1. Department of Clinical Oncology, Tadeusz Koszarowski Regional Oncology Center, Opole, Katowicka 66a, Poland
2. Department of Pathomorphology & Oncological Cytology, Wroclaw Medical University, Borowska 213, 50–556 Wroclaw, Poland
3. Department of Statistics, Wroclaw University of Economics, Komandorska 118–120, 53–345 Wroclaw, Poland
4. Department of Oncology & Division of Surgical Oncology, Wroclaw Medical University, pl. Hirszfelda 12, 53–413 Wroclaw, Poland
5. Lower Silesian Oncology Centre, pl. Hirszfelda 12, 53–413 Wroclaw, Poland