Hypoxia and the extracellular matrix (ECM) play crucial roles in tumor metastasis. Hypoxia, caused by reduced oxygen availability in solid tumors, influences ECM composition and organization, which in turn affects tumor and stromal cell behavior. Hypoxia-inducible factors (HIFs) regulate gene expression involved in angiogenesis, metabolism, and cancer cell invasion. The ECM, composed of collagens, proteoglycans, and other proteins, is dynamic and contributes to tumor progression. Hypoxia enhances ECM deposition and remodeling, which can facilitate metastasis. Hypoxia increases collagen gene expression and modifies collagen structure, promoting tumor stiffness and fibrosis. Hypoxia also recruits stromal cells and macrophages, which contribute to ECM remodeling and tumor progression. Hypoxia-induced ECM changes, such as increased collagen deposition and stiffness, create a microenvironment that supports cancer cell invasion and metastasis. The ECM's physical properties, including stiffness and alignment, influence cancer cell behavior. Hypoxia regulates ECM-modifying enzymes like P4HA and PLOD, which are essential for collagen modification. Targeting these enzymes or HIFs could be therapeutic strategies for cancer. HIF inhibitors and drugs that block collagen hydroxylases or lysyl oxidases are being explored for their potential to reduce tumor fibrosis and metastasis. Understanding the role of the ECM in tumor progression is critical for developing effective therapies to prevent metastasis.Hypoxia and the extracellular matrix (ECM) play crucial roles in tumor metastasis. Hypoxia, caused by reduced oxygen availability in solid tumors, influences ECM composition and organization, which in turn affects tumor and stromal cell behavior. Hypoxia-inducible factors (HIFs) regulate gene expression involved in angiogenesis, metabolism, and cancer cell invasion. The ECM, composed of collagens, proteoglycans, and other proteins, is dynamic and contributes to tumor progression. Hypoxia enhances ECM deposition and remodeling, which can facilitate metastasis. Hypoxia increases collagen gene expression and modifies collagen structure, promoting tumor stiffness and fibrosis. Hypoxia also recruits stromal cells and macrophages, which contribute to ECM remodeling and tumor progression. Hypoxia-induced ECM changes, such as increased collagen deposition and stiffness, create a microenvironment that supports cancer cell invasion and metastasis. The ECM's physical properties, including stiffness and alignment, influence cancer cell behavior. Hypoxia regulates ECM-modifying enzymes like P4HA and PLOD, which are essential for collagen modification. Targeting these enzymes or HIFs could be therapeutic strategies for cancer. HIF inhibitors and drugs that block collagen hydroxylases or lysyl oxidases are being explored for their potential to reduce tumor fibrosis and metastasis. Understanding the role of the ECM in tumor progression is critical for developing effective therapies to prevent metastasis.