Diagnosis, Prognosis, and Treatment of Triple-Negative Breast Cancer: A Review

Triple-negative breast cancer (TNBC) has become the most aggressive and worst prognostic subtype of breast cancer due to the lack of estrogen receptor, progesterone receptor and HER2 expression. This article systematically reviews the progress in the diagnosis, prognosis and treatment of TNBC. In terms of diagnosis, imaging techniques (such as dynamic contrast-enhanced MRI and multimodality ultrasound) combined with histological and immunohistochemical detection (such as Ki-67, PD-L1 expression) can improve the early diagnosis rate; molecular markers (PIM-1, miR-522) and subtype classification (LAR, IM, BLIS, MES) provide the basis for accurate classification. Prognostic evaluation requires a combination of clinicopathologic features (tumor size, lymph node metastasis, tumor-to-stroma ratio), molecular characteristics (BRCA mutation, PD-L1 expression), and prognostic scoring systems. In treatment strategies, chemotherapy remains the basis, but efficacy and side effects need to be balanced; neoadjuvant chemotherapy can improve the pathological complete response rate, while molecular markers (such as circulating tumor cells) help predict efficacy. In terms of targeted therapy, PARP inhibitors are significantly effective in patients with BRCA mutations, and antibody drug conjugates (eg, sacituzumab govitecan) provide new options for chemoresistant patients. In immunotherapy, PD-1/PD-L1 inhibitors combined with chemotherapy significantly improved progression-free survival, especially for PD-L1-positive patients. Combined therapy, metabolic reprogramming, and individualized treatment strategies need to be further explored in the future to overcome the heterogeneity and treatment resistance of TNBC. This article emphasizes the key role of multidisciplinary collaboration and precision medicine in optimizing TNBC management and provides an important reference for clinical practice and research direction.