The Comparative Safety of Epirubicin and Cyclophosphamide versus Docetaxel and Cyclophosphamide in Lymph Node-Negative, HR-Positive, HER2-Negative Breast Cancer (ELEGANT): A Randomized Trial

Simple Summary Anthracycline and taxane-based chemotherapy are the cornerstone of adjuvant therapy for early breast cancer. In recent years, several trials explored the efficacy of the anthracycline-free regimens, especially for HER2-negative breast cancer patients, which turned out to be a feasible alternative. However, there is no comparison between epirubicin and cyclophosphamide versus docetaxel and cyclophosphamide about their safety and efficacy to date. ELEGANT is the first phase III randomized trial comparing the safety and efficacy of EC versus TC, and it reports comprehensive safety profiles of both regimens with a primary endpoint of grade 3 to 4 neutropenia rate. Background: In adjuvant settings, epirubicin and cyclophosphamide (EC) and docetaxel and cyclophosphamide (TC) are both optional chemotherapy regimens for lymph node-negative, hormone receptor (HR)-positive, human epidermal receptor 2 (HER2)-negative breast cancer patients. Neutropenia is one of the most common adverse events (AEs) of these regimens. The rate of grade 3-4 neutropenia varies in different studies, and direct comparisons of safety profiles between EC and TC are lacking. Method: ELEGANT (NCT02549677) is a prospective, randomized, open-label, noninferior hematological safety trial. Eligible patients with lymph node-negative HR+/HER2-tumors (1:1) were randomly assigned to received four cycles of EC (90/600 mg/m(2)) or TC (75/600 mg/m(2)) every three weeks as adjuvant chemotherapy. The primary endpoint was the incidence of grade 3 or 4 neutropenia defined by National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 4.0 on an intention-to-treat basis. Noninferiority was defined as an upper 95% CI less than a noninferiority margin of 15%. Results: In the intention-to-treat population, 140 and 135 patients were randomized into the EC and TC arms, respectively. For the primary endpoint, the rate of grade 3 or 4 neutropenia is 50.71% (95% CI: 42.18%, 59.21%) in the EC arm and 48.15% (95% CI: 39.53%, 56.87%) in the TC arm (95%CI risk difference: -0.100, 0.151), showing the noninferiority of the EC arm. For secondary endpoints, the rate of all-grade anemia is higher in the EC arm (EC 42.86% versus TC 22.96%, p = 0.0007), and more patients suffer from nausea/vomiting, hair loss, and nail changes (p < 0.01) in the EC arm. No statistically different disease-free survival was observed between the two arms (p = 0.13). Conclusion: EC is not inferior to TC in the rate of grade 3 or 4 neutropenia, but more other AEs were observed in the EC group.