Reliable prognostic markers are needed in breast cancer management to help clionicians identity the patients with the high risk of recurrence and arrive at more rational decisions for treatment. The nuclear phosphoprotein p53 is faintly expressed
in all
normal cells and appears to function in suppressive regulation of cell cycle. Abnormally high levels of p53 parotein are found in many different types of cancer.
To evaluate prognostic significance of p53 gene mutation, the author analyzed the association between nuclear overexpression of p53 parotein on immunohistochemical stain of archival paraffin embedded tissue and following established progenestic
parameters of 49 breast cancer patients operated between September 1987 and August 1991 in Korea University Hospital : tumor size, axillary node involvement, menopausal status, estrogen receptor status, progesterone receptor status, DNA ploidy,
and
histological grade. Immunohistochemical stain of p53 protein was also perfomed on thn cases of fibroadenoma for negative control.
Twenty four (49%) cases showed overexpression of p53 protein in immunohistochemical staining usig two murine anitihuman p53 protein monoclonal antibodies (NCL-p53-DO7 & NCL-p53-240, Novocastra Lab., U.K.). Although associations were found between
p53
pverexpression and large tumor size, negativity of estrogen receptor, and negativity of progesterone receptor, a high statistical significance was found only between p53 overexpression and negativity of estrogen receptor (P<0.01).
In 47 cases which had followed up for more than 36 months(median 50 months), the overall survival showed no statistically significant difference between two groups of patients with or without p53 overexpression. But the p53 overexpression was
found
to
be significantly associated with the shorter relapse-rree survival of patients(P<0.02). When combined with estrogen receptor status, the overexpression of p53 protein may have a more significant role in prediction of prognosis.
As aresult of this study, it is concluded that the p53 gene mutation can be considered as a useful prognostic marker for breast cancer patients, and more aggressive therapeutic appoach is warranted to such group of patients with p53 gene
mutation.
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