1. Department of Hematology & Cancer Prevention, Chorzow, Faculty of Health Sciences, Bytom, Medical University of Silesia, 40-055 Katowice, Poland
2. Clinical Department of Hematology & Cancer Prevention, Municipal Hospital, 41-500 Chorzow, Poland
3. Institute of Economics, Finance & Management, Faculty of Management & Social Communication, Jagiellonian University, 31-007 Cracow, Poland