c-erb-B2 expression and response to treatment in metastatic breast cancer

The frequency of c-erb-B-2 expression, clinical correlates and treatment outcome was investigated in 92 patients with metastatic breast cancer. Positive c-erb-B-2 immunostaining was found in 24/92 (26%) of tumours, There was a statistically significant inverse correlation between c-erb-B-2 expression and ER status, There was also a significant inverse correlation between c-erb-B-2 expression and tumour free interval. c-erb-B-2 expression had no influence on response to treatment with tamoxifen among patients co-expressing both c-erb-B-2 and estrogen receptor (ER), Following chemotherapy (CAF) treatment there was a trend to a lower response rate among c-erb-B-2(+) as compared to c-erb-B-2(-) patients. However, more c-erb-B-2(+) patients had received prior adjuvant chemotherapy, and when this factor was included in a multivariate analysis only prior adjuvant chemotherapy treatment predicted for response to CAF chemotherapy for metastatic disease. Time to treatment failure (TTF) was significantly shorter among cerb B-2(+) as compared to c-erb-B-2(-) patients. The current study suggests that the c-erb-B-2 expression is found at similar frequency in metastatic as in primary breast cancer. Although c-erb-B-2 expression did not predict for response to either hormonal therapy or to chemotherapy for metastatic disease, patients with c-erb-B-2(+) metastatic lesions appear to have a more aggressive clinical course.