Abstract
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 down-staging 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.