 8) presented with new-onset facial paresis (62.5% left LGG) and 41.7% (n = 5) with aphasia (all left LGG) postoperatively. After one year, all eight patients had recovered from the facial paresis. Tumor removal within the M1 face area was not associated with permanent facial motor deficits.

Analysis of safety and efficacy of proton radiotherapy for IDH-mutated glioma WHO grade 2 and 3

PURPOSE

Proton beam radiotherapy (PRT) has been demonstrated to improve neurocognitive sequelae particularly. Nevertheless, following PRT, increased rates of radiation-induced contrast enhancements (RICE) are feared. How safe and effective is PRT for IDH-mutated glioma WHO grade 2 and 3?

METHODS

We analyzed 194 patients diagnosed with IDH-mutated WHO grade 2 (n = 128) and WHO grade 3 (n = 66) glioma who were treated with PRT from 2010 to 2020. Serial clinical and imaging follow-up was performed for a median of 5.1 years.

RESULTS

For WHO grade 2, 61% were astrocytoma and 39% oligodendroglioma while for WHO grade 3, 55% were astrocytoma and 45% oligodendroglioma. Median dose for IDH-mutated glioma was 54 Gy(RBE) [range 50.4-60 Gy(RBE)] for WHO grade 2 and 60 Gy(RBE) [range 54-60 Gy(RBE)] for WHO grade 3. Five year overall survival was 85% in patients with WHO grade 2 and 67% in patients with WHO grade 3 tumors. Overall RICE risk was 25%, being higher in patients with WHO grade 2 (29%) versus in patients with WHO grade 3 (17%, p = 0.13). RICE risk increased independent of tumor characteristics with older age (p = 0.017). Overall RICE was symptomatic in 31% of patients with corresponding CTCAE grades as follows: 80% grade 1, 7% grade 2, 13% grade 3, and 0% grade 3 + . Overall need for RICE-directed therapy was 35%.

CONCLUSION

These data demonstrate the effectiveness of PRT for IDH-mutated glioma WHO grade 2 and 3. The RICE risk differs with WHO grading and is higher in older patients with IDH-mutated Glioma WHO grade 2 and 3.

Radiation Therapy for IDH-Mutant Grade 2 and Grade 3 Diffuse Glioma: An ASTRO Clinical Practice Guideline

PURPOSE

This guideline provides evidence-based recommendations for adults with isocitrate dehydrogenase (IDH)-mutant grade 2 and grade 3 diffuse glioma, as classified in the 2021 World Health Organization (WHO) Classification of Tumours. It includes indications for radiation therapy (RT), advanced RT techniques, and clinical management of adverse effects.

METHODS

The American Society for Radiation Oncology convened a multidisciplinary task force to address 4 key questions focused on the RT management of patients with IDH-mutant grade 2 and grade 3 diffuse glioma. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

A strong recommendation for close surveillance alone was made for patients with oligodendroglioma, IDH-mutant, 1p/19q codeleted, WHO grade 2 after gross total resection without high-risk features. For oligodendroglioma, WHO grade 2 with any high-risk features, adjuvant RT was conditionally recommended. However, adjuvant RT was strongly recommended for oligodendroglioma, WHO grade 3. A conditional recommendation for close surveillance alone was made for astrocytoma, IDH-mutant, WHO grade 2 after gross total resection without high-risk features. Adjuvant RT was conditionally recommended for astrocytoma, WHO grade 2, with any high-risk features and strongly recommended for astrocytoma, WHO grade 3. Dose recommendations varied based on histology and grade. Given known adverse long-term effects of RT, consideration for advanced techniques such as intensity modulated radiation therapy/volumetric modulated arc therapy or proton therapy were given as strong and conditional recommendations, respectively. Finally, based on expert opinion, the guideline recommends assessment, surveillance, and management for toxicity management.

CONCLUSIONS

Based on published data, the American Society for Radiation Oncology task force has proposed recommendations to inform the management of adults with IDH-mutant grade 2 and grade 3 diffuse glioma as defined by WHO 2021 classification, based on the highest quality published data, and best translated by our task force of subject matter experts.

Chromatin structure predicts survival in glioma patients

The pathological changes in epigenetics and gene regulation that accompany the progression of low-grade to high-grade gliomas are under-studied. The authors use a large set of paired atac-seq and RNA-seq data from surgically resected glioma specimens to infer gene regulatory relationships in glioma. Thirty-eight glioma patient samples underwent atac-seq sequencing and 16 samples underwent additional RNA-seq analysis. Using an atac-seq/RNA-seq correlation matrix, atac-seq peaks were paired with genes based on high correlation values (|r²| > 0.6). Samples clustered by IDH1 status but not by grade. Surprisingly there was a trend for IDH1 mutant samples to have more peaks. The majority of peaks are positively correlated with survival and positively correlated with gene expression. Constructing a model of the top six atac-seq peaks created a highly accurate survival prediction model (r² = 0.68). Four of these peaks were still significant after controlling for age, grade, pathology, IDH1 status and gender. Grade II, III, and IV (primary) samples have similar transcription factors and gene modules. However, grade IV (recurrent) samples have strikingly few peaks. Patient-derived glioma cultures showed decreased peak counts following radiation indicating that this may be radiation-induced. This study supports the notion that IDH1 mutant and IDH1 wildtype gliomas have different epigenetic landscapes and that accessible chromatin sites mapped by atac-seq peaks tend to be positively correlated with expression. The data in this study leads to a new model of treatment response wherein glioma cells respond to radiation therapy by closing open regions of DNA.

Tumor Microenvironment in Glioma Invasion

A major malignant trait of gliomas is their remarkable infiltration capacity. When glioma develops, the tumor cells have already reached the distant part. Therefore, complete removal of the glioma is impossible. Recently, research on the involvement of the tumor microenvironment in glioma invasion has advanced. Local hypoxia triggers cell migration as an environmental factor. The transcription factor hypoxia-inducible factor (HIF) -1α, produced in tumor cells under hypoxia, promotes the transcription of various invasion related molecules. The extracellular matrix surrounding tumors is degraded by proteases secreted by tumor cells and simultaneously replaced by an extracellular matrix that promotes infiltration. Astrocytes and microglia become tumor-associated astrocytes and glioma-associated macrophages/microglia, respectively, in relation to tumor cells. These cells also promote glioma invasion. Interactions between glioma cells actively promote infiltration of each other. Surgery, chemotherapy, and radiation therapy transform the microenvironment, allowing glioma cells to invade. These findings indicate that the tumor microenvironment may be a target for glioma invasion. On the other hand, because the living body actively promotes tumor infiltration in response to the tumor, it is necessary to reconsider whether the invasion itself is friend or foe to the brain.

OUP accepted manuscript

Background

Population-based analyses of patterns of care and survival of older patients diagnosed with grade II-III oligodendroglioma (OLI) or astrocytoma (AST) can aid clinicians in their understanding and care of these patients.

Methods

We identified patients diagnosed between 2006 and 2015 with primary glioma diagnoses (OLI or AST) who were older than 65 years using the latest release of the Surveillance, Epidemiology, and End Results-Medicare–linked database. Medicare claims were used to identify cancer treatments (surgery, chemotherapy, and radiation therapy) from 2006 to 2016. Kaplan-Meier methodology was used to describe overall survival (OS). Cox proportional hazards regression was used to associate variables of interest, including treatments in a time-dependent manner, with OS. Hazard ratios (HRs) and 95% confidence intervals (CIs) from multivariable, cause-specific competing risk models identified associations with treatments. All statistical tests were 2-sided.

Results

We identified 1291 patients comprising 158 with OLI, 1043 with AST, and 90 with mixed histologies. Median OS was 6.5 (95% CI = 6.1 to 7.3) months for the overall cohort, 22.6 (95% CI = 13.9 to 33.1) months for OLI, and 5.8 (95% CI = 5.3 to 6.4) months for AST. Patients who received surgery and patients who received both chemotherapy and radiation therapy in combination experienced better OS (HR = 0.87, 95% CI = 0.79 to 0.96, and HR = 0.58, 95% CI = 0.35 to 0.96, respectively). Over the time frame studied, there was a 4.0% increase per year in prescription of chemotherapy (P = .03) and a 2.0% improvement in OS for each calendar year (P = .003).

Conclusions

We provide population-based evidence that patients older than 65 years with grade II-III glioma have experienced increased chemotherapy use as well as improvement in survival over time.

