Background: Bowel cancer is the most prevalent digestive system cancer and is the 4th largest cause of cancer-related death worldwide. In Iraq, colon and rectal cancer (CRC) is the 6th most common malignancy in males and the 5th in females. This cancer is sluggish in growth, which gives a window of opportunity to screen for both precursor lesions and early cancer. The Cluster of Differentiation 47 (CD47) protein is a type of transmembrane glycoproteins found on nearly all human cells, including non-hematopoietic and hematopoietic cells. CD47 promotes CRC growth by triggering angiogenesis and apoptosis of tumor cell. Objectives: To evaluate the immunohistochemical expression of (CD47) in various colorectal samples from Iraqi patients with CRC by immunohistochemistry (IHC) assay. Specimens and methods: A total of 45 paraffin-embedded CRC tissue specimens and clinical data were obtained from the Medical City Teaching Hospital in Baghdad and a number of private laboratories in Baghdad, Iraq. In addition, 30 control colon and rectum tissues with no significant pathology were collected from the Forensic Medicine Department for comparison purposes after taking the official approvals. Results: The results revealed a high expression of CD47 in CRC cases, but with no significant correlation with clinicopathological features. Also, the result of figures in this study revealed negative membranous expression of CD47 (score 0), strong membranous expression of CD47 (score 3), moderately membranous expression of CD47 (score 2), and weak membranous expression of CD47 (score 1) Conclusion: Patients with CRC had high CD47 expression, allowing tumor cells to modulate CD47SIRP inhibitory signaling and prevent immune cell attack.
