Isocitrate dehydrogenase (IDH) mutant gliomas are the most common adult, malignant primary brain tumors diagnosed in patients younger than 50, constituting an important cause of morbidity and ...mortality. In recent years, there has been significant progress in understanding the molecular pathogenesis and biology of these tumors, sparking multiple efforts to improve their diagnosis and treatment. In this consensus review from the Society for Neuro-Oncology (SNO), the current diagnosis and management of IDH-mutant gliomas will be discussed. In addition, novel therapies, such as targeted molecular therapies and immunotherapies, will be reviewed. Current challenges and future directions for research will be discussed.
Glioma, the most common central nervous system cancer in adults, has poor prognosis. Here we identify a new SNP associated with glioma risk, rs1920116 (near TERC), that reached genome-wide ...significance (Pcombined = 8.3 × 10(-9)) in a meta-analysis of genome-wide association studies (GWAS) of high-grade glioma and replication data (1,644 cases and 7,736 controls). This region has previously been associated with mean leukocyte telomere length (LTL). We therefore examined the relationship between LTL and both this new risk locus and other previously established risk loci for glioma using data from a recent GWAS of LTL (n = 37,684 individuals). Alleles associated with glioma risk near TERC and TERT were strongly associated with longer LTL (P = 5.5 × 10(-20) and 4.4 × 10(-19), respectively). In contrast, risk-associated alleles near RTEL1 were inconsistently associated with LTL, suggesting the presence of distinct causal alleles. No other risk loci for glioma were associated with LTL. The identification of risk alleles for glioma near TERC and TERT that also associate with telomere length implicates telomerase in gliomagenesis.
Temozolomide (TMZ) increases the overall survival of patients with glioblastoma (GBM), but its role in the clinical management of diffuse low-grade gliomas (LGG) is still being defined. DNA ...hypermethylation of the
O
6
-
methylguanine
-
DNA methyltransferase
(
MGMT)
promoter is associated with an improved response to TMZ treatment, while inactivation of the DNA mismatch repair (MMR) pathway is associated with therapeutic resistance and TMZ-induced mutagenesis. We previously demonstrated that TMZ treatment of LGG induces driver mutations in the RB and AKT–mTOR pathways, which may drive malignant progression to secondary GBM. To better understand the mechanisms underlying TMZ-induced mutagenesis and malignant progression, we explored the evolution of
MGMT
methylation and genetic alterations affecting MMR genes in a cohort of 34 treatment-naïve LGGs and their recurrences. Recurrences with TMZ-associated hypermutation had increased
MGMT
methylation compared to their untreated initial tumors and higher overall
MGMT
methylation compared to TMZ-treated non-hypermutated recurrences. A TMZ-associated mutation in one or more MMR genes was observed in five out of six TMZ-treated hypermutated recurrences. In two cases, pre-existing heterozygous deletions encompassing
MGMT
, or an MMR gene, were followed by TMZ-associated mutations in one of the genes of interest. These results suggest that tumor cells with methylated
MGMT
may undergo positive selection during TMZ treatment in the context of MMR deficiency.
Lack of standardized criteria measuring therapeutic response remains an obstacle to the development of better treatments for chronic GVHD (cGVHD). This cross-sectional prospective study examined the ...concurrent and predictive validity of 18 clinician-reported ('Form A') and 8 patient-reported ('Form B') response measures proposed by NIH criteria. Concurrent parameters of interest were NIH global score, cGVHD activity, Lee symptom score and SF36 PCS. Patient cohort included 193 adults with moderate-to-severe cGVHD. Measures associated with the highest number of outcomes were lung function score (LFS), 2-min walk, grip strength, 4-point health-care provider (HCP) and patient global scores, 11-point clinician- and patient-reported global symptom severity scores, and Karnofsky performance score (KPS). Measures associated with survival in univariate analyses led to a Cox model containing skin erythema, LFS, KPS, eosinophil count and interval from cGVHD diagnosis to enrollment as jointly associated with survival. In conclusion, 4-point HCP and patient global scores and 11-point clinician- and patient-reported global symptom severity scores are associated with the majority of concurrent outcomes. Skin erythema is a potentially reversible sign of cGVHD that is associated with survival. These results define a subset of measures that should be prioritized for evaluation in future studies.
Although fatigue is common after allogeneic hematopoietic cell transplantation, little is known about fatigue in patients with chronic GvHD (cGvHD). The aim of this study was to explore factors ...associated with fatigue in cGvHD. Data were drawn from a sequentially recruited, cross-sectional study of adults with moderate or severe cGvHD (n=263). Respondents were classified as fatigued or not fatigued based on their response to a single item regarding loss of energy from the Lee cGvHD Symptom Scale. In univariate analysis, factors significantly associated with fatigue included performance status, number of prior cGvHD therapies, cGvHD symptom bother, self-assessed physical and mental health, nutritional status, walk velocity and self-reported physical activity. There were no significant associations between fatigue and disease-related cGvHD variables. Multivariable logistic regression demonstrated that being less active and having pulmonary and/or muscle/joint symptoms were independently associated with fatigue. In conclusion, clinically significant fatigue was prevalent in more than one-third of subjects with cGvHD, and was disabling. Absence of association with measures of cGvHD severity underscores the need to elucidate the pathogenesis of fatigue and its relationship with inflammatory activity. Pulmonary and muscle/joint symptoms and physical inactivity represent potential targets for intervention in clinical studies.
mutations in low-grade gliomas (LGGs) results in improved survival and DNA hypermethylation compared to
wild-type LGGs.
