Assessing the impact of CMF/FEC/FEC-DOC/ETC (dose-dense) adjuvant chemotherapy in dependency of positive axillary lymph nodes on survival: A retrospective multicenter cohort study of 4,526 breast cancer patients receiving adjuvant chemotherapy.

Abstract

1074 Background: Adjuvant chemotherapy has changed dramatically in the last decades. Anthracycline-/taxane-based and dose-dense chemotherapy regimens improved survival in node positive breast cancer. This study tries to answer the following questions: (1) Are there differences in survival dependent on chemotherapy regimens in 0/0-3/4-10/<10 positive lymph nodes? (2) Is it possible to define a cut-off of positive lymph nodes for the use of Taxane-based and dose dense chemotherapy? Methods: This German is a multi-center [17 participating hospitals all are certified as breast cancer centers] retrospective cohort study. We included CMF (1.385), FEC (1.170), FEC-DOC (1.723), and dose-dense ETC (248) into the analysis. Results: In case of 0 LN CMF/FEC/FEC-DOC did not show significant differences in DFS, but OAS was significantly impaired by the use of FEC-DOC in 0 LN [p=0.024; HR=2.02 (95% CI: 1.10-3.73)] (no ETC use in 0 LN). In case of 1-3 positive LN CMF/FEC/FEC-DOC/ETC did not differ significantly in survival parameters. But in 4-10 LN FEC-DOC [p=0.049; HR=0.67 (95% CI: 0.44-0.99)] and ETC [p=0.024; HR=0.56 (95% CI: 0.34-0.93)] demonstrated a significant benefit in DFS and a strong trend in OAS. Dose-dense ETC showed a significant improvement in DFS [p=0.003; HR=0.35 (95% CI: 0.17-0.69)] and OAS [p=0.009; HR=0.35 (95% CI: 0.16-0.77)] in patients with >10 positive LN. Conclusions: Our data confirms that Taxane-based chemotherapy does not improve DFS in LN negative breast cancer, but rather demonstrated an inferior OAS. But in LN positive breast cancer we can demonstrate a benefit by the use of Taxane-based chemotherapy regimens. Furthermore, dose-dense ETC demonstrated a significant benefit in survival in >10 positive LN.