Analysis of Prognostic Factors of Low-Grade Gliomas in Adults Using Time-Dependent Competing Risk Models: A Population Study Based on the Surveillance, Epidemiology, and End Results Database

BACKGROUND

Because of multiple competing death outcomes and time-varying coefficients, using a Cox regression model to analyze the prognostic factors of low-grade gliomas (LGG) may lead to a possible bias. Therefore, we adopted time-dependent competing risk models to obtain accurate prognostic factors for LGG.

METHODS

In this retrospective cohort study, data were extracted from patients enrolled in the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2018. Univariate analysis was performed using the cumulative incidence function (CIF) and Kaplan-Meier (KM) function. Time-dependent competing risk and Cox regression models were used in the multivariable analysis.

RESULTS

A total of 2581 patients were diagnosed with low-grade glioma, among whom 889 died from low-grade glioma, 114 died from other causes, and the rest were alive. The time-dependent competing risk models indicated that age, sex, marital status, primary tumor site, histological type, tumor diameter, surgery, and year of diagnosis were significantly associated with low-grade glioma-specific death, and the relative effect of age, tumor diameter, surgery, oligodendroglioma, and mixed glioma on low-grade glioma-specific death changed over time. Compared with the competing risk models, the Cox regression model misestimated the hazard ratio (HR) of covariates on the outcome and even produced false-negative results.

CONCLUSIONS

The time-dependent competing risk models were better than the Cox regression model for evaluating the impact of covariates on low-grade glioma-specific mortality in the presence of competing risks and time-varying coefficients. The models identified the prognostic factors of LGG more accurately than the Cox regression model.

Radiation induced contrast enhancement after proton beam therapy in patients with low grade glioma - How safe are protons?

PURPOSE

The optimal treatment strategy for low-grade glioma (LGG) is still a matter of controversy. Considering that the prognosis is typically favorable, the prevention of late sequelae is of particular importance. Proton beam therapy (PRT) has the potential to further reduce the burden of treatment related side effects. We set out to evaluate the clinical outcome of proton irradiation with a particular focus on morphologic features on magnetic resonance imaging (MRI).

METHODS

We assessed prospectively 110 patients who received radiotherapy with protons for histologically proven LGG. Clinical and radiological information were analyzed resulting in more than 1200 available MRI examinations with a median follow-up of 39 months. Newly diagnosed contrast-enhancing lesions on MRI were delineated and correlated with parameters of the corresponding treatment plan. A voxel-based dose-matched paired analysis of the linear energy transfer (LET) inside vs outside lesions was performed.

RESULTS

Proton beam irradiation of patients with low-grade glioma results in overall survival (OS) of 90% after seven years. Median progression free survival had not yet been reached with surviving fraction of 54% after seven years. The incidence of temporary or clinically silent radiation induced contrast enhancement was significantly higher than previously assumed, however, symptomatic radiation necrosis was only detected in one patient. These radiation-induced contrast-enhancing lesions were almost exclusively seen at the distal beam end of the proton beam. In 22 out of 23 patients, the average LET of voxels inside contrast-enhancing lesions was significantly increased, compared to dose-matched voxels outside the lesions.

CONCLUSION

Symptomatic radiation necrosis following PRT was as rare as conventional photon-based treatment series suggest. However, the increased incidence of asymptomatic radiation-induced brain injuries with an increased average LET observed in this cohort provides strong clinical evidence to support the hypothesis that the relative biological effectiveness of protons is variable and different to the fixed factor of 1.1 currently used worldwide.

Pediatric and Adult Low-Grade Gliomas: Where Do the Differences Lie?

Two thirds of pediatric gliomas are classified as low-grade (LGG), while in adults only around 20% of gliomas are low-grade. However, these tumors do not only differ in their incidence but also in their location, behavior and, subsequently, treatment. Pediatric LGG constitute 65% of pilocytic astrocytomas, while in adults the most commonly found histology is diffuse low-grade glioma (WHO II), which mostly occurs in eloquent regions of the brain, while its pediatric counterpart is frequently found in the infratentorial compartment. The different tumor locations require different skillsets from neurosurgeons. In adult LGG, a common practice is awake surgery, which is rarely performed on children. On the other hand, pediatric neurosurgeons are more commonly confronted with infratentorial tumors causing hydrocephalus, which more often require endoscopic or shunt procedures to restore the cerebrospinal fluid flow. In adult and pediatric LGG surgery, gross total excision is the primary treatment strategy. Only tumor recurrences or progression warrant adjuvant therapy with either chemo- or radiotherapy. In pediatric LGG, MEK inhibitors have shown promising initial results in treating recurrent LGG and several ongoing trials are investigating their role and safety. Moreover, predisposition syndromes, such as neurofibromatosis or tuberous sclerosis complex, can increase the risk of developing LGG in children, while in adults, usually no tumor growth in these syndromes is observed. In this review, we discuss and compare the differences between pediatric and adult LGG, emphasizing that pediatric LGG should not be approached and managed in the same way as adult LCG.

Association of high-dose radiotherapy with improved survival in patients with newly diagnosed low-grade gliomas

BACKGROUND

The radiation dose for patients with low-grade gliomas (LGGs) is controversial. The objective of this study was to investigate the impact of the radiation dose on survival for patients with LGGs and especially for molecularly defined subgroups.

METHODS

Three hundred fifty-one patients with newly diagnosed LGGs from the multicenter Chinese Glioma Cooperative Group received postoperative radiotherapy (RT) in 2005-2018. The RT dose, as a continuous variable, was entered into a Cox regression model using penalized spline regression to allow for a nonlinear relationship between the RT dose and overall survival (OS) or progression-free survival (PFS). Inverse probability of treatment weighting (IPTW)-adjusted propensity scores were used to correct for potential confounders. Dose effects on survival within IDH mutation and 1p/19q codeletion defined subgroups were analyzed.

RESULTS

The risk of mortality and disease progression decreased sharply until 54 Gy. High-dose RT (≥54 Gy) was associated with significantly better 5-year OS (81.7% vs 64.0%; hazard ratio [HR], 0.33; P < .001) and PFS (77.4% vs 54.5%; HR, 0.46; P < .001) than low-dose RT (<54 Gy). IPTW correction confirmed the associations (HR for OS, 0.44; P = .001; HR for PFS, 0.48; P = .003). High-dose RT was associated with longer PFS (HR, 0.25; P = .002; HR, 0.21; P = .039) and OS (HR, 0.27; P = .006; HR, 0.07; P = .017) in IDH-mutant/1p/19q noncodeleted and IDH wild-type subgroups, respectively. No significant difference in survival was observed with high-dose RT in the IDH-mutant/1p/19q codeleted subgroup.

CONCLUSIONS

High-dose RT (≥54 Gy) was effective in LGGs. Patients with an IDH mutation/1p/19q noncodeletion or IDH wild-type may need to be considered for high-dose RT.

LAY SUMMARY

The radiotherapy dose-response was observed in patients with low-grade gliomas, and high-dose radiotherapy (≥54 Gy) was associated with improved survival. Patients with an IDH mutation/1p/19q noncodeletion or wild-type IDH may have improved survival with the administration of high-dose radiotherapy.

IDH Inhibitors and Beyond: The Cornerstone of Targeted Glioma Treatment

Diffuse low-grade gliomas account for approximately 20% of all primary brain tumors, they arise from glial cells and show infiltrative growth without histological features of malignancy. Mutations of the IDH1 and IDH2 genes constitute a reliable molecular signature of low-grade gliomas and are the earliest driver mutations occurring during gliomagenesis, representing a relevant biomarker with diagnostic, prognostic, and predictive value. IDH mutations induce a neomorphic enzyme that converts α-ketoglutarate to the oncometabolite D-2-hydroxyglutarate, which leads to widespread effects on cellular epigenetics and metabolism. Currently, there are no approved molecularly targeted therapies and the standard treatment for low-grade gliomas consists of radiation therapy and chemotherapy, with rising concern about treatment-related toxicities. Targeting D-2-hydroxyglutarate is considered a novel attractive therapeutic approach for low-grade gliomas and the insights from clinical trials suggest that mutant-selective IDH inhibitors are the ideal candidates, with a favorable benefit/risk ratio. A pivotal question is whether blocking IDH neomorphic activity may activate alternative oncogenetic pathways, inducing acquired resistance to IDH inhibitors. Based on this rationale, combination therapies to enhance the antitumor activity of IDH inhibitors and approaches aimed at exploiting, rather than inhibiting, the metabolism of IDH-mutant cancer cells, such as poly (adenosine 5'-diphosphate-ribose) polymerase inhibitors, are emerging from preclinical research and clinical trials. In this review, we discuss the pivotal role of IDH mutations in gliomagenesis and the complex interactions between the genomic and epigenetic landscapes, providing an overview of how, in the last decade, therapeutic approaches for low-grade gliomas have evolved.

