Prognosis in malignant glioma: a retrospective study of biopsy specimens by flow cytometry.

The DNA ploidy of a series of 78 gliomas has been estimated by flow cytometry using cell suspensions prepared from paraffin embedded material. Apart from two oligodendrogliomas the tumours were all astrocytomas. Forty-nine (63%) tumours were found to have a diploid DNA distribution and 29 (37%) an aneuploid DNA distribution. The two oligodendrogliomas were both DNA aneuploid. No correlation was found between DNA ploidy and histological grade or DNA ploidy and survival. Both ploidy groups appear to have responded equally to therapy. In this study the factors associated with a short survival were advancing age and the presence of vascular endothelial proliferation, while the DNA ploidy and the cytological features do not appear as useful in predicting survival when examining biopsy material.