Analysis of the Peritumoral Tissue Unveils Cellular Changes Associated with a High Risk of Recurrence.

BACKGROUND: The management of soft-tissue sarcoma (STS) relies on a multidisciplinary approach involving specialized oncological surgery combined with other adjuvant therapies to achieve optimal local disease control. Purpose and Results: Genomic and transcriptomic pseudocapsules of 20 prospective sarcomas were analyzed and revealed to be correlated with a higher risk of recurrence after surgery. CONCLUSIONS: A peritumoral environment that has been remodeled and infiltrated by M2 macrophages, and is less expressive of healthy tissue, would pose a significant risk of relapse and require more aggressive treatment strategies.

Liposomal Irinotecan Shows a Larger Therapeutic Index than Non-liposomal Irinotecan in Patient-Derived Xenograft Models of Pancreatic Cancer.

INTRODUCTION: Liposomal irinotecan promotes controlled sustained release of irinotecan (CPT-11), therefore, we hypothesize that the therapeutic index (quantitative measurement of the relative efficacy/safety ratio of a drug) will be higher for liposomal than non-liposomal irinotecan. METHODS: We compared the therapeutic indexes of liposomal and non-liposomal irinotecan in mice bearing subcutaneous patient-derived xenograft (PDX) pancreatic tumors under dosing regimens approximating the clinical setting. Following preliminary drug sensitivity/antitumor activity analyses on three PDX tumor models, one model was selected for analyses of efficacy, biomarker, toxicology, pharmacokinetics in mice receiving liposomal irinotecan (2.5, 10, 50 mg/kg/week) or non-liposomal irinotecan (10, 25, 50 mg/kg/week). The maximum tolerated dose (MTD) for each treatment was 50 mg/kg/week. RESULTS: Using the selected IM-PAN-001 model at the MTD (both treatments, 50 mg/kg/week), antitumor activity, phospho-histone gamma-H2AX protein staining in cancer cell nuclei, histological tumor regression, and plasma levels of CPT-11 and its active metabolite SN-38 after 24 h were greater with liposomal than non-liposomal irinotecan, but tumor SN-38 levels were similar. At the lowest doses assessed, antitumor activity, histological tumor regression, and jejunum and bone marrow toxicity were similar. Based on these findings, liposomal and non-liposomal irinotecan had therapeutic indexes of 20 and 5, respectively. CONCLUSION: This non-clinical study showed a fourfold broader therapeutic index with liposomal than non-liposomal irinotecan in mice bearing IM-PAN-001 PDX pancreatic tumors, even at optimal dosing for the two drugs. These findings support the clinical benefit observed with liposomal irinotecan in patients with pancreatic cancer.

Cell fusion enhances energy metabolism of mesenchymal tumor hybrid cells to sustain their proliferation and invasion.

BACKGROUND: Cell-to-cell fusion is emerging as a key element of the metastatic process in various cancer types. We recently showed that hybrids made from the spontaneous merging of pre-malignant (IMR90 E6E7, i.e. E6E7) and malignant (IMR90 E6E7 RST, i.e. RST) mesenchymal cells recapitulate the main features of human undifferentiated pleomorphic sarcoma (UPS), with a highly rearranged genome and increased spreading capacities. To better characterize the intrinsic properties of these hybrids, we investigated here their metabolic energy profile compared to their parents. RESULTS: Our results unveiled that hybrids harbored a Warburg-like metabolism, like their RST counterparts. However, hybrids displayed a much greater metabolic activity, enhancing glycolysis to proliferate. Interestingly, modifying the metabolic environmental conditions through the use of 5-aminoimidazole-4-carbox-amide-1-ß-D-ribofuranoside (AICAR), an activator of the 5'-adenosine monophosphate (AMP)-activated protein kinase (AMPK), specifically reduced the growth of hybrids, and also abrogated the invasive capacity of hybrids displaying enhanced glycolysis. Furthermore, AICAR efficiently blocked the tumoral features related to the aggressiveness of human UPS cell lines. CONCLUSION: Altogether, our findings strongly suggest that hybrids rely on higher energy flux to proliferate and that a drug altering this metabolic equilibrium could impair their survival and be potentially considered as a novel therapeutic strategy.

Acquisition of cancer stem cell capacities after spontaneous cell fusion.

