A web-based prognostic tool for extremity and trunk wall soft tissue sarcomas and its external validation.

BACKGROUND: We developed a web-based, prognostic tool for extremity and trunk wall soft tissue sarcoma to predict 10-year sarcoma-specific survival. External validation was performed. METHODS: Patients referred during 1987-2002 to Helsinki University Central Hospital are included. External validation was obtained from the Lund University Hospital register. Cox proportional hazards models were fitted with the Helsinki data. The previously described model (SIN) includes size, necrosis, and vascular invasion. The extended model (SAM) includes the SIN factors and in addition depth, location, grade, and size on a continuous scale. Models were statistically compared according to accuracy (area under the ROC curve=AUC) of 10-year sarcoma-specific survival prediction. RESULTS: The AUC of the SAM model in 10-year survival prediction in the Helsinki patient series was 0.81 as compared with 0.74 for the SIN model (P=0.0007). The corresponding AUCs in the external validation series were 0.77 for the SAM model and 0.73 for the SIN model (P=0.03). A web-based calculator for the SAM model is available at http://www.prognomics.org/sam. CONCLUSION: Addition of grade, depth, and location as well as tumour size on a continuous scale significantly improved the accuracy of the prognostic model when compared with a model that includes only size, necrosis, and vascular invasion.

Microvascular reconstruction after resection of soft tissue sarcoma of the leg.

BACKGROUND: Limb-sparing surgery and satisfactory functional outcome is the goal of extremity soft tissue sarcoma (STS) surgery. Tissue defects after tumour excision are often extensive, and microvascular reconstruction is frequently required. METHODS: Seventy-three patients with STS of the leg requiring microvascular reconstruction were treated between 1985 and 2006. Radiotherapy was delivered if the microscopic surgical margin was less than 2.5 cm. RESULTS: Mean follow-up was 65.9 months. Seventy-five free flaps were performed, with a success rate of 95 per cent. One patient died within a month of surgery. Five-year local recurrence-free survival was 82 per cent, metastasis-free survival 59 per cent, disease-free survival 56 per cent and disease-specific overall survival 70 per cent. Fifty-five (75 per cent) of the 73 patients were able to walk normally or had only minor walking impairment. CONCLUSION: Without microvascular reconstruction, amputation would have been necessary in most patients. Microvascular reconstruction is safe and reliable in lower extremity STS reconstruction.

Impact of the smallest surgical margin on local control in soft tissue sarcoma.

BACKGROUND: The aim was to review a single-institution experience of a prospective treatment protocol for soft tissue sarcoma of the extremity and trunk wall, with particular focus on the smallest surgical margin leading to local control. METHODS: The study included 270 patients who had surgery for soft tissue sarcoma at Helsinki University Central Hospital between 1987 and 1997. Resection margins were measured prospectively from tumour specimens. Radiotherapy was administered if the smallest margin measured less than 2.5 cm, irrespective of tumour grade. RESULTS: With a median follow-up of 6.6 years, the 5-year local control rate was 76.4 per cent. On multivariable analysis, the smallest surgical margin around the sarcoma (after radiotherapy) was prognostic for local control. A margin of at least 2.5 cm was associated with a local recurrence-free rate of 89.2 per cent at 5 years. Tumour size, depth or grade and patient's age had no independent prognostic effect on local control. CONCLUSION: Surgical margin had independent prognostic value for local control. A surgical margin of 2-3 cm provided reasonable local control of soft tissue sarcoma, even without radiotherapy. Radiotherapy is recommended for smaller margins, irrespective of tumour grade.

Gains and losses of DNA sequences in osteosarcomas by comparative genomic hybridization.

Our aim was to identify chromosomal regions that are likely to harbor previously unknown genes with an important role in the genesis of osteosarcoma. Comparative genomic hybridization was used to screen for losses and gains of DNA sequences along all chromosome arms in 11 tumors. Extensive genetic aberrations, with an average of 11 changes/tumor (range, 1-20), were found in 10 of the 11 specimens. High level amplifications of small chromosomal regions were detected in eight tumors. These involved the 12q12-q13 region (known to contain the SAS-MDM2 locus) and several previously unreported amplification sites such as 17p11-p12, 3q26, and Xq12. When all DNA sequence gains were evaluated, the gains at 8q and Xp were most common (45%). The most common losses of DNA sequences were seen at 2q, 6q, 8p, and 10p (36%). In conclusion, despite the very complex pattern of genetic changes in osteosarcomas, certain chromosomal regions appear to be affected more often than others. Most of these regions have not previously been reported to be implicated in osteosarcomas and may thus highlight locations of novel genes with an important role in the development and progression of these tumors.

Surgically treated patients with axial and peripheral Ewing's sarcoma family of tumours: A population based study in Finland during 1990-2009.

