Breast cancer is the most frequent malignant neoplasm worldwide. In emerging countries such as Mexico, there has been an increase in its frequency and mortality [1, 2] and it is the second most frequent neoplasm after cervical carcinoma. Between 25,000 and 30,000 new cases are diagnosed annually. Unfortunately, only a few women have regular mammography screening so the proportion of patients with locally advanced disease at diagnosis is high. In 2003, only 5-10% of newly diagnosed cases in Mexico were clinical stages 0 or I [2]. Surgical resection with axillary lymph node dissection constitutes the treatment of choice associated with neoadjuvant therapy and postoperative chemotherapy and/or radiation therapy.