BACKGROUND: Cancer stem/Initiating cell (CS/IC) hypothesis argues that CS/ICs are responsible of tumour initiation, drug resistance, metastasis or disease relapse. Their detection in several cancers supports this concept. However, their origin is still misunderstood. Cell fusion is shown to take part in the formation of CS/ICs, i.e. fusion between mesenchymal stem cell and cancer cell. In a previous paper, we described that fusion leads to hybrids with metastatic capacity. This process triggered genomic rearrangements in hybrid cells together with increased metastasis development. Here, we hypothesize that cell fusion could be strong enough to provoke a cellular reprogramming and the acquisition of CS/IC properties, promoting metastasis formation. METHODS: After spontaneous cell fusion between E6E7 (IMR90 with the oncogenes E6 and E7) and RST (IMR90 fully transformed) cell lines, hybrid cells were selected by dual antibiotic selection. Cancer stem cells capacities were evaluated regarding capacity to form spheres, expression of stem cell markers and the presence of ALDHhigh cells. RESULTS: Our data show that after cell fusion, all hybrids contain a percentage of cells with CS/ICs properties, regarding. Importantly, we lastly showed that NANOG inhibition in H1 hybrid decreases this migration capacity while having no effect on the corresponding parental cells. CONCLUSIONS: Altogether these results indicate that the combination of CS/ICs properties and genomic rearrangement in hybrids is likely to be key to tumour progression.

Genome remodeling upon mesenchymal tumor cell fusion contributes to tumor progression and metastatic spread.

Cell fusion in tumor progression mostly refers to the merging of a cancer cell with a cell that has migration and immune escape capabilities such as macrophages. Here we show that spontaneous hybrids made from the fusion of transformed mesenchymal cells with partners from the same lineage undergo nonrecurrent large-scale genomic rearrangements, leading to the creation of highly aneuploid cells with novel phenotypic traits, including metastatic spreading capabilities. Moreover, in contrast to their parents, hybrids were the only cells able to recapitulate in vivo all features of human pleomorphic sarcomas, a rare and genetically complex mesenchymal tumor. Hybrid tumors not only displayed specific mesenchymal markers, but also combined a complex genetic profile with a highly metastatic behavior, like their human counterparts. Finally, we provide evidence that patient-derived pleomorphic sarcoma cells are inclined to spontaneous cell fusion. The resulting hybrids also gain in aggressiveness, exhibiting superior growth capacity in mouse models. Altogether, these results indicate that cell fusion has the potential to promote cancer progression by increasing growth and/or metastatic capacities, regardless of the nature of the companion cell. Moreover, such events likely occur upon sarcoma development, paving the way for better understanding of the biology, and aggressiveness of these tumors.

Recurrent DMD Deletions Highlight Specific Role of Dp71 Isoform in Soft-Tissue Sarcomas.

Soft-tissue sarcomas (STS) are rare tumors whose oncogenesis remains unknown and for which no common therapeutic target has yet been identified. Analysis of 318 STS by CGH array evidenced a frequent deletion affecting the DMD gene (encoding dystrophin isoforms) in 16.5% of STS, including sarcomas with complex genomics, gastrointestinal tumors (GIST), and synovial sarcomas (SS). These deletions are significantly associated with metastatic progression, thus suggesting the role of DMD downregulation in the acquisition of aggressive phenotypes. We observed that targeted deletions of DMD were restricted to the 5' region of the gene, which is responsible for the transcription of Dp427. Analysis of STS tumors and cell lines by RNA sequencing revealed that only the Dp71 isoform was widely expressed. Dp427 depletion had no effect on cell growth or migration. However, Dp71 inhibition by shRNA dramatically reduced the cell proliferation and clonogenicity of three STS cell lines, likely by altering the cell cycle progression through the G2/M-phase. Our work demonstrates that DMD deletions are not restricted to myogenic tumors and could be used as a biomarker for metastatic evolution in STS. Dp71 seems to play an essential role in tumor growth, thus providing a potential target for future STS treatments.

Fusion-mediated chromosomal instability promotes aneuploidy patterns that resemble human tumors.

