Superior outcome after neoadjuvant chemotherapy with docetaxel, anthracycline, and cyclophosphamide versus docetaxel plus cyclophosphamide: results from the NATT trial in triple negative or HER2 positive breast cancer

The purpose of this study is to evaluate the efficacy and safety of docetaxel plus cyclophosphamide (TC) compared with docetaxel, anthracycline, and cyclophosphamide (TEC) in neoadjuvant treatment of triple negative or HER2 positive breast cancer. Eligible breast cancer patients were randomized to receive six cycles of TC or TEC. The primary end point was pathological complete remission (pCR). Secondary end points included safety, clinical response rate, and survival outcome. One hundred and two patients were initially randomized and 96 patients were available for efficacy analysis. 96.9 % patients were treated with epirubicin as an anthracycline agent. pCR rates were 6.8 % (3/45) and 17.6 % (9/51) in TC and TEC group, respectively, P = 0.113. After a mean follow up of 20 (3–36) months, non-anthracycline-containing TC regimen treatment resulted in a worse event-free survival (adjusted hazard ratio [HR] 2.42; 95 % CI 1.11–5.30) and disease-free survival (HR 2.85; 95 % CI 1.21–6.74) compared with TEC regimen, which was more apparent in triple negative subtype. Severe adverse event rates were similar, except that patients treated with TEC had a higher rate of neutropenia and leucopenia. TEC treatment had a superior survival outcome and trend of higher pCR rate compared with TC in this trial setting, especially in triple negative subtype, which deserves further validation.