Effects of brain radiotherapy on cognitive performance in adult low-grade glioma patients: A systematic review

Grade II gliomas are slow growing tumours that usually affect younger patients. The mainstream treatment modality at present is surgical. The role of radiation therapy in the management of grade II gliomas has been the subject of considerable debate. Radiation therapy has a proven potential to prolong progression free and overall survival in high-risk patients, but may also produce long-term cognitive deficits. Since grade II glioma patients are expected to live several years, retention of cognitive capacity and quality of life is an equally important endpoint as prolonging progression free survival. Our overarching goal is to critically review the available evidence on the possible neuropsychological effects of postoperative radiotherapy in adult grade II glioma patients. We performed a systematic literature search in Medline, Embase and Cochrane databases up to 1st of May 2020 for studies assessing the cognitive effects of radiation therapy on grade II glioma patients. Eleven studies meeting our inclusion criteria provide either negative or contradictory data regarding the cognitive domains affected, while major confounding variables remain incompletely addressed. The available evidence does not adequately support the notion that current radiation therapy protocols independently produce substantial cognitive decline in grade II glioma patients and therefore it would be premature to argue that radiation associated cognitive morbidity outweighs the benefit of prolonged survival. A large prospective study incorporating a full battery of neuropsychological testing, sufficiently long-term follow-up period and tight control of confounders is due to provide high quality data.

An Iatrogenic Model of Brain Small-Vessel Disease: Post-Radiation Encephalopathy

We studied 114 primitive cerebral neoplasia, that were surgically treated, and underwent radiotherapy (RT), and compared their results to those obtained by 190 patients diagnosed with subcortical vascular dementia (sVAD). Patients with any form of primitive cerebral neoplasia underwent whole-brain radiotherapy. All the tumor patients had regional field partial brain RT, which encompassed each tumor, with an average margin of 2.6 cm from the initial target tumor volume. We observed in our patients who have been exposed to a higher dose of RT (30–65 Gy) a cognitive and behavior decline similar to that observed in sVAD, with the frontal dysexecutive syndrome, apathy, and gait alterations, but with a more rapid onset and with an overwhelming effect. Multiple mechanisms are likely to be involved in radiation-induced cognitive impairment. The active site of RT brain damage is the white matter areas, particularly the internal capsule, basal ganglia, caudate, hippocampus, and subventricular zone. In all cases, radiation damage inside the brain mainly focuses on the cortical–subcortical frontal loops, which integrate and process the flow of information from the cortical areas, where executive functions are “elaborated” and prepared, towards the thalamus, subthalamus, and cerebellum, where they are continuously refined and executed. The active mechanisms that RT drives are similar to those observed in cerebral small vessel disease (SVD), leading to sVAD. The RT’s primary targets, outside the tumor mass, are the blood–brain barrier (BBB), the small vessels, and putative mechanisms that can be taken into account are oxidative stress and neuro-inflammation, strongly associated with the alteration of NMDA receptor subunit composition.

Lower Grade Gliomas

PURPOSE OF REVIEW

Low-grade gliomas (LGG) are a group of primary brain tumors that arise from supporting glial cells. They are characterized by a mutation in the isocitrate dehydrogenase (IDH) enzyme and include astrocytomas and oligodendrogliomas. They usually affect young adults, and their main treatment consists of surgical resection, followed by radiation and chemotherapy in selected patients. This article reviews recent research on the clinical and molecular aspects of the disease and innovative therapeutic modalities in the process.

RECENT FINDINGS

Newly identified clinical and molecular features are currently used in the classification of LGG and applied in treatment-planning decisions. Advanced studies on the cellular level have an advanced understanding of the metabolic effects induced by IDH mutations, offering opportunities for specific targeted therapies that may improve patient outcomes. Such findings may lead to a paradigm shift in the treatment of these tumors. Although LGG are sensitive to radiation and chemotherapy, these therapies are not curative, and patient survival remains limited, raising the need for more creative and effective interventions.

The biological and clinical basis for early referral of low grade glioma patients to a surgical neuro-oncologist

The discovery of IDH1/2 (isocitrate dehydrogenase) mutation in large scale, genomewide mutational analyses of gliomas has led to profound developments in understanding tumourigenesis, and restructuring of the classification of both high and low grade gliomas. Owing to this progress made in the recognition of molecular markers which predict tumour behavior and treatment response, the increasing importance of adjuvant treatments such as chemo- and radiotherapy, and the tremendous advances in surgical technique and intraoperative monitoring which have facilitated superior extents of resection whilst preserving neurological functioning and quality of life, contemporary management of low grade glioma (LGG) has switched from a passive, observant approach to a more active, interventional one. Furthermore, this has implications for the manner in which patients with incidentally discovered and/or asymptomatic LGG are managed, and this review of the biological behaviour of LGG, as well as its clinical investigation and management, should act as a timely reminder to all clinicians of the importance of referring LGG patients early to a surgical neuro-oncologist who is not only familiar and acquainted with the vagaries of this disease process, but who, in addition, is devoted to delivering care to these patients with the support of a multi-disciplinary clinical decision-making unit, comprising medical neuro-oncologists, radiation oncologists and allied health professionals.

Phase 2 Study of a Temozolomide-Based Chemoradiation Therapy Regimen for High-Risk, Low-Grade Gliomas: Long-Term Results of Radiation Therapy Oncology Group 0424

PURPOSE

To report the long-term outcomes of the RTOG 0424 study of a high-risk, low-grade glioma population treated with concurrent and adjuvant temozolomide (TMZ) and radiation therapy (RT).

METHODS AND MATERIALS

For this single-arm, phase 2 study, patients with low-grade gliomas with ≥3 risk factors (age ≥40 years, astrocytoma, bihemispheric tumor, size ≥6 cm, or preoperative neurologic function status >1) received RT (54 Gy in 30 fractions) with TMZ and up to 12 cycles of post-RT TMZ. The initial primary endpoint P was overall survival (OS) at 3 years after registration. Secondary endpoints included progression-free survival (PFS) and the association of survival outcomes with methylation status. The initial 3-year report of this study was published in 2015.

RESULTS

The study accrued 136 patients, of whom 129 were analyzable. The median follow-up for surviving patients was 9.0 years. The 3-year OS was 73.5% (95% confidence interval, 65.8%-81.1%), numerically superior to the 3-year OS historical control of 54% (P < .001). The median survival time was 8.2 years (95% confidence interval, 5.6-9.1). Five- and 10-year OS rates were 60.9% and 34.6%, respectively, and 5- and 10-year PFS rates were 46.8% and 25.5%, respectively.

CONCLUSIONS

The long-term results confirmed the findings from the initial report for efficacy, suggesting OS and PFS outcomes with the RT-TMZ regimen exceeded historical control groups treated with radiation alone. Toxicity was acceptable.

IDH1-R132H acts as a tumor suppressor in glioma via epigenetic up-regulation of the DNA damage response

Patients with glioma whose tumors carry a mutation in isocitrate dehydrogenase 1 (IDH1^R132H) are younger at diagnosis and live longer. IDH1 mutations co-occur with other molecular lesions, such as 1p/19q codeletion, inactivating mutations in the tumor suppressor protein 53 (TP53) gene, and loss-of-function mutations in alpha thalassemia/mental retardation syndrome X-linked gene (ATRX). All adult low-grade gliomas (LGGs) harboring ATRX loss also express the IDH1^R132H mutation. The current molecular classification of LGGs is based, partly, on the distribution of these mutations. We developed a genetically engineered mouse model harboring IDH1^R132H, TP53 and ATRX inactivating mutations, and activated NRAS G12V. Previously, we established that ATRX deficiency, in the context of wild-type IDH1, induces genomic instability, impairs nonhomologous end-joining DNA repair, and increases sensitivity to DNA-damaging therapies. In this study, using our mouse model and primary patient-derived glioma cultures with IDH1 mutations, we investigated the function of IDH1^R132H in the context of TP53 and ATRX loss. We discovered that IDH1^R132H expression in the genetic context of ATRX and TP53 gene inactivation (i) increases median survival in the absence of treatment, (ii) enhances DNA damage response (DDR) via epigenetic up-regulation of the ataxia-telangiectasia-mutated (ATM) signaling pathway, and (iii) elicits tumor radioresistance. Accordingly, pharmacological inhibition of ATM or checkpoint kinases 1 and 2, essential kinases in the DDR, restored the tumors' radiosensitivity. Translation of these findings to patients with IDH1^132H glioma harboring TP53 and ATRX loss could improve the therapeutic efficacy of radiotherapy and, consequently, patient survival.

