Abstract: Circular RNAs (circRNAs) are non-coding RNAs with closed-loop structure. In recent years, with the rapid
development of high-throughput RNA sequencing (RNA-seq) technologies and bioinformatics, more and more circRNAs
have been found in tumor tissues. Studies have shown that circRNAs can regulate the transcription and translation of target genes through the mechanism of miRNA sponge or binding to proteins in cells, and thus widely participate in the
pathophysiological processes including growth, differentiation, development and apoptosis of cells, providing a new direction for the prevention, diagnosis and treatment of related diseases. Breast cancer is the most common malignant tumor in women, with a high degree of heterogeneity. The establishment of therapeutic targets based on tumor molecular biological characteristics has become the key to individualized and accurate treatment. In this review, the formation mechanism and biological function of circRNAs and their effects on the occurrence, development and prognosis of breast cancer are summarized as follows.

Key words: breast neoplasms, cell proliferation, circRNAs, progress, treatment