A prospective study, in which women with clinically stage III breast cancer underwent multidisciplinary therapy by using primary (neoadyuvant) chemotherapy, followed randomly by loco-regionally therapy, either with surgery or radiotherapy; and postoperative systemic chemotherapy (coadyuvant), in both groups of treatment, was conduced at the Peruvian Institute of Neoplasic Diseases. This is a randomized, prospective, descriptive, interventionist and analitical clinical study. Clinical response to primary chemotherapy was positive in 80,23% of cases, complete resolution was observed in 18,60% of cases, partial resolution in 61,63% of cases and there was absolutely no response in 19,77% of cases. No residual neoplasm, patologically proven,was observed in 8,33% of surgical cases. We demonstrated that high-dose primary chemotherapy, using only 2 drugs (cyclophosfamide and 5-fluorouracil), use...