Preoperative chemotherapy and endocrine therapy in patients with breast cancer

This review focuses on the aims, results, advantages, and possible disadvantages of preoperative chemotherapy and endocrine therapy. We present the recent improvements in terms of pathologic response rates that have resulted from new combinations of drugs. The change of established prognostic factors during neoadjuvant treatment, the need for new markers, and the consequences in terms of clinical decision-making are demonstrated. We discuss the risk of local relapse after breast-conserving surgery, which was made feasible by preoperative chemotherapy. A short overview of current neoadjuvant cytostatic, endocrine, and immunotherapy trials is provided. Future opportunities for tailoring therapy to each individual patient based on early information from the primary tumor are discussed. Important considerations and results of recent endocrine trials that analyzed possible tamoxifen-resistance in subgroups are reported. New opportunities exist to evaluate the efficacy of new cancer drugs more rapidly in the neoadjuvant setting than in the metastatic and adjuvant setting. This approach offers the possibility of monitoring prognostic markers in the primary tumor before, during, and after treatment with specific chemotherapeutic agents. With respect to recent findings of gene-array techniques, it is likely that the advances in this technology will lead to improved prognostic statements. It will show the influence of therapy on gene expression profiles in the course of treatment and might enable us to identify chemoresistance of specific tumors rather early. This could potentially lead to a new direction of cancer therapy.