1. Medical Center for Postgraduate EducationWarsawPoland
2. Department of General, Endocrine and Transplant SurgeryMedical University of GdańskGdańskPoland
3. Department of Gastroenterological OncologyThe Maria Sklodowska-Curie Memorial Cancer Centre and Institute of OncologyWarsawPoland
4. Department of Gastroenterology and HepatologyMedical Centre for Postgraduate EducationWarsawPoland