Neoadjuvant chemotherapy for breast cancer.

Primary or neoadjuvant chemotherapy in early breast cancer offers the chance to use the tumour as an in vivo measure of response, with the additional possibility of downstaging and avoidance of mastectomy. Tumour response to preoperative chemotherapy correlates with the outcome and could be a surrogate for evaluating the effect of chemotherapy on micrometastases. Randomized studies have shown that preoperative chemotherapy is as effective as postoperative chemotherapy, but there has not been a significant increase in the disease-free survival or overall survival in the groups studied. The overall response rates reported have varied between 60% and 100% with complete clinical responses from 10% to almost 50%, avoiding mastectomy in most cases. Clinical responders have a better prognosis than nonresponders; pathological complete remissions at present offer the best prediction of good long-term outcome, but occur in less than 20% of patients. Biological predictors reflecting changes in apoptosis and/or proliferation may in the future offer the best surrogate markers for long-term outcome, and trials have recently begun in this area.