Programmed death ligand I (PDL-1) Expression in renal cell carcinoma: A retrospective cohort study

Background and objectives: Inhibition of programed death -1and programed death ligand-1 pathway enhances antitumor activity of T lymphocytes, therefore, provides a new strategy for tumor treatment utilizing immunotherapy. The aim of this study to assess the frequency of programed death ligand-1 expression in renal cell carcinoma by using the immunohistochemistry and to correlate the results the clinicopathologic parameters. Methods: This is a cross sectional retrospective study performed in Duhok City from 2017-2022 on fifty-four formalin fixed paraffin embedded blocks of nephrectomy specimens diagnosed as renal cell carcinoma and collected from central lab of Duhok and some private labs. Two sections were prepared from each block, one section was stained with hematoxylin and eosin for histological analysis and the other one was used for immunohistochemical assessment of programed death ligand-1then the results were correlated with various clinicopathological parameters. Results: Programed death ligand -1; membranous expression was positive in 19 cases (35.2%) of renal cell carcinoma out of 54 cases. There was no significant correlation between programed death ligand -1 expression and age (p= 0.991), gender (p= 0.272), multifocality (p= 0.607), tumor size (p= 0.796), histological subtype (p= 0.107), tumor stage (p= 0.546), nuclear grade (p= 0.781), surgical margins involvement (p= 0.119) and lymphovascular invasion (p= 0.4), but there was statistically significant correlation with nodal metastases (p= 0.039). Conclusion: Programmed death ligand -1/ Combined positive score was ?1 in about one third (35.2%) of renal cell carcinoma cases and this result can be utilized for the provision of immune checkpoint inhibitor (ICIs), regardless the age, gender, histological type, stage, nuclear grade, and the presence of lymphovascular invasion (LVI).