Impact of the Relative Dose Intensity of Neoadjuvant Chemotherapy With Anthracycline Followed by Taxane on the Survival of Patients With Human Epidermal Growth Factor Receptor 2-negative Breast Cancer: The JONIE1 Study

BACKGROUND/AIM: We evaluated the impact of the relative dose intensity (RDI) of neoadjuvant chemotherapy (NAC) on the survival of patients with breast cancer (BC). PATIENTS AND METHODS: This randomized phase II trial included 188 patients with human epidermal growth factor receptor 2 (HER2)-negative BC treated with anthracycline followed by paclitaxel as NAC. We grouped patients using a relative dose intensity (RDI) threshold of 85% and evaluated clinicopathological features and clinical outcomes. RESULTS: The 5-year overall survival rate was 91.2% and 76.3%, when RDI ≥85% and <85%, respectively (p=0.015). Age, tumor, and node status, and the RDI were significantly different on univariate analysis, but not on multivariate analysis. An exploratory subgroup analysis revealed that a low RDI was associated with low overall survival of patients with obesity, T1/2 disease, and lymph node metastases. CONCLUSION: Maintaining the RDI of NAC is crucial for achieving the survival benefit in selected patients with HER2-negative BC.