A multicenter prospective phase II trial of neoadjuvant epirubicin, cyclophosphamide, and 5-fluorouracil (FEC100) followed by cisplatin-docetaxel with or without trastuzumab in locally advanced breast cancer.

Purpose: To evaluate the efficacy and safety profile of the (FEC100) followed by cisplatin/docetaxel with and without trastuzumab as primary chemotherapy for patients with locally advanced breast cancer (LABC).

Methods: Eighty patients with LABC (T2-T4, N0-N2, M0) were enrolled to receive 24 weeks of neoadjuvant chemotherapy using epirubicin, cyclophosphamide, and 5-fluorouracil (FEC100) followed by cisplatin and docetaxel, plus trastuzumab if HER2 positive. The primary endpoint was pathologic complete response (pCR) in breast and axilla in separate HER2-negative and HER2-positive cohort.

Results: Eighty patients were evaluable for analysis of which 51 were HER2 negative and 29 HER2 positive: median age: 43 years, premenopausal: 82%, median tumor size: 7.0 cm (4-10), stage IIB: 25% and IIIA/IIIB: 75%, both ER/PR positive: 56%, HER2 positive (3+) by IHC staining: 36%. Clinical complete response was seen in 48%, and clinical partial response was seen in 52%. Overall the pathologic complete response (pCR) was 36% in breast, 64 % in axilla, and 32% in both breast and axilla. Analysis of pCR in breast and axilla, as a function of the hormonal receptor (HR) and HER2, was as follows: HR(+)/HER2(-): 11%; HR(+)/HER(+): 56 %; HR(-)/HER2(-): 36%; HR(-)/HER2(+): 62%.

Conclusion: In this series of locally advanced breast cancer, the combination of (FEC100) followed by cisplatin/docetaxel with and without trastuzumab was very active obtaining an impressive rate of pCR, particularly in HER2-positive and triple negative disease, which merits further investigation.