To compare multiparametric diagnostic performance with diffusion-weighted, dynamic susceptibility-weighted contrast material-enhanced perfusion-weighted, and susceptibility-weighted magnetic ...resonance (MR) imaging for differentiating primary central nervous system lymphoma (PCNSL) and atypical glioblastoma.
This retrospective study was institutional review board-approved and informed consent was waived. Pretreatment MR imaging was performed in 314 patients with glioblastoma, and a subset of 28 patients with glioblastoma of atypical appearance (solid enhancement with no visible necrosis) was selected. Parameters of diffusion-weighted (apparent diffusion coefficient ADC), susceptibility-weighted (intratumoral susceptibility signals ITSS), and dynamic susceptibility-weighted contrast-enhanced perfusion-weighted (relative cerebral blood volume rCBV) imaging were evaluated in these 28 patients with glioblastoma and 19 immunocompetent patients with PCNSL. A two-sample t test and χ(2) test were used to compare parameters.The diagnostic performance for differentiating PCNSL from glioblastoma was evaluated by using logistic regression analyses with leave-one-out cross validation.
Minimum, maximum, and mean ADCs and maximum and mean rCBVs were significantly lower in patients with PCNSL than in those with glioblastoma (P < .01, respectively), whereas mean ADCs and mean rCBVs allowed the best diagnostic performance. Presence of ITSS was significantly lower in patients with PCNSL (32% six of 19) than in those with glioblastoma (82% 23 of 28) (P < .01). Multiparametric assessment of mean ADC, mean rCBV, and presence of ITSS significantly increased the probability for differentiating PCNSL and atypical glioblastoma compared with the evaluation of one or two imaging parameters (P < .01), thereby correctly predicting histologic results in 95% (18 of 19) of patients with PCNSL and 96% (27 of 28) of patients with atypical glioblastoma.
Combined evaluation of mean ADC, mean rCBV, and presence of ITSS allowed reliable differentiation of PCNSL and atypical glioblastoma in most patients, and these results support an integration of advanced MR imaging techniques for the routine diagnostic workup of patients with these tumors.
Despite extensive preclinical research on immunotherapeutic approaches, malignant glioma remains a devastating disease of the central nervous system for which standard of care treatment is still ...confined to resection and radiochemotherapy. For peripheral solid tumors, immune checkpoint inhibition has shown substantial clinical benefit, while promising preclinical results have yet failed to translate into clinical efficacy for brain tumor patients. With the advent of high-throughput sequencing technologies, tumor antigens and corresponding T cell receptors (TCR) and antibodies have been identified, leading to the development of chimeric antigen receptors (CAR), which are comprised of an extracellular antibody part and an intracellular T cell receptor signaling part, to genetically engineer T cells for antigen recognition. Due to efficacy in other tumor entities, a plethora of CARs has been designed and tested for glioma, with promising signs of biological activity. In this review, we describe glioma antigens that have been targeted using CAR T cells preclinically and clinically, review their drawbacks and benefits, and illustrate how the emerging field of transgenic TCR therapy can be used as a potent alternative for cell therapy of glioma overcoming antigenic limitations.
Summary Background Radiotherapy is the standard care in elderly patients with malignant astrocytoma and the role of primary chemotherapy is poorly defined. We did a randomised trial to compare the ...efficacy and safety of dose-dense temozolomide alone versus radiotherapy alone in elderly patients with anaplastic astrocytoma or glioblastoma. Methods Between May 15, 2005, and Nov 2, 2009, we enrolled patients with confirmed anaplastic astrocytoma or glioblastoma, age older than 65 years, and a Karnofsky performance score of 60 or higher. Patients were randomly assigned 100 mg/m2 temozolomide, given on days 1–7 of 1 week on, 1 week off cycles, or radiotherapy of 60·0 Gy, administered over 6–7 weeks in 30 fractions of 1·8–2·0 Gy. The primary endpoint was overall survival. We assessed non-inferiority with a 25% margin, analysed for all patients who received at least one dose of assigned treatment. This trial is registered with ClinicalTrials.gov , number NCT01502241. Findings Of 584 patients screened, we enrolled 412. 373 patients (195 randomly allocated to the temozolomide group and 178 to the radiotherapy group) received at least one dose of treatment and were included in efficacy analyses. Median overall survival was 8·6 months (95% CI 7·3–10·2) in the temozolomide group versus 9·6 months (8·2–10·8) in the radiotherapy group (hazard ratio HR 1·09, 95% CI 0·84–1·42, pnon-inferiority =0·033). Median event-free survival (EFS) did not differ significantly between the temozolomide and radiotherapy groups (3·3 months 95% CI 3·2–4·1 vs 4·7 4·2–5·2; HR 1·15, 95% CI 0·92–1·43, pnon-inferiority =0·043). Tumour MGMT promoter methylation was seen in 73 (35%) of 209 patients tested. MGMT promoter methylation was associated with longer overall survival than was unmethylated status (11·9 months 95% CI 9·0 to not reached vs 8·2 months 7·0–10·0; HR 0·62, 95% CI 0·42–0·91, p=0·014). EFS was longer in patients with MGMT promoter methylation who received temozolomide than in those who underwent radiotherapy (8·4 months 95e% CI 5·5–11·7 vs 4·6 4·2–5·0), whereas the opposite was true for patients with no methylation of the MGMT promoter (3·3 months 3·0–3·5 vs 4·6 months 3·7–6·3). The most frequent grade 3–4 intervention-related adverse events were neutropenia (16 patients in the temozolomide group vs two in the radiotherapy group), lymphocytopenia (46 vs one), thrombocytopenia (14 vs four), raised liver-enzyme concentrations (30 vs 16), infections (35 vs 23), and thromboembolic events (24 vs eight). Interpretation Temozolomide alone is non-inferior to radiotherapy alone in the treatment of elderly patients with malignant astrocytoma. MGMT promoter methylation seems to be a useful biomarker for outcomes by treatment and could aid decision-making. Funding Merck Sharp & Dohme.