Oncogenesis is considered to result from chromosomal instability, in addition to oncogene and tumor-suppressor alterations. Intermediate to aneuploidy and chromosomal instability, genome doubling is a frequent event in tumor development but the mechanisms driving tetraploidization and its impact remain unexplored. Cell fusion, one of the pathways to tetraploidy, is a physiological process involved in mesenchymal cell differentiation. Besides simple genome doubling, cell fusion results in the merging of two different genomes that can be destabilized upon proliferation. By testing whether cell fusion is involved in mesenchymal oncogenesis, we provide evidence that it induces genomic instability and mediates tumor initiation. After a latency period, the tumor emerges with the cells most suited for its development. Furthermore, hybrid tumor genomes were stabilized after this selection process and were very close to those of human pleomorphic mesenchymal tumors. Thus genome restructuring triggered by cell fusion may account for the chromosomal instability involved in oncogenesis.

RCBTB1 Deletion Is Associated with Metastatic Outcome and Contributes to Docetaxel Resistance in Nontranslocation-Related Pleomorphic Sarcomas.

Half of soft-tissue sarcomas are tumors with complex genomics, which display no specific genetic alterations and respond poorly to treatment. It is therefore necessary to find new therapeutic targets for these sarcomas. Despite genetic heterogeneity across samples, oncogenesis may be driven by common pathway alterations. Therefore, genomic and transcriptomic profiles of 106 sarcomas with complex genomics were analyzed to identify common pathways with altered genes. This brought out a gene belonging to the "cell cycle" biological pathway, RCBTB1 (RCC1 And BTB Domain Containing Protein 1), which is lost and downregulated in 62.5% of metastatic tumors against 34% of non-metastatic tumors. A retrospective study of three sarcoma cohorts revealed that low RCBTB1 expression is prognostic for metastatic progression, specifically in patients that received chemotherapy. In vitro and in vivo, RCBTB1 overexpression in leiomyosarcoma cells specifically sensitized to docetaxel-induced apoptosis. This was associated with increased mitotic rate in vitro and higher growth rate of xenografts. By contrast, RCBTB1 inhibition decreased cell proliferation and protected sarcoma cells from apoptosis induced by docetaxel. Collectively, these data evidenced that RCBTB1 is frequently deleted in sarcomas with complex genomics and that its downregulation is associated with a higher risk of developing metastasis for patients receiving chemotherapy, likely due to their higher resistance to docetaxel.

Regulation of RNA polymerase III transcription during transformation of human IMR90 fibroblasts with defined genetic elements.

RNA polymerase (Pol) III transcribes small untranslated RNAs that are essential for cellular homeostasis and growth. Its activity is regulated by inactivation of tumor suppressor proteins and overexpression of the oncogene c-MYC, but the concerted action of these tumor-promoting factors on Pol III transcription has not yet been assessed. In order to comprehensively analyse the regulation of Pol III transcription during tumorigenesis we employ a model system that relies on the expression of five genetic elements to achieve cellular transformation. Expression of these elements in six distinct transformation intermediate cell lines leads to the inactivation of TP53, RB1, and protein phosphatase 2A, as well as the activation of RAS and the protection of telomeres by TERT, thereby conducting to full tumoral transformation of IMR90 fibroblasts. Transformation is accompanied by moderately enhanced levels of a subset of Pol III-transcribed RNAs (7SK; MRP; H1). In addition, mRNA and/or protein levels of several Pol III subunits and transcription factors are upregulated, including increased protein levels of TFIIIB and TFIIIC subunits, of SNAPC1 and of Pol III subunits. Strikingly, the expression of POLR3G and of SNAPC1 is strongly enhanced during transformation in this cellular transformation model. Collectively, our data indicate that increased expression of several components of the Pol III transcription system accompanied by a 2-fold increase in steady state levels of a subset of Pol III RNAs is sufficient for sustaining tumor formation.

Recurrent TRIO Fusion in Nontranslocation-Related Sarcomas.

