<qa>  What is the standard of care for locally advanced breast cancer?Large clinical trials have confirmed the value of systemic adjuvant therapy in decreasing the risk of recurrence and death in patients with early breast cancer. However, the need to identify breast cancer patients who will benefit from adjuvant therapy, while sparing others from the side effects of futile treatment, is spurring research into predictive markers of chemotherapy sensitivity and resistance. In the adjuvant setting, extremely large trials and long follow-up would be required to prospectively validate the predictive value of biomarkers of chemotherapy sensitivity or resistance. In part this is because response is not directly observable. Preoperative chemotherapy for large tumors 3cm or inoperable breast cancer is well established and is the standard of care for locally advanced breast cancer. Data from large series of patients have demonstrated that preoperative neoadjuvant chemotherapy leads to significant reduction of tumor size downstaging and improves both the rate and the cosmetic results of breast- conserving surgery. The degree of response to neoadjuvant therapy has been shown to predict improved overall survival. This is therefore an attractive setting to study predictors of response because tissue is accessible from pre- therapeutic biopsies and tumor response is directly observable. 