ABSTRACT
Breast cancer is the most common malignant tumor in women, and metastasis is the main cause of death in breast cancer patients. Circular RNA (circRNA) is prevalent, abundant in organisms, and are characterized by their stable structure, conserved sequences, and specific expression. CircRNA have emerged as crucial regulators in diverse human cancers including breast cancer. Increasing evidence suggests that circRNA are aberrantly expressed in tissues and cell lines of breast cancer and involved in breast cancer metastasis. However, systematic knowledge regarding circRNA involvement in metastatic breast cancer remains unclear. This review outline functional circRNA associated with breast cancer metastasis and discuss their underlying mechanisms, providing new ideas for early prediction, diagnosis and treatment of breast cancer metastasis in the future.