The Impact of Iron on Cancer-Related Immune Functions in Oncology: Molecular Mechanisms and Clinical Evidence

Iron metabolism plays a dual role in cancer, serving as an essential nutrient for cellular functions and a potential catalyst for tumor growth and immune evasion. Here, we cover the complex interplay between iron levels within the serum or in the microenvironment and cancer therapy, focusing on how iron deficiency and overload can impact immune function, tumor progression, and treatment efficacy. On the one hand, we highlight iron deficiency as a factor of primary immune responses and its adverse effects on anti-cancer immunotherapy efficacy. On the other hand, we also stress the impact of iron overload as an essential factor contributing to tumor growth, creating a suppressive tumor microenvironment that hinders immune checkpoint inhibitor immunotherapy. Overall, we emphasize the necessity of the personalized management of iron levels in oncology patients as a critical element in treatment optimization to achieve favorable outcomes. Based on these considerations, we believe that close and careful monitoring and the tailored balancing of iron supplementation strategies should be the subject of further clinical studies, and routine iron management should be implemented in oncology clinical practice and integrated into cancer therapy protocols.