PROGNOSTIC-SIGNIFICANCE OF FLOW-CYTOMETRY DEOXYRIBONUCLEIC-ACID ANALYSIS OF HUMAN ASTROCYTOMAS

FLOW CYTOMETRY WAS used to determine the deoxyribonucleic acid ploidy and proliferative activity of 230 astrocytomas. The relationships amon g survival, ploidy, proliferation, histological features, and clinical variables were analyzed. Multivariate analysis confirmed the independ ent prognostic significance of the S-phase fraction (P < 0.01), ploidy (P = 0.04), age at diagnosis (P < 0.001), extent of surgery (P < 0.01 ), and sex (P = 0.03). Three groups with significantly different survi val were defined based on S-phase fraction ranges of < 3%, 3%-5.9%, an d greater than or equal to 6%. The strong correlation between the S-ph ase fraction and survival confirmed the importance of quantitative pro liferation assays in predicting tumor behavior and demonstrated that s pecific reference ranges can be defined for clinical application. The weaker association between ploidy and survival leaves the usefulness o f the determination of ploidy with flow cytometry in doubt.