Early versus delayed postoperative radiotherapy for treatment of low-grade gliomas

BACKGROUND

This is an update of the review originally published in 2011 and first updated in 2015. In most people with low-grade gliomas (LGG), the primary treatment regimen remains a combination of surgery followed by postoperative radiotherapy. However, the optimal timing of radiotherapy is controversial. It is unclear whether to use radiotherapy in the early postoperative period, or whether radiotherapy should be delayed until tumour progression occurs.

OBJECTIVES

To assess the effects of early postoperative radiotherapy versus radiotherapy delayed until tumour progression for low-grade intracranial gliomas in people who had initial biopsy or surgical resection.

SEARCH METHODS

Original searches were run up to September 2014. An updated literature search from September 2014 through November 2019 was performed on the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 11), MEDLINE via Ovid (September 2014 to November week 2 2019), and Embase via Ovid (September 2014 to 2019 week 46) to identify trials for inclusion in this Cochrane review update.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared early versus delayed radiotherapy following biopsy or surgical resection for the treatment of people with newly diagnosed intracranial LGG (astrocytoma, oligodendroglioma, mixed oligoastrocytoma, astroblastoma, xanthoastrocytoma, or ganglioglioma). Radiotherapy may include conformal external beam radiotherapy (EBRT) with linear accelerator or cobalt-60 sources, intensity-modulated radiotherapy (IMRT), or stereotactic radiosurgery (SRS).

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed the trials for inclusion and risk of bias, and extracted study data. We resolved any differences between review authors by discussion. Adverse effects were also extracted from the study report. We performed meta-analyses using a random-effects model with inverse variance weighting.

MAIN RESULTS

We included one large, multi-institutional, prospective RCT, involving 311 participants; the risk of bias in this study was unclear. This study found that early postoperative radiotherapy was associated with an increase in time to progression compared to observation (and delayed radiotherapy upon disease progression) for people with LGG but did not significantly improve overall survival (OS). The median progression-free survival (PFS) was 5.3 years in the early radiotherapy group and 3.4 years in the delayed radiotherapy group (hazard ratio (HR) 0.59, 95% confidence interval (CI) 0.45 to 0.77; P < 0.0001; 311 participants; 1 trial; low-quality evidence). The median OS in the early radiotherapy group was 7.4 years, while the delayed radiotherapy group experienced a median overall survival of 7.2 years (HR 0.97, 95% CI 0.71 to 1.33; P = 0.872; 311 participants; 1 trial; low-quality evidence). The total dose of radiotherapy given was 54 Gy; five fractions of 1.8 Gy per week were given for six weeks. Adverse effects following radiotherapy consisted of skin reactions, otitis media, mild headache, nausea, and vomiting. Rescue therapy was provided to 65% of the participants randomised to delayed radiotherapy. People in both cohorts who were free from tumour progression showed no differences in cognitive deficit, focal deficit, performance status, and headache after one year. However, participants randomised to the early radiotherapy group experienced significantly fewer seizures than participants in the delayed postoperative radiotherapy group at one year (25% versus 41%, P = 0.0329, respectively).

AUTHORS' CONCLUSIONS

Given the high risk of bias in the included study, the results of this analysis must be interpreted with caution. Early radiation therapy was associated with the following adverse effects: skin reactions, otitis media, mild headache, nausea, and vomiting. People with LGG who underwent early radiotherapy showed an increase in time to progression compared with people who were observed and had radiotherapy at the time of progression. There was no significant difference in overall survival between people who had early versus delayed radiotherapy; however, this finding may be due to the effectiveness of rescue therapy with radiation in the control arm. People who underwent early radiation had better seizure control at one year than people who underwent delayed radiation. There were no cases of radiation-induced malignant transformation of LGG. However, it remained unclear whether there were differences in memory, executive function, cognitive function, or quality of life between the two groups since these measures were not evaluated.

Prognostic Factors and Nomogram Predicting Survival in Diffuse Astrocytoma

Background Prognosis of low-grade glioma are currently determined by genetic markers that are limited in some countries. This study aimed to use clinical parameters to develop a nomogram to predict survival of patients with diffuse astrocytoma (DA) which is the most common type of low-grade glioma. Materials and Methods Retrospective data of adult patients with DA from three university hospitals in Thailand were analyzed. Collected data included clinical characteristics, neuroimaging findings, treatment, and outcomes. Cox's regression analyses were performed to determine associated factors. Significant associated factors from the Cox regression model were subsequently used to develop a nomogram for survival prediction. Performance of the nomogram was then tested for its accuracy. Results There were 64 patients with DA with a median age of 39.5 (interquartile range [IQR] = 20.2) years. Mean follow-up time of patients was 42 months (standard deviation [SD] = 34.3). After adjusted for three significant factors associated with survival were age ≥60 years (hazard ratio [HR] = 5.8; 95% confidence interval [CI]: 2.09-15.91), motor response score of Glasgow coma scale < 6 (HR = 75.5; 95% CI: 4.15-1,369.4), and biopsy (HR = 0.45; 95% CI: 0.21-0.92). To predict 1-year mortality, sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the curve our nomogram was 1.0, 0.50, 0.45, 1.0, 0.64, and 0.75, respectively. Conclusions This study provided a nomogram predicting prognosis of DA. The nomogram showed an acceptable performance for predicting 1-year mortality.

Survival and Prognosis of Patients with Pilocytic Astrocytoma: A Single-Center Study

Background

Pilocytic astrocytoma (PA) is a brain tumor that is relatively more common in children and young adults.

Methods

We retrospectively reviewed the medical records of patients with PA treated at a single center between 1988 and 2018.

Results

We included 31 subjects with PA. The median age at diagnosis was 13.4 years, and the median follow-up duration was 9.9 years. The total PA group had a 10-year disease-specific survival (DSS) rate of 92.6% [95% confidence interval (CI), 82.6–100] and 10-year progression-free survival (PFS) rate of 52.8% (95% CI, 32.0–73.6). In patients aged <20 years, tumors were more likely to be located in sites in which gross total tumor resection (GTR) was impossible. No statistically significant difference in 10-year DSS was found between the GTR (100%) and non-GTR (89.7%; 95% CI, 76.2–100; p=0.374) groups. However, a statistically significant difference in 10-year PFS was found between the GTR (100%) and non-GTR groups (30.7%; 95% CI, 8.6–52.8; p=0.012). In the non-GTR group, no statistically significant difference in 10-year DSS was found between the patients who received immediate additional chemotherapy and/or radiotherapy (Add-Tx group, 92.9%; 95% CI, 79.4–100) and the non-Add-Tx group (83.3%; 95% CI, 53.5–100; p=0.577). No statistically significant difference in 10-year PFS was found between the Add-Tx group (28.9%; 95% CI, 1.7–56.1) and non-Add-Tx group (33.3%; 95% CI, 0–70.9; p=0.706).

Conclusion

The PFS of the patients with PA in our study depended only on the degree of surgical excision associated with tumor location. This study is limited by its small number of patients and retrospective nature. A multicenter and prospective study is necessary to confirm these findings.

Long-term neurocognitive and other side effects of radiotherapy, with or without chemotherapy, for glioma

BACKGROUND

Gliomas are brain tumours arising from glial cells with an annual incidence of 4 to 11 people per 100,000. In this review we focus on gliomas with low aggressive potential in the short term, i.e. low-grade gliomas. Most people with low-grade gliomas are treated with surgery and may receive radiotherapy thereafter. However, there is concern about the possible long-term effects of radiotherapy, especially on neurocognitive functioning.

OBJECTIVES

To evaluate the long-term neurocognitive and other side effects of radiotherapy (with or without chemotherapy) compared with no radiotherapy, or different types of radiotherapy, among people with glioma (where 'long-term' is defined as at least two years after diagnosis); and to write a brief economic commentary.

SEARCH METHODS

We searched the following databases on 16 February 2018 and updated the search on 14 November 2018: Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 11) in the Cochrane Library; MEDLINE via Ovid; and Embase via Ovid. We also searched clinical trial registries and relevant conference proceedings from 2014 to 2018 to identify ongoing and unpublished studies.

SELECTION CRITERIA

Randomised and non-randomised trials, and controlled before-and-after studies (CBAS). Participants were aged 16 years and older with cerebral glioma other than glioblastoma. We included studies where patients in at least one treatment arm received radiotherapy, with or without chemotherapy, and where neurocognitive outcomes were assessed two or more years after treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias. We assessed the certainty of findings using the GRADE approach.

