1 Department of Cancer Prevention and Department of Oncological Gastroenterology, The Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland; Department of Gastroenterology, Hepatology, and Oncology, Medical Center for Postgraduate Education, Warsaw, Poland; MRC Cancer Unit, University of Cambridge, Cambridge, UK.
2 Department of Cancer Prevention and Department of Oncological Gastroenterology, The Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland; Department of Gastroenterology, Hepatology, and Oncology, Medical Center for Postgraduate Education, Warsaw, Poland; Institute of Health and Society, University of Oslo, Oslo, Norway.