PCNA and protein P53 in recurrent supratentorial glial brain tumors: studies on correlation between morphology and tumor progression.

Thirty seven cases of recurrent gliomas with survival time from 3 month to 13 years were investigated morphologically and immunohistochemically to evaluate progression and transformation of tumors. Using antibodies against PCNA and p53 the proportion of positively marked cells (nuclei) to all tumor cells was assessed at both primary and secondary surgery. This was compared with morphology and survival time between first and second surgery. In 10 cases (27.0%) there were no positively marked cells. In the remaining 27 cases (73.0% of the whole group), the following indices (percents of positive cells) were calculated: for patients with survival below 1 year (mean = 9m) 28.3% PCNA-positive cells and 30.3% p53-positive cells at first operation. For recidiving tumors both indices were lower namely for PCNA 20.9% and for protein p53-26.7%. For patients with survival over 1 year (mean = 4.8y) the index after I operation for PCNA was 25.5% and was higher than found after II operation-22.3%. In contrary, the index for protein p53 was 20.1% after I operation and was lower as compared with the index after II operation-28.2%. Eleven of twelve fibrillary astrocytomas and all five gemistocytic astrocytomas at first operation underwent changes towards malignisation. The immunocytochemical results confirm the high phenotypic differentiation what is reflected in different indices for PCNA and p53 of tumors.