C Sotiriou

Institut Jules Bordet, Bruxelles, Brussels Capital Region, Belgium

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Publications (69)367.52 Total impact

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    ABSTRACT: Brain metastases (BMs) pose a clinical challenge in breast cancer (BC). Lapatinib or temozolomide showed activity in BM. Our study assessed the combination of both drugs as treatment for patients with HER2-positive BC and BM. Eighteen patients were enrolled, with sixteen of them having recurrent or progressive BM. Any type of previous therapy was allowed, and disease was assessed by gadolinium (Gd)-enhanced magnetic resonance imaging (MRI). The primary end points were the evaluation of the dose-limiting toxicities (DLTs) and the determination of the maximum-tolerated dose (MTD). The secondary end points included objective response rate, clinical benefit and duration of response. The lapatinib-temozolomide regimen showed a favorable toxicity profile because the MTD could not be reached. The most common adverse events (AEs) were fatigue, diarrhea and constipation. Disease stabilization was achieved in 10 out of 15 assessable patients. The estimated median survival time for the 16 patients with BM reached 10.94 months (95% CI: 1.09-20.79), whereas the median progression-free survival time was 2.60 months [95% confidence interval (CI): 1.82-3.37]. The lapatinib-temozolomide combination is well tolerated. Preliminary evidence of clinical activity was observed in a heavily pretreated population, as indicated by the volumetric reductions occurring in brain lesions.
    Annals of Oncology 09/2013; · 7.38 Impact Factor
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    ABSTRACT: Over the past few decades, Fourier transform infrared (FTIR) spectroscopy coupled to microscopy has been recognized as an emerging and potentially powerful tool in cancer research and diagnosis. For this purpose, histological analyses performed by pathologists are mostly carried out on biopsied tissue that undergoes the formalin-fixation and paraffin-embedding (FFPE) procedure. This processing method ensures an optimal and permanent preservation of the samples, making FFPE-archived tissue an extremely valuable source for retrospective studies. Nevertheless, as highlighted by previous studies, this fixation procedure significantly changes the principal constituents of cells, resulting in important effects on their infrared (IR) spectrum. Despite the chemical and spectral influence of FFPE processing, some studies demonstrate that FTIR imaging allows precise identification of the different cell types present in biopsied tissue, indicating that the FFPE process preserves spectral differences between distinct cell types. In this study, we investigated whether this is also the case for closely related cell lines. We analyzed spectra from 8 cancerous epithelial cell lines: 4 breast cancer cell lines and 4 melanoma cell lines. For each cell line, we harvested cells at subconfluence and divided them into two sets. We first tested the "original" capability of FTIR imaging to identify these closely related cell lines on cells just dried on BaF2 slides. We then repeated the test after submitting the cells to the FFPE procedure. Our results show that the IR spectra of FFPE processed cancerous cell lines undergo small but significant changes due to the treatment. The spectral modifications were interpreted as a potential decrease in the phospholipid content and protein denaturation, in line with the scientific literature on the topic. Nevertheless, unsupervised analyses showed that spectral proximities and distances between closely related cell lines were mostly, but not entirely, conserved after FFPE processing. Finally, PLS-DA statistical analyses highlighted that closely related cell lines are still successfully identified and efficiently distinguished by FTIR spectroscopy after FFPE treatment. This last result paves the way towards identification and characterization of cellular subtypes on FFPE tissue sections by FTIR imaging, indicating that this analysis technique could become a potential useful tool in cancer research.
    The Analyst 05/2013; · 4.23 Impact Factor
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    ABSTRACT: Fourier transform infrared (FTIR) imaging was applied on histopathological specimens of breast cancer of different tumor histological grades. Focus was given to the extracellular matrix. FTIR spectral changes were observed when examining the extracellular matrix close to and far from carcinoma. Major changes were observed, in particular in the relative intensities of the collagen bands at 1640 and 1630 cm(-1). PCA analysis and global fitting indicate a continuous progression in collagen spectral features when moving away from the tumor. These preliminary results suggest FTIR spectral features present in the 1700-1600 cm(-1) spectral range could be used as spectral markers to identify cancer-induced modifications in collagen. This chemical imaging approach to analyze the breast cancer microenvironment could be used in the future for improving diagnostics of breast cancer.
