High pathologic complete response in HER 2-positive locally advanced breast cancer after primary systemic chemotherapy with weekly docetaxel and epirubicin

Background: To evaluate pathological complete response rate and to identifythe predictor of response after primary systemic chemotherapy(PST) with weekly docetaxel and epirubicin for locally advancedbreast cancer. Methods: Sixty-three patients with locally advanced breast cancer receivedthree cycles PST on day 1 and 8 of each 3-week cycle with epirubicinand docetaxel (epirubicin 45 mg/m² intravenous bolus, docetaxel35 mg/m² in 100 ml normal saline infused 1 h), followed by surgeryand adjuvant chemotherapy with cyclophosphamide, epirubicinand 5-fluorouracil. The pathological complete response was definedas no invasive carcinoma in breast and axillary nodes afterPST. Results: The median tumor sizes (by ultrasound) before and after PSTwere 6.2 and 2.5 cm, respectively. The negative estrogen receptor(ER) by immunochemical stain was found in 33 (52.4%) patientsand HER-2/neu-overexpression in 12 (19.0%) patients. Clinicaloverall response rate (ORR) was 89% (95% confidence intervals(95% CI: 81–97), including 38% complete response (95%CI: 26–50), sonographical ORR was 97% (95% CI: 93–100).The pathological complete response were found in 11 patients(18%, 95% CI: 9–27), and 15(24%, 95% CI: 13–35)patients achieved breast only pathological complete response.Nine (27.3%) of thirty-three ER (–) patients and 5 (41.7%)of 12 HER2-positive patients achieved pathological completeresponse. Conclusion: PST with weekly docetaxel and epirubicin were well-toleratedand very high pathological complete response rate was achievedin HER-2/neu-overexpression tumors.