Primary medical therapy for operable breast cancer

For over a decade pre-operative systemic therapy has been used in early, operable breast cancer. However, we do not yet know its exact role, nor have we yet established the indications for chemotherapy as opposed to endocrine therapy. It offers an opportunity to improve our understanding of the biology of breast cancer, in particular the difference between those tumours that do and those that do respond not to primary therapy. However, there is still much that could be learnt from this approach, and unresolved issues remain, particularly pertaining to the appropriate postoperative treatment strategies for women with tumours that have demonstrated in vivo drug resistance.