Professional Education

  • Doctor of Philosophy, Katholieke Universiteit Leuven (2013)
  • Doctor of Philosophy, MariaSklodowska-CurieMemorialCancerCenter&Institut (2013)
  • Master of Science, Warsaw University of Life Sciences (2009)

Stanford Advisors

All Publications

  • Combination approach for detecting different types of alterations in circulating tumor DNA in leiomyosarcoma. Clinical cancer research : an official journal of the American Association for Cancer Research Przybyl, J., Chabon, J. J., Spans, L., Ganjoo, K., Vennam, S., Newman, A. M., Forg√≥, E., Varma, S., Zhu, S., Debiec-Rychter, M., Alizadeh, A. A., Diehn, M., van de Rijn, M. 2018


    The clinical utility of circulating tumor DNA (ctDNA) monitoring has been shown in tumors that harbor highly recurrent mutations. Leiomyosarcoma (LMS) represents a type of tumor with a wide spectrum of heterogeneous genomic abnormalities; thus, targeting hotspot mutations or a narrow genomic region for ctDNA detection may not be practical. Here we demonstrate a combinatorial approach that integrates different sequencing protocols for the orthogonal detection of single nucleotide variants (SNVs), small indels and copy number alterations (CNAs) in ctDNA.We employed Cancer Personalized Profiling by deep Sequencing (CAPP-Seq) for the analysis of SNVs and indels, together with a genome-wide interrogation of CNAs by Genome Representation Profiling (GRP). We profiled 28 longitudinal plasma samples and 25 tumor specimens from 7 patients with LMS.We detected ctDNA in 6 of 7 of these patients with >98% specificity for mutant allele fractions down to a level of 0.01%. We show that results from CAPP-Seq and GRP are highly concordant, and the combination of these methods allows for more comprehensive monitoring of ctDNA by profiling a wide spectrum of tumor-specific markers. By analyzing multiple tumor specimens in individual patients obtained from different sites and at different times during treatment, we observed clonal evolution of these tumors that was reflected by ctDNA profiles.Our strategy allows for a comprehensive monitoring of a broad spectrum of tumor-specific markers in plasma. Our approach may be clinically useful not only in LMS but also in other tumor types that lack recurrent genomic alterations.

    View details for DOI 10.1158/1078-0432.CCR-17-3704

    View details for PubMedID 29463554

  • Macrophage infiltration and genetic landscape of undifferentiated uterine sarcomas. JCI insight Przybyl, J., Kowalewska, M., Quattrone, A., Dewaele, B., Vanspauwen, V., Varma, S., Vennam, S., Newman, A. M., Swierniak, M., Bakula-Zalewska, E., Siedlecki, J. A., Bidzinski, M., Cools, J., van de Rijn, M., Debiec-Rychter, M. 2017; 2 (11)


    Endometrial stromal tumors include translocation-associated low- and high-grade endometrial stromal sarcomas (ESS) and highly malignant undifferentiated uterine sarcomas (UUS). UUS is considered a poorly defined group of aggressive tumors and is often seen as a diagnosis of exclusion after ESS and leiomyosarcoma (LMS) have been ruled out. We performed a comprehensive analysis of gene expression, copy number variation, point mutations, and immune cell infiltrates in the largest series to date of all major types of uterine sarcomas to shed light on the biology of UUS and to identify potential novel therapeutic targets. We show that UUS tumors have a distinct molecular profile from LMS and ESS. Gene expression and immunohistochemical analyses revealed the presence of high numbers of tumor-associated macrophages (TAMs) in UUS, which makes UUS patients suitable candidates for therapies targeting TAMs. Our results show a high genomic instability of UUS and downregulation of several TP53-mediated tumor suppressor genes, such as NDN, CDH11, and NDRG4. Moreover, we demonstrate that UUS carry somatic mutations in several oncogenes and tumor suppressor genes implicated in RAS/PI3K/AKT/mTOR, ERBB3, and Hedgehog signaling.

    View details for DOI 10.1172/jci.insight.94033

    View details for PubMedID 28570276

  • Metastatic potential is determined early in synovial sarcoma development and reflected by tumor molecular features INTERNATIONAL JOURNAL OF BIOCHEMISTRY & CELL BIOLOGY Przybyl, J., Sciot, R., Wozniak, A., Schoffski, P., Vanspauwen, V., Samson, I., Siedlecki, J. A., Rutkowski, P., Debiec-Rychter, M. 2014; 53: 505-513


    Synovial sarcoma (SynSa) is an aggressive mesenchymal tumor, comprising approximately 10% of all soft tissue sarcomas. Over half of SynSa patients develop metastasis or local recurrence, but the underlying molecular mechanisms of the aggressive clinical behavior remain poorly characterized.Sixty-four frozen tumor specimens from 54 SynSa patients were subjected to array comparative genomic hybridization (aCGH) and gene expression profiling. The examined set of tumor specimens included 16 primary tumors from untreated patients who did not develop metastasis/local recurrence (SynSa1 group), 26 primary tumors from untreated patients who developed metastases or local recurrence during follow-up (SynSa2 group), and 22 metachronous metastatic/recurrent SynSa tumors (SynSa3 group).AURKA and KIF18A, which play important roles in various mitotic events, were the two most up-regulated genes in SynSa2 and SynSa3 groups compared to the SynSa1 group. Expression profiles of SynSa2 and SynSa3 tumors did not show any significant differences. Analysis of genomic index (GI) based on aCGH profiles demonstrated that the SynSa1 group consisted of tumors with significantly less complex genomes compared to SynSa2 and SynSa3 groups. There was no significant difference in genome complexity between SynSa2 and SynSa3 tumors.Primary SynSa tumors from patients who develop metastases or local recurrence share common molecular features with metastatic/recurrent tumors. Presented data suggest that the aggressive clinical SynSa behavior is determined early in tumorigenesis and might be related to impaired regulation of mitotic mechanisms. This article is part of a Directed Issue entitled: Rare Cancers.