The WHO 2007 classification of tumors of the CNS distinguishes between diffuse astrocytoma WHO grade II (A II
WHO2007
) and anaplastic astrocytoma WHO grade III (AA III
WHO2007
). Patients with A II
...WHO2007
are significantly younger and survive significantly longer than those with AA III
WHO2007
. So far, classification and grading relies on morphological grounds only and does not yet take into account
IDH
status, a molecular marker of prognostic relevance. We here demonstrate that WHO 2007 grading performs poorly in predicting prognosis when applied to astrocytoma carrying
IDH
mutations. Three independent series including a total of 1360 adult diffuse astrocytic gliomas with
IDH
mutation containing 683 A II
IDHmut
, 562 AA III
IDHmut
and 115 GBM
IDHmut
have been examined for age distribution and survival. In all three series patients with A II
IDHmut
and AA III
IDHmut
were of identical age at presentation of disease (36–37 years) and the difference in survival between grades was much less (10.9 years for A II
IDHmut
, 9.3 years for AA III
IDHmut
) than that reported for A II
WHO2007
versus AA III
WHO2007
. Our analyses imply that the differences in age and survival between A II
WHO2007
and AA III
WHO2007
predominantly depend on the fraction of
IDH
-non-mutant astrocytomas in the cohort. This data poses a substantial challenge for the current practice of astrocytoma grading and risk stratification and is likely to have far-reaching consequences on the management of patients with
IDH
-mutant astrocytoma.
The aim of this study was to compare changes in signal intensity (SI) ratios of the dentate nucleus (DN) to pons and cerebrospinal fluid (CSF) on unenhanced T1-weighted magnetic resonance imaging ...(MRI) scans between the first and last MRI using the linear gadolinium-based contrast agent gadobenate dimeglumine.
The study was approved by the ethical committee of the University of Heidelberg (S-324/2014), and written informed consent was waived due to the retrospective character of the study. Fifty patients who underwent at least 5 consecutive MRI examinations (plus an additional last MRI for reference) with the exclusive use of gadobenate dimeglumine were analyzed retrospectively. The difference of DN-to-pons and DN-to-CSF mean SI ratios was calculated on unenhanced T1-weighted images between the first and last examination. Results were compared with previously published data on gadopentetate dimeglumine and gadoterate meglumine.
Signal intensity ratio differences for DN-to-pons and DN-to-CSF were significantly greater than 0 (pons: 0.0399 ± 0.0307, P < 0.001; CSF: 0.1439 ± 0.1524, P < 0.001). No control variable consistently predicted the SI ratio difference for the DN-to-pons and the DN-to-CSF ratio. Compared with previously published data, the difference in SI increase between gadopentetate dimeglumine and gadobenate dimeglumine was not significant for the DN-to-pons ratio (P = 0.906). In contrast, the DN-to-CSF ratio difference was significantly lower (P < 0.001) for gadobenate dimeglumine. Dentate nucleus-to-pons (P < 0.001) and DN-to-CSF (P = 0.017) ratio differences were both significantly higher for gadobenate dimeglumine than for gadoterate meglumine.
The present study found an increase in SI in the DN after serial injections of gadobenate dimeglumine. Further studies are needed to clarify the potential of different linear gadolinium-based contrast agents to cause SI increase in the DN.
The present review introduces recent progress in eliciting the role of mutant isocitrate dehydrogenase (IDH) in gliomas, especially regarding its mode of action as a modulator of antitumor immune ...response, and provides rationales for targeting mutant IDH in glioma immunotherapy. Both the development of small molecule inhibitors repressing the enzymatic activity of mutant IDH and novel, mechanism-led combination immunotherapies are discussed.
