Cytophotometric investigations in recurrent gliomas: correlation of DNA-parameters with WHO-grade, proliferation index and recurrence-free interval

DNA-cytophotometry is one of the methods that may contribute to a more prec ise evaluation of the biological behaviour of tumours in addition to the WH O-classification. In this study 121 tumour specimens of 50 patients sufferi ng from gliomas with one or up to three recurrencies were investigated. In all cases the histological type and WHO-grade and the Ki-67/MIB1 labeling i ndex were determined. DNA cytophotometry was performed after single cell pr eparation on Feulgen-stained preparations,and the following parameters were calculated: stemline ploidy, 5c-exceeding rate,and 2c-deviation index. Statistical evaluation revealed a highly significant correlation between re currence-free interval and WHO-grade only.The DNA parameters, however, furn ished additional information about increasing genetic instability in the ma jority of the recurrencies independently of changes in the WHO-grade. They thus seem to be useful as additional parameters for the determination of gl ioma progression.