[Analysis of DNA histograms and histopathologic assessment of necrosis after preoperative chemotherapy of osteosarcoma in children and youth].

Analysis of nucler DNA content (DNA histograms by flow cytometry) in 26 children and youth with osteosarcoma treated at the National Research Institute of Mother and Child, was carried out. The relationship between aneuploid populations, index DNA and phases of cell cycle and the clinical course, histopathologic grading and histopathologic assessment of preoperative chemotherapy effect (% of tumour necrosis) were analysed. Osteosarcomas in children with changed schedules of chemotherapy (therapy complications) in relation to the above parameters were also examined. The results show, that increased aneuploid population and index DNA (less distinct for S phase of anueptoid population) are linked with weaker chemotherapy effect. It can indicate a bigger proliferative potential in this kind of tumours - it often occurs with a more dramatic course of disease. According to the authors flow cytometry studies are helpful and complementary to histopathologic diagnosis.