p53 is a nuclear phosphoprotein which is normally expressed at very low level in all mammalian cells and plays a role in the regulation of cell proliferation. It has also been suggested that normal P53 wild type) serves as a tumor suppressor gene
,
and
inhibits the oncogene-mediated cellular transformation and the rate of cellular proliferation. But, wild type p53 is hardly stained by immunohistochemistry because of its low intracellular concentration and very short half-life.
Mutant form of p53 protein is detectable in various human malignancies e.g. colon stomach, lung and breast cancer by immunohistochemical stain because of its prolonged half-life, In breast cancer, p53 protein kexpressin has been regarded as an
unfavorable prognostic factor, but the results of studies about the relationship between the p53 protein expression and prognosis are equivocal.
So, author performed this study to evaluate the prognostic significance of p53 expression in 54 patients with primary breast cancer who underwent surgical treatment at Wonkwang University Hospital from October 1985 to September 1991. Follow-up
period
was 24-91 months(mean: 54.7 months).
p53 protein was stained by immunohistochemical methods in formalin-fixed, paraffin-embedded tissues using monoclonal antibody(DAKO-p53, DO-7). The prognostic significance of p53 protein was evaluated by positivity and 5-yer survival rate, and
comparing
with well-known prognostic factors of breast cancer.
P53 protein was expressed 48.1%(26/54) of primary breast cancers. 5-year survival rate of patients with p53 protein expression was 42.0%, and that of patients without p53 protein expression was 76.4%(p=0.0277)
There was no relationship between p53 protein expression and tumor size, lymph node metastasis, histologic grade or vascular invasion.
These results suggest that p53 protein expression is another independent prognostic factor in primary breast cancer.
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