The Role of the Tumor Microenvironment in Cancer Progression and Metastasis

The tumor microenvironment (TME) is the complex ecosystem surrounding a tumor. It is a complex and continuously evolving entity. The TME comprises a variety of complex components, such as cancer cells, immune cells, stromal cells, and extracellular matrix, that precisely regulate the interaction of tumor cells with other components, allowing tumor cells to continue to metastasize, escape immune surveillance, resist apoptosis, and proliferate. Researchers believe that the TME is not just a silent bystander but instead an active promoter of cancer progression. At the onset of tumor growth, a dynamic and reciprocal relationship is developed between cancer cells and components of the tumor microenvironment; this relationship supports cancer cell survival, local invasion, and metastatic dissemination. In this article, we discuss the role of the various components of the TME in the progression and metastasis of cancer, the pathways influenced by the TME, and the drugs that can treat tumors by targeting the components of the TME.