1. The Maria Sklodowska-Curie National Research Institute of Oncology, 02-781 Warsaw, Poland
2. Department of General, Oncological and Vascular Surgery, 5th Military Clinical Hospital in Kraków, 30-901 Kraków, Poland
3. Department of Medical Education, Jagiellonian University Medical College, 30-688 Kraków, Poland
4. Chair of Surgery, Faculty of Medicine and Health Sciences, Andrzej Frycz Modrzewski Kraków University, 30-705 Kraków, Poland