Immunohistochemical expression of p53 protein in invasive breast carcinoma: Clinicopathologic correlations

The results of immunohistochemical expression of p53 protein in 106 invasiv e breast cancers were correlated with conventional pathologic prognostic pa rameters. Archival formalin-fixed, paraffin-embedded tissue sections of the se cases were stained with a monoclonal antibody (Ab-2), raised against p53 protein using a peroxidase-labelled streptavidin biotin kit. Fifty-six (53 %) showed positive nuclear staining; 31 were considered weakly, 21 moderate ly and 4 strongly positive. Forty-three (77%) of these positive cases stain ed less than 50% of the tumor cells, with a significant association between intensity and proportion of nuclei stained (p<0.05). p53 staining also cor related with histologic grade (p<0.005) but not with tumor size nor clinica l stage (p>0.05). The follow-up data did not reveal any statistically signi ficant survival advantage for patients with p53 negative tumors.