Immunohistochemical study of c-erbB-2 expression in primary breast cancer.

An immunohistochemical (IHC) study of the c-erbB-2 protein was performed in paraffin-embedded tissues from 506 primary breast carcinomas. An overexpression of c-erbB-2 was detected in 32% of the tumors and was correlated with a negative estrogen receptor status, increasing tumor size as well as axillary lymph node involvement. The five-year disease free survival was analyzed in 183 patients who have been followed for at least five years. No statistically significant association of c-erbB-2 status with survival was shown. However, longer survival in women over 50 years compared to under 50 years of age was detected among the c-erbB-2 positive patients. In the multivariate Cox's regression analysis, lymph node and vascular invasions were independent prognostic indicators among these patients. But c-erbB-2 status and other factors did not predict the relapse of breast cancer. However, these data may not negate the benefit of c-erbB-2 detected by IHC for identification of patients who have a poor prognosis and require more aggressive adjuvant therapy. Further studies in a larger group of patients with longer follow-up time may provide more valid information.

Serum c-erbB-2 protein in breast cancer patients.

Measurements of c-erbB-2 protein were done in sera of 20 normal women, 22 benign breast disease patients and in respectively 43 and 51 samples from primary breast cancer patients obtained prior to and after surgical interventions. Mean value of serum c-erbB-2 in non-malignant women was insignificantly different from the value in the breast cancer group. Positivity rate of serum c-erbB-2 in the cancer group was 13.8 per cent. Increasing postoperative serum c-erbB-2 concentrations were in good association with severity, progressiveness and relapse of breast cancer independently of other variables such as age, menopausal status, tumor size, axillary node invasion, ER or PR status. Pretreatment serum c-erbB-2 positivity was inversely correlated to ER status but relation to other prognostic parameters of breast cancer was not found. Agreement between c-erbB-2 measured in serum by enzymeimmunoassay and in tissue by immunohistochemical assay was also found. Our data confirmed that in primary breast cancer patients, monitoring of circulating c-erbB-2 protein levels after operation are useful for detecting the recurrence and/or metastasis of the disease especially in ER positive breast cancer. Pretreatment serum c-erbB-2 concentrations do not have benefit for early diagnosis of the tumor.