PURPOSE: Despite various differences, nontranslocation-related sarcomas (e.g., comprising undifferentiated pleomorphic sarcoma, leiomyosarcoma, myxofibrosarcoma) are unified by their complex genetics. Extensive analysis of the tumor genome using molecular cytogenetic approaches showed many chromosomal gains, losses, and translocations per cell. Genomic quantitative alterations and expression variations have been extensively studied by adapted high-throughput approaches, yet translocations still remained unscreened. We therefore analyzed 117 nontranslocation-related sarcomas by RNA sequencing to identify fusion genes. EXPERIMENTAL DESIGN: We performed RNA sequencing and applied a bioinformatics pipeline dedicated to the detection of fusion transcripts. RT-PCR and Sanger sequencing were then applied to validate predictions and to search for recurrence and specificity. RESULTS: Among the 6,772 predicted fusion genes, 420 were in-frame. One recurrent rearrangement, consistently involving TRIO with various partners, was identified in 5.1% of cases. TRIO translocations are either intrachromosomal with TERT or interchromosomal with LINC01504 or ZNF558 Our results suggest that all translocations led to a truncated TRIO protein either directly or indirectly by alternative splicing. TRIO rearrangement is associated with a modified transcriptomic program to immunity/inflammation, proliferation and migration, and an increase in proliferation. CONCLUSIONS: TRIO fusions have been identified in four different sarcoma histotypes, likely meaning that they are not related to a primary oncogenic event but rather to a secondary one implicated in tumor progression. Moreover, they appear to be specific to nontranslocation-related sarcomas, as no such rearrangement was identified in sarcomas with simple genetics. More cases could lead to a significant association of these fusions to a specific clinical behavior. Clin Cancer Res; 23(3); 857-67. ©2016 AACR.

RNA sequencing validation of the Complexity INdex in SARComas prognostic signature.

BACKGROUND: Prognosis of metastatic outcome in soft tissue sarcomas is an important clinical challenge since these tumours can be very aggressive (up to 50% of recurring events). A gene expression signature, Complexity INdex in SARComas (CINSARC), has been identified as a better prognostic factor compared to the current international grading system defined by the Fédération Nationale des Centres de Lutte Contre le Cancer. Since CINSARC has been established on frozen tumours analysed by microarrays, we were interested in evaluating its prognostic capacity using next generation sequencing (NGS) on formalin-fixed, paraffin-embedded (FFPE) blocks to better fit laboratory practices. METHODS: Metastatic-free survivals (training/validation approach with independent datasets) and agreement values in classification groups were evaluated. Also, RNA degradation threshold has been established for FFPE blocks and differences in gene expression due to RNA degradation were measured. RESULTS: CINSARC remains a strong prognostic factor for metastatic outcome in both microarray and RNA-seq technologies (P < 0.05), with similar risk-group classifications (77%). We defined quality threshold to process degraded RNA extracted from FFPE blocks and measured similar classifications with frozen tumours (88%). CONCLUSION: These results demonstrate that CINSARC is a platform and material independent prognostic signature for metastatic outcome in various sarcomas. This result opens access to metastatic prognostication in sarcomas through NGS analysis on both frozen and FFPE tumours via the CINSARC signature.

Heterogeneous Mechanisms of Secondary Resistance and Clonal Selection in Sarcoma during Treatment with Nutlin.

Nutlin inhibits TP53-MDM2 interaction and is under investigation in soft-tissue sarcomas (STS) and other malignancies. Molecular mechanisms of secondary resistance to nutlin in STS are unknown. We performed whole-transcriptome sequencing (RNA-seq) on three pretreatment and secondary resistant STS cell lines selected based on their high primary sensitivity to nutlin. Our data identified a subset of cancer gene mutations and ploidy variations that were positively selected following treatment, including TP53 mutations in 2 out of 3 resistant cell lines. Further, secondary resistance to nutlin was associated with deregulation of apoptosis-related genes and marked productive autophagy, the inhibition of which resulted in significant restoration of nutlin-induced cell death. Collectively, our findings argue that secondary resistance to nutlin in STS involved heterogeneous mechanisms resulting from clonal evolution and several biological pathways. Alternative dosing regimens and combination with other targeted agents are needed to achieve successful development of nutlin in the clinical setting.

PRIMA-1(MET) induces death in soft-tissue sarcomas cell independent of p53.

