Durable Treatment-Free Remission in BRCA1-Associated Metastatic Triple-Negative Breast Cancer with Brain and Radiologically Diagnosed Hepatic Metastases: A Case Report

INTRODUCTION: Metastatic triple-negative breast cancer (TNBC) is associated with aggressive clinical behavior and poor survival, particularly in patients with brain and visceral metastases. We describe an exceptionally durable treatment-free remission in a young woman with metastatic TNBC and a subsequently identified pathogenic germline BRCA1 variant. METHODS: We retrospectively reviewed the patient's clinical course, radiological and histopathological findings, systemic and local treatments, genetic testing, and long-term follow-up. RESULTS: In 2008, the patient was diagnosed with grade 3 triple-negative invasive ductal carcinoma and hepatic lesions considered metastatic based on computed tomography (CT), magnetic resonance imaging (MRI), and multidisciplinary assessment. Following six cycles of fluorouracil, doxorubicin, and cyclophosphamide (FAC), the hepatic lesions regressed. In 2009, she developed a solitary, histologically confirmed left frontal brain metastasis, which was surgically resected and treated with postoperative radiotherapy. Subsequent breast and hepatic disease progression was treated with 15 cycles of docetaxel plus bevacizumab, resulting in a marked radiological response. Following isolated locoregional progression in 2011, without radiologically active distant disease, she underwent modified radical mastectomy with axillary dissection followed by locoregional radiotherapy. A pathogenic germline BRCA1 variant was identified in 2020. She has received no systemic anticancer therapy since December 2010 and remained in complete clinical and radiological remission as of June 2026, more than 17 years after diagnosis of the brain metastasis. CONCLUSIONS: This case documents an exceptionally prolonged treatment-free remission in metastatic TNBC despite a history of radiologically diagnosed hepatic metastases and a histologically confirmed brain metastasis. Although the contributions of tumor biology and individual treatments cannot be established, the clinical course highlights the heterogeneity of metastatic TNBC and the importance of individualized multidisciplinary management.