dr. Franceska Dedeurwaerdere (MD)

Detection of microsatellite instability (MSI) is important in the classification and treatment of colon-, gastric and endometrial tumors and as tumoragnostic prediction for immunotherapy response. Sequencing can be used for the detection of MSI, but has not been studied/vaidated in the Belgian context. We look into the use of sequencing for routine screening for MSI on paraffin-embedded biopsies (FFPE) of solid tumors. 
In diagnostics of brain tumors, sarcomas and carcinomas of unknown primary origin, the use of the tumoral epigentic profile, obtained by methylation-profiling is emerging. The gold standard for  methylation-profiling, with the  Illumina Methylation EPIC 850K BeadChip platform generates a methylation-profile, a copy number variation (CNV)-plot and information on the methylation-status of specific genpromoters eg. MGMT and MLH1. The groupe of Prof. Nico Callewaert (UGent-VIB) recently developed a new, cheaper technique for methylation-profiling by cf-RRBS (cell-free Reduced Representation Bisulfite Sequencing). We investigate wether cfRRBS on FFPE generates comparable results as the golden standard regarding methylation-profile based tumorclassification, CNV-profile and methylation status of specific genpromoters. 
Recent findings suggest that gastric/pyloric metaplasia in the right colon is an early event in carcinogenesis in the serrated pathway characterized by the CpG island methylation phenotype (CIMP) often associated with MSI. The optimalisation of sequencing for MSI-detection and cf-RRBS on FFPE-material should help us to investigate the following research question: the hypothesis of gastric metaplasia as early event in the carcinogenesis along the serrated pathway in colontumors raises the question wether there is a relationship regarding methylation profile and immunohistochemical phenotype between the MSI-and/or CIMP-subgroup of colonic and gastric adenocarcinomas.
 

• Trainee in pathology (1996-2002)
• Staff pathologist, Clinique de l’Europe (2002-2003)
• Staff pathologist, Imeldaziekenhuis Bonheiden (2003-2009)
• Head of Department, Pathology Lab Imeldaziekenhuis Bonheiden (2007-2009)
• Staff pathologist, “Heilig-Hartziekenhuis Roeselare-Menen (AZ Delta)” and Sint-Andriesziekenhuis Tielt, 2010-present
• Head of Department,  Pathology Lab, AZ Delta-Sint Andries Tielt (2010-present)
• President, Cooperative Society for Pathology (2014-present)
• Doctoral Fellow, Department of Pathology, Ghent University Hospital (2020-present)
   

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• Department of Pathology, PAD-building, entrance 23, Ghent University Hospital, Corneel Heymanslaan 10, 9000 Ghent, Belgium