Prognostic value of flow cytometry and correlation to some conventional prognostic factors: a retrospective study of archival specimens of 134 astrocytomas.

Abstract

The S-phase fraction and the DNA ploidy type in 134 astrocytomas (18 Grade II, 46 Grade III, and 70 Grade IV astrocytomas) were studied using flow cytometry in a retrospective study of archival tumor specimens. A high grade of malignancy was associated with both a high S-phase fraction (p < 0.0001) and an aneuploid DNA pattern (p < 0.0001). There was no aneuploid DNA pattern found in the fibrillary astrocytomas (World Health Organization (WHO) Grade II); where-as the aneuploid pattern was observed in 80% of all the glioblastomas multiforme (WHO Grade IV). The age and gender of the patients were not significantly related to the flow cytometry parameters. The survival of patients with Grade II or III astrocytomas was significantly longer when their tumors exhibited a tetraploid DNA pattern or had a low S-phase fraction. In patients with Grade IV tumors, there was no correlation between length of survival and either the DNA ploidy or the S-phase fraction. In a multivariate Cox regression analysis of data obtained in patients with Grade II and III astrocytomas, age, grade of malignancy, DNA ploidy, and S-phase fraction were independent prognostic factors.