1. Institute of Clinical and Preventive Medicine, University of Latvia, Riga, Latvia;
2. Faculty of Continuing Education, Riga Stradins University, Riga, Latvia;
3. Faculty of Medicine, University of Latvia, Riga, Latvia;
4. Department of Research, Riga East University Hospital, Riga, Latvia;
5. Academic Histology Laboratory, Riga, Latvia;
6. Digestive Diseases Centre, “GASTRO”, Riga, Latvia;
7. Prevention and Implementation Group, International Agency for Research on Cancer, Lyon, France