-mutant LGGs become hypomethylated during progression. It's uncertain if ...methylation changes occur during
wild-type GBM progression and if the methylome can be reprogrammed. This phase I study evaluated the safety, tolerability, efficacy and methylome changes after L-methylfolate (LMF) treatment, in combination with temozolomide and bevacizumab in patients with recurrent high-grade glioma.
Fourteen patients total, 13 with GBM, one with anaplastic astrocytoma, all
wild-type were enrolled in the study. All patients received LMF at either 15, 30, 60, or 90 mg daily plus temozolomide (75mg/m
5 days per month) and bevacizumab (10mg/kg every two weeks).
No MTD was identified. LMF treated had mOS of 9.5 months (95% CI, 9.1-35.4) comparable to bevacizumab historical control 8.6 months (95% CI, 6.8-10.8). Six patients treated with LMF survived more than 650 days. Across all treatment doses the most adverse events were diarrhea (7%, 1 patient, grade 2), reflux (7%, 1 patient, grade 2), and dysgeusia (7%, 1 patient, grade 2). In the six brains donated at death, there was a 25% increase in DNA methylated CpGs compared to the paired initial tumor.
LMF in combination with temozolomide and bevacizumab was well tolerated in patients with recurrent
wild-type high-grade glioma. This small study did not establish a superior efficacy with addition of LMF compared to standard bevacizumab therapy, however, this study did show methylome reprogramming in high-grade glioma.
Genome-wide association studies have implicated single nucleotide polymorphisms (SNPs) in 7 genes as glioma risk factors, including 2 (TERT, RTEL1) involved in telomerase structure/function. We ...examined associations of these 7 established glioma risk loci with age at diagnosis among patients with glioma.
SNP genotype data were available for 2286 Caucasian glioma patients from the University of California, San Francisco (n = 1434) and the Mayo Clinic (n = 852). Regression analyses were performed to test for associations between "number of risk alleles" and "age at diagnosis," adjusted for sex and study site and stratified by tumor grade/histology where appropriate.
Four SNPs were significantly associated with age at diagnosis. Carrying a greater number of risk alleles at rs55705857 (CCDC26) and at rs498872 (PHLDB1) was associated with younger age at diagnosis (P = 1.4 × 10(-22) and P = 9.5 × 10(-7), respectively). These SNPs are stronger risk factors for oligodendroglial tumors, which tend to occur in younger patients, and their association with age at diagnosis varied across tumor subtypes. In contrast, carrying more risk alleles at rs2736100 (TERT) and at rs6010620 (RTEL1) was associated with older age at diagnosis (P = 6.2 × 10(-4) and P = 2.5 × 10(-4), respectively). These SNPs are risk factors for all glioma grades/histologies, and their association with age at diagnosis was consistent across tumor subgroups.
Carrying a greater number of risk alleles might be expected to decrease age at diagnosis. However, glioma susceptibility conferred by variation in telomerase-related genes did not follow this pattern. This supports the hypothesis that telomerase-related mechanisms of telomere maintenance are more associated with gliomas that develop later in life than those utilizing telomerase-independent mechanisms (ie, alternative lengthening of telomeres).
Patients with brain tumors including intracranial meningiomas are at increased risk for developing deep vein thrombosis (DVTs) and suffering thromboembolic events (VTEs). Many surgeons are concerned ...that early use of low dose enoxaparin may increase the risk of intracranial hemorrhage which outweighs the benefit of DVT/VTE reduction. We aimed to address concerns around the use of enoxaparin after meningioma resection in the development of postoperative intracranial hemorrhages and DVT/VTEs. This is a retrospective review of 86 patients with intracranial meningiomas who underwent craniectomy and surgical resection of the mass, treated by one attending surgeon at UCSF Medical Center between 2000 and 2005. Within 48 h after surgery patients treated 2003–2005 routinely received enoxaparin therapy unless there was documented intracranial hemorrhage, lumbar subarachnoid drain, enoxaparin hypersensitivity, or thrombocytopenia (
n
= 24). These were compared to a cohort treated 2000–2002 who did not receive the drug (
n
= 62). Exclusion criteria were prior VTEs or coagulopathies. The groups were similar in tumor and surgical characteristics. Enoxaparin therapy did not increase the incidence of intracranial hemorrhage following surgical meningioma resection and the incidence of DVTs/VTEs was 0% (
n
= 0) versus 4.8% (
n
= 3) in the non-enoxaparin group. Results did not reach statistical significance. In this retrospective study, postoperative administration of enoxaparin following meningioma resection does not increase the risk of intracranial hematoma though enoxaparin administration may slightly decrease the incidence of post-surgical thromboembolic events. Due to study design and power, we were not able to demonstrate DVT/VTE reduction with statistical significance.
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