MAIN RESULTS

The review includes nine studies: seven studies were of low-grade glioma and two were of grade 3 glioma. Altogether 2406 participants were involved but there was high sample attrition and outcome data were available for a minority of people at final study assessments. In seven of the nine studies, participants were recruited to randomised controlled trials (RCTs) in which longer-term follow-up was undertaken in a subset of people that had survived without disease progression. There was moderate to high risk of bias in studies due to lack of blinding and high attrition, and in two observational studies there was high risk of selection bias. Paucity of data and risk of bias meant that evidence was of low to very low certainty. We were unable to combine results in meta-analysis due to diversity in interventions and outcomes.The studies examined the following five comparisons.Radiotherapy versus no adjuvant treatmentTwo observational studies contributed data. At the 12-year follow-up in one study, the risk of cognitive impairment (defined as cognitive disability deficits in at least five of 18 neuropsychological tests) was greater in the radiotherapy group (risk ratio (RR) 1.95, 95% confidence interval (CI) 1.02 to 3.71; n = 65); at five to six years the difference between groups did not reach statistical significance (RR 1.38, 95% CI 0.92 to 2.06; n = 195). In the other study, one subject in the radiotherapy group had cognitive impairment (defined as significant deterioration in eight of 12 neuropsychological tests) at two years compared with none in the control group (very low certainty evidence).With regard to neurocognitive scores, in one study the radiotherapy group was reported to have had significantly worse mean scores on some tests compared with no radiotherapy; however, the raw data were only given for significant findings. In the second study, there were no clear differences in any of the various cognitive outcomes at two years (n = 31) and four years (n = 15) (very low certainty evidence).Radiotherapy versus chemotherapyOne RCT contributed data on cognitive impairment at up to three years with no clear difference between arms (RR 1.43, 95% CI 0.36 to 5.70, n = 117) (low-certainty evidence).High-dose radiotherapy versus low-dose radiotherapyOnly one of two studies reporting this comparison contributed data, and at two and five years there were no clear differences between high- and low-dose radiotherapy arms (very low certainty evidence).Conventional radiotherapy versus stereotactic conformal radiotherapyOne study involving younger people contributed limited data from the subgroup aged 16 to 25 years. The numbers of participants with neurocognitive impairment at five years after treatment were two out of 12 in the conventional arm versus none out of 11 in the stereotactic conformal radiotherapy arm (RR 4.62, 95% CI 0.25 to 86.72; n = 23; low-certainty evidence).Chemoradiotherapy versus radiotherapyTwo RCTs tested for cognitive impairment. One defined cognitive impairment as a decline of more than 3 points in MMSE score compared with baseline and reported data from 2-year (110 participants), 3-year (91 participants), and 5-year (57 participants) follow-up with no clear difference between the two arms at any time point. A second study did not report raw data but measured MMSE scores over five years in 126 participants at two years, 110 at three years, 69 at four years and 53 at five years. Authors concluded that there was no difference in MMSE scores between the two study arms (P = 0.4752) (low-certainty evidence).Two RCTs reported quality of life (QoL) outcomes for this comparison. One reported no differences in Brain-QoL scores between study arms over a 5-year follow-up period (P = 0.2767; no raw data were given and denominators were not stated). The other trial reported that the long-term results of health-related QoL showed no difference between the arms but did not give the raw data for overall HRQoL scores (low-certainty evidence).We found no comparative data on endocrine dysfunction; we planned to develop a brief economic commentary but found no relevant economic studies for inclusion.

AUTHORS' CONCLUSIONS

Radiotherapy for gliomas with a good prognosis may increase the risk of neurocognitive side effects in the long term; however the magnitude of the risk is uncertain. Evidence on long-term neurocognitive side effects associated with chemoradiotherapy is also uncertain. Neurocognitive assessment should be an integral part of long-term follow-up in trials involving radiotherapy for lower-grade gliomas to improve the certainty of evidence regarding long-term neurocognitive effects. Such trials should also assess other potential long-term effects, including endocrine dysfunction, and evaluate costs and cost effectiveness.

Contrast-enhancement in supratentorial low-grade gliomas: a classic prognostic factor in the molecular age

BACKGROUND

Contrast enhancement (CE) is found in 10-60% of low-grade gliomas. Its prognostic significance is controversial, and its correlation with IDH mutations and 1p/19q codeletion is elusive. The aim of this study is to investigate whether CE is associated with molecular characteristics of low-grade gliomas and uncover its prognostic value.

MATERIALS AND METHODS

All confirmed histological cases of low-grade gliomas diagnosed at our institution between years 2000-2016 were reviewed (n = 102). Spinal and brainstem localization, only-biopsied tumours with ring-like enhancement and incomplete medical records were excluded.

RESULTS

Mean age was 42 years ( ± 13.9 years), and 63.6% were male. The median follow-up time was 79.8 months. CE was present on 25% of preoperative MRI, and 25% of patients were considered high-risk according to Pignatti score. Most were astrocytomas (67%) and 87.2% were surgically removed. IDH mutation was found in 64.6% of tumour samples, and 18.8% had a 1p/19q codeletion. No subgroup differences were observed according to CE except for presurgical performance status and postoperative chemotherapy. IDH status and 1p/19q codeletion were evenly distributed. On univariate analysis, age, size > 6 cm, CE, extent of resection, Pignatti score, IDH mutation and 1p/19q codeletion were significantly associated to OS. On multivariate analysis, only CE and IDH status were independently associated to OS. CE remained a significant prognostic factor in IDH-mutant non-codeleted tumours when analysed by tumour subtype.

CONCLUSION

CE in low-grade gliomas provides prognostic information in IDH-mutant non-codeleted tumours, although its meaning remains uncertain in IDH-wildtype gliomas.

Therapeutic Interventions in Adult Low-Grade Gliomas

Treating adult low-grade gliomas (LGGs) is particularly challenging due to the highly infiltrative nature of this type of brain cancer. Although surgery, radiotherapy, and chemotherapy are the mainstay treatment modalities for LGGs, the optimal combination management plan for a particular patient based on individual symptoms and the risk of treatment-induced toxicity remains unclear. This review highlights the competency and limitations of standard treatment options while providing an essential therapeutic update regarding current clinical trials aimed at implementing targeted therapies with morbidity rates lower than those for current LGG treatments and also augmenting the killing of cancerous cells while maintaining an improved quality of life.

The Risk Assessment in Low-Grade Gliomas: An Analysis of the European Organization for Research and Treatment of Cancer (EORTC) and the Radiation Therapy Oncology Group (RTOG) criteria

Diffuse low-grade gliomas (LGG) are rare tumors that affect young adult patients. The European Organization for Research and Treatment of Cancer (EORTC) and the Radiation Therapy Oncology Group (RTOG) have both developed their own clinical prognostic scores to assist clinicians in treatment decision-making. These criteria have been used to include patients in phase III studies. To date, it is unknown which is the best score to define the prognosis of LGG. Additionally, a pure clinical classification is probably not a sufficiently informative basis for choosing the proper treatment in different situations. A combined score with both clinical and molecular features will likely be indispensable.

The role of clinical and molecular factors in low-grade gliomas: what is their impact on survival?

AIM

To evaluate relevance of clinical and molecular factors in adult low-grade gliomas (LGG) and to correlate with survival.

METHODS

We reviewed records from adult LGG patients from 1991 to 2015 who received surgery and had sufficient tissue to molecular biomarkers characterization.

RESULTS

213 consecutive LGG patients were included: 17.4% were low-risk, according to Radiation Therapy Oncology Group (RTOG) risk assessment. IDH 1/2 mutation, 1p/19q co-deletion, MGMT methylation were found in 93, 50.8 and 65.3% of patients. Median follow-up was 98.3 months. In univariate analysis, overall survival was influenced by extent of resection (p = 0.011), IDH mutation (p < 0.001), 1p/19q co-deletion (p = 0.015) and MGMT methylation (p = 0.013). In multivariate analysis, RTOG clinical risk (p = 0.006), IDH mutation (p < 0.001) and 1p/19q co-deletion (p = 0.035) correlated with overall survival. RTOG clinical risk (p = 0.006), IDH mutation (p < 0.001) and 1p/19q co-deletion (p = 0.035) correlated with overall survival.

CONCLUSION

Both clinical and molecular factors are essential to determine prognosis and treatment strategies.

Supratentorial Extraventricular Ependymoma: Retrospective Analysis of 15 Patients at a Single Institution

BACKGROUND

Supratentorial extraventricular ependymoma (STEE) is an extremely rare central nervous system (CNS) neoplasm, the clinical characteristics and optimal treatment of which remain unclear. We retrospectively analyzed the clinical characteristics and treatment outcomes of 15 patients with STEE.

