Long-Term Efficiency and Toxicity of Adjuvant Dose-Dense Sequential Adriamycin-Paclitaxel-Cyclophosphamide Chemotherapy in High-Risk Breast Cancer

Abstract

Objectives: To perform a protocol-specified analysis of the dose-dense adriamycin-paclitaxel-cyclophosphamide (ddATC) study. Methods: Survival and late toxicity were analyzed in 55 patients enrolled to receive 4 × adriamycin 60 mg/m², 4 × paclitaxel 200 mg/m², 4 × cyclophosphamide 800 mg/m², every 2 weeks, with cardioxane and filgrastim support. Kaplan-Meier curves were used to analyze relapse-free survival (RFS), distant disease-free survival (DDFS), and overall survival (OS). Survival analyses were performed according to the presence of casting-type calcifications on the mammogram. Results: After a median follow-up time of 78.5 (64.3–100.0) months, 29 (52.7%) patients were free of relapse (local, regional, distant or contralateral breast cancer), 34 (61.8%) patients were free of distant metastases, and 36 patients (65.5%) survived. The median times of RFS, DDFS and OS were not yet reached at 100.0 months. The median RFS, DDFS and OS times among breast cancer patients with tumors not associated with casting-type calcifications were >100.0 months, the corresponding parameters among patients with tumors accompanied by casting calcifications were 11.5 (p < 0.001), 11.5 (p < 0.001) and 29.6 months (p = 0.035), respectively. None of the patients developed myelodysplastic syndrome or leukemia. No cardiac failure occurred during the follow-up period. Conclusions: Our results indicate that adjuvant sequential ddATC is an efficient and less toxic chemotherapy regimen in high-risk breast cancer. The presence of casting-type calcifications on the mammogram points to a special biologic nature with very poor prognosis.