Sequential adjuvant docetaxel and anthracycline chemotherapy for node positive breast cancers: a retrospective study

Anthracyclines and taxanes are the most active agents in the adjuvant treatment of breast cancer (BC). They can be used simultaneously or sequentially. The optimal schedule and duration for their administration is unknown. We analyzed the efficacy of sequential adjuvant anthracycline and docetaxel administration in node positive BC patients. Node positive BC patients (N=539) from 6 medical oncology centers in Turkey who received sequential adjuvant anthracycline-based regimens and taxane chemotherapy were included in this study between 2006 - 2010. One-hundred and thirty-eight (25%) patients received 3 cycles of anthracycline-based chemotherapy followed by 3 cycles of docetaxel (3+3) and 401 (75%) patients received 4 cycles of anthracycline-based chemotherapy followed by 4 cycles of docetaxel (4+4). Prognostic factors analyzed were estrogen receptor (ER), progesterone receptor (PR), HER2, tumor grade, and nodal status in relation to disease free survival (DFS) and HER2 status in relation to overall survival (OS). The patient median age was 48 years (range 18-79). Most common grade 3-4 toxicities were neutropenia, mucositis and arthralgia. No treatment-related toxic deaths were seen. With a median follow up of 26 months (range 1-115) 61 (11.3%) recurrences and 11 (2%) deaths were registered. Three-year DFS was 81% and OS 96% for all patients. There was no statistically significant difference between 3+3 and 4+4 groups in terms of survival (3-year DFS 88% and 79% [p=0.28] and OS 97% and 95% [p=0.60), respectively). Sequential chemotherapy with 4+4 cycles of anthracycline and docetaxel every 3 weeks is an acceptable regimen for adjuvant treatment of node positive BC patients. Duration of chemotherapy should be planned depending on prognostic factors. In this study there was no difference between 3+3 and 4+4 groups in DFS and OS despite the presence of good prognostic factors in the 3+3 group.