    The Analyst 05/2013; · 4.23 Impact Factor
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    ABSTRACT: BACKGROUND: Gene expression signatures indicative of tumor proliferative capacity and tumor-immune cell interactions have emerged as principal biology-driven predictors of breast cancer outcomes. How these signatures relate to one another in biological and prognostic contexts remains to be clarified. RESULTS: To investigate the relationship between proliferation and immune gene signatures, we analyzed an integrated dataset of 1,954 clinically-annotated breast tumor expression profiles randomized into training and test sets to allow two-way discovery and validation of gene-survival associations. Hierarchical clustering revealed a large cluster of distant metastasis-free survival-associated genes with known immunological functions that further partitioned into three distinct immune metagenes likely reflecting: B-cells and/or plasma cells;, T-cells and natural killer cells,;and monocytes and dendritic cells. A proliferation metagene allowed stratification of cases into proliferation tertiles. The prognostic strength of these metagenes was largely restricted to tumors within the highest proliferation tertile, though intrinsic subtype-specific differences were observed in the intermediate and low proliferation tertiles. In highly proliferative tumors, high-tertile immune metagene expression equated with reduced risk of metastasis while tumors with low-tertile expression of any one of the three immune metagenes were associated with poor outcome despite higher expression of the other two metagenes. CONCLUSIONS: These findings suggest that a productive interplay among multiple immune cell types at the tumor site promotes long-term anti-metastatic immunity in a proliferation-dependent manner. The emergence of a subset of effective immune responders among highly proliferative tumors has novel prognostic ramifications.
    Genome biology 04/2013; 14(4):R34. · 10.30 Impact Factor
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    ABSTRACT: Fourier transform infrared (FTIR) imaging was applied on histopathological specimens of breast cancer of different tumor histological grades. Focus was given to the extracellular matrix. FTIR spectral changes were observed when examining the extracellular matrix close to and far from carcinoma. Major changes were observed, in particular in the relative intensities of the collagen bands at 1640 and 1630 cm-1. PCA analysis and global fitting indicate a continuous progression in collagen spectral features when moving away from the tumor. These preliminary results suggest FTIR spectral features present in the 1700 – 1600 cm-1 spectral range could be used as spectral markers to identify cancer-induced modifications in collagen. This chemical imaging approach to analyze the breast cancer microenvironment could be used in the future for improving diagnostics of breast cancer.
    The Analyst 04/2013; · 3.97 Impact Factor
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    ABSTRACT: The 2012 IMPAKT task force investigated the medical usefulness of current methods for the classification of breast cancer into the 'intrinsic' molecular subtypes (luminal A, luminal B, basal-like and HER2). A panel of breast cancer and/or gene expression profiling experts evaluated the analytical validity, clinical validity and clinical utility of two approaches for molecular subtyping of breast cancer: the prediction analysis of microarray (PAM)50 assay and an immuno-histochemical (IHC) surrogate panel including oestrogen receptor (ER), HER2 and Ki67. The panel found the currently available evidence on the analytical validity and clinical utility of Ki67 based on a 14% cut-off and PAM50 to be inadequate. The majority of the working group members found the available evidence on the analytical validity, clinical validity and clinical utility of ER/HER2 to be convincing. The panel concluded that breast cancer classification into molecular subtypes based on the IHC assessment of ER, HER2 and Ki67 with a 14% cut-off and on the PAM50 test does not provide sufficiently robust information to modify systemic treatment decisions, and recommended the use IHC for ER and HER2 for the identification of clinically relevant subtypes of breast cancers. Methods for breast cancer classification into molecular subtypes should, however, be incorporated into clinical trial design.
