Evaluation of the relationship between CD47 expression and prognostic parameters in renal cell carcinomas

Renal cell carcinomas are the 9th most common cancer in men and the 4th in women. It is the 16th most common cause of cancer-related deaths worldwide and the mortality rate increases by 1.5-5.9% every year. CD47, a cell surface protein, also known as integrin-associated protein (IAP), is a member of the immunoglobulin family. CD47 plays an important role in many biological processes such as immune cell activation, cell migration and neural development. Studies have shown that CD47 protein expression has increased in many tumors, such as bladder, ovary, prostate, breast and colon carcinoma, and its increased expression is associated with poor prognosis. In this study; we aimed to evaluate CD47 expression and the correlation of CD47 expression with prognostic parameters (tumor type, tumor diameter, histologic grade, pathological stage, capsule invasion, lymphovascular invasion and metastasis) in renal cell tumors. The samples included in this study were obtained from the archives of Gaziantep University Pathology Department, between 2005 and 2018. The study group consisted of 160 cases of renal cell carcinoma and 26 oncocytoma, with a total number of 186 cases. Renal carcinoma cases included 37 clear cell RCC,30 chromophobe RCC, 30 papillary type 1 RCC, 29 papillary type 2 RCC and 34 were unclassified RCC . The immunohistochemical antibody of CD47 was studied using an automated immunohistochemistry-staining device (Ventana Ultra Auto-Stainer). The cytoplasmic or membranous staining for CD47 was accepted as positive if more than 1% of tumor cells were positive. Endothelial cells were used as a positive control. A significant correlation between CD47 expression and the groups was found. In unclassified RCC cases; a statistically significant relationship between CD47 expression and survival, metastasis and capsule invasion was found. No significant correlation between CD47 expression and prognostic parameters among the other groups was found. Our study was the first to investigate CD47 expression in renal tumors. Further large-scale studies are needed to determine the expression profile of CD47 antibody in renal cell tumors. Keywords: renal carcinoma, CD47, prognosis