Carboplatin plus taxanes are non-inferior to epirubicin plus cyclophosphamide followed by taxanes as adjuvant chemotherapy for early triple-negative breast cancer

Abstract

Purpose: Platinum plays an important role in the treatment of triple-negative breast cancer (TNBC) in neoadjuvant and metastatic settings. However, its role in an adjuvant setting remains unclear.

Methods: In this non-inferior randomized phase 2 trial, we randomly assigned 308 chemotherapy-naive patients with histologically confirmed TNBC after primary surgery to receive either six cycles of TP (docetaxel: 75 mg/m² or paclitaxel 175 mg/m² d1; carboplatin AUC = 5, day 1), or four cycles of EC (epirubicin: 90 mg/m²; cyclophosphamide: 600 mg/m², day 1) followed by four cycles of T (docetaxel: 75 mg/m² or paclitaxel 175 mg/m², day 1). The primary end point was the disease-free survival (DFS) rate at 5 years. Both regimens were repeated every 3 weeks. The prognostic and predictive value of germline breast cancer gene mutations and programmed death ligand-1 (PD-L1) expression was evaluated.

Results: At a median follow-up of 66.9 months, the 5-year DFS rate was 85.8% in the EC-T arm, and 84.4% in the TP arm (p non-inferiority = 0.034, p log-rank = 0.712). The 5-year overall survival (OS) rate was 94.4% in the EC-T arm and 93.5% in the TP arm (p = 0.770). Patients in the TP arm showed better compliance and experienced significantly lower frequencies of G3/4 neutrocytopenia and G3/4 alopecia, but higher rates of G1-4 thrombocytopenia than those in the EC-T arm. Patients with PD-L1 expressing tumors showed significantly improved DFS and OS.

Conclusions: This study indicates that carboplatin plus taxanes could be a feasible adjuvant chemotherapy for patients with early TNBC who are cannot tolerate intensive chemotherapy with anthracycline.

Keywords: Adjuvant chemotherapy; BRCA mutation; PD-L1; Platinum; Triple-negative breast cancer.