[Analysis of PCNA, Ki67, AgNOR and p53 expression in brain glial tumors]

Abstract

Background and purpose: The aim of this study was to evaluate clinical usefulness of proliferating cell nuclear antigen (PCNA), Ki67 antigen, p53 protein and silver-binding nucleolar organizer regions (AgNOR) in brain glial tumors.

Material and methods: The investigation of PCNA, Ki67 and p53 was carried out on a group of 120 patients with glial tumors operated on at the Neurosurgical Department of Wroclaw Medical University including 63 patients operated again because of recurrence. AgNOR was evaluated on a group of 64 patients including 38 patients operated again. Classical histological tests, immunohistochemical tests for PCNA, p53 and Ki67 activity with monoclonal antibodies (DACO) and histochemical tests for AgNOR were performed on every specimen of tumor tissue. The level of 40% for PCNA, 2.75 (equal to median) for AgNOR and 5% for Ki67 and p53 was adopted as significant.

Results: Mean expression of PCNA of glial tumors grade I and II was 32%, grade III and IV - 44% (p<0.05). Mean expression of AgNOR was 1.88 and 3.16 (p=0.00001), respectively. Average PCNA expression in recurrent tumors to 12 months was 52.7% and for later recurrences - 35.4% (p<0.05). Average expressions of AgNOR were 3.38 and 2.68 (p<0.05), respectively. Differences of Ki67 and p53 expressions were not significant.

Conclusions: PCNA and AgNOR expressions correlate with proliferative activity, growth rate and histological malignancy, reaching high values in highly malignant and early recurrent tumors. Antigens Ki67 and p53 do not seem to be predictive markers of glial tumors.