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- Ofverholm, Ingegerd, et al.
(author)
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Comprehensive Genomic Profiling Alters Clinical Diagnoses in a Significant Fraction of Tumors Suspicious of Sarcoma
- 2024
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In: Clinical Cancer Research. - : American Association for Cancer Research (AACR). - 1078-0432 .- 1557-3265. ; 30:12, s. 2647-2658
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Journal article (peer-reviewed)abstract
- Purpose: Tumor classification is a key component in personalized cancer care. For soft-tissue and bone tumors, this classification is currently based primarily on morphology assessment and IHC staining. However, these standard-of-care methods can pose challenges for pathologists. We therefore assessed how whole-genome and whole-transcriptome sequencing (WGTS) impacted tumor classification and clinical management when interpreted together with histomorphology.Experimental Design: We prospectively evaluated WGTS in routine diagnostics of 200 soft-tissue and bone tumors suspicious for malignancy, including DNA and RNA isolation from the tumor, and DNA isolation from a peripheral blood sample or any non-tumor tissue.Results: On the basis of specific genomic alterations or absence of presumed findings, WGTS resulted in reclassification of 7% (13/197) of the histopathologic diagnoses. Four cases were downgraded from low-grade sarcomas to benign lesions, and two cases were reclassified as metastatic malignant melanomas. Fusion genes associated with specific tumor entities were found in 30 samples. For malignant soft-tissue and bone tumors, we identified treatment relevant variants in 15% of cases. Germline pathogenic variants associated with a hereditary cancer syndrome were found in 22 participants (11%).Conclusions: WGTS provides an important dimension of data that aids in the classification of soft-tissue and bone tumors, correcting a significant fraction of clinical diagnoses, and identifies molecular targets relevant for precision medicine. However, genetic findings need to be evaluated in their morphopathologic context, just as germline findings need to be evaluated in the context of patient phenotype and family history.
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| 2. |
- Skorpil, Mikael, et al.
(author)
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The effect of radiotherapy on fat content and fatty acids in myxoid liposarcomas quantified by MRI
- 2017
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In: Magnetic Resonance Imaging. - : Elsevier. - 0730-725X .- 1873-5894. ; 43, s. 37-41
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Journal article (peer-reviewed)abstract
- Background: Myxoid liposarcomas are highly radiosensitive. Consequently radiotherapy is often used pre-operatively to reduce tumor volume and lessen the post-operative deficit. In soft-tissue sarcomas therapy response is mainly evaluated using magnetic resonance imaging (MRI) and the fundamental criterion for a positive response is decreased tumor size. In myxoid liposarcomas an increased fat content is also known to occur as a response to radiotherapy. Objective: To highlight the difficulties of MRI for therapy response evaluation in irradiated myxoid liposarcomas, by using MRI Dixon techniques enabling objective quantification of proton density fat fraction (%) and the number of double bonds (ndb; unsaturation degree) of fatty acids. Secondly, to compare quantitative fat fraction measurements versus visual grading of fat content on T1-weighted images. Case descriptions: Prior to surgery, two patients with myxoid liposarcoma were treated with 50 Gy. Following radiotherapy, both tumors on MRI showed reduced size, elevated fat fraction and transformed fat fraction histograms with diverse changes of ndb, while histopathological specimens showed discordant treatment effects; one case having good response and the other having poor response. Conclusions: A decrease in tumor size and increase in fat content on MRI cannot be interpreted as positive therapy response in radiotherapy of myxoid liposarcomas. Our data also give further supporting evidence that differentiation and maturation of tumor cells is the cause for the lipoma-like areas seen after radiotherapy. Finally, quantitative MRI Dixon techniques are preferable to visual grading for estimating the fat content in lipomatous tumors.
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| 3. |
- Arbajian, Elsa, et al.
(author)
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A Benign Vascular Tumor With a New Fusion Gene: EWSR1-NFATC1 in Hemangioma of the Bone.
- 2013
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In: American Journal of Surgical Pathology. - 1532-0979. ; 37:4, s. 613-616
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Journal article (peer-reviewed)abstract
- The EWSR1 gene in chromosome band 22q12 is a promiscuous fusion partner involved in a vast array of tumors characterized by gene fusions. In this study, we report the finding of a new fusion gene, EWSR1-NFATC1, in a hemangioma of the bone; genetic rearrangements have not previously been described in this tumor type. Chromosome banding analysis showed a t(18;22)(q23;q12) translocation as the sole change. Fluorescence in situ hybridization mapping suggested the involvement of each of the 2 partner genes, and reverse transcriptase polymerase chain reaction revealed an in-frame EWSR1-NFATC1 transcript. NFATC1 has not previously been shown to be involved in a fusion chimera. However, NFATC2, encoding another member of the same protein family, is known to be a fusion partner for EWSR1 in a subgroup of Ewing sarcoma. Thus, our findings further broaden the spectrum of neoplasms associated with EWSR1 fusion genes, add a new partner to the growing list of EWSR1 chimeras, and suggest that chromosomal rearrangements of pathogenetic, and possibly also diagnostic, significance can be present in benign vascular bone tumors.
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| 6. |
- Brodin, Bertha A., et al.