BACKGROUND: The aim of this study was to explore the efficacy and define mechanisms of action of PRIMA-1(MET) as a TP53 targeted therapy in soft-tissue sarcoma (STS) cells. METHODS: We investigated effects of PRIMA-1(MET) on apoptosis, cell cycle, and induction of oxidative stress and autophagy in a panel of 6 STS cell lines with different TP53 status. RESULTS: Cell viability reduction by PRIMA-1(MET) was significantly observed in 5 out of 6 STS cell lines. We found that PRIMA-1(MET) was capable to induce cell death not only in STS cells harboring mutated TP53 but also in TP53-null STS cells demonstrating that PRIMA-1(MET) can induce cell death independently of TP53 in STS cells. We identified an important role of reactive oxygen species (ROS), involved in PRIMA-1(MET) toxicity in STS cells leading to a caspase-independent cell death. ROS toxicity was associated with autophagy induction or JNK pathway activation which represented potential mechanisms of cell death induced by PRIMA-1(MET) in STS. CONCLUSIONS: PRIMA-1(MET) anti-tumor activity in STS partly results from off-target effects involving ROS toxicity and do not deserve further development as a TP53-targeted therapy in this setting.

Genomic index predicts clinical outcome of intermediate-risk gastrointestinal stromal tumours, providing a new inclusion criterion for imatinib adjuvant therapy.

PURPOSE: Imatinib mesylate is the front-line targeted therapy for gastrointestinal stromal tumours (GISTs). Patient's eligibility to adjuvant imatinib after primary tumour resection is currently based on histological and clinical risk assessment. While therapeutic options are clear for the very-low, low and high-risk subpopulations, no standard is actually available for the tumours classified as intermediate. Since we recently validated genomic index (GI), a measure of the level of genomic alterations, as a strong predictor of clinical outcome in GIST, we asked whether it could also represent a novel prognostic factor for the intermediate subgroup. EXPERIMENTAL DESIGN: 82 intermediate risk patients were selected based on the Armed Forces Institute of Pathology (AFIP) classification for genomic profiling. RESULTS: Data revealed that even if studied samples generally harboured a combination of the typical genetic aberrations found in GIST, i.e. 1p, 14q 22q deletions and frequently lost CDKN2A locus on chromosome 9, they profoundly differed from each other on the total number of genomic changes and GI value. Kaplan-Meier analyses of metastatic-free survival unveiled that stratification of the tumours by the GI value at a cutoff of 10 separated the good from the poor prognosis patients, proven that metastatic-risk in GIST intermediate patients is strongly associated with high GI values and genome complexity. CONCLUSION: GI is validated here as a robust marker to predict intermediate-GIST clinical outcome. Applicable in numerous Pathology Laboratories already using array comparative genomic hybridisation (CGH) with formalin-fixed paraffin-embedded (FFPE) samples, this assay presently stands as an efficient tool for the clinical management of intermediate GIST-patients.

Gene expression identifies heterogeneity of metastatic behavior among high-grade non-translocation associated soft tissue sarcomas.

BACKGROUND: The biologic heterogeneity of soft tissue sarcomas (STS), even within histological subtypes, complicates treatment. In earlier studies, gene expression patterns that distinguish two subsets of clear cell renal carcinoma (RCC), serous ovarian carcinoma (OVCA), and aggressive fibromatosis (AF) were used to separate 73 STS into two or four groups with different probabilities of developing metastatic disease (PrMet). This study was designed to confirm our earlier observations in a larger independent data set. METHODS: We utilized these gene sets, hierarchical clustering (HC), and Kaplan-Meier analysis, to examine 309 STS, using Affymetrix chip expression profiling. RESULTS: HC using the combined AF-, RCC-, and OVCA-gene sets identified subsets of the STS samples. Analysis revealed differences in PrMet between the clusters defined by the first branch point of the clustering dendrogram (p = 0.048), and also among the four different clusters defined by the second branch points (p < 0.0001). Analysis also revealed differences in PrMet between the leiomyosarcomas (LMS), dedifferentiated liposarcomas (LipoD), and undifferentiated pleomorphic sarcomas (UPS) (p = 0.0004). HC of both the LipoD and UPS sample sets divided the samples into two groups with different PrMet (p = 0.0128, and 0.0002, respectively). HC of the UPS samples also showed four groups with different PrMet (p = 0.0007). HC found no subgroups of the LMS samples. CONCLUSIONS: These data confirm our earlier studies, and suggest that this approach may allow the identification of more than two subsets of STS, each with distinct clinical behavior, and may be useful to stratify STS in clinical trials and in patient management.

Intimal sarcoma is the most frequent primary cardiac sarcoma: clinicopathologic and molecular retrospective analysis of 100 primary cardiac sarcomas.

