Abstract
The aims of this study were to investigate the impact of the relative dose intensity (RDI) of chemotherapy on disease-free survival (DFS) and overall survival (OS), to identify the optimal RDI cut-off points with the docetaxel, epirubicin and cyclophosphamide (TEC) regimen for stage I-III breast cancer patients and to explore the adverse events in these patients. To achieve this, we performed a retrospective analysis of breast cancer patients treated at the First Affiliated Hospital of Chongqing Medical University in 2011. The results showed that among 293 patients with the TEC regimen, 85% and 80% were the cut-off points at which a high RDI was associated with better overall survival (HR = 2.04; 95% CI 1.13, 3.70; p = 0.02) and disease-free survival (HR = 1.97; 95% CI 1.14-3.42; p = 0.02), respectively. Among 169 HR(+) patients, 80% was the cut-off point for DFS (HR = 2.33; 95% CI 1.07-5.08; p = 0.03), and 85% was the cut-off point for OS (HR = 3.00; 95% CI 1.24-7.26; p = 0.02). Among 105 HR(-) patients, 80% was the cut-off point for OS (HR = 2.86; 95% CI 1.05-7.80; p = 0.04). Of 293 patients, neutropenia, nausea, and vomiting were found to be correlated with the level of RDI. In conclusion, a higher RDI of chemotherapy is associated with better survival but with a higher probability of causing adverse events. To optimize survival benefits, the RDI should be maintained ≥ 85% for HR(+) patients and ≥ 80% for HR(-) patients.