The role of HER2 in metastatic breast cancer treated with a combination of taxanes and cisplatin

Background: A combination of taxanes and cisplatin have shown modest activity as second-line chemotherapy in breast cancer patients who have been exposed to anthracyclines. The purpose of this study was to retrospectively assess whether HER2 is associated with clinical sensitivity or with prognostic significance in breast cancer patient groups who had received chemotherapy with taxanes and cisplatin. Methods: Patients were treated either with docetaxel 60 mg/m2 or paclitaxel 175 mg/m² in combination with cisplatin 50 mg/m² every 3 weeks. The tumor specimens were checked for estrogen receptor (ER), progestrone receptor (PR), and HER2 status by immunohistochemical stain. Prognostic factors such as performance status, status of metastases, history of prior anthracycline response, and biomarkers such as ER and HER2 were analyzed. Results: Ninety patients were eligible for HER2 assessment. Only eighty-five patients were eligible for response assessment. The overall response rate to chemotherapy with the taxanes/cisplatin regimen was 52%. In patients who were HER2-positive, the response rate was 62% and in HER2-negative patients, it was 46%, p = 0.17. Univariate analysis showed no prognostic factors were significant in predicting a response to chemotherapy. In addition, it appeared that there was no difference in time to progression and overall survival based on HER2 status. Conclusions: Our results indicated that HER2 status is independent of a response to a taxanes/cisplatin combination and is also not a prognostic factor for survival.