Both the EGFR expression and PCNA labeling index increase with increasing grades of astrocytomas with a significantly high percentage of cells showing positive staining for both EGFR and PCNA in GBM and Grade III astrocytomas compared to Grade II astrocytomas.
Survival analysis was restricted to the group of diffuse astrocytomas (48 patients). pRb expression did not correlate with histological type, grade or p53 expression, while a moderately strong correlation existed between pRb expression and the percentages of proliferating cell nuclear antigen (PCNA) and MIB-1-positive cells.
Paraffin-embedded surgical specimens from 56 human astrocytomas (8 pilocytic [I degree] astrocytomas, 9 low grade [II degrees] fibrillary astrocytomas, 9 high grade [III degrees] astrocytomas and 30 glioblastomas) were immunostained with the anti-PCNA, anti-p53, anti-Ki-67 and anti EGFR antibodies.