Final results of a phase II trial of preoperative TAC (docetaxel/doxorubicin/cyclophosphamide) in stage III breast cancer.

BACKGROUND: The use of preoperative chemotherapy for breast cancer has been demonstrated to result in similar disease-free survival (DFS) and overall survival (OS) as postoperative adjuvant chemotherapy. Additionally, the rate of pathologic complete response (pCR) in the breast after preoperative chemotherapy has been shown to correlate with survival. The objective of this study was to determine the pCR rate in patients with stage III breast cancer treated with 4 cycles of TAC (docetaxel 75 mg/m2, doxorubicin 50 mg/m2, cyclophosphamide 500 mg/m2) on day 1 before surgery. PATIENTS AND METHODS: From November 1998 through August 2001, we treated 40 patients (mean age, 47 years) with stage III breast cancer with TAC administered every 3 weeks for 4 cycles.
RESULTS: We now report follow-up at 24 months. Responses were seen in 83% of patients, with 25% experiencing a clinical complete response, of which 4 patients (10%) had pCRs. At a follow-up of 2 years, data on DFS and OS are available on 37 patients: 12 patients (38%) had disease progression, and 7 patients (21%) had died. Despite the use of prophylactic ciprofloxacin, some degree of myelosuppression was seen in all patients, with 24 patients (63%) experiencing grade 3/4 neutropenia.
CONCLUSION: Based on the pCR rate seen in this trial, docetaxel given concomitantly with AC (doxorubicin/cyclophosphamide) for 4 cycles does not appear to be superior to 4 cycles of AC as preoperative treatment for stage III breast cancer. Based on other trials, longer durations of therapy and/or sequencing of AC and docetaxel may result in a higher pCR rate.