Clinicopathologic and Prognostic Significance of CD47 Expression and Tumor-associated Macrophages in Endometrial Carcinoma

Tumor-associated macrophages (TAMs) influence cancer progression. CD47 is an antiphagocytic molecule aiding tumor resistance against host immune surveillance. The relationship between CD47 expression and TAM-related microenvironment in endometrial carcinoma (EC) is poorly understood. The expression and prognostic significance of CD47 and CD163-labeled TAMs in 165 EC cases was assessed with CD47 and CD163 immunohistochemical studies. CD47 expression was found in 156/165 (94.6%) cases. CD47 expression was significantly higher in nonendometrioid carcinomas. CD47 overexpression was associated with histologic grade. High epithelial and stromal TAMs counts were also associated with high tumoral CD47 expression. High epithelial, stromal, and margin TAMs counts were associated with higher histologic grade and lymphovascular invasion. Epithelial TAMs counts were higher in patients with nonendometrioid carcinomas (P=0.0001) and cases with recurrence (P=0.018). High stromal TAMs counts were associated with deeper myometrial invasion (P=0.017) and the presence of distant metastasis (P=0.024). The counts of margin TAMs was significantly correlated with the depth of myometrial invasion, lymphovascular invasion, FIGO stage, lymph node metastases, distant metastasis, and recurrence (P=0.0001, 0.0001, 0.004, 0.005, 0.014, and 0.04, respectively). CD47 expression was not associated with overall survival (OS) and progression-free survival. However, high epithelial and stromal TAM counts were associated with shorter OS. Besides, high epithelial and margin TAM counts were associated with shorter progression-free survival. Furthermore, increased stromal and margin TAM counts were determined to be an independent prognostic marker of reduced OS. TAM count is, therefore, a significant prognostic factor in EC and the CD47 assessment has potential benefit for future clinical use.