Tumor shrinkage evaluation during and after preoperative doxorubicin and cyclophosphamide followed by docetaxel in patients with breast cancer

Aim: To evaluate the relative activity of the sequential administration of doxorubicin and cyclophosphamide (AC) followed by docetaxel alone, as primary systemic therapy in patients with breast cancer, using an in vivo chemosensitivity predictive assay. Patients and Methods: Patients with stage IIIII breast cancer received two cycles of AC (60/600 mg/m2 every 3 weeks) followed by two cycles of docetaxel (100 mg/m2 every 3 weeks). All patients underwent comprehensive breast imaging prior to chemotherapy, after two AC and after docetaxel. Results: Forty-two patients were accrued and evaluated by intention-totreat analysis. After two cycles of AC, the median tumor shrinkage was 18.3%, whereas treatment with docetaxel provided an additional median tumor shrinkage of 34.2%. Pathological complete remission was observed in 5 patients (11.9%), whereas 26 patients (61.9%) experienced a partial response. Conclusion: The relative contribution of docetaxel to tumor mass reduction seemed to be greater than that of AC. However, the slow rate of tumor shrinkage observed may indicate that the activity of the first 2 cycles of AC is carried over into the part of treatment with docetaxel.