    Annals of Oncology 12/2012; 23(12):2997-3006. · 7.38 Impact Factor
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    ABSTRACT: Background The genomic grade index (GGI) completes the prognostic value of histological grade (HG). Other proliferation markers include the mitotic activity index (MAI) and the Ki67 immunohistochemistry (IHC) status. We compared the prognostic value of GGI, HG, MAI, Ki67 IHC and messenger RNA (mRNA) status in node-positive breast cancer (BC) patients treated with adjuvant anthracycline-based chemotherapy in the prospective PACS01 trial.Patients and methodsThe five proliferation-related parameters (GGI, Ki67 mRNA expression and centrally determined HG, MAI, and Ki67 IHC status) of tumours were available for 204 cases and analysed as continuous values. We compared the correlations of each one with the other proliferation-related parameters and with histoclinical variables including the disease-free survival (DFS).ResultsExpected correlations were observed between the five parameters and for each parameter with biological features (hormone-receptor and HER2 status, molecular subtypes), but the GGI displayed the strongest correlations. The GGI outperformed the prognostic performance of the four other proliferation-related parameters for the DFS in all 204 patients and in the 95 HG2 patients. In multivariate analysis including the classical prognostic factors, only GGI remained significant. Finally, the GGI outperformed the prognostic performance of MKI67 mRNA expression in a series of 1599 samples and 656 HG2 cases.Conclusions In this small pilot biomarker study ancillary to the PACS01 trial, the GGI outperforms the prognostic performance of centrally determined HG, MAI, Ki67 IHC status and mRNA expression. Further validation is warranted in larger series.
    Annals of Oncology 11/2012; · 7.38 Impact Factor
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    ABSTRACT: Background The prognostic value of histologic grade (HG) in invasive lobular carcinoma (ILC) remains uncertain, and most ILC tumors are graded as HG2. Genomic grade (GG) is a 97-gene signature that improves the prognostic value of HG. This study evaluates whether GG may overcome the limitations of HG in ILC.Methods Gene expression data were generated from frozen tumor samples, and GG calculated according to the expression of 97 genes. The prognostic value of GG was assessed in a stratified Cox regression model for invasive disease-free survival (IDFS) and overall survival (OS).ResultsA total of 166 patients were classified by GG. HG classified 33 (20%) tumors as HG1, 120 (73%) as HG2 and 12 (7%) as HG3. GG classified 106 (64%) tumors as GG low (GG1), 29 (17%) as GG high (GG3) and 31 (19%) as equivocal (cases not classified as GG1 or GG3). The median follow-up time was 6.5 years. In multivariate analyses, GG was associated with IDFS [HR(GG3 vs GG1) 5.6 (2.1-15.3); P < 0.001] and OS [HR(GG3 vs GG1) 7.2, 95% CI (1.6-32.2); P = 0.01].ConclusionsGG outperformed HG in ILC and added prognostic value to classic clinicopathologic variables, including nodal status.
    Annals of Oncology 10/2012; · 7.38 Impact Factor
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    ABSTRACT: Background Human epidermal growth factor receptor 2 (HER2) overexpression is detected in approximately 15% to 20% of all breast cancers (BCs). A revolutionary change in the prognosis of this subgroup of patients has occurred since trastuzumab therapy was introduced into daily clinical practice. However, because trastuzumab resistance is common, new molecules with complementary and/or synergistic mechanisms of action have been developed. Pertuzumab is a new anti-HER2 humanized monoclonal antibody that prevents the formation of HER2 dimers.Material and methodsA computer-based literature search was carried out using PubMed (keywords: breast neoplasm, dimerization, HER-2, pertuzumab); data reported at international meetings are included.ResultsThis paper describes pertuzumab's mechanism of action, safety, and role in HER2-positive BCs. It also explores the role of pertuzumab as a single agent or combined with trastuzumab by reviewing data from preclinical research to ongoing clinical trials. Recently published trials, particularly the CLEOPATRA study, highlight the efficacy, tolerability, and increase in disease-free survival associated with this novel agent when combined with trastuzumab.Conclusion The pertuzumab and trastuzumab anti-HER2 dual blockade is likely to represent a substantial advance for patients with HER2-positive BCs and a new milestone on the way to personalized medicine.
