PURPOSE: Laboratory studies suggest that primary systemic therapy (PST) could improve
control of micrometastatic disease and impact on overall survival (OS). This article examines
the rationale for and preclinical and clinical data of PST in operable breast cancer and the
potential role of intermediate biomarkers as predictive and/or prognostic factors for response
and survival. DESIGN AND METHOD: We conducted an extensive literative review
(including MEDLINE) on preclinical studies, single-arm feasibility studies, large randomized …

Primary systemic chemotherapy (PST) was first used in early 1970s for the treatment of
locally advanced breast cancer; in this setting primary chemotherapy was administered to
allow for radical surgery and the objective response rates were high with a substantial
proportion of patients amenable to surgery. On the basis of this activity, PST was
subsequently used to treat operable locally advanced or large primary tumors to increase
the rate of conservative surgery. First generation clinical trials demonstrated that breast …