Globally, breast cancer (BC) is the leading cause of cancer-related death for women. BC is characterized by heterogeneity, aggressive behavior, and high metastatic potential. Chemotherapy, administered as monotherapy or adjuvant therapy, remains a cornerstone of treatment; however, acquired drug resistance is a significant clinical challenge. Deciphering mechanisms of drug resistance will be central to developing more efficient treatment options and improving patient outcomes. The current review examines the multifaceted nature of exosomes in conferring drug resistance in BC through complex communication networks within the tumor microenvironment. We further explore recent advances in understanding how exosomes contribute to resistance against established chemotherapeutic agents such as tamoxifen, paclitaxel, doxorubicin, platinum-based drugs, trastuzumab, and newer immunotherapies, such as immune checkpoint inhibitors. Moreover, we discuss existing systematic approaches to investigating the exosome–drug resistance relationship in BC. Finally, we explore promising therapeutic approaches to overcome exosome-dependent drug resistance in BC, highlighting potential avenues for improved treatment efficacy. Investigating the distinct functions and cargo of exosomes offers potential for developing innovative approaches to overcoming treatment resistance.
在全球范围内，乳腺癌是女性癌症相关死亡的首要原因。乳腺癌具有异质性、侵袭性行为和高转移潜能的特征。化疗作为单一疗法或辅助疗法，仍然是治疗的基石；然而，获得性耐药是一个重大的临床挑战。解析耐药机制对于开发更有效的治疗方案和改善患者预后至关重要。本综述探讨了外泌体在乳腺癌中通过肿瘤微环境内的复杂通讯网络赋予耐药性的多方面性质。我们进一步探讨了近期在理解外泌体如何促进对既定化疗药物（如他莫昔芬、紫杉醇、多柔比星、铂类药物、曲妥珠单抗）以及新型免疫疗法（如免疫检查点抑制剂）产生耐药性方面的进展。此外，我们讨论了研究乳腺癌中外泌体与耐药关系的现有系统方法。最后，我们探讨了克服乳腺癌中外泌体依赖性耐药的有前景的治疗方法，并强调了提高治疗效果的潜在途径。研究外泌体的独特功能及其携带物，为开发克服治疗耐药性的创新方法提供了潜力。
肿瘤(癌症)患者之家