ABSTRACT
Primary systemic - or neoadjuvant - chemotherapy (PST) is the standard of care in locally advanced breast cancer and it has also become an option in primary operable disease for patients who are candidates for adjuvant systemic chemotherapy. There are several advantages of administering PST: tumor downstaging--improving the chance of breast conserving surgery; in vivo assessment of tumor sensitivity to the chosen therapeutic regimen; and, early control of micrometastatic disease. On the other hand, the rate of tumor response can be used as a surrogate prognostic marker and for rapid screening of efficiency of new drugs. PST initially referred to systemic chemotherapy, but in recent years endocrine--and now multiple targeted therapies--are available in most of the countries within the confines of clinical trials.
