Tumor associated macrophages in gynecologic cancers

The complex tumor microenvironment in gynecologic cancers plays a major role in modulating anti-tumor immune responses. The interaction of cancer cells with the diverse spectrum of immune effector cells has an important impact on the efficacy of standard chemotherapy and novel immunotherapy approaches. In this review, we specifically focus on the role of macrophages in ovarian, endometrial and cervical cancers. We discuss the origins of macrophages and their polarization state dictated by the microenvironment's cues. Within the tumor niche, tumor-associated macrophages (TAMs) promote tumor growth and mediate immune-suppression thereby effecting treatment responses. We outline clinical strategies that directly target TAMs, including inhibition of macrophage differentiation, prevention of the recruitment of monocytes to the tumor, enhancement of phagocytosis and immune checkpoint blockade.