The relationship between survival and flow cytometric
DNA-ploidy and other prognostic factors such as histological subtype, anatomical
tumor site, patient sex and age was investigated in 153 patients with intracranial
neuroepithelial tumors who underwent surgical treatment. We found a trend toward poorer survival from
anaplastic astrocytomas and
glioblastomas with respect to low-grade (I and II)
astrocytomas (which did not differ significantly); accordingly, patients were grouped into these 3 histologic subgroups. Thirty-seven of the 153
tumors (24.2%) were
aneuploid with a median
DNA-index (DI) of 1.3 (range: 1.2-2.0).
DNA-ploidy correlated with histology, since
anaplastic astrocytomas and
glioblastomas were significantly (p = 0.041) more frequently
aneuploid (around 30%) than low-grade
astrocytomas (around 10%). Patients with
DNA-
aneuploid tumors (i.e., with DI not equal to 1.00) survived for a shorter time (31.4 weeks) than patients with
DNA diploid
tumors (75.1 weeks) (p less than 0.001). This difference was confirmed by Cox's multivariate analysis.
Aneuploid tumors were associated with a poorer survival (p = .0002) when compared with diploid
tumors, resulting in a relative risk point estimate (RR) of 2.41, 95% confidence interval (Cl) = 1.55-3.74. Histological subtype was also significantly associated with survival (p less than 0.0001), with RRs of 2.09, 95% Cl = 1.13-3.86 and 3.59, 95% Cl = 1.96-6.59 for
anaplastic astrocytomas and
glioblastomas, respectively, compared to low-grade
astrocytomas. We therefore suggest that the flow cytometric measurement of
DNA-ploidy has relevant significance in predicting survival in patients treated for intracranial
neuroepithelial tumors.