Pathologic Response to Short Intensified Taxane-free Neoadjuvant Chemotherapy in Patients with Highly Proliferative Operable Breast Cancer

Objectives: Breast cancer treatment relies on 3 major phenotypical subtypes, including the triple-negative (TN), HER2-positive, and hormone receptor-positive (estrogen receptor/progesterone receptor(+)) ones. We retrospectively determined the clinical and pathologic response rates to intensified taxane-free neoadjuvant chemotherapy according to these phenotypical classes in a series of patients with highly proliferative operable breast cancer, and examined the patterns of recurrence. Methods: Patients with early breast cancer with highly proliferative (S-phase fraction >4%) operable tumors of >3 cm received 4 cycles of intensified neoadjuvant chemotherapy with high-dose cyclophosphamide (doxorubicin 70 mg/m(2) d1, cyclophosphamide 700 mg/m(2) d1/d8, and 5 FU 700 mg/m(2) d1-d5) every 3 weeks. Results: Fifty-five patients were included in the analysis. Patients with TN phenotype experienced a high pathologic complete response (pCR) rate to intensified chemotherapy in comparison with patients with HER2-positive and estrogen receptor/progesterone receptor(+) tumors (47%, 0%, and 12%, respectively). Forty percent of patients with TN breast cancer recurred after a median follow-up of nearly 11 years, but only 22% of those achieving a pCR. Conclusions: A high pCR rate to short intensified neoadjuvant chemotherapy with high-dose cyclophosphamide was achieved in patients with operable highly proliferative TN breast cancer, and pCR was associated with a low rate of recurrence.