Impact of tumor biology, particularly triple-negative status, on response to pre-operative sequential, dose-dense epirubicin, cyclophosphamide followed by docetaxel in breast cancer.

BACKGROUND: The central objective of this study was to determine the predictive impact of several established tumor biological factors (PgR, ER, HER2 and Ki-67) on response to pre-operative chemotherapy in primary breast cancer.

PATIENTS AND METHODS: 59 primary M0 breast cancer patients received pre-operative sequential dose-dense epirubicin and cyclophosphamide followed by docetaxel (19 patients at dosage 100 mg/m(2), 40 patients at 75 mg/m(2)).

RESULTS: Pathological complete remission (pCR) occurred in 17 patients (29%) and at least partial remission in 42 (71%). Higher proliferation (Ki-67) and lack of hormone receptors (either or both) were significant predictive factors for pCR; moreover, 8/11 (73%) patients with triple-negative tumors (HER2(-)/ER(-)/PgR(-)) had pCR (p=0.001). Breast conserving surgery was achieved in 46/59 patients (78%). Hand-foot syndrome occurred in 12/19 patients treated at the higher docetaxel dosage but only 1/40 of the remaining patients. Higher docetaxel dosage was associated with improved pCR in the non-triple-negative subgroup.

CONCLUSION: The tumor biology of hormone receptor-negative, especially triple-negative, and highly proliferating breast cancer is associated with strongly positive response to dose-dense, pre-operative epirubicin/cyclophosphamide/docetaxel chemotherapy.