Since breast carcinoma is a group of heterogeneous tumours, the prognosis for each is determined in terms of a whole range of clinical and pathological factors which can be divided into traditional (tumour size, lymph node status, histological grade, hormone receptors, proliferation index) and new factors most of which are still being researched. This book show the prognostic value of the analysed MMP-2, MMP-9 and APN/CD13 expression in breast cancer patients. The expression of MMP-2,MMP-9 and APN/CD13 in breast cancer patients is an unfavourable prognostic indicator of the disease, and an indicator of the need for more aggresive treatment in patients with negative lymph nodes. Therefore, in the future the inhibition of these proteins could play a role in preventing breast cancer and stop the development of metastases in already existing breast carcinoma. I hope this book will contribute to the incorporation of new prognostic factors into the increasing number of studies and clinical trials that will provide new contributions to the coming era of personalised medicine and help in the choice of the best individual therapeutic option for each patient.