CD47 plays dual role in colorectal carcinoma, independently on CD 68: an immunohistochemical study

Background Colorectal cancer (CRC) is the third most common cancer. Tumor-associated macrophages can affect tumor cell proliferation, stromal formation and dissolution, vascularization, and both pro- and anti-neoplastic inflammation. Cluster of differentiation 68 (CD68) plays a critical role in promoting phagocytosis; however, its function in tumor immunity remains unknown. CD47, a cell-surface receptor expressed by macrophages, provides a potent ‘don’t eat me‘ signal that allows tumor cells to evade immune destruction. Purpose Investigate immunohistochemical expression of CD68 and CD47 in CRCs and its correlation with clinicopathological features. Results CD68 and epithelial expression of CD47 were significantly in favor of CRC ( P value = 0.001, <0.001, respectively) compared with adenoma specimens. Also, high epithelial CD47 was associated with the absence of gross perforation and a higher number of investigated lymph. However, low stromal CD47 was significantly correlated with less tumor metastasis and less tumor recurrence. Moreover, epithelial, and stromal CD47 expression were significantly correlated in CRC. ( P =0.033) in CRC. Conclusion Both CD68 and CD47 play a role in colorectal carcinogenesis being expressed more in CRC compared with adenoma cases. However, CD47 carries good prognostic impact when expressed by tumor cells in contrary to its stromal expression suggesting dual opposing role of CD47 in CRC according to its localization. So, future target therapy against CD68 or CD47 should be cautiously administered.