[Polish Paediatric Leukaemia/Lymphoma Study Group - 25 years of activity].

In 1974, Professor Jerzy Armata initiated the organization of a multicentre cooperative group, which later became known as the Polish Paediatric Leukaemia/Lymphoma Study Group (PPL/LSG). At first the Group included three centres headed by Professor J. Armata (Cracow), Professor U. Radwanska (Poznan) and Professor J. Boguslawska-Jaworska (Wroclaw), but gradually it extended to nine university departments of paediatric hematologic oncology. Within the past 25 years, the introduction and employment of standardized, common treatment regimens based on our experience, as well as on the results of other oncological groups in Europe and the United States, resulted in a significant improvement of therapeutic results in childhood cancer, especially of the lymphatic and haematopoetic systems. The improvement in the recovery rates was as follows: in acute lymphoblastic leukaemia: from 25% to 84%, in non-Hodgkin's lymphoma recovery: from 28% to 82%, in Hodgkin's disease: from 80% to 90%. In acute non-lymphoblastic leukaemia the improvement in treatment results (from 15% to 40%) was also significant but still unsatisfactory.