We report novel molecular and pathologic features of sarcomas involving the heart. Intimal sarcoma appears as the most frequent primary cardiac sarcoma within the largest described series of 100 primary cardiac sarcomas. Immunohistochemical analysis, fluorescence in situ hybridization, real-time polymerase chain reaction, and array-comparative genomic hybridization were performed on materials from 65 women and 35 men, aged 18 to 82 years (mean 50 y), retrieved from the French Departments of Pathology, between 1977 and early 2013. Right and left heart was involved in 44 and 56 cases, respectively. There were 42 intimal sarcomas, 26 angiosarcomas, 22 undifferentiated sarcomas, 7 synovial sarcomas, 2 leiomyosarcomas, and 1 peripheral neuroectodermal tumor. All but 1 angiosarcomas originated from the right heart, whereas 83% of the intimal sarcomas and 72% of the undifferentiated sarcomas were from the left heart. MDM2 overexpression was immunohistochemically observed in all intimal sarcomas, as well as in 10 of the 22 undifferentiated sarcomas and in 5 of the 26 angiosarcomas. MDM2 amplification was only demonstrated in intimal sarcomas. Genomic analysis showed a complex profile, with recurrent 12q13-14 amplicon involving MDM2, 4q12 amplicon involving KIT and PDGFRA, 7p12 gain involving EGFR, and 9p21 deletion targeting CDKN2A. Immunohistochemical detection of MDM2 overexpression can easily detect intimal sarcoma, provided that molecular aberration is proved. As resections are limited to the left atrium, this histologic subtype could benefit from therapies targeting PDGFRA or MDM2.

Prognostic value of PLAGL1-specific CpG site methylation in soft-tissue sarcomas.

Soft tissue sarcomas (STS) are rare, complex tumors with a poor prognosis. The identification of new prognostic biomarkers is needed to improve patient management. Our aim was to determine the methylation status of the 118 CpG sites in the PLAGL1 tumor-suppressor gene P1 CpG island promoter and study the potential prognostic impact of PLAGL1 promoter methylation CpG sites in STS. Training cohorts constituted of 28 undifferentiated sarcomas (US) and 35 leiomyosarcomas (LMS) were studied. PLAGL1 mRNA expression was investigated by microarray analysis and validated by RT-qPCR. Pyrosequencing was used to analyze quantitative methylation of the PLAGL1 promoter. Associations between global promoter or specific CpG site methylation and mRNA expression were evaluated using Pearson's product moment correlation coefficient. Cox univariate and multivariate proportional hazard models were used to assess the predictive power of CpG site methylation status. Sixteen CpG sites associated with PLAGL1 mRNA expression were identified in US and 6 in LMS. Statistical analyses revealed an association between CpG107 methylation status and both overall and metastasis-free survival in US, which was confirmed in a validation cohort of 37 US. The exhaustive study of P1 PLAGL1 promoter methylation identified a specific CpG site methylation correlated with mRNA expression, which was predictive for both metastasis-free and overall survival and may constitute the first US-specific biomarker. Such a biomarker may be relevant for identifying patients likely to derive greater benefit from treatment.

Fibrosarcoma-like lipomatous neoplasm: a reappraisal of so-called spindle cell liposarcoma defining a unique lipomatous tumor unrelated to other liposarcomas.

The term "spindle cell liposarcoma" has been applied to liposarcomas (LPSs) composed predominantly or exclusively of spindled cells. These tumors have been considered variants of well-differentiated LPS (WDL), myxoid LPS, and spindle cell lipoma, suggesting that this is a heterogenous group of lesions. Using strict morphologic criteria and molecular and immunohistochemical analyses, we have identified a homogenous group of spindle cell lipomatous tumors, histologically and genetically distinct from other forms of LPS, which we have called "fibrosarcoma-like lipomatous neoplasm." Cases classified as "spindle cell LPS" or "low-grade LPS with spindle cell features" were reviewed. Final selection criteria included: (1) an exclusive low-grade spindle cell component resembling fibrosarcoma; (2) a mixture of bland fibroblastic cells resembling the preadipocyte and early-adipocyte stage of embryonic fat; and (3) molecular-genetic analysis that excluded other forms of lipomatous tumors. Of the initial 25 cases identified, comparative genomic hybridization (CGH) was uninformative in 2 cases; 5 were reclassified as WDL on the basis of molecular data (MDM2 amplification) and 6 as spindle cell lipoma (CGH profiles with a few gains and losses including a constant loss of chromosome 13 and frequent losses of chromosomes 16 and 6). The 12 remaining cases showed flat CGH profiles; of these cases, 11 were negative for DDIT3 gene rearrangements, and 1 result was uninterpretable. Patients ranged in age from 15 to 82 years (mean 50 y); male patients were affected slightly more often (7:5). Tumors arose in the deep (6) and superficial (3) soft tissue of the groin (4), buttock (3), thigh (2), flank (1), shoulder (1), and paratesticular tissue (1) and ranged in size from 2 to 20 cm (mean 7.5 cm). Clinical follow-up in 11 patients (9 mo to 20 y; mean 68 mo) showed no recurrences or metastases. As defined above, "fibrosarcoma-like lipomatous neoplasm" is a unique lipomatous tumor that should be distinguished from WDL/(low-grade) dedifferentiated LPS and myxoid LPS on combined histologic/molecular features because of its better prognosis.

