Unlike small breast cancers, which are now treated conservatively by primary tumorectomy, the most important lesions (T2 and T3) as usually treated tumorectomy, the most important lesions (T2 and T3) as usually treated by mastectomy. However, in patients with these large lesions attempts may be made at conserving the breast with reliable oncological safety and good cosmetic results. Depending on clinical presentation, one or the other of two therapeutic approaches may be considered. The most common treatment is preoperative radiotherapy of 45 Gy which, in more than 50 p. 100 of the cases results in a tumoral regression that is sufficient for secondary tumorectomy to be performed. In some patients, the first-line treatment consists of wide tumoral excision as part of a reductive mammaplasty, followed by radiation.