Tumor-Associated Macrophages and Myeloid-Derived Suppressor Cells as Immunosuppressive Mechanism in Ovarian Cancer Patients: Progress and Challenges.

Cancers are complex masses of malignant cells and nonmalignant cells that create the tumor microenvironment (TME). Non-transformed cells of the TME such as tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) have been observed in the TME of ovarian cancer (OC) patients. Although these subsets may contribute to each step of carcinogenesis and are commonly associated with poor prognosis, still little is known about creation of the protumor microenvironment in OC. In this review, we focused on the nature and prognostic significance of TAMs and MDSCs in OC patients. Moreover, we discuss the main problems and challenges that must be overcome by researchers and clinicians to enrich our knowledge about the immunosuppressive microenvironment of cancers.