Background: patients with triple negative breast cancer has poor survival outcomes. Achievement of pathological complete response (pCR) after neoadjuvant chemotherapy can significantly improve survival of these patients, however some patients will relapse even after pCR. Methods: we reviewed prospectively-maintained outcomes database of N.N. Blokhin NMRCO. We extracted information about patients with locally advanced non-metastatic (stage IIIA-IIIC) triple negative breast cancer who were treated with neoadjuvant platinum based chemotherapy in 2014-2018 years. All included patients were tested for the presence of BRCA1/2 mutation with whole-exome next-generation sequencing or for “founder” hot-spot mutations. Results: we identified 80 patients who received neoadjuvant treatment with various platinum-based regimens. Pathological complete response rate was 62.5%. BRCA-mutations was found at 22 (27.5%) patients. Median follow-up time was 35.6 months (17.0 – 61.3). 2-year DFS was 77.3%, and 3-year DFS was 70.0%, there was significant differences in DFS in patients, who achieved and patients with residual tumor – 85,2% vs 64,3% (p=0,028). 2-year OS was 91%, 3-year OS was 78,5%. 18 patient had disease progression, the most common sites of disease progression were brain (9 [50.0%]), lungs (5 [27.8%]), 3 (16.7%) patients had locoregional relapses and 1 (5,6%) liver metastases. We separately analysed characteristics of patients with brain metastases (table). There were no significant differences in tumour pathologic response and patient age. All patients, who relapced after pCR, had brain metastases. We also found, that 7 of 9 patients with brain metastases had different BRCA mutations. Brain metastases developed in 40,9% (9/22) of patients with BRCA1 mutations and 3,4% (2/58) of patients with wild type BRCA1 (p<0,00001). Conclusions:BRCA1 mutation is significant prognostic factor for brain metastases development in locally advanced triple negative breast cancer.