METHODS

Fifteen patients with STEE were identified, and their clinical, radiologic, and surgical records were reviewed.

RESULTS

The 15 patients included 6 males (40%) and 9 females (60%), with a median age of 15 years. Nine patients (60%) underwent gross total resection, 5 patients (33.3%) underwent subtotal resection, and 1 patient (6.7%) underwent biopsy. Eight patients received adjuvant radiotherapy, and 3 received adjuvant chemotherapy. The 5-year overall survival (OS) rates of patients with World Health Organization (WHO) grade II and grade III STEE were 100% and 30%, respectively, and the corresponding 2-year progression-free survival (PFS) rates were 77.8% and 20%. The differences in OS and PFS rates between WHO grades II and III STEE were statistically significant (P < 0.01 and 0.02, respectively). Anaplastic histology (WHO grade III) was a poor prognostic factor for PFS (P = 0.04). The recurrence pattern was local recurrence in all patients; all cases were treated primarily by redo surgery. Three patients with recurrent WHO grade II STEE were alive at more than 64, 52, and 44 months after redo surgery.

CONCLUSIONS

STEE is an extremely rare CNS neoplasm. The histological grade of STEE is an important prognostic factor. Microsurgical resection might play a major role in both initial treatment and treatment of recurrent tumors.

Methods for the evaluation of biomarkers in patients with kidney and liver diseases: multicentre research programme including ELUCIDATE RCT

Background

Protein biomarkers with associations with the activity and outcomes of diseases are being identified by modern proteomic technologies. They may be simple, accessible, cheap and safe tests that can inform diagnosis, prognosis, treatment selection, monitoring of disease activity and therapy and may substitute for complex, invasive and expensive tests. However, their potential is not yet being realised.

Design and methods

The study consisted of three workstreams to create a framework for research: workstream 1, methodology – to define current practice and explore methodology innovations for biomarkers for monitoring disease; workstream 2, clinical translation – to create a framework of research practice, high-quality samples and related clinical data to evaluate the validity and clinical utility of protein biomarkers; and workstream 3, the ELF to Uncover Cirrhosis as an Indication for Diagnosis and Action for Treatable Event (ELUCIDATE) randomised controlled trial (RCT) – an exemplar RCT of an established test, the ADVIA Centaur® Enhanced Liver Fibrosis (ELF) test (Siemens Healthcare Diagnostics Ltd, Camberley, UK) [consisting of a panel of three markers – (1) serum hyaluronic acid, (2) amino-terminal propeptide of type III procollagen and (3) tissue inhibitor of metalloproteinase 1], for liver cirrhosis to determine its impact on diagnostic timing and the management of cirrhosis and the process of care and improving outcomes.

Results

The methodology workstream evaluated the quality of recommendations for using prostate-specific antigen to monitor patients, systematically reviewed RCTs of monitoring strategies and reviewed the monitoring biomarker literature and how monitoring can have an impact on outcomes. Simulation studies were conducted to evaluate monitoring and improve the merits of health care. The monitoring biomarker literature is modest and robust conclusions are infrequent. We recommend improvements in research practice. Patients strongly endorsed the need for robust and conclusive research in this area. The clinical translation workstream focused on analytical and clinical validity. Cohorts were established for renal cell carcinoma (RCC) and renal transplantation (RT), with samples and patient data from multiple centres, as a rapid-access resource to evaluate the validity of biomarkers. Candidate biomarkers for RCC and RT were identified from the literature and their quality was evaluated and selected biomarkers were prioritised. The duration of follow-up was a limitation but biomarkers were identified that may be taken forward for clinical utility. In the third workstream, the ELUCIDATE trial registered 1303 patients and randomised 878 patients out of a target of 1000. The trial started late and recruited slowly initially but ultimately recruited with good statistical power to answer the key questions. ELF monitoring altered the patient process of care and may show benefits from the early introduction of interventions with further follow-up. The ELUCIDATE trial was an ‘exemplar’ trial that has demonstrated the challenges of evaluating biomarker strategies in ‘end-to-end’ RCTs and will inform future study designs.

Conclusions

The limitations in the programme were principally that, during the collection and curation of the cohorts of patients with RCC and RT, the pace of discovery of new biomarkers in commercial and non-commercial research was slower than anticipated and so conclusive evaluations using the cohorts are few; however, access to the cohorts will be sustained for future new biomarkers. The ELUCIDATE trial was slow to start and recruit to, with a late surge of recruitment, and so final conclusions about the impact of the ELF test on long-term outcomes await further follow-up. The findings from the three workstreams were used to synthesise a strategy and framework for future biomarker evaluations incorporating innovations in study design, health economics and health informatics.

Trial registration

Current Controlled Trials ISRCTN74815110, UKCRN ID 9954 and UKCRN ID 11930.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 3. See the NIHR Journals Library website for further project information.

Challenges in the management of childhood low-grade glioma in a developing country

BACKGROUND

Treatment modality impacts outcome of childhood low-grade glioma (LGG). Optimizing management in developing countries can be challenging. This study evaluates the clinical characteristics, treatment, and factors influencing outcome of childhood LGG in Saudi Arabia.

PATIENTS AND METHODS

This study retrospectively evaluated 59 children consecutively diagnosed with LGG between January 2001 and June 2016.

RESULTS

Median age at diagnosis was 6.0 years. Pilocytic astrocytoma represented 64.9% of cases. The anatomic site was cerebellar in 23.7%, cerebral in 18.6%, hypothalamic-optic pathway in 33.9%, and midline in 23.7%. The 5-year overall survival (OS) and progression-free survival (PFS) were 90.6 ± 4.7 and 54.3 ± 8.4%, respectively. Initial treatment was observation in 28.8%, surgery alone in 35.6%, chemotherapy in 13.6%, radiotherapy in 5.1%, and combined in 16.9% of cases. The corresponding 5-year PFS was 56.3 ± 15.6, 53.3 ± 14.0, 22.9 ± 19.7, 33.3 ± 27.2, and 88.9 ± 10.5%, respectively (p = 0.006). Among the 61% who had surgical intervention (either alone or in combination with other therapies), 22% achieved complete resection with 5-year radiation/progression-free survival (RPFS) of 87.5 ± 11.7% compared to 27.6 ± 10.8% for subtotal resection/biopsy and 62.2 ± 17.0% for no surgery (p = 0.013). Adjuvant therapy for residual tumor improved survival with 5-year PFS of 66.7 ± 19.2% for chemotherapy and 100% for radiotherapy compared to 12.5 ± 11.4% for observation (p = 0.033).

CONCLUSIONS

We identified variability in the outcomes of LGG. Fewer surgeries with lower rates of total resection were noted, compared to reports from international cooperative groups. The extent of resection was predictive of RPFS. Adjuvant therapy improved the outcome of patients with residual disease, resulting in PFS rates comparable to international data.

Risk Factors for Malignant Transformation of Low-Grade Glioma

PURPOSE

The incidence, risk factors, and outcomes of low-grade glioma patients who undergo malignant transformation (MT) in the era of temozolomide are not well known. This study evaluates these factors in a large group of World Health Organization grade 2 glioma patients treated at a tertiary-care institution.

METHODS AND MATERIALS

Patient, tumor, and treatment factors were analyzed using an institutional review board-approved low-grade glioma database. Characteristics were compared using χ² and Wilcoxon signed rank tests. Time to event was summarized using proportional hazards models. Univariate and multivariate survival analyses were performed.

RESULTS

Of a total of 599 patients, 124 underwent MT; 76 (61.3%) had biopsy-proven MT. The MT incidence was 21%, and the median time to MT was 56.4 months. The 5- and 10-year progression-free survival rates were 30.6% ± 4.2% and 4.8% ± 1.9%, respectively, for MT patients and 60% ± 2.4% and 38% ± 2.7%, respectively, for non-MT patients. The 5- and 10-year overall survival rates were 75% ± 4.0% and 46% ± 5.0%, respectively, for MT patients and 87% ± 1.7% and 78% ± 2.3%, respectively, for non-MT patients. On multivariate analysis, older age (P = .001), male sex (P = .004), multiple tumor locations (P = .004), chemotherapy alone (P = .012), and extent of resection (P = .045) remained significant predictors of MT.

CONCLUSIONS

MT affects survival. Risk factors include older age, male sex, multiple tumor locations, use of chemotherapy alone, and presence of residual disease. Our finding that initial interventions could affect the rate of MT is provocative, but these data should be validated using data from prospective trials. In addition to improving survival, future therapeutic efforts should focus on preventing MT.

