Physiology of Gastrointestinal, Hepatic, and Pancreatic Cancer
Cancers are complex physiological systems that are influenced by the host and have systemic effects on the host. Dietary, lifestyle, and metabolic states of the host are involved in regulation of the promotion of a cancer; and the cancer can have effects on multiple organ systems through release of soluble cytokines and chemokines and vesicles (exosomes) carrying tumor-derived factors to distant sites. Metastases are another physiological process including migration, vascular function on host organ factors. Finally, the primary tumor itself represents multiple interacting cell types in addition to the cancer cells, including endothelial cells, inflammatory and immune cells, neural elements, endocrine elements, and stromal fibroblasts. Communication between these cell types is essential for regulation of growth and metastasis of the tumor. Considerations of these local and systemic effects related to cancer involve investigations utilizing physiological principles and methods and are of significant interest for readers of the American Journal of Physiology-Gastrointestinal and Liver Physiology.