Relationship between AgNOR proteins, Ki-67 antigen, p53 immunophenotype and differentiation markers in archival breast carcinomas

The present study investigated (i) the relationship between standardised mo rphometric AgNOR parameters (argyrophilic nucleolar organiser region-associ ated proteins) and MIB1 growth fraction, and (ii) their correlation with im munohistochemical p53, sex steroid receptor status and histopathological di fferentiation grade in serial paraffin sections from 39 breast carcinomas. Ten sections were double-stained for AgNOR/MIB1. AgNOR parameters correlate d significantly with MIB1 growth fraction and p53 protein expression. Signi ficant inverse correlation was found between proliferation markers and oest rogen/progesterone receptor status and histopathological grade. AgNOR expre ssion was significantly higher in cycling (MIB1 positive) tumour cells, tha n in resting (MIB1 negative) ones, however with exceptions. We conclude, th at standardised AgNOR parameters correlate with markers of increased malign ant potential in breast carcinomas. However, AgNORs seem to reflect prolife ration independent cellular and nucleolar activity of tumour cells, as well . We recommend the use of standardised AgNOR analysis for obtaining sound r esults in routine paraffin sections.