SEOM clinical guideline of diagnosis and management of low-grade glioma (2017)

Diffuse infiltrating low-grade gliomas include oligodendrogliomas and astrocytomas, and account for about 5% of all primary brain tumors. Treatment strategies for these low-grade gliomas in adults have recently changed. The 2016 World Health Organization (WHO) classification has updated the definition of these tumors to include their molecular characterization, including the presence of isocitrate dehydrogenase (IDH) mutation and 1p/19p codeletion. In this new classification, the histologic subtype of grade II-mixed oligoastrocytoma has also been eliminated. The precise optimal management of patients with low-grade glioma after resection remains to be determined. The risk–benefit ratio of adjuvant treatment must be weighed for each individual.

A mathematical model describes the malignant transformation of low grade gliomas: Prognostic implications

Gliomas are the most frequent type of primary brain tumours. Low grade gliomas (LGGs, WHO grade II gliomas) may grow very slowly for the long periods of time, however they inevitably cause death due to the phenomenon known as the malignant transformation. This refers to the transition of LGGs to more aggressive forms of high grade gliomas (HGGs, WHO grade III and IV gliomas). In this paper we propose a mathematical model describing the spatio-temporal transition of LGGs into HGGs. Our modelling approach is based on two cellular populations with transitions between them being driven by the tumour microenvironment transformation occurring when the tumour cell density grows beyond a critical level. We show that the proposed model describes real patient data well. We discuss the relationship between patient prognosis and model parameters. We approximate tumour radius and velocity before malignant transformation as well as estimate the onset of this process.

Identifying clinical risk in low grade gliomas and appropriate treatment strategies, with special emphasis on the role of surgery

INTRODUCTION

Diffuse low-grade glioma (DLGG) is a chronic tumoral disease that ineluctably grows, migrates along white matter pathways, and progresses to a higher grade of malignancy. Areas covered: To determine the best individualized treatment attitude for each DLGG patient, and to redefine it over the years, i.e. to optimize the 'onco-functional balance' of serial and multimodal therapies, the understanding of the natural history of this chronic disease is crucial but not sufficient. A paradigmatic shift is to tailor the individual management according to the dynamic relationships between DLGG course and neural remodeling. In this spirit, a better knowledge of brain plasticity in a connectomal account of cerebral processing has enabled a dramatic improvement of both oncological and functional outcomes in DLGG patients, by increasing overall survival while preserving (or even improving) the quality of life. Expert commentary: Here, we propose an individualized and recursive therapeutic strategy in DLGG, leading to the concept of a 'personalized functional neuro-oncology', by emphasizing the role of early and maximal safe surgical resection(s) reliably achieved using intraoperative mapping of cortico-subcortical networks in awake patients.

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.

Treatment of Adult Lower-Grade Glioma in the Era of Genomic Medicine

By convention, gliomas are histopathologically classified into four grades by the World Health Organization (WHO) legacy criteria, in which increasing grade is associated with worse prognosis and grades also are subtyped by presumed cell of origin. This classification has prognostic value but is limited by wide variability of outcome within each grade, so the classification is rapidly undergoing dramatic re-evaluation in the context of a superior understanding of the biologic heterogeneity and molecular make-up of these tumors, such that we now recognize that some low-grade gliomas behave almost like malignant glioblastoma, whereas other anaplastic gliomas have outcomes comparable to favorable low-grade gliomas. This clinical spectrum is partly accounted for by the dispersion of several molecular genetic alterations inherent to clinical tumor behavior. These molecular biomarkers have become important not only as prognostic factors but also, more critically, as predictive markers to drive therapeutic decision making. Some of these, in the near future, will likely also serve as potential therapeutic targets. In this article, we summarize the key molecular features of clinical significance for WHO grades II and III gliomas and underscore how the therapeutic landscape is changing.

Repeat surgery for recurrent low-grade gliomas should be standard of care

The importance of surgery and maximal extent of resection (EOR) is well established in primary low-grade glioma (LGG) management. However, the role of surgery in the management of recurrent LGG is less clear. A recent review on the management of recurrent LGG concluded there was insufficient evidence to recommend surgery. Here, we summarize the recent advances regarding the role of surgery, radiotherapy (RT) and chemotherapy in the management of recurrent LGG. There is increasing evidence to support maximal EOR for treating recurrent LGG, as it may improve progression free survival (PFS) after recurrence and overall survival (OS). Based on the studies presented in this review, we suggest that repeat surgery with maximal EOR should be standard of care for recurrent LGG treatment.

Temozolomide low-dose chemotherapy in newly diagnosed low-grade gliomas: activity, safety, and long-term follow-up

PURPOSE

To explore the efficacy and toxicity of an extended schedule of temozolomide (50 mg/mq 1 week on/1 week off) in a population of newly diagnosed low-grade gliomas (LGG).

METHODS

Primary endpoints were progression-free survival (PFS) at 12 and 24 months and response rate evaluated with Response Assessment in Neuro-Oncology Criteria. Secondary endpoints were clinical benefit (reduction of seizures frequency), reduction of steroid, and modifications of Karnofsky Performance Status.

RESULTS

From 2006 to 2009, we enrolled 14 consecutive patients with newly diagnosed LGG: 8 grade II astrocytomas, 2 oligodendroglioma, and 4 oligo-astrocytoma. Temozolomide was administered for 18 cycles (mean) per patient (range 3-24 cycles). In 57.5% (n = 8), we observed stable disease, 28.5% (n = 4) presented a minor response, and 14% (n = 2) showed progression. Five patients presented early progression during the first year of treatment and the study was stopped. A relevant clinical benefit was observed in 85% of patients (seizure control). After 6 years of follow-up, only 4 patients died. Prolonged PFS was associated with 1p-19q codeletion over 1p-19q intact (35 vs 4 months; p<0.04) and IDH1 mutation over IDH1 wild-type (36 vs 6 months; p<0.009).

CONCLUSIONS

The study was interrupted for the high rate of progression observed in the first 14 patients enrolled. However, our results show that an extended low dose of temozolomide presents interesting activity with objective response and clinical benefit, but does not seem to prevent progression in patients presenting unfavorable molecular prognostic factors.

Implementation of Talairach Atlas Based Automated Brain Segmentation for Radiation Therapy Dosimetry

Radiotherapy for brain cancer inevitably results in irradiation of uninvolved brain. While it has been demonstrated that irradiation of the brain can result in cognitive deficits, dose-volume relationships are not well established. There is little work correlating a particular cognitive deficit with dose received by the region of the brain responsible for the specific cognitive function. One obstacle to such studies is that identification of brain anatomy is both labor intensive and dependent on the individual performing the segmentation. Automatic segmentation has the potential to be both efficient and consistent. Brains2 is a software package developed by the University of Iowa for MRI volumetric studies. It utilizes MR images, the Talairach atlas, and an artificial neural network (ANN) to segment brain images into substructures in a standardized manner. We have developed a software package, Brains2DICOM, that converts the regions of interest identified by Brains2 into a DICOM radiotherapy structure set. The structure set can be imported into a treatment planning system for dosimetry. We demonstrated the utility of Brains2DICOM using a test case, a 34-year-old man with diffuse astrocytoma treated with three-dimensional conformal radiotherapy. Brains2 successfully applied the Talairach atlas to identify the right and left frontal, parietal, temporal, occipital, subcortical, and cerebellum regions. Brains2 was not successful in applying the ANN to identify small structures, such as the hippocampus and caudate. Further work is necessary to revise the ANN or to develop new methods for identification of small structures in the presence of disease and radiation induced changes. The segmented regions-of-interest were transferred to our commercial treatment planning system using DICOM and dose-volume histograms were constructed. This method will facilitate the acquisition of data necessary for the development of normal tissue complication probability (NTCP) models that assess the probability of cognitive complications secondary to radiotherapy for intracranial and head and neck neoplasms.

Principles of radiation therapy

Although resection remains the mainstay in the treatment of gliomas, microscopically complete resection of most central nervous system tumors remains challenging, and is, in fact, rarely accomplished. Considering their invasive nature, gross total resections to clearly negative margins often do or would require removal or transection of functional brain, with likely serious neurologic deficits. Consequently, radiotherapy has emerged as an indispensable component of therapy. It is delivered primarily by external-beam radiotherapy or brachytherapy techniques. Herein, we present the biologic principles, techniques, and applications of radiotherapy in glioma treatment today.

The role of radiotherapy in the management of patients with diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline

QUESTIONS

(1) What is the optimal role of external beam radiotherapy in the management of adult patients with newly diagnosed low-grade glioma (LGG) in terms of improving outcome (i.e., survival, complications, seizure control or other reported outcomes of interest)? (2) Which radiation strategies (dose, timing, fractionation, stereotactic radiation, brachytherapy, chemotherapy) improve outcomes compared to standard external beam radiation therapy in the initial management of low grade gliomas in adults? (3) Do specific factors (e.g., age, volume, extent of resection, genetic subtype) identify subgroups with better outcomes following radiation therapy than the general population of adults with newly diagnosed low-grade gliomas?

