Prostate cancer (PC), accounts for more than one-fourth of all cancer diagnoses, and the most frequently diagnosed cancer among men in 2022. The immunoglobulin (IG) Program death ligand-1(PD-1) cell surface receptor is predominantly expressed on the surface of many cells. The purpose of this study was to demonstrate the relationship between Program death ligand expression and some aggressive features of prostate cancer including perineural invasion, vascular invasion and necrosis. Thirty cases of prostate cancer with age range from 60 to 80 year old and 30 cases of normal prostate tissue with age under 25 year old were separated into two groups in a retrospective case-control research that encompassed 60 cases. All malignant cases were examined by consultant pathologists for the diagnosis of prostate carcinoma, and each block of tissue was divided into two slides, one for hematoxylin and eosin (H&E) staining and the other for immunoglobulin (IHC) staining of PDL-1. The expression pattern of Program Death Ligand was investigated in these samples and its relationship to particular clinic-pathological characteristics. Despite it was not expressed in healthy prostatic tissue, program death ligand demonstrated to be positive in prostate cancer with vascular invasion, perineural invasion, and necrosis, while it was negative in healthy prostatic tissue. High expression of Program death ligand was correlated with poor differentiation, neural invasion, and vascular invasion; these criteria indicate that the expression of Program death ligand is associated with high grade and aggressive tumors. The current study confirms that perineural invasion, vascular invasion, and necrosis are all accompanied by a rise in Program death ligand expression regardless their grade and stage
