Correlation of Histological Localization of Tumor-associated Macrophages with Clinicopathological Features in Endometrial Cancer

Background: To clarify the pathophysiological role of tumor-associated macrophages (TAMs), we performed clinicopathological analysis of CD68+ cells in 70 cases of human endometrial cancer. Materials and Methods: Using immunohistochemistry for CD68, we classified CD68+ cells into four groups: (a) those infiltrated into cancer cell nests or in close contact with cancer cells (nest TAM); (b) those in necrosis in the tumor center (hot-spot TAM); (c) those infiltrated into cancer stroma (stroma TAM); and (d) those distributed along the invasive margin of a tumor (Margin TAM). Results: The aggregation of nest TAM related to high relapse-free survival rate after surgery. On the contrary, increased hot-spot TAM was a hazard to relapse-free survival and was proportionately-associated with clinical stage, myometrial invasion and histological differentiation. The extent of stroma TAM was associated with the presence of lymph node metastasis. Conclusion: Our findings demonstrate that the histological location of infiltrated TAMs may be taken into account in the clinical evaluation of endometrial cancer.