Since the discovery of highly frequent IDH mutations in low-grade gliomas and nonsolid malignancies, its tumor cell-intrinsic effects have been intensively investigated. Tumor cells expressing mutant IDH display profound alterations of redox control capacity, phospholipid profile, and ATP supply. Recent findings suggest that IDH mutations - via intricate, yet druggable pathways - cause immunological alterations, highlighting the importance of oncogenic drivers as modulators of antitumor immunity and targets for immunotherapy.
Mutant IDH is not only a disease-defining biomarker and oncogenic driver in glioma, but is also a neoantigen and a regulator of glioma immune evasion. Effective and specific strategies targeting the immunomodulatory properties of mutant IDH may complement current (immuno-)therapeutic strategies and approved antiglioma treatments to improve outcome.
O6‐methylguanine‐DNA‐methyltransferase (MGMT) promoter methylation identifies a subpopulation of glioblastoma patients with more favorable prognosis and predicts a benefit from alkylating agent ...chemotherapy (CT). Little is known about its prevalence and clinical significance in older glioblastoma patients. We studied 233 glioblastoma patients aged 70 years or more (144 males, 89 females, median age: 74 years, range: 70.0–86.6 years), who were prospectively enrolled in the German Glioma Network, for MGMT promoter methylation by methylation‐specific PCR (MSP) in all patients and DNA pyrosequencing in 166 patients. MGMT data were correlated with patient outcome. Median progression‐free survival (PFS) was 4.8 months (95% CI: 4.3–5.3) and median overall survival (OS) was 7.7 months (95% CI: 6.3–9.0). MGMT promoter methylation was detected by MSP in 134 patients (57.5%). For the whole cohort, PFS was 5.2 versus 4.7 months (p = 0.207) and OS was 8.4 versus 6.4 months (p = 0.031) in patients with versus without MGMT promoter methylation. Patients with MGMT methylated tumors had longer PFS when treated with radiotherapy (RT) plus CT or CT alone compared to patients treated with RT alone. Patients with MGMT unmethylated tumors appeared to derive no survival benefit from CT, regardless of whether given at diagnosis together with RT or as a salvage treatment. Patients treated with RT plus CT or CT alone demonstrated longer OS when pyrosequencing revealed >25% MGMT methylated alleles. Taken together, MGMT promoter methylation may be a useful biomarker to stratify elderly glioblastoma patients for treatment with versus without alkylating agent CT.
Currently, the most widely used criteria for assessing response to therapy in high-grade gliomas are based on two-dimensional tumor measurements on computed tomography (CT) or magnetic resonance ...imaging (MRI), in conjunction with clinical assessment and corticosteroid dose (the Macdonald Criteria). It is increasingly apparent that there are significant limitations to these criteria, which only address the contrast-enhancing component of the tumor. For example, chemoradiotherapy for newly diagnosed glioblastomas results in transient increase in tumor enhancement (pseudoprogression) in 20% to 30% of patients, which is difficult to differentiate from true tumor progression. Antiangiogenic agents produce high radiographic response rates, as defined by a rapid decrease in contrast enhancement on CT/MRI that occurs within days of initiation of treatment and that is partly a result of reduced vascular permeability to contrast agents rather than a true antitumor effect. In addition, a subset of patients treated with antiangiogenic agents develop tumor recurrence characterized by an increase in the nonenhancing component depicted on T2-weighted/fluid-attenuated inversion recovery sequences. The recognition that contrast enhancement is nonspecific and may not always be a true surrogate of tumor response and the need to account for the nonenhancing component of the tumor mandate that new criteria be developed and validated to permit accurate assessment of the efficacy of novel therapies. The Response Assessment in Neuro-Oncology Working Group is an international effort to develop new standardized response criteria for clinical trials in brain tumors. In this proposal, we present the recommendations for updated response criteria for high-grade gliomas.
The DNA repair enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) antagonizes the genotoxic effects of alkylating agents. MGMT promoter methylation is the key mechanism of MGMT gene silencing and ...predicts a favorable outcome in patients with glioblastoma who are exposed to alkylating agent chemotherapy. This biomarker is on the verge of entering clinical decision-making and is currently used to stratify or even select glioblastoma patients for clinical trials. In other subtypes of glioma, such as anaplastic gliomas, the relevance of MGMT promoter methylation might extend beyond the prediction of chemosensitivity, and could reflect a distinct molecular profile. Here, we review the most commonly used assays for evaluation of MGMT status, outline the prerequisites for standardized tests, and evaluate reasons for difficulties in reproducibility. We critically discuss the prognostic and predictive value of MGMT silencing, reviewing trials in which patients with different types of glioma were treated with various chemotherapy schedules, either up-front or at recurrence. Standardization of MGMT testing requires comparison of different technologies across laboratories and prospectively validated cut-off values for prognostic or predictive effects. Moreover, future clinical trials will need to determine, for each subtype of glioma, the degree to which MGMT promoter methylation is predictive or prognostic, and whether testing should become routine clinical practice.
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