The article presents a clinical observation of the patient of 38 y.o. with cancer of the left breast stage IIIC урТ4bN3М0L1V1. On the 1st step of the treatment the patient had 2 courses of CAF neoadjuvant chemotherapy, on the 2nd step – extended radical mastectomy on the left with intraoperative photodynamic therapy and closure of the defect with ТRАМ-flap, on the 3rd step – continuation of the chemotherapy (8 courses), on the 4th step – radiation therapy to the chest wall on the left and zones of regional lymph drainage, targeted therapy with herceptin a (1 year). Four years later a silicone implant was inserted into the left breast. Corrective surgery (reduction mammoplasty on the right side) was performed in april, 2017. Currently, the patient has remission of the disease of the left breast, the period of remission accounts for 8 years.