Prevention of implant-associated spinal infections: the GAID-protocol

ObjectiveThe purpose of this study is to investigate the efficacy of the GAID-Protocol, a bundle of intra- and postoperative infection prevention measures, to reduce implant-associated infections in patients undergoing posterior spinal fusion with instrumentation. These preventive measures are organized into a protocol that includes recommendations for four critical areas of implant protection (acronym GAID): Gloves, Antiseptics: sodium hypochlorite/hypochlorous acid (NaOCl/HOCl), Implants and Drainage-use in large wounds.MethodsWe performed a single-site retrospective review of cases undergoing posterior spinal fusion with instrumentation for primarily degenerative spinal diseases before and after implementation of the GAID-Protocol that was specifically designed to protect against implant-associated infections. The primary outcome was postoperative wound complications requiring surgical intervention, with a particular focus on infectious spondylitis/discitis.Results230 cases were included: 92 (Group A) before and 138 (Group B) after protocol implementation. Overall, wound complications requiring surgical intervention occurred in 7.6% patients in Group A and in 3.6% patients in Group B (p = 0.2297). Of these, infectious spondylitis/discitis was present in 5.4% in Group A and in none of Group B (p = 0.0096). The ratio of infectious spondylitis/discitis to other wound problems was 71% to 29% in Group A, while it was 0% to 100% in Group B (p = 0.0278). The mean time interval between the first revision surgery for wound complications and hospital discharge was significantly different, 38 days SD 20.3 in Group A and 14.4 days SD 8.6 in Group B (p = 0.0442).ConclusionsIn our study, adherence to the GAID-Protocol resulted in a shift from severe to significantly less severe and easier to treat wound complications. Adoption of the GAID-Protocol might contribute to the reduction of implant-associated infections

Downstream and Intermediate Interactions of Synovial Sarcoma-Associated Fusion Oncoproteins and Their Implication for Targeted Therapy

Synovial sarcoma (SS), an aggressive type of soft tissue tumor, occurs mostly in adolescents and young adults. The origin and molecular mechanism of the development of SS remain only partially known. Over 90% of SS cases are characterized by the t(X;18)(p11.2;q11.2) translocation, which results mainly in the formation of SS18-SSX1 or SS18-SSX2 fusion genes. In recent years, several reports describing direct and indirect interactions of SS18-SSX1/SSX2 oncoproteins have been published. These reports suggest that the fusion proteins particularly affect the cell growth, cell proliferation, TP53 pathway, and chromatin remodeling mechanisms, contributing to SS oncogenesis. Additional research efforts are required to fully explore the protein-protein interactions of SS18-SSX oncoproteins and the pathways that are regulated by these partnerships for the development of effective targeted therapy

Nieuwe prognostische en predictieve merkers voor geselecteerde sarcomen van de weke delen

