Significance of overexpression of p53 protein in human breast cancer

: Overexpression of p53 protein was examined by immunohistochemical assay. In 143 primary breast cancer patients, consisting of 18 patients with family history of breast cancer or past history of breast cancer and 125 patients with no such histories. In the later 125 patients, overexpression of p53 was shown in 42 patients (33.6%), however in the former 18 patients, p53 overexpression was found in 15 (83.3%). It was suggested that p53 protein is frequently overexpressed in patients with high risks like history of breast cancer and family history of breast. On the other hand, regarding the value of p53 overexpression as a prognostic indicator, an univariate analysis demonstrated that the relapse free survival of patients with over 50% p53 positive all rate was significantly worse compared to that of patients with less than 50% p53 positive all rate (p < 0.05). However multivariate analysis did not demonstrate the significant value (p < 0.1), suggesting that overexpression of p53 is marginal as a prognostic indicator.