Preoperative Systemic Therapy

Abstract

Neoadjuvant (preoperative) therapy is defined as the first systemic treatment a patient receives when nonmetastatic breast cancer is diagnosed. Neoadjuvant treatment has the ability to shrink tumors and was first used, in the 1970s, in patients with inoperable locally-advanced or inflammatory disease. Data from several retrospective analyses showed that the application of multimodal treatment consisting of neoadjuvant chemotherapy, surgery, radiotherapy, and hormonal therapy improved survival for patients with locally-advanced breast cancer (LABC) [1–2]. The role of neoadjuvant treatment has evolved since this time; indeed, in the last two decades, preoperative chemotherapy has also been performed in women with large operable breast cancer in order to downstage the tumor and thus enabling breast-conservative surgery. More recently, the preoperative approach has also been tested in patients with early breast cancer, suitable for conservative surgery, in order to allow a more rapid evaluation of new therapies without the need for long-term follow-up to demonstrate a survival advantage [3–27]. The absence after neoadjuvant chemotherapy of residual tumor (pCR; pathologic complete response) is associated with a very favorable long-term outcome, suggesting that pCR could be a marker for long-term effects on disseminated tumor cells [28]. However, different definitions of pCR have been reported in the past (i.e. no residual tumor in breast, no residual tumor in breast and axilla, only residual DCIS), since there was not a general agreement about the prognostic impact of residual carcinoma in situ in the breast, and of the persistence of residual tumor only in the axillary nodes.