(author)
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Drug sensitivity testing on patient-derived sarcoma cells predicts patient response to treatment and identifies c-Sarc inhibitors as active drugs for translocation sarcomas
- 2019
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In: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 120:4, s. 435-443
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Journal article (peer-reviewed)abstract
- BACKGROUND: Heterogeneity and low incidence comprise the biggest challenge in sarcoma diagnosis and treatment. Chemotherapy, although efficient for some sarcoma subtypes, generally results in poor clinical responses and is mostly recommended for advanced disease. Specific genomic aberrations have been identified in some sarcoma subtypes but few of them can be targeted with approved drugs. METHODS: We cultured and characterised patient-derived sarcoma cells and evaluated their sensitivity to 525 anti-cancer agents including both approved and non-approved drugs. In total, 14 sarcomas and 5 healthy mesenchymal primary cell cultures were studied. The sarcoma biopsies and derived cells were characterised by gene panel sequencing, cancer driver gene expression and by detecting specific fusion oncoproteins in situ in sarcomas with translocations. RESULTS: Soft tissue sarcoma cultures were established from patient biopsies with a success rate of 58%. The genomic profile and drug sensitivity testing on these samples helped to identify targeted inhibitors active on sarcomas. The cSrc inhibitor Dasatinib was identified as an active drug in sarcomas carrying chromosomal translocations. The drug sensitivity of the patient sarcoma cells ex vivo correlated with the response to the former treatment of the patient. CONCLUSIONS: Our results show that patient-derived sarcoma cells cultured in vitro are relevant and practical models for genotypic and phenotypic screens aiming to identify efficient drugs to treat sarcoma patients with poor treatment options.
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| 8. |
- Dahlén, Anna, et al.
(author)
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Fusion, disruption, and expression of HMGA2 in bone and soft tissue chondromas
- 2003
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In: Modern Pathology. - 1530-0285. ; 16:11, s. 1132-1140
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Journal article (peer-reviewed)abstract
- Soft tissue and skeletal chondromas are rare entities, and only 21 cases with abnormal karyotypes have been reported. A survey of these, and 10 new cases reported herein, showed that the 12q13-15 segment is nonrandomly involved in structural rearrangements in chondromas. The HMGA2 (HMGI-C) locus in 12q15 is frequently rearranged in other benign mesenchymal tumors, and this study aimed at characterizing the expression of HMGA2 in chondromatous tumors. The material consisted of 8 soft tissue and 6 skeletal chondromas, as well as of 14 skeletal chondrosarcomas. All cases had been cytogenetically analyzed. Expression of HMGA2 could be assessed by RT-PCR in 8 chondromas and 13 chondrosarcomas. HMGA2 was expressed in 4 of six soft tissue chondromas, all displaying 12q-rearrangements at cytogenetic analysis. A truncated transcript (exons 1-3), but not a full-length (exons 1-5) transcript, was detected in three of them, suggesting activation through an intragenic rearrangement. One soft tissue chondroma had a t(3;12)(q27;q15), and the RT-PCR analysis revealed an HMGA2-LPP fusion transcript, composed of HMGA2 exons 1-3 and LPP exons 9-11. An identical fusion transcript previously has been identified in lipoma and pulmonary chondroid hamartoma. In the fourth soft tissue chondroma, a full-length transcript was detected, indicating expression of at least one intact allele. Both skeletal chondromas expressed HMGA2. In one of them, a full-length transcript was detected, even though 12q was cytogenetically unaffected. A truncated or full-length transcript was found in 8 of 13 chondrosarcomas, 4 of which displayed 12q rearrangements. Possibly, cryptic rearrangements were present among the many complex marker chromosomes in the remaining 4 cases.
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| 9. |
- Hansén Nord, Karolin, et al.
(author)
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Retained heterodisomy is associated with high gene expression in hyperhaploid inflammatory leiomyosarcoma.
- 2012
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In: Neoplasia. - : Elsevier BV. - 1522-8002. ; 14:9, s. 807-U156
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Journal article (peer-reviewed)abstract
- Inflammatory leiomyosarcoma (ILMS) is a soft tissue tumor that morphologically resembles conventional leiomyosarcoma (LMS) admixed with a prominent inflammatory infiltrate. Genetic data on ILMS are still limited but have suggested that this entity is characterized by hyperhaploidy (24-34 chromosomes). This low chromosome number is otherwise uncommon in neoplasia and has been found only in 0.2% to 0.3% of cytogenetically investigated tumors. Here, three ILMS were investigated using cytogenetic, single-nucleotide polymorphism (SNP) array, and global gene expression analyses. All cases displayed a hyperhaploid origin. Combined with previously reported cases, hyperhaploidy has been found in six of seven cytogenetically investigated ILMS. The copy number distribution of individual chromosomes is clearly nonrandom; the hyperhaploid clones of all six cases displayed disomy for chromosomes 5 and 20, and two copies of chromosomes 18, 21, and 22 were also common. All chromosomes identified as disomic showed a biparental origin by SNP array analysis; whether this is of pathogenetic importance is not known. Compared with conventional LMS, ILMS had a distinct gene expression signature. Furthermore, the number of chromosome copies correlated well with gene expression levels; disomic chromosomes showed higher gene expression levels than monosomic chromosomes, a finding that has not previously been reported for hyperhaploid tumors. Taken together, our findings suggest that disomy for some chromosomes, notably 5 and 20, as well as distorted gene expression achieved through massive loss of other chromosomes are essential features of ILMS.
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