During tumor progression, several types of inflammatory cells are
recruited into the tumor site, where they participate in tumor-associated
inflammation, such as fibroblasts, granulocytes, lymphocytes and macrophages.
Macrophages infiltrating into the tumor microenvironment are termed tumorassociated
macrophages (TAMs). In response to multiple stimuli, macrophages
undergo recruitment and polarization, and play an important role in further tumor
development. In this article, we present a review of the mechanism of macrophage’
recruitment, and the role that TAMs play in promoting immunosuppression, tumor progress and
metastasis, as well as chemoresistance and future therapeutic strategies.