BACKGROUND: The surgical treatment of Ewing's sarcoma family tumours (ESFTs) is challenging especially with axial tumours. The aim of the study was to analyse surgical treatment and outcome in a nationwide, population-based material consisting of surgically treated axial and peripheral ESFTs of bone and soft tissue. METHODS: The data were collected from the Finnish National Cancer Registry and the medical records of patients diagnosed during 1990-2009. Fifty-seven patients with surgically treated ESFTs were included, 22 with an axial and 35 with a peripheral primary tumours. The surgical treatment, its complications, survival and prognostic factors were analysed. RESULTS: Fifty-four patients underwent surgery with a curative intent and three underwent de-bulking operations. Bone reconstruction was performed in six patients with an axial and 15 with a peripheral tumour. Positive resection margins were associated with a worse five-year local relapse-free survival (33% vs. 84% for those with resection margins free of tumour cells, p = 0.003). The five-year sarcoma-specific survival was affected only by an axial location of the primary (61% vs. 89% for those with a peripheral tumour, p = 0.031). The late complications were mainly associated with bone reconstruction and more frequent among patients with a peripheral compared to an axial tumour (p = 0.031). CONCLUSIONS: In the treatment of ESFTs, achieving adequate resection margins is crucial to avoid local relapses. Surgical complications are common particularly with bone reconstruction.

Clinical significance of genetic imbalances revealed by comparative genomic hybridization in chondrosarcomas.

DNA copy number changes were studied by comparative genomic hybridization (CGH) in 50 chondrosarcoma samples from 45 patients. Mean number of genetic aberrations in primary tumors was 4.8 +/- 1.8. The most frequently gained regions were 20q12-qter (37%), 20q (32%), 8q24.1-qter (27%), 20p (24%), and 14q24-qter (24%). Losses were 5.5 times less frequent than gains and observed mainly at Xcen-q21, 6cen-q22, and 18cen-q11.2 (11% each). Recurrent and metastatic tumors showed a mean of 4.0 +/- 2.2 aberrations per sample. The most frequently gained regions were chromosome 7 (4 cases), 5q14-q32 (4 cases), 6p (3 cases), and 12q (3 cases). Losses of DNA sequences were 3.4 times less frequent than gains. Histological tumor grade was significantly associated with metastasis-free survival (P = .002) and overall survival (P = .003), being the strongest prognostic factor tested. A statistically significant correlation was found between gain at 8q24.1-qter and shorter overall survival (P = .01) but not with local recurrence or metastasis-free survival. Gain at 14q24-qter was associated with a trend to shorter overall survival (P = .05) but neither with an increased risk for local recurrence nor with metastasis-free survival. In a multivariate analysis, only the tumor grade associated with overall survival (P = .02). In a multivariate analysis together with the tumor grade, gain at 8q24.1-qter did not retain its significance (P = .44), indicating that this imbalance is not an independent prognostic factor.

Microsatellite markers as tools for characterization of DNA amplifications evaluated by comparative genomic hybridization.

To test the applicability of microsatellite markers in the study of DNA amplifications evaluated by comparative genomic hybridization, we analyzed 55 highly polymorphic microsatellite marker loci from six liposarcoma tumors (seven specimens) and from one atypical lipoma with a gain or high-level amplification at 12q13-22. Twelve-trisomic neoplastic cells from a patient with B-cell chronic lymphocytic leukemia were used as a positive control, in which 74% of informative loci showed allelic imbalance. In every tumor specimen microsatellite marker loci analysis showed allelic imbalance. The amplicons were discontinuous, indicating the presence of separate amplicons in the 12q13-22 region. Not only gains but also losses as well as concomitant gains and losses of alleles were observed. The use of microsatellite markers has several advantages: gene loci as well as flanking DNA loci can be analyzed, it is fast and lends itself to automation, and allows a large number of marker loci to be analyzed simultaneously.

A recurrent chondromyxoid fibroma with chromosome aberrations ins(5;2)(q13;p21p25) and 2p deletion: a case report.

We report a patient with a recurrent chondromyxoid fibroma, a rare benign tumor of the bone with clonal aberrations in chromosomes 2 and 5. Karyotyping, chromosome painting, interphase cytogenetics by in situ hybridization, and DNA flow cytometry were used. The karyotype was interpreted as 46,XX,der(2)ins(5;2)(q13;p21p25),der(2)ins(5;2)(q13;p21p25), der(5)ins(5;2) (q13;p21p25).

Cytogenetic study of 249 consecutive patients examined for a bone tumor.

