Inflammation in Cancer Development

Inflammation plays an important role to the development of cancer and promotes all stages of tumorigenesis. Cancer cells, as well as inflammatory cells, carry out reciprocal interactions to form an inflammatory tumor microenvironment (TME). Cancer cells within the TME are highly able to change their phenotypic and functional characteristics. Here, we review the relationship between inflammation and infection in cancer origins, and the mechanisms whereby inflammation and infection drive tumor formation. We discuss how infection promotes tumorigenesis related to inflammatory processes typically found in autoimmune diseases, release of inflammatory mediators induced by tumors, inflammation induced by therapy in cancer, and stimuli for induction of inflammation during tumorigenesis, including spatiotemporal considerations. A better understanding of the fundamental rules of engagement that govern the molecular and cellular mechanisms of tumor-promoting inflammation will be essential for further development of cancer therapies.