Purpose: To evaluate the efficacy and safety of docetaxel, cisplatin, and trastuzumab as primary systemic therapy for human epidermal growth factor receptor 2 (HER2) -positive, locally advanced breast cancer (LABC).
Patients and methods: Forty-eight patients with immunohistochemistry-confirmed HER2-positive LABC or inflammatory breast cancer received 12 weeks of docetaxel, cisplatin, and trastuzumab with filgrastim, followed by surgery, adjuvant doxorubicin and cyclophosphamide, and locoregional radiotherapy with or without tamoxifen. The primary end point was pathologic complete response (pCR) in breast.
Results: Baseline mean tumor size was 9.2 cm (range, 4 to 32 cm). pCR occurred in breast in 11 patients (23%; 95% CI, 12% to 37%) and breast and axilla in eight patients (17%; 95% CI, 8% to 30%). pCR rates in breast (HER2 positive, seven of 30 patients, 23% v HER2 negative, four of 18 patients, 22%; P > .05) and breast and axilla (four of 30 patients, 13% v four of 18 patients, 22%, respectively; P > .05) were similar regardless of HER2 status by fluorescence in situ hybridization (FISH). At a median follow-up time of 43 months, 4-year progression-free survival (PFS) rate was 81% (95% CI, 64% to 90%); overall survival (OS) rate was 86% (95% CI, 71% to 94%). In patients with pCR in breast and axilla, PFS and OS rates were 100% (95% CI, inestimable). In patients without pCR, PFS rate was 76% (95% CI, 57% to 88%; P = .15, log-rank test), and OS rate was 83% (95% CI, 66% to 92%; P = .21). Survival rates were similar regardless of FISH status. There were only two grade 4 adverse events.
Conclusion: Twelve weeks of docetaxel, cisplatin, and trastuzumab is clinically active and leads to excellent survival in patients with large, HER2-positive tumors.