Tsantoulis Petros

Dr. Petros Tsantoulis

Precision oncology, Lab leader



Genetic alterations contribute significantly to the development of a cancerous tumor and explain important aspects of its behavior. Using appropriate analyses like DNA/RNA sequencing we can identify such genetic alterations in a biological sample. The interpretation and integration of this information in cancer care is often called “personalized oncology” or “precision oncology” and is expected to improve clinical decision-making, allowing us to better adapt therapy to each individual.

Precision oncology depends on the discovery and validation of clinically relevant biomarkers, that is biological features that differentiate patients and predict prognosis or response to treatment. Our work is focused on biomarker development in various cancer types and with a variety of analytical approaches. We explore the most promising biomarkers with advanced software and cutting-edge bioinformatic techniques in collaboration with the the Bioinformatics Core Facility (Dr Mauro Delorenzi) in the Swiss Institute of Bioinfomatics.

Our work is grounded on the conviction that research must be closely related with clinical application. Since 2016 we are heading the Molecular Tumor Board, a collaboration with the Department of Pathology and the Department of Genetics that brings together experts from oncology, pathology, genetics and bioinformatics in order to provide structured interpretation of advanced molecular analyses in a clinical environment. The Molecular Tumor Board operates in parallel with the Lausanne university hospital (CHUV) and has studied over 250 patients in two years. Several case reports detailing the association between specific molecular features and treatment responses are under preparation and one has already been published in a high-profile journal.

In addition, our group interacts closely with the national network for personalized health (SPHN) and the “Precision Oncology” driver project of Pr Olivier Michielin, with which we are formally associated. Specific objectives include the effort to build experience in precision oncology by systematically, continuously harvesting clinical data and the introduction of a national educational molecular tumor board. We believe this is of particular importance since the efficient use of clinical data is required to enable the development of robust biomarkers.

Research overview

The common theme underlying all our studies is the desire to properly re-classify cancer types with the inclusion of molecular features and how to use that information to predict clinically relevant outcomes. We recently published a study that demonstrates the frequent occurrence of copy number alterations involving the PI3 kinase pathway in anal cancer recurrence and an association between the burden of copy number alterations and patient survival. In addition, we have submitted for publication a model based on the expression of two genes that predicts the probability of liver metastasis in different cancer types. Another major project that we are currently undertaking involves the systematic comparison of colorectal liver metastases with their respective primaries across multiple dimensions, such as gene expression, exome sequence, methylation and copy number profile.