Impressive effect of cisplatin monotherapy on a patient with heavily pretreated triple-negative breast cancer with poor performance.

Systemic therapy for metastatic triple-negative breast cancer (TNBC) still remains challenging because there are no targeted agents or endocrine therapies currently available. The present case report documents the successful use of cisplatin monotherapy to manage a heavily pretreated TNBC patient showing poor response to therapy. The patient was a 51-year-old woman who had already undergone several lines of systemic chemotherapy for widespread TNBC. Although the mutation analysis performed on DNA isolated from blood cells and progressed lesion samples confirmed the tumor to be germline BRCA wild-type, cisplatin monotherapy was administered based on the increasing evidence of safety and efficacy of platinum for breast cancer. After three cycles of cisplatin treatment, the patient's metastatic lesions dramatically improved without any major toxicity, and she completed 17 cycles with good response. This case study indicates that patients with heavily pretreated TNBC can potentially achieve a good response to cisplatin monotherapy.