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  • American Association for Cancer Research (AACR)  (19)
  • 1
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 69, No. 23 ( 2009-12-01), p. 9065-9072
    Abstract: Gliomas are the most common primary brain tumors with heterogeneous morphology and variable prognosis. Treatment decisions in patients rely mainly on histologic classification and clinical parameters. However, differences between histologic subclasses and grades are subtle, and classifying gliomas is subject to a large interobserver variability. To improve current classification standards, we have performed gene expression profiling on a large cohort of glioma samples of all histologic subtypes and grades. We identified seven distinct molecular subgroups that correlate with survival. These include two favorable prognostic subgroups (median survival, & gt;4.7 years), two with intermediate prognosis (median survival, 1–4 years), two with poor prognosis (median survival, & lt;1 year), and one control group. The intrinsic molecular subtypes of glioma are different from histologic subgroups and correlate better to patient survival. The prognostic value of molecular subgroups was validated on five independent sample cohorts (The Cancer Genome Atlas, Repository for Molecular Brain Neoplasia Data, GSE12907, GSE4271, and Li and colleagues). The power of intrinsic subtyping is shown by its ability to identify a subset of prognostically favorable tumors within an external data set that contains only histologically confirmed glioblastomas (GBM). Specific genetic changes (epidermal growth factor receptor amplification, IDH1 mutation, and 1p/19q loss of heterozygosity) segregate in distinct molecular subgroups. We identified a subgroup with molecular features associated with secondary GBM, suggesting that different genetic changes drive gene expression profiles. Finally, we assessed response to treatment in molecular subgroups. Our data provide compelling evidence that expression profiling is a more accurate and objective method to classify gliomas than histologic classification. Molecular classification therefore may aid diagnosis and can guide clinical decision making. [Cancer Res 2009;69(23):9065–72]
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2009
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  • 2
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 25, No. 24 ( 2019-12-15), p. 7455-7462
    Abstract: Patients with 1p/19q codeleted low-grade glioma (LGG) have longer overall survival and better treatment response than patients with 1p/19q intact tumors. Therefore, it is relevant to know the 1p/19q status. To investigate whether the 1p/19q status can be assessed prior to tumor resection, we developed a machine learning algorithm to predict the 1p/19q status of presumed LGG based on preoperative MRI. Experimental Design: Preoperative brain MR images from 284 patients who had undergone biopsy or resection of presumed LGG were used to train a support vector machine algorithm. The algorithm was trained on the basis of features extracted from post-contrast T1-weighted and T2-weighted MR images and on patients' age and sex. The performance of the algorithm compared with tissue diagnosis was assessed on an external validation dataset of MR images from 129 patients with LGG from The Cancer Imaging Archive (TCIA). Four clinical experts also predicted the 1p/19q status of the TCIA MR images. Results: The algorithm achieved an AUC of 0.72 in the external validation dataset. The algorithm had a higher predictive performance than the average of the neurosurgeons (AUC 0.52) but lower than that of the neuroradiologists (AUC of 0.81). There was a wide variability between clinical experts (AUC 0.45–0.83). Conclusions: Our results suggest that our algorithm can noninvasively predict the 1p/19q status of presumed LGG with a performance that on average outperformed the oncological neurosurgeons. Evaluation on an independent dataset indicates that our algorithm is robust and generalizable.
    Type of Medium: Online Resource
    ISSN: 1078-0432 , 1557-3265
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2019
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  • 3
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 28, No. 12 ( 2022-06-13), p. 2527-2535
    Abstract: In a post hoc analysis of the CATNON trial (NCT00626990), we explored whether adding temozolomide to radiotherapy improves outcome in patients with IDH1/2 wildtype (wt) anaplastic astrocytomas with molecular features of glioblastoma [redesignated as glioblastoma, isocitrate dehydrogenase–wildtype (IDH-wt) in the 2021 World Health Organization (WHO) classification of central nervous system tumors]. Patients and Methods: From the randomized phase III CATNON study examining the addition of adjuvant and concurrent temozolomide to radiotherapy in anaplastic astrocytomas, we selected a subgroup of IDH1/2wt and H3F3Awt tumors with presence of TERT promoter mutations and/or EGFR amplifications and/or combined gain of chromosome 7 and loss of chromosome 10. Molecular abnormalities including MGMT promoter methylation status were determined by next-generation sequencing, DNA methylation profiling, and SNaPshot analysis. Results: Of the 751 patients entered in the CATNON study, 670 had fully molecularly characterized tumors. A total of 159 of these tumors met the WHO 2021 molecular criteria for glioblastoma, IDH-wt. Of these patients, 47 received radiotherapy only and 112 received a combination of radiotherapy and temozolomide. There was no added effect of temozolomide on either overall survival [HR, 1.19; 95% confidence interval (CI), 0.82–1.71] or progression-free survival (HR, 0.87; 95% CI, 0.61–1.24). MGMT promoter methylation was prognostic for overall survival, but was not predictive for outcome to temozolomide treatment either with respect to overall survival or progression-free survival. Conclusions: In this cohort of patients with glioblastoma, IDH-wt temozolomide treatment did not add benefit beyond that observed from radiotherapy, regardless of MGMT promoter status. These findings require a new well-powered prospective clinical study to explore the efficacy of temozolomide treatment in this patient population.
