Hijacking homeostasis: the brain-body neural circuitry in tumor pathogenesis and emerging therapeutic frontiers

Cancer research is undergoing a paradigm shift from solely studying tumor cells to investigating systemic effects of cancer in the tumor macroevironment, with an emphasis on the interactions between host organs and tumors. The theory of homeostasis is an important basis for explaining biological functions from the perspective of the organism. Organic homeostasis relies on brain-body crosstalk through interception, immunoception, nociception and other supervisory processes, guaranteeing normal physiological function. Recent studies reveal that malignant tumors can hijack and exploit the brain and its central-peripheral neuronal networks to disrupt the body's homeostasis. Tumors likely disrupt normal brain-body crosstalk by establishing bidirectional brain-tumor connections. On the contrary, organism utilize these mechanisms to hinder tumorigenesis and progression. Standing at the perspective of brain-body crosstalk also promotes the conceptional evolution of cancer initiation and development, and more importantly, provides additional insight for cancer treatment. In this review, we summarize current knowledge about brain-body crosstalk under tumor-bearing contexts and propose some novel anti-cancer strategies.