The Role and Mechanisms of Tumor-Derived Exosomes in the Formation of the Premetastatic Niche

The premetastatic niche is a specialized microenvironment established by tumor cells prior to the formation of metastatic foci in distant organs. This niche provides an optimal landing site for circulating tumor cells. As key mediators of intercellular communication, exosomes play a pivotal role in shaping the premetastatic niche. This review analyzes the effects of exosomes on premetastatic niche formation from multiple perspectives, including angiogenesis, metabolic reprogramming, matrix remodeling, immune response, organicity, and epithelial-mesenchymal transition (EMT). Their value in tumor diagnosis, prognosis, and treatment, as well as the challenges and opportunities for future clinical transformation are discussed. This article presents a narrative review conducted in accordance with the SANRA guidelines.