乳腺癌是女性最常见的恶性肿瘤类型。外泌体是细胞膜的来源，通过胞吐释放的细胞外囊泡。它们携带脂质、蛋白质、DNA和不同形式的RNA，包括环状RNA。环状RNA是一类新型的非编码RNA，具有闭合环状，与乳腺癌等几种癌症有关。外泌体中含有大量的被称为外泌体环状RNA的circRNAs。通过干扰几种生物途径，外泌体环状RNA在癌症中可以具有促增殖或抑制作用。考虑到肿瘤发展和进展以及其对治疗抗性的影响，已经研究了外泌体环状RNA在乳腺癌中的参与。然而，其确切机制仍不清楚，外泌体环状RNA在乳腺癌中没有可用的临床意义。在这里，我们强调外泌体环状RNA在乳腺癌进展中的作用，并强调最近circRNA作为治疗靶点和乳腺癌诊断的潜力发展。版权所有© 2023 Hussen，Mohamadtahr，Abdullah，Hidayat，Rasul，Hama Faraj，Ghafouri-Fard，Taheri，Khayamzadeh和Jamali。

Breast cancer is the most prevalent type of malignancy among women. Exosomes are extracellular vesicles of cell membrane origin that are released via exocytosis. Their cargo contains lipids, proteins, DNA, and different forms of RNA, including circular RNAs. Circular RNAs are new class of non-coding RNAs with a closed-loop shape involved in several types of cancer, including breast cancer. Exosomes contained a lot of circRNAs which are called exosomal circRNAs. By interfering with several biological pathways, exosomal circRNAs can have either a proliferative or suppressive role in cancer. The involvement of exosomal circRNAs in breast cancer has been studied with consideration to tumor development and progression as well as its effects on therapeutic resistance. However, its exact mechanism is still unclear, and there have not been available clinical implications of exo-circRNAs in breast cancer. Here, we highlight the role of exosomal circRNAs in breast cancer progression and to highlight the most recent development and potential of circRNAas therapeutic targets and diagnostics for breast cancer.Copyright © 2023 Hussen, Mohamadtahr, Abdullah, Hidayat, Rasul, Hama Faraj, Ghafouri-Fard, Taheri, Khayamzadeh and Jamali.