Impact of tumor biological factors on response to pre-operative epirubicin and paclitaxel chemotherapy in primary breast cancer.

Background: The objective of this study was to determine the predictive impact of several established tumor biological factors (progesterone receptor, estrogene receptor, HER2/neu, and Ki-67) on response to pre-operative combination chemotherapy with epirubicin and paclitaxel in a representative group of primary breast cancer patients.
Patients and Methods: Thirty-eight primary breast cancer patients (metastasis-negative) received pre-operative chemotherapy with epirubicin and paclitaxel. The response characteristics analyzed included pathological complete response and partial remission determined by 3D ultrasound, as well as down-staging and breast conserving surgery.
Results: Pathologically complete response occurred in six patients. Overexpression of HER2/neu, low (negative) hormone receptors and high Ki-67 were all significant positive predictive factors for response to pre-operative chemotherapy.
Conclusion: HER2/neu overexpression is predictive for response not only to trastuzumab, but also to epirubicin and paclitaxel.