The Role of PDL1 Immunostain Expression in RCC: A Clinicopathological Study

Abstract

Background: The expression of programmed death-ligand 1 (PD-L1) on malignant cells is one method by which the immune system might evade tumorigenesis. PD-1/PD-L1 pathway inhibition improves immunity against tumours. The study aimed to evaluate the statement of PDL1 immunostain in renal cell carcinoma. Methods: A case series of research, both prospective and retrospective, was conducted on fifty primary renal cell cancer samples. Hematoxylin and eosin (H and E) stained glass slides were processed from Formalin-fixed and paraffin-embedded (FFPE) blocks and were revised regarding diagnosis. PD-L1 immunohistochemical stain (PD-L1 IHC) was conducted for all cases, PD-L1 IHC 22C3 pharmDx (Dako) monoclonal mouse anti-PD-L1 employing Autostainer Link 48's EnVision FLEX visualization system. Results: PDL1 is found to be expressed in 56 %, showing positivity in males mainly in score 3, 63.6%. The frequency of scores in PDL1 expression with histological variant shows statistical significance in score 3 with p- value 0.02. According to the stages, stage 1 was the most common, grades 2 and 3 were strongly positive expressions and showed the left side was strongly positive while the right side was the most common weak positive. Conclusions: Positive expression of PDL1 was found in 56% of the study sample. The positivity of the PDL1 score was reported mainly in males. PDL1 score with a histological variant of renal cell carcinoma showed a significant difference among the variants at score 3 with a high prevailing of clear cell carcinoma.