Impact of neoadjuvant chemotherapy on locoregional surgical treatment of breast cancer.

Preoperative (neoadjuvant) chemotherapy (NC) has become the standard of care for patients with locally advanced breast cancer and is being increasingly used in those with large operable disease. Its main clinical advantages from a surgical therapy standpoint include the potential for conversion of patients requiring mastectomy to breast-conservation candidates, the potential for improving the cosmetic outcome following lumpectomy by decreasing the size of the primary breast tumor even if the patient is a lumpectomy candidate at presentation, and the potential for converting patients who present with positive axillary nodes and who would initially require axillary lymph node dissection to candidates for sentinel lymph node biopsy alone. Important steps are required from the time of diagnosis until the time of surgical resection to ensure successful locoregional therapy outcomes in patients treated with NC. They include accurate assessment of the location and extent of the primary breast tumor and determination of axillary nodal status before and after NC. This information is critical for successful execution of the surgical plan and to optimize the use of adjuvant radiotherapy following NC. In the future, development of more active neoadjuvant chemotherapy regimens and novel molecular and imaging techniques will undoubtedly lead to further individualization of breast cancer surgical management following NC, including the possibility of avoiding surgical resection in cases with a high likelihood of achieving a pathological complete response.