An evaluation of predictive factors involved in clinical or pathological response to primary chemotherapy in advanced breast cancer.

BACKGROUND: The usefulness of primary chemotherapy has been widely recognized and applied to routine clinical practice to improve prognosis by downstaging. Nevertheless, none of many trials has been able to show a positive effect of primary chemotherapy in terms of prognosis, and predictive factors of outcome have not been defined and are still under investigation.

METHODS: Primary chemotherapy was given to 50 patients with advanced breast cancer. Predictive factors involved in clinical or pathological response to primary chemotherapy (3 cycles of CE(F) therapy ) were investigated.

RESULTS: The response rate in all patients was 56.0% (CR: 3 patients PR: 25 patients) and 64.1% in patients without distant metastases. MIB-1 was related to the clinical response and EIC (extensive intraductal component) was related to the pathological response; the response was high in patients with EIC negative tumors. Responders had tumors with higher proliferative activity, which decreased significantly after chemotherapy. Patients with a decrease of more than 30% in proliferative activity after chemotherapy had significantly higher disease-free survival rates.

CONCLUSION: The proliferative activity and EIC status were useful predictors of clinical or pathological response to primary chemotherapy. A decrease in proliferative activity by chemotherapy significantly correlated with clinical response and reflected a favorable prognosis. The number of patients benefiting from primary chemotherapy might steadily increase by detecting these predictive factors.