Preoperative (neoadjuvant) systemic treatment of breast cancer.

Preoperative systemic treatment (PST) is a valid option not only for advanced breast cancer stages but also for operable breast cancer. We know that disease-free and overall survival after PST are equivalent to those after adjuvant therapy. Furthermore, PST is able to improve surgical treatment by increasing the rate of breast conservation surgery, which minimises psychological distress for patients fearing mastectomy. Response to PST is a predictor of long-term outcome and gives prognostic information after a short-term interval in contrast to adjuvant trials, which do not show their results until after a 5- to 10-year follow-up. More often, endocrine non-responsive tumours demonstrate a pathological complete response (pCR). Thus, PST can change the formerly bad prognostic marker into one that indicates a favourable prognosis if pCR is achieved by PST. If PST is performed outside clinical trials, anthracycline/taxane-based regimens should be used, especially in sequential prolonged schedules. The use of aromatase inhibitors in preoperative endocrine therapy in elderly postmenopausal patients with endocrine-responsive breast cancer yields a larger proportion of local response than tamoxifen. The duration of PST is not well established, but at least four cycles of chemotherapy should be administered and endocrine therapy needs a minimal time to show greatest benefit when given for at least 3-4 months . The concurrent use of chemotherapy and endocrine drugs did not show any benefit, even in endocrine-responsive tumours and should therefore be avoided. Sentinel node biopsy is a reasonable approach, but this technique should be reserved for experienced surgeons. PCR is the most important surrogate marker of PST, demonstrating an improved disease-free and overall survival. But even if pCR of the primary tumour is achieved, the detection of lymph node metastases is the most important prognostic factor, indicating a substantial risk of cancer recurrence. PST will lead to individualised (tailored) treatment in patients with primary breast cancer.