    Type of Medium: Online Resource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2022
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  • 4
    Online Resource
    Online Resource
    American Association for Cancer Research (AACR) ; 2011
    In:  Cancer Research Vol. 71, No. 8_Supplement ( 2011-04-15), p. 3936-3936
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 71, No. 8_Supplement ( 2011-04-15), p. 3936-3936
    Abstract: Gliomas are the most common primary brain tumors with heterogeneous morphology and variable prognosis. Histological classification, combined with the patients’ prognostic features, often guides treatment decisions. Unfortunately, differences in histology are subtle and therefore, diagnosis is subject to a large interobserver variability. To improve classification, we did expression profiling on fresh frozen tumor material of 276 glioma samples of all histological subtypes. This resulted in seven molecular subgroups, which correlated significantly better with survival than histology. When validated in prospective studies these molecular clusters could contribute to clinical decision making. However, there is a lack of fresh frozen glioma material, and until now clinical studies have been performed on formalin fixed paraffin embedded (FFPE) material. Therefore, we would like to see whether our molecular clusters are reproducible in FFPE material. Expression profiling was performed on 57 paired snap-frozen/FFPE glioma samples of all histological and molecular subtypes and three non-diseased brain samples. We collected FFPE material from the same patients that were included in our previous study (Gravendeel et al. Cancer Res 2009). FFPE expression profiling was performed using Hu_Ex_1.0_st “exon” arrays (Affymetrix) in combination with Nugen WT-Ovation technology (FFPE V2 and Exon modules). FFPE expression profiles were assigned to a molecular cluster based on its nearest centroid using the 20.000 most variably expressed exons. Preliminary analysis indicates that approximately 75% of all samples were assigned to the correct molecular cluster. Survival data confirmed that the molecular clusters identified using FFPE material retained significant prognostic value, similar to those obtained using fresh frozen material (p=0.0016). Our data indicate that exon arrays in combination with Nugen WT technology are a suitable platform to perform expression profiling on FFPE samples. We are currently expanding our dataset to include FFPE samples from a large phase III European trial. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3936. doi:10.1158/1538-7445.AM2011-3936
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2011
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  • 5
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 28, No. 11 ( 2022-06-01), p. 2440-2448
    Abstract: Despite recent advances in the molecular characterization of gliomas, it remains unclear which patients benefit most from which second-line treatments. The TAVAREC trial was a randomized, open-label phase II trial assessing the benefit of the addition of the angiogenesis inhibitor bevacizumab to treatment with temozolomide in patients with a first enhancing recurrence of World Health Organization grade 2 or 3 glioma without 1p/19q codeletion. We evaluated the prognostic significance of genome-wide DNA methylation profiles and copy-number variations on the TAVAREC trial samples. Experimental Design: Isocitrate dehydrogenase (IDH) mutation status was determined via Sanger sequencing and IHC. DNA methylation analysis was performed using the MethylationEPIC BeadChip (Illumina) from which 1p/19q codeletion, MGMT promoter methylation (MGMT-STP27), and homozygous deletion of CDKN2A/B were determined. DNA methylation classes were determined according to classifiers developed in Heidelberg and The Cancer Genome Atlas (TCGA; “Heidelberg” and “TCGA” classifier respectively). Results: DNA methylation profiles of 122 samples were successfully determined. As expected, most samples were IDH-mutant (89/122) and MGMT promotor methylated (89/122). Methylation classes were prognostic for time to progression. However, Heidelberg methylation classes determined at time of diagnosis were no longer prognostic following enhancing recurrence of the tumor. In contrast, TCGA methylation classes of primary samples remained prognostic also following enhancing recurrence. Homozygous deletions in CDKN2A/B were found in 10 of 87 IDH-mutated samples and were prognostically unfavorable at recurrence. Conclusions: DNA methylome Heidelberg classification at time of diagnosis is no longer of prognostic value at the time of enhancing recurrence. CDKN2A/B deletion status was predictive of survival from progression of IDH-mutated tumors.
