P53 QUANTITATIVE IMMUNOCYTOCHEMICAL ANALYSIS IN BREAST CARCINOMAS

A series of 200 breast carcinomas was investigated on frozen sections using PAI, 1801 p53 monoclonal antibody and streptavidin biotin peroxi dase complex. Densitometric analysis of the immunoprecipitates was ass essed by processing digitized microscopic images. p53 was observed in the nucleus of 48% of the tumors. Some tumors (14 of 91) tested in par allel on paraffin sections were negative, although positive on frozen sections. Image analysis showed that the surfaces positive with anti-p 53 and the staining intensity were decreased (P < .01) on paraffin sec tions. The p53 tumor expression was independent of patient age, tumor size, axillary lymph node status, HER-2/neu and cathepsin D expression , and nuclear morphometric parameters. However, p53 correlated with hi gh histological grade (P < .01), lack of estrogen receptor (ER) (P = . 0015) and progesterone (PR) (P = .0065) antigenic sites, pS2 detection (P = .03), high Ki-67 immunoreactivity (P = .018), large silver-stain ed nucleolar organizer region (AgNOR) nuclear surface ratio (P < .02), and degree of hyperploidy (P < .03), and was more often observed in t he comedocarcinomas, The results suggest that p53 expression in breast carcinomas is not a totally independent prognostic indicator and that the clinical relevance and prognostic significance of p53 expression in breast carcinomas can be reliably assessed provided that the proced ures are standardized, particularly with regard to the use of frozen s ections and image analysis processing of the immunodetection. Copyrigh t (C) 1995 by W.B. Saunders Company