Chapter 27 – Tumor-associated Macrophages in Cancer Growth and Progression

Tumor development and progression are strongly linked to inflammation and macrophage infiltration is a major component of the inflammatory reactions associated with neoplasia. Plasticity is a hallmark of mononuclear phagocytes, which undergo polarized diverse forms of activation. Metabolic adaptation is a key component of macrophage plasticity and polarization, instrumental to their function in homeostasis, immunity and inflammation. Tumor-associated macrophages (TAM) and related immature myeloid suppressor cells generally have properties of an M2-like population. TAM produce growth factors, have immunoregulatory and immunosuppressive activity, stimulate angiogenesis and provide tissue remodeling, invasion and metastasis. Thus, TAM are a key component of cancer-promoting inflammatory reactions.