    Type of Medium: Online Resource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2022
    detail.hit.zdb_id: 1225457-5
    detail.hit.zdb_id: 2036787-9
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  • 6
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 65, No. 24 ( 2005-12-15), p. 11335-11344
    Abstract: Oligodendrogliomas are a specific subtype of brain tumor of which the majority responds favorably to chemotherapy. In this study, we made use of expression profiling to identify chemosensitive oligodendroglial tumors. Correlation of expression profiles to loss of heterozygosity on 1p and 19q, common chromosomal aberrations associated with response to treatment, identified 376, 64, and 60 differentially expressed probe sets associated with loss of 1p, 19q or 1p, and 19q, respectively. Correlation of expression profiles to the tumors' response to treatment identified 16 differentially expressed probe sets. Because transcripts associated with chemotherapeutic response were identified independent of common chromosomal aberrations, expression profiling may be used as an alternative approach to the tumors' 1p status to identify chemosensitive oligodendroglial tumors. Finally, we correlated expression profiles to survival of the patient after diagnosis and identified 103 differentially expressed probe sets. The observation that many genes are differentially expressed between long and short survivors indicates that the genetic background of the tumor is an important factor in determining the prognosis of the patient. Furthermore, these transcripts can help identify patient subgroups that are associated with favorable prognosis. Our study is the first to correlate gene expression with chromosomal aberrations and clinical performance (response to treatment and survival) in oligodendrogliomas. The differentially expressed transcripts can help identify patient subgroups with good prognosis and those that will benefit from chemotherapeutic treatments. (Cancer Res 2005; 65(24): 11335-44)
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2005
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  • 7
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 76, No. 3 ( 2016-02-01), p. 525-534
    Abstract: The results from the randomized phase II BELOB trial provided evidence for a potential benefit of bevacizumab (beva), a humanized monoclonal antibody against circulating VEGF-A, when added to CCNU chemotherapy in patients with recurrent glioblastoma (GBM). In this study, we performed gene expression profiling (DASL and RNA-seq) of formalin-fixed, paraffin-embedded tumor material from participants of the BELOB trial to identify patients with recurrent GBM who benefitted most from beva+CCNU treatment. We demonstrate that tumors assigned to the IGS-18 or “classical” subtype and treated with beva+CCNU showed a significant benefit in progression-free survival and a trend toward benefit in overall survival, whereas other subtypes did not exhibit such benefit. In particular, expression of FMO4 and OSBPL3 was associated with treatment response. Importantly, the improved outcome in the beva+CCNU treatment arm was not explained by an uneven distribution of prognostically favorable subtypes as all molecular glioma subtypes were evenly distributed along the different study arms. The RNA-seq analysis also highlighted genetic alterations, including mutations, gene fusions, and copy number changes, within this well-defined cohort of tumors that may serve as useful predictive or prognostic biomarkers of patient outcome. Further validation of the identified molecular markers may enable the future stratification of recurrent GBM patients into appropriate treatment regimens. Cancer Res; 76(3); 525–34. ©2016 AACR.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2016
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  • 8
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 67, No. 12 ( 2007-06-15), p. 5635-5642
    Abstract: Aberrant splice variants are involved in the initiation and/or progression of glial brain tumors. We therefore set out to identify splice variants that are differentially expressed between histologic subgroups of gliomas. Splice variants were identified using a novel platform that profiles the expression of virtually all known and predicted exons present in the human genome. Exon-level expression profiling was done on 26 glioblastomas, 22 oligodendrogliomas, and 6 control brain samples. Our results show that Human Exon arrays can identify subgroups of gliomas based on their histologic appearance and genetic aberrations. We next used our expression data to identify differentially expressed splice variants. In two independent approaches, we identified 49 and up to 459 exons that are differentially spliced between glioblastomas and oligodendrogliomas, a subset of which (47% and 33%) were confirmed by reverse transcription-PCR (RT-PCR). In addition, exon level expression profiling also identified & gt;700 novel exons. Expression of ∼67% of these candidate novel exons was confirmed by RT-PCR. Our results indicate that exon level expression profiling can be used to molecularly classify brain tumor subgroups, can identify differentially regulated splice variants, and can identify novel exons. The splice variants identified by exon level expression profiling may help to detect the genetic changes that cause or maintain gliomas and may serve as novel treatment targets. [Cancer Res 2007;67(12):5635–8]
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2007
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  • 9