Chromosome analysis was performed on 304 samples of 249 consecutive patients examined for a possible bone tumor. The series consisted of 86 nonneoplastic disorders, 108 benign and 78 malignant primary bone tumors, and 32 other bone malignancies. In the group of nonneoplastic disorders, one sample from an infectious lesion demonstrated a clonal chromosome aberration, i.e., additional material in the short arm of chromosome 1. Simple clonal aberrations were noted in six of 75 successfully cultured benign tumors, e.g., a chondromyxoid fibroma with an insertion type translocation from 2p21p25 to 5q13 and 2p deletion and a nonossifying fibroma with del(4)(p14). Complex clonal aberrations were evident in 21 of 54 successfully cultured malignant primary bone tumors and eight of 21 secondary bone malignancies. The complexity of clonal aberrations correlated with the grade of malignancy as the osteosarcomas and chondrosarcomas of high-grade demonstrated chaotic abnormalities. Six Ewing's sarcomas demonstrated the t(11;22)(q24;q12); in one this was the sole abnormality, and in five additional changes were evident: der(1;16)(q10;p10) in one. Homogeneously staining elongated areas interpreted as HSR were observed in three patients, all of whom had a highly malignant tumor. The most frequent nonclonal abnormality was telomeric association, which was observed mainly in giant cell tumors.

Novel findings in gene expression detected in human osteosarcoma by cDNA microarray.

cDNA microarray analysis was used to screen for gene expression alterations in human osteosarcoma cell lines. The analysis using three cell lines revealed changes in the expression of several genes in comparison with normal human osteoblasts. Among the 5,184 sequences that were analyzed, 35 showed aberrant expression in all the cell lines. Eight of these showed overexpression and 27 underexpression compared to their expression levels in osteoblasts. The most highly up-regulated genes included heat shock protein 90beta and polyadenylate-binding protein-like 1. Commonly down-regulated genes included fibronectin 1 and thrombospondin 1. RT-PCR was used to verify these changes in the cell lines and in three primary osteosarcoma samples. This study shows that (1) gene expression pattern in osteosarcoma cell lines differs considerably from normal osteoblasts, (2) osteosarcoma cell lines can be used as a model system to detect novel gene expression alterations present in primary tumors, (3) the overexpression of heat shock protein 90beta and polyadenylate-binding protein-like 1, and (4) the down-regulation of fibronectin 1 and thrombospondin 1 may play a role in the development and/or progression of osteosarcoma. This study indicates that microarray-based expression surveys may be used to establish the molecular fingerprint of osteosarcoma, however, larger cDNA chips and more tumor specimens are required to define the clinically relevant gene expression patterns.

No DNA copy number changes in osteochondromas: a comparative genomic hybridization study.

Cytogenetic changes in osteochondroma samples were studied by comparative genomic hybridization and by chromosome banding. No DNA copy number changes (15 patients) or chromosomal aberrations (9 patients) were observed in any of the patients.

Overrepresentation of 1q21-23 and 12q13-21 in lipoma-like liposarcomas but not in benign lipomas: a comparative genomic hybridization study.

Twenty lipomatous tumors, including eight lipoma-like liposarcomas and 12 benign lipomas, were analyzed using comparative genomic hybridization (CGH). DNA sequence copy number changes detected in five lipoma-like liposarcomas (mean, 1.1 aberrations/tumor; range, 0-2) consisted of gains of 12q13-21 (five tumors) and 1q21-23 (four tumors). Two of the tumors showed high-level amplification at 12q14-21 and one tumor at 1q21-22. No copy number changes were found in lipomas. Overrepresentation of 1q and 12q sequences was a recurrent finding in lipoma-like liposarcomas but not in lipomas. Thus, CGH may help in the differential diagnosis of low-grade or borderline adipose neoplasms.

A cytogenetic study of malignant fibrous histiocytoma.

We report the results of cytogenetic analysis of malignant fibrous histiocytoma of soft tissue (MFH). Seven of 12 successfully cultured MFHs had complex clonal aberrations, including translocations, deletions, and unidentifiable marker chromosomes. Telomeric associations were observed in five and the double minute phenomenon in four of seven MFHs with abnormal karyotypes. In one case (a storiform-pleomorphic MFH, grade IV) with a complex polyploid karyotype, two clonal ring chromosomes were present, one interpreted as r(19)(p13q13), one unidentified. In two tumors, clonal structural rearrangements of chromosome 1 were seen: del(1)(q21) in a storiform-pleomorphic MFH, grade IV, and add (1)(q21 or q32), t(1;10)(p22;q22) in a myxoid MFH, grade I. The remaining five MFHs had normal karyotypes, but in two of them nonclonal, structural aberrations were found. The modal chromosome number in the studied MFHs varied widely, but the majority of tumors with abnormal karyotypes had polyploid chromosome complements (five of seven cases). Our results confirm many of the previous findings and indicate that double minutes (dmins) may be more frequent in MFH than previously reported.