    View details for DOI 10.1016/j.biocel.2014.05.006

    View details for Web of Science ID 000340340400060

    View details for PubMedID 24842110

  • Genetics of rare mesenchymal tumors: Implications for targeted treatment in DFSP, ASPS, CCS, GCTB and PEComa INTERNATIONAL JOURNAL OF BIOCHEMISTRY & CELL BIOLOGY Rutkowski, P., Przybyl, J., Switaj, T. 2014; 53: 466-474


    Soft tissue and bone sarcomas comprise a heterogeneous group of mesenchymal tumors that include roughly 130 distinct diagnostic entities. Many of them are exceptionally rare, with only few cases diagnosed worldwide each year. Development of novel targeted treatment in this group of tumors is of special importance since many sarcoma subtypes are resistant to conventional chemotherapy and the effective therapeutic options are limited. In this review we aim to discuss the molecular implications for targeted therapy in selected rare soft tissue and bone sarcoma subtypes, including dermatofibrosarcoma protuberans (DFSP), alveolar soft part sarcoma (ASPS), clear cell sarcoma (CCS), giant cell tumor of bone (GCTB) and perivascular epithelioid cell neoplasms (PEComas). This article is part of a Directed Issue entitled: Rare cancers.

    View details for DOI 10.1016/j.biocel.2014.03.024

    View details for Web of Science ID 000340340400056

    View details for PubMedID 24704529

  • Identification of a novel, recurrent MBTD1-CXorf67 fusion in low-grade endometrial stromal sarcoma INTERNATIONAL JOURNAL OF CANCER Dewaele, B., Przybyl, J., Quattrone, A., Ferreiro, J. F., Vanspauwen, V., Geerdens, E., Gianfelici, V., Kalender, Z., Wozniak, A., Moerman, P., Sciot, R., Croce, S., Amant, F., Vandenberghe, P., Cools, J., Debiec-Rychter, M. 2014; 134 (5): 1112-1122

    View details for DOI 10.1002/ijc.28440

    View details for Web of Science ID 000328246700010

  • Chromosome Instability Accounts for Reverse Metastatic Outcomes of Pediatric and Adult Synovial Sarcomas JOURNAL OF CLINICAL ONCOLOGY Lagarde, P., Przybyl, J., Brulard, C., Perot, G., Pierron, G., Delattre, O., Sciot, R., Wozniak, A., Schoffski, P., Terrier, P., Neuville, A., Coindre, J., Italiano, A., Orbach, D., Debiec-Rychter, M., Chibon, F. 2013; 31 (5): 608-615


    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.One hundred patients who had primary untreated SS tumors were selected for expression and genomic profiling in a training/validation approach.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.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.

    View details for DOI 10.1200/JCO.2012.46.0147

    View details for Web of Science ID 000314820400019

    View details for PubMedID 23319690

  • Extended Adjuvant Therapy with Imatinib in Patients with Gastrointestinal Stromal Tumors Recommendations for Patient Selection, Risk Assessment, and Molecular Response Monitoring MOLECULAR DIAGNOSIS & THERAPY Rutkowski, P., Przybyl, J., Zdzienicki, M. 2013; 17 (1): 9-19


    On the basis of the recently published results of a clinical trial comparing 12 and 36 months of imatinib in adjuvant therapy for gastrointestinal stromal tumors (GISTs), which demonstrated clinical benefit of longer imatinib treatment in terms of delaying recurrences and improving overall survival, both the US Food and Drug Administration and the European Medicines Agency have updated their recommendations and approved 36 months of imatinib treatment in patients with v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT)-positive GISTs (also known as CD117-positive GISTs) at high risk of recurrence after surgical resection of a primary tumor. This article discusses patient selection criteria for extended adjuvant therapy with imatinib, different classifications of risk of recurrence, and assessment of the response to therapy.

    View details for DOI 10.1007/s40291-013-0018-7

    View details for Web of Science ID 000318043100002

    View details for PubMedID 23355099

    View details for PubMedCentralID PMC3565084

  • Recurrent and novel SS18-SSX fusion transcripts in synovial sarcoma: description of three new cases TUMOR BIOLOGY Przybyl, J., Sciot, R., Rutkowski, P., Siedlecki, J. A., Vanspauwen, V., Samson, I., Debiec-Rychter, M. 2012; 33 (6): 2245-2253


    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.

    View details for DOI 10.1007/s13277-012-0486-0

    View details for Web of Science ID 000311201500046

    View details for PubMedID 22976541

    View details for PubMedCentralID PMC3501176

  • Downstream and intermediate interactions of synovial sarcoma-associated fusion oncoproteins and their implication for targeted therapy. Sarcoma Przybyl, J., Jurkowska, M., Rutkowski, P., Debiec-Rychter, M., Siedlecki, J. A. 2012; 2012: 249219-?


    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.

    View details for DOI 10.1155/2012/249219

    View details for PubMedID 22550415

    View details for PubMedCentralID PMC3329658