    Annals of Oncology 08/2012; · 7.38 Impact Factor
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    ABSTRACT: Greater understanding of the biology of triple-negative breast cancer (TNBC) is needed to discern the roughly 60% of node-negative patients who are already cured with locoregional therapy from the 40% who need adjuvant systemic therapy to be cured. Recent evidence suggests that patients with TNBC whose tumours have an activated immune response gene signature have a more favourable outcome than TNBC patients without this signature. For the group who needs additional systemic therapy, the challenge remains to choose the right systemic drug combination for the right TNBC sub-type. Significant heterogeneity exists within the TNBC class that is exemplified by differing chemotherapeutic sensitivity observed for some sub-types. This heterogeneity establishes the need for identifying differentiating molecular markers within the overall class of TNBC disease, which may help refine therapeutic management. In this review, we discuss some of these promising predictive molecular markers for tailoring therapy. In addition, several gene expression profiling and functional studies employing genetic screens that help to establish TNBC sub-groups with varying sensitivities to a variety of targeted therapies currently under clinical investigation are conferred. It is anticipated that a greater understanding of the biology of TNBC and its complex heterogeneity will reveal novel targets or identify markers around which clinical trials in molecularly well-defined sub-groups can be designed.
    Annals of Oncology 08/2012; 23 Suppl 6:vi13-vi18. · 7.38 Impact Factor
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    ABSTRACT: All cancers carry somatic mutations in their genomes. A subset, known as driver mutations, confer clonal selective advantage on cancer cells and are causally implicated in oncogenesis, and the remainder are passenger mutations. The driver mutations and mutational processes operative in breast cancer have not yet been comprehensively explored. Here we examine the genomes of 100 tumours for somatic copy number changes and mutations in the coding exons of protein-coding genes. The number of somatic mutations varied markedly between individual tumours. We found strong correlations between mutation number, age at which cancer was diagnosed and cancer histological grade, and observed multiple mutational signatures, including one present in about ten per cent of tumours characterized by numerous mutations of cytosine at TpC dinucleotides. Driver mutations were identified in several new cancer genes including AKT2, ARID1B, CASP8, CDKN1B, MAP3K1, MAP3K13, NCOR1, SMARCD1 and TBX3. Among the 100 tumours, we found driver mutations in at least 40 cancer genes and 73 different combinations of mutated cancer genes. The results highlight the substantial genetic diversity underlying this common disease.
    Nature 06/2012; 486(7403):400-4. · 38.60 Impact Factor
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    ABSTRACT: In trials in triple negative breast cancer (TNBC), oestrogen and progesterone receptor negativity should be defined as < 1% positive cells. Negativity is a ratio of <2 between Her2 gene copy number and centromere of chromosome 17 or a copy number of 4 or less. In routine practice, immunohistochemistry is acceptable given stringent quality assurance. Triple negativity emerging after neoadjuvant treatment differs from primary TN and such patients should not enter TNBC trials. Patients relapsing with TN metastases should be eligible even if their primary was positive. Rare TN subtypes such as apocrine, adenoid-cystic and low-grade metaplastic tumours should be excluded. TN and basal-like (BL) signatures overlap but are not equivalent. Since the significance of basal cytokeratin or EGFR overexpression is not known and we lack validated assays, these features should not be used to subclassify TN tumours. Tissue collection in trials is mandatory so the effect on outcome of different tumour phenotypes and BRCA mutation can be explored. No prospective studies have established that TN tumours have particular sensitivity or resistance to any specific chemotherapy agent or radiation. TNBC patients should be treated according to tumour and clinical characteristics.