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 73, No. 19 ( 2013-10-01), p. 5858-5868
    Abstract: Although the CpG island methylator phenotype (CIMP) was first identified and has been most extensively studied in colorectal cancer, the term “CIMP” has been repeatedly used over the past decade to describe CpG island promoter methylation in other tumor types, including bladder, breast, endometrial, gastric, glioblastoma (gliomas), hepatocellular, lung, ovarian, pancreatic, renal cell, and prostate cancers, as well as for leukemia, melanoma, duodenal adenocarninomas, adrenocortical carcinomas, and neuroblastomas. CIMP has been reported to be useful for predicting prognosis and response to treatment in a variety of tumor types, but it remains unclear whether or not CIMP is a universal phenomenon across human neoplasia or if there should be cancer-specific definitions of the phenotype. Recently, it was shown that somatic isocitrate dehydrogenase-1 (IDH1) mutations, frequently observed in gliomas, establish CIMP in primary human astrocytes by remodeling the methylome. Interestingly, somatic IDH1 and IDH2 mutations, and loss-of-function mutations in ten-eleven translocation (TET) methylcytosine dioxygenase-2 (TET2) associated with a hypermethylation phenotype, are also found in multiple enchondromas of patients with Ollier disease and Mafucci syndrome, and leukemia, respectively. These data provide the first clues for the elucidation of a molecular basis for CIMP. Although CIMP appears as a phenomenon that occurs in various cancer types, the definition is poorly defined and differs for each tumor. The current perspective discusses the use of the term CIMP in cancer, its significance in clinical practice, and future directions that may aid in identifying the true cause and definition of CIMP in different forms of human neoplasia. Cancer Res; 73(19); 5858–68. ©2013 AACR.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2013
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  • 10
    Online Resource
    Online Resource
    American Association for Cancer Research (AACR) ; 2011
    In:  Cancer Research Vol. 71, No. 8_Supplement ( 2011-04-15), p. 3932-3932
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 71, No. 8_Supplement ( 2011-04-15), p. 3932-3932
    Abstract: We have performed expression profiling on 276 glioma samples of all histological subtypes, which resulted in the identification of seven distinct molecular subgroups. Interestingly, pilocytic astrocytomas (PAs) (n=6; adults) were assigned to one specific molecular cluster, together with four other, more malignant, gliomas. All the non-PAs were histologically diagnosed as higher grade gliomas with pilocytic features. Interestingly, there was a dramatic difference between survival of PAs and gliomas of other histological subtypes in this molecular cluster ( & gt;10.6 years vs. 3.4 (avg.) years; p = 0.03). Validation with an external dataset containing only PAs (GSE12907) showed that PAs are virtually always assigned to this molecular cluster, confirming the stability of the cluster. However, similar to our dataset, a subset of samples of both the REMBRANDT (8%) and TCGA (1%) datasets was also assigned to this molecular cluster. To further explore the differences between PAs and non-PAs in this molecular cluster, we performed genotyping using SNP 6.0 chip arrays. As reported previously, all PAs have only one larger genetic aberration; a focal amplification on locus 7q34, which is indicative for the presence of the tandem duplication KIAA1549-BRAF. One of the four samples of other histology also had this identical genetic aberration as PAs. The other (3/4) non-PA gliomas showed more genetic aberrations than the PAs. All patients harboring the KIAA1549-BRAF duplication were still alive (“survivors”) at the moment of writing this abstract (survival 10.6-19.6 years), whereas the remaining patients (“non-survivors”) all died within 0.44-2.7 years. High copy EGFR amplification was seen in none of the survivors but all of the other tumors. None of the samples in this cluster showed an IDH1-132H mutation. Closer inspection of the SNP arrays indicated that all non-survivors are tetraploid, whilst tumors of all survivors are near diploid (except for 3n on 7q34). The ploidy of all samples is currently validated using Fluorescence In Situ Hybridization (FISH). Polyploidy was not observed in any of the other molecular clusters. Validation with the REMBRANDT and the TCGA datasets showed that non-PAs assigned to this molecular cluster had a poor survival, similar to the non-PAs in our dataset. Interestingly, tetraploidy and EGFR amplification were also seen in the GBM samples from the TCGA that were assigned to this cluster. Gliomas from other molecular subtypes did not show tetraploidy on SNP chip data. In conclusion, we have discovered and validated a glioma subtype that shares molecular (RNA expression profile) and histological features with PAs. In spite of these similarities (and in contrast to the PAs), such tumors have a relatively poor prognosis. They are characterized by EGFR amplification and a near tetraploid cytogenetic profile. Identification of this specific subtype may have important therapeutic consequences. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3932. doi:10.1158/1538-7445.AM2011-3932
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2011
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    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
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