Current Studies on the Hypoxic Tumor Microenvironment in Thyroid Cancer: From Molecular Mechanisms to Clinical...

Hypoxia is a hallmark feature of solid tumors and is increasingly recognized as an important factor in tumor progression, aggressiveness, and therapeutic resistance. In the tumor microenvironment, hypoxia is associated with genetic instability, abnormal angiogenesis, metabolic reprogramming, and crosstalk with oncogenic signaling pathways, thereby potentially enhancing tumor invasiveness and metastatic potential. Furthermore, hypoxia may impair the sensitivity of tumor cells to conventional therapies and contribute to treatment resistance. This article reviews current evidence on the role of hypoxia in thyroid cancer, focusing on its biological effects, clinical implications, and therapeutic relevance. Available studies suggest that hypoxia may affect thyroid cancer progression and treatment tolerance by modulating hypoxia-inducible factor (HIF) signaling, epithelial-mesenchymal transition (EMT), angiogenesis, metabolic adaptation, cancer stem-like properties, extracellular matrix remodeling, and stress-adaptive responses. However, the strength of evidence varies across these pathways, and many hypoxia-targeted strategies remain under preclinical investigation. Approaches such as HIF inhibition, redifferentiation therapy, and vascular modulation may offer potential therapeutic directions for advanced and refractory thyroid cancer. Given the marked heterogeneity of thyroid cancer, further thyroid cancer-specific studies are needed to clarify the prognostic and therapeutic significance of hypoxia.