1. Department of Gastroenterology, Hepatology and Oncology, Center of Postgraduate Medical Education, Warsaw, Poland
2. Department of Gastroenterological Oncology, Maria Sklodowska-Curie Institute – Oncology Center, Warsaw, Poland
3. Department of Pathomorphology, Center of Postgraduate Medical Education, Warsaw, Poland
4. Department of Pathology and Laboratory Medicine, Maria Sklodowska-Curie Institute – Oncology Center, Warsaw, Poland
5. Department of Cancer Prevention, Maria Sklodowska-Curie Institute – Oncology Center, Warsaw, Poland