    Breast (Edinburgh, Scotland) 02/2012; 21(1):20-6. · 2.09 Impact Factor
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    ABSTRACT: The HER2/neu oncogene encodes a receptor-like tyrosine kinase whose overexpression in breast cancer predicts poor prognosis and resistance to conventional therapies. However, the mechanisms underlying aggressiveness of HER2 (human epidermal growth factor receptor 2)-overexpressing tumors remain incompletely understood. Because it assists epidermal growth factor (EGF) and neuregulin receptors, we overexpressed HER2 in MCF10A mammary cells and applied growth factors. HER2-overexpressing cells grown in extracellular matrix formed filled spheroids, which protruded outgrowths upon growth factor stimulation. Our transcriptome analyses imply a two-hit model for invasive growth: HER2-induced proliferation and evasion from anoikis generate filled structures, which are morphologically and transcriptionally analogous to preinvasive patients' lesions. In the second hit, EGF escalates signaling and transcriptional responses leading to invasive growth. Consistent with clinical relevance, a gene expression signature based on the HER2/EGF-activated transcriptional program can predict poorer prognosis of a subgroup of HER2-overexpressing patients. In conclusion, the integration of a three-dimensional cellular model and clinical data attributes progression of HER2-overexpressing lesions to EGF-like growth factors acting in the context of the tumor's microenvironment.
    Oncogene 12/2011; 31(31):3569-83. · 8.56 Impact Factor
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    JNCI Journal of the National Cancer Institute 11/2011; 103(22):1656. · 14.34 Impact Factor
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    ABSTRACT: Uncontrolled proliferation is a hallmark of cancer. In breast cancer, immunohistochemical assessment of the proportion of cells staining for the nuclear antigen Ki67 has become the most widely used method for comparing proliferation between tumor samples. Potential uses include prognosis, prediction of relative responsiveness or resistance to chemotherapy or endocrine therapy, estimation of residual risk in patients on standard therapy and as a dynamic biomarker of treatment efficacy in samples taken before, during, and after neoadjuvant therapy, particularly neoadjuvant endocrine therapy. Increasingly, Ki67 is measured in these scenarios for clinical research, including as a primary efficacy endpoint for clinical trials, and sometimes for clinical management. At present, the enormous variation in analytical practice markedly limits the value of Ki67 in each of these contexts. On March 12, 2010, an international panel of investigators with substantial expertise in the assessment of Ki67 and in the development of biomarker guidelines was convened in London by the co-chairs of the Breast International Group and North American Breast Cancer Group Biomarker Working Party to consider evidence for potential applications. Comprehensive recommendations on preanalytical and analytical assessment, and interpretation and scoring of Ki67 were formulated based on current evidence. These recommendations are geared toward achieving a harmonized methodology, create greater between-laboratory and between-study comparability, and allow earlier valid applications of this marker in clinical practice.
    CancerSpectrum Knowledge Environment 09/2011; 103(22):1656-64. · 14.07 Impact Factor
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    ABSTRACT: The developmental mechanisms through which the cerebral cortex increased in size and complexity during primate evolution are essentially unknown. To uncover genetic networks active in the developing cerebral cortex, we combined three-dimensional reconstruction of human fetal brains at midgestation and whole genome expression profiling. This novel approach enabled transcriptional characterization of neurons from accurately defined cortical regions containing presumptive Broca and Wernicke language areas, as well as surrounding associative areas. We identified hundreds of genes displaying differential expression between the two regions, but no significant difference in gene expression between left and right hemispheres. Validation by qRTPCR and in situ hybridization confirmed the robustness of our approach and revealed novel patterns of area- and layer-specific expression throughout the developing cortex. Genes differentially expressed between cortical areas were significantly associated with fast-evolving non-coding sequences harboring human-specific substitutions that could lead to divergence in their repertoires of transcription factor binding sites. Strikingly, while some of these sequences were accelerated in the human lineage only, many others were accelerated in chimpanzee and/or mouse lineages, indicating that genes important for cortical development may be particularly prone to changes in transcriptional regulation across mammals. Genes differentially expressed between cortical regions were also enriched for transcriptional targets of FoxP2, a key gene for the acquisition of language abilities in humans. Our findings point to a subset of genes with a unique combination of cortical areal expression and evolutionary patterns, suggesting that they play important roles in the transcriptional network underlying human-specific neural traits.
