Purpose The purpose of this study is to determine the response, tolerability, and long-term outcome of a neoadjuvant platinum-containing regimen for locally advanced breast cancer (LABC) and to search for a correlation between pathologic complete response (pCR) and predefined biomarkers in this cohort. Patients and Methods Patients with LABC received 8 cycles of either sequence A or B. Sequence A was doxorubicin 60 mg/m 2 and paclitaxel 175 mg/m 2 (AT) every 3 weeks × 4 followed by cisplatin (C) 60 mg/m 2 and paclitaxel 90 mg/m 2 (CT) every 2 weeks × 4. Sequence B was CT × 4 (with paclitaxel dose escalation) followed by AT × 4. In addition to estrogen receptor (ER) and HER2, immunohistochemistry for MDR-1, MRP-1, topoisomerase IIα (topo IIα), and p53 was performed. Results A total of 88 patients were evaluable for response and toxicity. Median follow-up was 97 months. The overall pCR rate was 21.5%. For subgroups ER+/HER2+, HER2+ and double negative (ER+/HER2+) disease, the pCR rates were 5.9%, 23.3%, and 35%, respectively ( P = .006). Five-year overall survival for the entire cohort was 71.1%. Five-year overall survival was 88.1% (95% CI, 77.1%-99.1%) for the ER+/HER2+ group compared with 68.5% (95% CI, 51.3%-85.7%) and 49.5% (95% CI, 27.4%-71.6%) in the HER2+ and “double-negative” group, respectively ( P = .0077). Overexpression of topo IIα was correlated with pCR ( P < .001). There were no toxic deaths. Conclusion A platinum-containing neoadjuvant regimen was well tolerated and achieved a pCR comparable to other recent studies of multiagent chemotherapy. Further studies tailored for specific breast cancer subtypes are required.
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