We were able to demonstrate that p53 expression in breast carcinomas means a significantly worse prognosis for grade II tumors (overall survival, P = 0.0002; disease-free period, P = 0.0116), for overall survival in the case of estrogen-receptor-positive tumors (P = 0.014), and for tumors showing increased proliferation activity (overall survival, P = 0.0477).
In summary, a new sensitive and quantitative LIA suitable for routine analysis of p53 protein in steroid receptor cytosol preparations from breast tumours has been developed to confirm the prognostic importance of p53 protein accumulation in human breast cancer.
The results lend further support to the view that inherited mutations in p53 alleles are not a significant contributor to breast cancer predisposition and it is not, therefore, clinically worthwhile to screen predisposed or potentially predisposed families for germline mutations in the p53 gene.
To evaluate the prognostic relevance of mutant p53 protein overexpression and DNA flow cytometry in primary breast cancer we correlated these factors with the common prognostic parameters such as tumor size, lymph node status, grading, menopausal status and receptor status.
Growth factor requirement, oncogene expression and TP53 mutations of a tumorigenic and a non-tumorigenic subline of the human breast carcinoma cell line, HMT-3909.
The number of known genes for which there is now good evidence for their role in the development of breast cancer is still limited, and basically restricted to TP53 and ERBB2.
A number of independent groups using different methods of detection have shown that p53 alterations are associated with more aggressive tumor biologic factors and a poorer prognosis in breast cancer patients.
We conclude that (1) p53 immunoreactivity in breast lesions should not be used as exclusive evidence of malignancy and (2) p53 immunoreactivity in benign breast lesions may not identify a subset of patients at increased risk for breast carcinoma.
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 procedures are standardized, particularly with regard to the use of frozen sections and image analysis processing of the immunodetection.
This study was designed to test the hypothesis that p53 gene alterations are related to the difference in prognosis between black and white breast cancer patients.
Germ-line mutations of the tumor-suppressor gene p53 have been observed in some families with the Li-Fraumeni syndrome (LFS), a familial cancer syndrome in which affected relatives develop a diverse set of early-onset malignancies including breast carcinoma, sarcomas, and brain tumors.
It could be tempting to hypothesize that the evaluation of the combined mdm2/p53 immunohistochemical phenotype in human breast carcinoma could give us better prognostic information than the evaluation of the expression of the p53 protein alone.
Our data confirm previous reports of a putative tumour-suppressor gene, distinct from TP53, on distal chromosome 17p which is associated with breast cancer.
Regardless of differences in their protein-expression pattern, a majority of the p53 gene mutations were suggested to function in a recessive mode and to be involved in the development of histologically aggressive breast cancer.