    PLoS ONE 01/2011; 6(3):e17753. · 3.53 Impact Factor
  • European Journal of Cancer - EUR J CANCER. 01/2011; 47.
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    ABSTRACT: The aim of this study was to investigate whether lymph node involvement in breast cancer is influenced by gene or miRNA expression of the primary tumor. For this purpose, we selected a very homogeneous patient population to minimize heterogeneity in other tumor and patient characteristics. First, we compared gene expression profiles of primary tumor tissue from a group of 96 breast cancer patients balanced for lymph node involvement using Affymetrix Human U133 Plus 2.0 microarray chip. A model was built by weighted Least-Squares Support Vector Machines and validated on an internal and external dataset. Next, miRNA profiling was performed on a subset of 82 tumors using Human MiRNA-microarray chips (Illumina). Finally, for each miRNA the number of significant inverse correlated targets was determined and compared with 1000 sets of randomly chosen targets. A model based on 241 genes was built (AUC 0.66). The AUC for the internal dataset was 0.646 and 0. 651 for the external datasets. The model includes multiple kinases, apoptosis-related, and zinc ion-binding genes. Integration of the microarray and miRNA data reveals ten miRNAs suppressing lymph node invasion and one miRNA promoting lymph node invasion. Our results provide evidence that measurable differences in gene and miRNA expression exist between node negative and node positive patients and thus that lymph node involvement is not a genetically random process. Moreover, our data suggest a general deregulation of the miRNA machinery that is potentially responsible for lymph node invasion.
    Breast Cancer Research and Treatment 11/2010; 129(3):767-76. · 4.47 Impact Factor
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    D Fumagalli, C Sotiriou
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    ABSTRACT: Breast cancer is a complex disease and even at a favourable stage, such as the pT1N0 one, it is unlikely to be understood and cured by focusing only on single gene or protein alterations determined with suboptimal technologies, as the standard clinico-pathological predictors are. Improving breast cancer treatment will require a more systematic, structured and multidimensional approach able to integrate tumour biology, disease burden and host-related factors. In this scenario, multigene predictors capturing gene-expression profiling or other molecular measurements have great potential for improving breast cancer management. Nevertheless, even if the gene signatures generated so far clearly represent a step forward in the prediction of patient outcome, they are still showing some limitations that nowadays are the basis for the development of a second generation of multigene predictors. Their strength will stand in the investigation of the tumour-surrounding stroma and tumour microenvironment, in the interrogation of different molecular subtypes of breast cancer as distinct entities and in the ability to predict both early and late relapse. It is prospected that the greater accuracy of this new wave of predictors will provide substantial support to the existing decision tools and will significantly ameliorate our current ability to define breast cancer prognosis.
    Annals of Oncology 10/2010; 21 Suppl 7:vii103-6. · 7.38 Impact Factor
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    ABSTRACT: The International Cancer Genome Consortium (ICGC) was launched to coordinate large-scale cancer genome studies in tumours from 50 different cancer types and/or subtypes that are of clinical and societal importance across the globe. Systematic studies of more than 25,000 cancer genomes at the genomic, epigenomic and transcriptomic levels will reveal the repertoire of oncogenic mutations, uncover traces of the mutagenic influences, define clinically relevant subtypes for prognosis and therapeutic management, and enable the development of new cancer therapies.
    Nature 04/2010; 464:993-8. · 38.60 Impact Factor

Publication Stats

2k Citations
367.52 Total Impact Points

Institutions

  • 2001–2012
    • Institut Jules Bordet
      Bruxelles, Brussels Capital Region, Belgium
  • 1998–2010
    • Université Libre de Bruxelles
      • Bordet Institute
      Bruxelles, Brussels Capital Region, Belgium
  • 2004
    • Vrije Universiteit Brussel
      Bruxelles, Brussels Capital Region, Belgium
    • National Cancer Institute (USA)
      Maryland, United States