Efficacy of dose dense doxorubicin and cyclophosphamide followed by paclitaxel versus conventional dose doxorubicin, cyclophosphamide followed by paclitaxel or docetaxel in patients with node-positive breast cancer: A retrospective study of the Anatolian Society of Medical Oncology

Background: Adding taxanes to adjuvant antracycline and cyclophosphamide (AC) in combination may provide significant improvement in node-positive and high risk node-negative breast cancer (BC) patients. However, the optimal dose and the role of dose-dense (DD) chemotherapy have yet to be determined. The aim of this study was to compare the efficacy of a DD paclitaxel (P)-AC combination with conventional weekly P-AC or docetaxel D-AC combinations in patients with node-positive breast cancer. Materials and Methods: Newly diagnosed 280 node-positive BC patients diagnosed from 1998 to 2013 in three clinics were retrospectively analyzed. Demographic and medical data were collected from the medical charts. Patients were categorized to 3 groups according to treatment arms: arm A, ddAC-P; arm B, weekly P and AC combination; and arm C; T and AC combination. Adjuvant trastuzumab was added for HER2-positive patients. Kaplan-Meier survival analysis was carried out for disease free survival (DFS) and overall survival (OS). The log-rank test was used to examine the statistical significance of the differences observed between the groups. Two-sided P values <0.05 were considered statistically significant. Results: Of the total of 280 patients, 101 were in arm A, 114 in arm B and 65 in arm C.The median ages were 49, 50 and 46, respectively (p=0.11). Median follow-up was 39 (3-193) months. Stage, lymphovascular and perineural invasion, receptor patern, and menopausal status were similar in the 3 treatment arms, but HER2 positivity was significantly lower in arm A, compared to arms B and C (25.7%, 53.1%, 41.5% in arms A, B and C, respectively; p<0.001). Also grade 3 tumors were significantly less frequent in treatment arm A compared to arm B and C (27.3%, 56.8% and 49.2% , respectively, p=0.01). Afterunivariate and multivariate analysis were performed, 3-year DFS rates were 89%, 81%, and 75%, respectively (p=0.12) and three year OS rates were 96.6%, 89%, and 75% (p=0.62). Conclusions: In this study, no significant difference was found between adjuvant dose dense and conventional taxane treatment regimens.