Proliferating cell nuclear antigen (PCNA): expression in samples of human astrocytic gliomas.

In this retrospective study, 55 astrocytic tumours were stained with monoclonal antibody PC10 which recognizes the proliferating cell nuclear antigen (PCNA) in formalin fixed, paraffin-wax embedded sections. All the cases were graded using the Daumas-Duport system and the PCNA labelling indices (LIs) were correlated with tumour grades. Mean PCNA LI was 4.1% in the grade II, 8.1% in the grade III and 26.1% in the grade IV group. Six juvenile and cerebellar (grade I) astrocytomas had a mean PCNA LI of 5.6%. In general PCNA LI increased with tumour grade, but there was considerable variation of LIs especially in grade IV tumours which often had very high PCNA LIs (up to 72.7%). PC10 may be a useful complementary technique in surgical neuropathology, but the significance of the high LIs, seen in a proportion of glioblastomas, needs to be further determined.