Soft tissue sarcomas (STS) comprise a heterogeneous group of malignant mesenchymal tumors that include more than 130 distinct diagnostic entities. They arise from various types of connective tissues, especially adipocytic tissue, muscles, nerves, deep skin fibroblasts, blood vessels, bones and cartilage. There is also a relatively large subgroup of sarcomas of uncertain origin. STS represent approximately 1% of all neoplasms in adults and more than 10% of neoplasms diagnosed in children. Many of STS subtypes harbor specific cytogenetic changes, such as chromosome translocations, gene point mutations and genomic copy number aberrations.These tumors are characterized by poor clinical outcome and the currently accepted clinical prognostic factors in STS do not accurately discriminate between low risk and high risk patients. Better understanding of STS biology is important to improve diagnosis, develop more reliable molecular prognostic and predictive factors, and to propose new potential therapeutic targets. Development of novel agents for targeted therapy is of special importance because many STS subtypes are resistant to conventional chemotherapy and the effective STS treatment options are limited. Moreover, the STS research is often circumscribed by the scarcity of samples available for analysis. It has been recently perceived that only for four STS subtypes the cytogenetic information is available for more than 100 cases and that for many STS subtypes only less than 10 cases have been analyzed.The first specific objective of this project was identification of new prognostic and predictive markers associated with long term survival of patients with synovial sarcomas (SynSa). Microarray technology (array CGH and gene expression microarrays) was applied to understand the biology of these tumors and to select genes which are differentially expressed in tumor tissues. Using a training/validation set strategy on collected 100 primary specimens from patients with long clinical follow-up, we tested the hypothesis that specific CINSARC (complexity index in sarcomas) gene expression signature predicts metastatic outcome in translocation-related sarcomas, as it does in non-translocation related sarcomas of the complex genotypes. We have also examined the prognostic significance of Genomic Index (GI), reflecting the complexity of genomic rearrangements in tumor specimens based on array CGH profile. We have demonstrated that both CINSARC gene signature and GI outperform current prognostic grading system and provide information that would influence the clinical decisions. Additionally, we pointed to the potentially predictive value of GI, especially in pediatric SynSa patients. The results of this collaborative study are described in Paper I.We performed the detection of SynSa specific fusion transcripts SS18-SSX1/2 in all cases examined for gene expression and genomic alterations, to confirm the diagnosis and provide additional molecular characteristics of patients included in this study. Application of RT-PCR allowed us to identify atypical fusion transcripts in three patients, which are depicted in Paper III. In this thesis, we described the first case with a complex translocation which involved another gene, i.e. REPS2 (RALBP1 associated Eps domain containing 2), located on the X chromosome at Xp22. This novel transcript variant was detected both in primary and metastatic specimens derived from the same patient. Apparently, this variant preserved the transforming function of the usual SS18-SSX1 fusion oncogene, which indicates that the mechanism of tumorigenesis in this case might have been similar as in other SynSa cases.In the second part of this project we intended to explore the hypothesis that the detection of circulating tumor cells (CTCs) in the peripheral blood (PB) can serve as a prognostic marker of the disease outcome in Ewing sarcoma (ES) patients. To reach this aim we evaluated ES specific fusion oncogenes (EWS-FLI1 and EWS-ERG) as markers of the presence of sarcoma cells in routinely collected PB specimens, and correlated these results with disease outcome. Moreover, we searched for the CTC markers alternative to already known fusion transcripts, basing on available gene expression profiling data. We tested the hypothesis that selected tissue specific markers can be used to detect metastatic cells in PB of ES patients. As presented in Paper II, the expression of typical EWS-FLI1/ERG fusion transcripts in the PB was found in two (6%) of patients, and the additional 76% of patients carried the unusual shorter in lenght EWS-FLI1 fusion transcripts, which may imply ES as a systemic disease. We have also observed the abnormal expression of CDH2 and CDT2 genes in the PB of a subset of ES patients, which significantly correlated with worse overall survival (OS). We suggest that combination of metastasis presence at diagnosis, a well-established clinical negative prognostic factor, with evaluation of CDH2 expression level, may predict poor prognosis in ES patients with the higher accuracy. This study demonstrates the prognostic value of molecular PB testing at the time of routine histopathological diagnosis.In the third part of this thesis (Paper IV) we aimed to identify genes involved in a recurrent t(X;17)(p11.2;q21.33) translocation identified in two independent low-grade endometrial stromal sarcoma (ESS) patients. We described the molecular characteristics of these tumors, by a combination of cytogenetic and molecular methods, microarrays and next-generation whole transcriptome sequencing. We identified MBTD1 (malignant brain tumor domain-containing 1) and CXorf67 (chromosome X open reading frame 67) as fusion partners involved in the novel reciprocal rearrangement. Gene expression profiling demonstrated that cases with MBTD1-CXorf67 transcript cluster together with the classical low-grade ESS cases carrying previously described JAZF1-associated fusions. In array CGH analysis, no genomic imbalances at the t(X;17) breakpoints were identified, indicating that MBTD1-CXorf67 is a balanced translocation. The chimeric fusion gene MBTD1-CXorf67 identifies yet another cytogenetically distinct subgroup of low-grade ESS and offers the opportunity to shed more light on the biological functions of the two poorly characterized genes.<w:latentstyles deflockedstate="false" defunhidewhenused="true" defsemihidden="true" defqformat="false" defpriority="99"  status: publishe

Detection of SS18-SSX1/2 fusion transcripts in circulating tumor cells of patients with synovial sarcoma

Abstract A recent study on 15 patients with synovial sarcoma demonstrated very low prevalence of tumor-specific fusion transcripts in peripheral blood specimens. Our results in an independent cohort of 38 patients with synovial sarcoma support these findings. Synovial sarcoma patients could greatly benefit from a non-invasive monitoring of tumor burden by liquid biopsies. However, given the low detection rate of SS18-SSX1/2 in circulation, we conclude that alternative markers other than the tumor-type specific fusion transcripts should be considered

Recurrent and novel SS18-SSX fusion transcripts in synovial sarcoma: description of three new cases

Synovial sarcoma (SS) is an aggressive type of tumor, comprising approximately 10 % of soft tissue sarcomas. Over 90 % of SS cases are characterized by the t(X;18)(p11.2;q11.2) translocation, which results mainly in the formation of oncogenic SS18-SSX1 or SS18-SSX2 fusions. In a typical SS18-SSX fusion transcript, exon 10 of SS18 is fused to exon 6 of SSX1/2. However, several variant fusion transcripts have been already described. In the present study, we examined the fusion transcript type in a series of 40 primary untreated SS tumor specimens using reverse transcription polymerase chain reaction and fluorescence in situ hybridization assay. We detected SS18-SSX1 transcript in 22 (55 %) patients and SS18-SSX2 transcript in 17 (42.5 %) patients, while in one patient, none of SS18-SSX1/2 fusion transcripts were identified. Among the cases under study, two tumors carried novel SS18-SSX1 and SS18-SSX2 variant translocations that were allegedly created by an alternative splicing, and in additional case, an unusual translocation variant previously described by other group was found. Our data suggest that alternative splicing may play an important role in novel fusion transcript formation, and additionally we show that it may be a recurrent event in SS. Furthermore, we describe the first case of a complex rearrangement possibly linking SS to REPS2 gene.status: publishe

Gene expression profiling of low-grade endometrial stromal sarcoma indicates fusion protein-mediated activation of the Wnt signaling pathway

Low-grade endometrial stromal sarcomas (LGESS) harbor chromosomal translocations that affect proteins associated with chromatin remodeling Polycomb Repressive Complex 2 (PRC2), including SUZ12, PHF1 and EPC1. Roughly half of LGESS also demonstrate nuclear accumulation of β-catenin, which is a hallmark of Wnt signaling activation. However, the targets affected by the fusion proteins and the role of Wnt signaling in the pathogenesis of these tumors remain largely unknown.status: accepte