Breast cancer is the most common cancer and the leading cause of cancer death among women. Despite all efforts, about 11,939 deaths and 50,000 new diagnoses for breast cancer were estimated among Italian women in 2016. Therefore new approaches are needed to improve the survival and higher remission rates. We present a case of a woman with carcinoma of the breast and multiple metastases after right mastectomy, axillary dissection, repeated cycles of chemo and radiotherapy, and estrogen block. Biological method formulated by Prof. L. Di Bella (DBM) produced a complete and stable objective response without toxicity. The DBM includes antiproliferative molecules, such as somatostatin, prolactin and estrogen inhibitors together with differentiating and apoptotic molecules such as melatonin (MLT), Retinoids, Vitamin E, D3, Vit. C, Calcium, Amino sugars, associated with metronomic microdoses of chemotherapy drugs. The blood tests did not show any damage but a progressive reduction of Prolactin, Estradiol, and IGF1, and continuing low levels of GH. The objective result of this case, in the absence of toxicity, demonstrates the efficacy of the treatment and is in agreement with the positive results already published on the use of the DBM. Not requiring hospital or day hospital admission, and with no significant toxicity, the DBM avoided the significant side effects of chemo- and radiotherapy. We believe that this case can encourage more interest and more in-depth studies on the possibilities that have been opened up in oncology by the DBM treatment of the metastatic breast cancer.