Inflammation and cancer

Extensive evidence supports the concept that chronic inflammation increases cancer risk. Inflammatory responses play critical roles at multiple stages of tumor development, including initiation, promotion, invasion, and metastasis. Inflammation also affects immune surveillance and the immune response to therapy. Immune cells that infiltrate tumors engage in an extensive and dynamic crosstalk with cancer cells and some of the molecular events that mediate this cell-to-cell communication are now better understood. This chapter focuses on the tumor-promoting role of immune and inflammatory responses and draw parallels between tumor-promoting inflammation and “normal” functions of inflammation in tissue regeneration and host defense. Moreover, we discuss the key roles and timing of inflammatory action in cancer, describe the sources of inflammation-initiating stimuli, and outline underlying mechanisms of how inflammation can promote cancer at the various stages of tumor evolution.