Genetic profiling identifies two classes of soft-tissue leiomyosarcomas with distinct clinical characteristics.

PURPOSE: Data about the prognostic factors of soft-tissue leiomyosarcomas and their correlation with molecular profile are limited. EXPERIMENTAL DESIGN: From 1990 to 2010, 586 adult patients with a primary soft-tissue leiomyosarcoma were included in the French Sarcoma Group (GSF) database after surgery of the primary tumor. Multivariate analyses were conducted by Cox regression model in a backward stepwise procedure. Genetic profiling was conducted for 73 cases. RESULTS: Median age was 59 years (range, 21-98 years). The median follow-up of patients alive was 46 months. The 5-year metastasis-free survival (MFS) rate was 51% (95% location and grade > I were independent adverse prognostic factors for MFS). The 5-year overall survival (OS) rate was 63% [95% confidence interval (CI), 59-67]. On multivariate analysis, age ≥ 60 years old, tumor size > 5 cm, deep location, and grade > I were independent adverse prognostic factors for OS. Molecular profiling identified specific clusters with activation of different biologic pathways: retroperitoneal leiomyosarcomas are characterized by overexpression of genes involved in muscle differentiation and nonretroperitoneal leiomyosarcomas characterized by overexpression of genes mainly involved in extracellular matrix, wounding, and adhesion pathways. The CINSARC signature but not comparative genomic hybridization (CGH) profiling was predictive of outcome. CONCLUSION: Soft-tissue leiomyosarcomas represent a heterogeneous group of tumors with at least two categories, retroperitoneal and extremities leiomyosarcomas, having specific clinical outcome and molecular features. Future clinical trials should consider this heterogeneity for a better stratification of patients.

Chromosome instability accounts for reverse metastatic outcomes of pediatric and adult synovial sarcomas.

PURPOSE: Synovial sarcoma (SS) occurs in both children and adults, although metastatic events are much more common in adults. Whereas the importance of the t(X;18) translocation in SS oncogenesis is well established, the genetic basis of SS metastasis is still poorly understood. We recently reported expression (CINSARC; Complexity Index in Sarcoma) and Genomic Index prognostic signatures related to chromosome integrity in sarcomas and GI stromal tumors. Here we investigate whether these signatures can also predict outcomes in SS. PATIENTS AND METHODS: One hundred patients who had primary untreated SS tumors were selected for expression and genomic profiling in a training/validation approach. RESULTS: CINSARC and Genomic Index have strong independent and validated prognostic values (P < .001). By comparing expression profiles of tumors with or without metastasis, 14 genes that are common to the CINSARC signature were identified, and the two top-ranked genes, KIF14 and CDCA2, were validated as prognostic markers in an independent cohort. Comparing genomic profiles of adult versus pediatric SS, we show that metastasis is associated with genome complexity in both situations and that the adult genome is more frequently rearranged. Accordingly, pediatric patients with an even genomic profile do not develop metastasis. CONCLUSION: Metastasis development in SS is strongly associated with chromosome complexity, and CINSARC and Genomic Index are validated independent prognostic factors. The differences in metastasis frequency between adults and children are associated with genome instability, which is much more frequent in adults. Genomic Index is potentially the best overall biomarker and clearly the most clinically relevant, considering that genome profiling from formalin-fixed samples is already used in pathology.