Cellular DNA content parameters as prognostic indicators in human astrocytomas

Objective: Clinical parameters such as grade, size and/or location of the tumor are good predictors of outcome in patients with astrocytoma. The objective of this study was to determine whether DNA content parameters have a prognostic significance for this group of tumors. Methods: Following optimization and validation of methodology for evaluating cellular DNA content parameters (CDCP), tumor DNA ploidy and percent S phase fraction (SPF) were determined from 64 patients using formalin fixed, paraffin embedded specimens (mean coefficient of variation = 4.94) obtained over a 10-year period. Median survival times correlated with grade (I/ II = 1154 vs. III/IV = 483 days, P = 0.0317). Fifty-five percent of the specimens contained DNA aneuploid (DNA-A) components (average SPF = 18.3%) and 45% were DNA diploid (DNA- D) ( average SPF = 9.6%). Survival did not correlate with overall differences in DNA ploidy ( DNA- D = 181 vs. DNA-A = 206 days, P = 0.6314) when treated and untreated tumors were analyzed. However, a trend for prolonged median survival was observed in patients whose tumors were untreated with respect to cytotoxic therapy based on DNA ploidy status (DNA-D = 275 vs. DNA-A = 15 days, P = 0.3408). Survival for all patients did not correlate with median SPF (< 13.5% av. = 121 vs. > 13.5% av. = 154 days, P = 0.6534). Conclusion: DNA content parameters may correlate with the natural history and treatment outcome of newly diagnosed untreated patients with astrocytomas.