Cytogenetic study of extraskeletal mesenchymal chondrosarcoma. A case report.

Extraskeletal mesenchymal chondrosarcoma (EMC) is a rare and highly malignant type of chondrosarcoma of soft tissue origin. We performed a cytogenetic study on a patient with EMC. Cytogenetic analysis revealed the tumor karyotype: 48-49,XX, t(4;9)(q23;q22), add(10)(q?26), +16, ?del(19)(p13), +1-2mar[cp12] / 48-50,idem, t(1;20)(q21;q13), +mar[cp6] / 46,XX [7].

Clinical correlations of genetic changes by comparative genomic hybridization in Ewing sarcoma and related tumors.

Our previous comparative genomic hybridization (CGH) study of Ewing sarcoma and related tumors showed that DNA sequence copy number increases of 1q21-q22 and of chromosomes 8 and 12 were associated with trends toward poor survival (Armengol et al., Br J Cancer 1997, 75, 1403-1409). These trends were not statistically significant. In the present study, we analyzed 28 primary Ewing sarcomas and related tumors by CGH to study whether these (or other) changes have prognostic value in these tumors. Twenty-one tumors (75%) had changes with a mean of 1.9 changes per tumor. The most frequent aberration was gain of chromosome 8 in 10 tumors (36%). Five tumors (18%) had copy number increases at 1q21-22 and 5 had gain of 7q. Copy number increase of 6p21.1-pter, gain of chromosome 12, and loss of 16q were seen in 11%. Copy number increases of 1q21-q22 and of chromosomes 8 and 12 were associated with trends toward worse outcome, but the differences did not reach statistical significance. A novel finding is the association of copy number increase at 6p with worse distant disease-free (P = 0.04) and overall survival (P = 0.004). To confirm this finding and to see whether copy number increases of 1q21-q22 and of chromosomes 8 and 12 have definite prognostic value, a larger number of cases needs to be studied.

Measurement of growth rate of lung metastases in 21 patients with bone or soft-tissue sarcoma.

The volume doubling time (T2) of 52 lung metastases in 21 patients was calculated from measurements done on plain chest radiographs. Follow-up times ranged from 14 to 819 days. The measurements were fairly well reproducible in the majority of patients, although considerable discrepancies in T2 estimates made by two independent observers were found in a few patients. The median doubling time was 34.9 days (estimated 95% range 3.9 to 352 days). The variation of T2:s between patients was significantly (P = 0.0001) larger than that between T2: of multiple metastases in the same patients. The growth of the metastases seemed to be well described by a simple exponential function in all patients with more than two measurements, without evidence of Gompertzian growth. There seemed to be a linear correlation between the logarithm of T2 and log-survival time from diagnosis of metastatic disease, even if only one third of the variation of survival times between patients could be explained by differences in T2. T2 was not a significant factor for survival in Cox-analysis (P = 0.10).

Ring chromosomes in parosteal osteosarcoma contain sequences from 12q13-15: a combined cytogenetic and comparative genomic hybridization study.

Seven parosteal osteosarcoma (POS) samples, six of which were cytogenetically characterized, were studied by using comparative genomic hybridization (CGH). All samples showed DNA sequence copy number changes (mean, six aberrations/tumor; range, 1-13); gains were more frequent than losses. Gain of 12q13-15 sequences was found in every tumor and correlated with the presence of ring chromosomes. High-level amplification, which was detected in four tumors, was seen only in chromosome 12, with 12q13-14 as the minimal common region. By using chromosome painting, one of the rings of one case was shown to be composed entirely of chromosome 12 material. Together with previous data, our findings show that gain of 12q13-15 sequences is a characteristic feature of POS and that these sequences are contained within the ring chromosomes.

Dedifferentiated chondrosarcoma with t(9;22)(q34;q11-12).

Translocation t(9;22)(q22-31;q11-12) is associated with the myxoid variant of chondrosarcoma. We present here a report of a patient with a dedifferentiated grade IV chondrosarcoma, which originated from the iliac bone and contained areas of grade I chondrosarcoma. There was no evidence of myxoid differentiation. The tumor had the karyotype 46,X,-X,t(9;22)(q34;q11-12), + mar[5]/52-61,x?,2-3 min,inc[9]/46,XX[2]. It is possible that the different breakpoints in the t(9;22) may reflect different histopathologic subgroups of chondrosarcoma.

Growth rate of lung metastases and S-phase fraction as determined by flow cytometry from the primary tumour in 25 patients with bone or soft-tissue sarcomas.

A significant correlation (r = -0.48) was found between the logarithm of the S-phase fraction of the primary tumour (SPF) and the logarithm of the doubling time of lung metastases (T2). The estimated median cell loss factor was 88% (range 35-99%).