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- Mandahl, Nils, et al.
(author)
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Cytogenetic aberrations and their prognostic impact in chondrosarcoma
- 2002
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In: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257. ; 33:2, s. 188-200
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Journal article (peer-reviewed)abstract
- Chondrosarcoma is the second most common primary malignancy of bone. Cytogenetic data are available from close to 100 cases, including all subtypes of chondrosarcoma. Specific chromosomal rearrangements have been identified only in extraskeletal myxoid chondrosarcoma (EMC). Strong prognostic factors are largely missing, although size and, in particular, histologic tumor grade have been implicated. In the present study, we investigated the genomic aberrations in 59 chondrosarcomas (six grade 1, 24 grade 2, and 29 grade 3, including dedifferentiated tumors), excluding EMC, by chromosome banding analysis and DNA flow cytometry and correlated the findings with clinical outcome. Hyperhaploid to near-diploid karyotypes were found in half of the cases, and there was a good correlation between cytogenetics and flow cytometry data; discrepancies were seen primarily in cases with normal karyotypes and in those with -Y as the sole anomaly. Abnormal karyotypes, excluding those with -Y as the only change, were found in 36 cases. No recurrent structural aberration was found, but a nonrandom pattern of aberrations was seen. Total or partial gains and losses were the dominant karyotypic features. Genomic imbalances found in at least 10 cases included -1p36, -1p13-p22, -4, -5q13-q31, -6q22-qter, +7p13-pter, -9p22-pter, -10p, -10q24-qter, -11p13-pter, -11q25, +12q15-qter, -13q21-qter, -14q24-qter, -18p, -18q22-qter, +19, +20pter-q11, +21q, and -22q13. At the latest follow-up, 19 patients had experienced distant metastases, and the 5-year metastasis-free survival rate was 0.69. By univariate analysis, malignancy grade and loss of material from 6q, 10p, 11p or 11q, 13q, and 22q were associated with impaired metastasis-free survival. Only -13q was an independent prognostic factor for metastasis, regardless of tumor grade or size.
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- Menghi-Sartorio, Samantha, et al.
(author)
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DNA copy number amplifications in sarcomas with homogeneously staining regions and double minutes
- 2001
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In: Cytometry. - : Wiley. - 0196-4763 .- 1097-0320. ; 46:2, s. 79-84
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Journal article (peer-reviewed)abstract
- To identify DNA amplifications in sarcomas, comparative genomic hybridization was performed on 27 cases that were likely to display high-level DNA copy number gains. In all cases, chromosome banding analysis had revealed homogeneously staining regions or double minutes, i.e., cytogenetic signs of gene amplification. In most cases, gains predominated over losses. Low-level amplifications (ratio 1.3:1.5) were seen in 20 cases. High-level amplifications (ratio >1.5) exceeded the frequencies seen in published, unselected sarcomas of similar histotypes and were detected in 16 tumors: 4/4 osteosarcomas, 5/8 malignant fibrous histiocytomas, 3/7 leiomyosarcomas, 1/2 myosarcomas, 0/1 liposarcoma, 0/1 rhabdomyosarcoma, 1/1 pleomorphic sarcoma, 0/1 myxofibrosarcoma, 1/1 malignant mesenchymona, and 1/1 malignant schwannoma, with two to four chromosomal regions involved in nine tumors. Recurrent amplifications involved 1p33-p32, 5p15-p14, 7pter-p12, 7q21-qter, 8q21.3-qter, 11q22-q23, 16p13.2-p12, 19q12-q13.1, 20q11.2-qter, and 22q12-q13. Most of the recurrent gains/amplifications we detected have been reported in sarcomas previously. A novel gain/amplification was seen at 2q14.3-q21 in five cases of four sarcoma types. The disparate pattern of amplified sequences, the poor correspondence between the localization of low- and high-level amplifications, and the chromosomal position of homogeneously staining regions suggest the involvement of many genes in the amplifications and that the genes rarely maintain their native position in these tumors.
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- Tarkkanen, Maija, et al.
(author)
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Comparative genomic hybridization of postirradiation sarcomas
- 2001
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In: Cancer. - 1097-0142. ; 92:7, s. 1992-1998
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Journal article (peer-reviewed)abstract
- BACKGROUND. Radiotherapy is a known risk factor for sarcoma development. Postirradiation sarcomas arise within the radiation field after a latency period of several years and usually are highly malignant. Very little is yet known about their genetic changes. METHODS. Twenty-seven postirradiation sarcomas were analyzed by comparative genomic hybridization, which allows genome-wide screening of DNA sequence copy number changes. RESULTS. Copy-number aberrations were detected in 20 (74%) tumors. The mean number of aberrations per tumor was 5.3 with gains outnumbering losses. The most frequent gains affected the minimal common regions of 7q11.2-q21 and 7q22 in 30% and 7p15-pter in 26%. Gain of 8q23-qter was detected in 22%. The most frequent losses affected 11q23-qter and 13q22-q32 in 22%. In osteosarcomas, the most frequent aberration was loss of 1p21-p31, in malignant fibrous histiocytomas (MFH) gain of 7cen-q22, and in fibrosarcomas gain of 7q22. The findings in postirradiation osteosarcomas and MFHs were compared with findings in sporadic osteosarcomas and MFHs, reported previously by the authors. In sporadic osteosarcomas, gains outnumbered losses, but, in postirradiation osteosarcomas, losses were more frequent than gains. Loss at 1p was rare in sporadic osteosarcoma (3%) but frequent (57%) in postirradiation osteosarcomas. Gains at 7q were frequent both in postirradiation and sporadic MFH. CONCLUSIONS. According to previous studies on different types of sporadic sarcomas, gains at 7q or 8q are associated with poor prognosis or large tumor size. Thus, the frequent gains at 7q and 8q might have been responsible in part for the poor prognosis of postirradiation sarcomas. Also, however, some of their clinical features, i.e., high malignancy grade, late diagnosis, and central location, are associated with a poor prognosis.
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