Relative effects of immunohistochemical expressions of c-erbB-2, p53, and bcl-2 oncoproteins on the survival of advanced breast cancer patients after endocrine therapy

c-erbB-2, p53, and bcl-2 oncoproteins were detected immunohistochemically in 92 recurrent or advanced breast cancer tumors just before an endocrine therapy, adreno-oophorectomy. Estrogen receptors (ER) and partly progesterone receptors were concomitantly assayed in the same tumor tissues. Twenty-eight percent (26/92) of c-erbB-2, 16% (15/92) of p53, and 11% (10/92) of bcl-2 expressions were shown to be positive. There were no significant correlations of these oncoproteins with clinical background characteristics of the patients, except the inverse relation between p53 expression and ER status (p=0.0033). Of these covariates, ER status was shown to be the only predictor of response to endocrine therapy. In the absence of ER measurement, p53 expression was a significant predictor of the response. Kaplan-Meier curves showed that ER had a significant and p53 expression had a marginal effect on the overall survival length of the patients, c-erB-2 or bcl-2 were indifferent to survival or response. It is concluded that p53 immunohistochemical expression might be a supplementary predictor next to ER status of the overall survival as well as response of advanced breast cancer patients treated with endocrine therapy, and that p53 alteration might modify the ER dependent hormone-responsiveness of breast cancer.