TARGET POPULATION

These recommendations apply to adults with newly diagnosed diffuse LGG.

RECOMMENDATIONS

OUTCOMES IN ADULT PATIENTS WITH NEWLY DIAGNOSED LOW GRADE GLIOMA TREATED WITH RADIOTHERAPY: Level I Radiotherapy is recommended in the management of newly diagnosed low-grade glioma in adults to prolong progression free survival, irrespective of extent of resection. Level II Radiotherapy is recommended in the management of newly diagnosed low grade glioma in adults as an equivalent alternative to observation in preserving cognitive function, irrespective of extent of resection. Level III Radiotherapy is recommended in the management of newly diagnosed low grade glioma in adults to improve seizure control in patients with epilepsy and subtotal resection. Level III Radiotherapy is recommended in the management of newly diagnosed low-grade glioma in adults to prolong overall survival in patients with subtotal resection. Level III Consideration of the risk of radiation induced morbidity, including cognitive decline, imaging abnormalities, metabolic dysfunction and malignant transformation, is recommended when the delivery of radiotherapy is selected in the management of newly diagnosed low-grade glioma in adults. STRATEGIES OF RADIOTHERAPY IN ADULT PATIENTS WITH NEWLY DIAGNOSED LOW GRADE GLIOMA: Level I Lower dose radiotherapy is recommended as an equivalent alternative to higher dose immediate postoperative radiotherapy (45-50.4 vs. 59.4-64.8 Gy) in the management of newly diagnosed low-grade glioma in adults with reduced toxicity. Level III Delaying radiotherapy until recurrence or progression is recommended as an equivalent alternative to immediate postoperative radiotherapy in the management of newly diagnosed low-grade glioma in adults but may result in shorter time to progression. Level III The addition of chemotherapy to radiotherapy is not recommended over whole brain radiotherapy alone in the management of low-grade glioma, as it provides no additional survival benefit. Level III Limited-field radiotherapy is recommended over whole brain radiotherapy in the management of low-grade glioma. Level III Either stereotactic radiosurgery or brachytherapy are recommended as acceptable alternatives to external radiotherapy in selected patients. PROGNOSTIC FACTORS IN ADULT PATIENTS WITH NEWLY DIAGNOSED LOW GRADE GLIOMA TREATED WITH RADIOTHERAPY: Level II It is recommended that age greater than 40 years, astrocytic pathology, diameter greater than 6 cm, tumor crossing the midline and preoperative neurological deficit be considered as negative prognostic indicators when predicting overall survival in adult low grade glioma patients treated with radiotherapy. Level II It is recommended that smaller tumor size, extent of surgical resection and higher mini-mental status exam be considered as positive prognostic indicators when predicting overall survival and progression free survival in patients in adult low grade glioma patients treated with radiotherapy. Level III It is recommended that seizures at presentation, presence of oligodendroglial histological component and 1p19q deletion (along with additional relevant factors-see Table 1) be considered as positive prognostic indicators when predicting response to radiotherapy in adults with low grade gliomas. Level III It is recommended that increasing age, decreasing performance status, decreasing cognition, presence of astrocytic histological component (along with additional relevant factors (see Tables 1, 2) be considered as negative prognostic indicators when predicting response to radiotherapy.

Management of patients with recurrence of diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline

TARGET POPULATION

These recommendations apply to adult patients with recurrent low-grade glioma (LGG) with initial pathologic diagnosis of a WHO grade II infiltrative glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

PATHOLOGY AT RECURRENCE

QUESTION

Do pathologic and molecular characteristics predict outcome/malignant transformation at recurrence?

RECOMMENDATIONS

IDH STATUS AND RECURRENCE: (Level III) IDH mutation status should be determined as LGGs with IDH mutations have a shortened time to recurrence. It is unclear whether knowledge of IDH mutation status provides benefit in predicting time to progression or overall survival. TP53 STATUS AND RECURRENCE: (Level III) TP53 mutations occur early in LGG pathogenesis, remain stable, and are not recommended as a marker of predisposition to malignant transformation at recurrence or other measures of prognosis. MGMT STATUS AND RECURRENCE: (Level III) Assessment of MGMT status is recommended as an adjunct to assessing prognosis as LGGs with MGMT promoter methylation are associated with shorter PFS (in the absence of TMZ) and longer post-recurrence survival (in the presence of TMZ), ultimately producing similar overall survival to LGGs without MGMT methylation. The available retrospective reports are conflicting and comparisons between reports are limited CDK2NA STATUS AND RECURRENCE: (Level III) Assessment of CDK2NA status is recommended when possible as the loss of expression of the CDK2NA via either methylation or loss of chromosome 9p is associated with malignant progression of LGGs. PROLIFERATIVE INDEX AND RECURRENCE: (Level III) It is recommended that proliferative indices (MIB-1 or BUdR) be measured in LGGs as higher proliferation indices are associated with increased likelihood of recurrence and shorter progression free and overall survival. 1P/19Q STATUS AND RECURRENCE: There is insufficient evidence to make any recommendations.

CHEMOTHERAPY AT RECURRENCE

QUESTION

What role does chemotherapy have in LGG recurrence?

RECOMMENDATIONS

TEMOZOLOMIDE AND RECURRENCE: (Level III) Temozolomide is recommended in the therapy of recurrent LGG as it may improve clinical symptoms. Oligodendrogliomas and tumors with 1p/19q co-deletion may derive the most benefit. PCV AND RECURRENCE: (Level III) PCV is recommended in the therapy of LGG at recurrence as it may improve clinical symptoms with the strongest evidence being for oligodendrogliomas. CARBOPLATIN AND RECURRENCE : (Level III) Carboplatin is not recommended as there is no significant benefit from carboplatin as single agent therapy for recurrent LGGs. OTHER TREATMENTS (NITROSUREAS, HYDROXYUREA/IMANITIB, IRINOTECAN, PACLITAXEL) AND RECURRENCE: There is insufficient evidence to make any recommendations. It is recommended that individuals with recurrent LGGs be enrolled in a properly designed clinical trial to assess these chemotherapeutic agents.

RADIATION AT RECURRENCE

QUESTION

What role does radiation have in LGG recurrence?

RECOMMENDATIONS

RADIATION AT RECURRENCE WITH NO PREVIOUS IRRADIATION: (Level III) Radiation is recommended at recurrence if there was no previous radiation treatment. RE-IRRADIATION AT RECURRENCE: (Level III) It is recommended that re-irradiation be considered in the setting of LGG recurrence as it may provide benefit in disease control.

SURGERY AT RECURRENCE

There is insufficient evidence to make any specific recommendations. It is recommended that individuals with recurrent LGGs be enrolled in a properly designed clinical trial to assess the role of surgery at recurrence.

Gamma Knife treatment of low-grade gliomas in children

BACKGROUND

Low-grade gliomas have good overall survival rates in pediatric patients compared to adults. There are some case series that reported the effectiveness and safety of Gamma Knife radiosurgery, yet they are limited in number of patients. We aimed to review the relevant literature for pediatric low-grade glial tumors treated with stereotactic radiosurgery, specifically Gamma Knife radiosurgery, and to present an exemplary case.

CASE DESCRIPTION

A 6-year-old boy was admitted to clinic due to head trauma. He was alert, cooperative, and had no obvious motor or sensorial deficit. A head CT scan depicted a hypodense zone at the right caudate nucleus. The brain magnetic resonance imaging (MRI) depicted a mass lesion at the same location. A stereotactic biopsy was performed. Histopathological diagnosis was low-grade astrocytoma (grade II, World Health Organization (WHO) classification, 2007). Gamma Knife radiosurgery was applied to the tumor bed. Tumor volume was 21.85 cm(3). Fourteen gray was given to 50% isodose segment of the lesion (maximal dose of 28 Gy). The tumor has disappeared totally in 4 months, and the patient was tumor-free 21 months after the initial treatment.

DISCUSSION AND CONCLUSION

The presented literature review represents mostly single-center experiences with different patient and treatment characteristics. Accordingly, a mean/median margin dose of 11.3-15 Gy with Gamma Knife radiosurgery (GKRS) is successful in treatment of pediatric and adult low-grade glial tumor patients. However, prospective studies with a large cohort of pediatric patients should be conducted to make a more comprehensive conclusion for effectiveness and safety of GKRS in pediatric low-grade glial tumors.