More data were obtained from the Regional Silesian Cancer
Register, including facts on children diagnosed with cancer in a
given area; these data were provided by the Cancer Epidemiology Unit
of the Oncology Center at The Maria Skłodowska-Curie Institute in
Gliwice (The database verifies and eliminates duplicated and
repeatedly reported cases). This study focused on data of newly
registered cases from January 1, 1995 to December 31, 2004.