PD-L1 Expression and Clinicopathological Factors in Renal Cell Carcinoma: A Comparison of Antibody Clone 73-10 With Clone 28-8

Abstract

Background/Aim: Expression of programmed death ligand-1 (PD-L1) is associated with poor prognosis in renal cell carcinoma (RCC). Although a new antibody clone for immunohistochemical assay, 73-10, has shown greater sensitivity than other assays (28-8, 22C3, SP142, and SP263) in non-small cell lung cancer, PD-L1 expression using 73-10 has never been assessed in RCC. Therefore, this study aimed to evaluate the association of clinicopathological factors with PD-L1 expression detected by clone 73-10 and compare it with that detected by 28-8. Patients and Methods: Tissue microarray samples from 582 patients who underwent radical or partial nephrectomy for RCC were immunohistochemically assessed using clones 73-10 and 28-8. Results: The positivity for PD-L1 expression in RCC by 73-10 was higher than that of 28-8 and significantly associated with worse pathological factors and a higher risk of cancer-specific mortality. Conclusion: Positivity for PD-L1 expression by 73-10, as compared to 28-8, was associated with worse clinicopathological factors and prognosis for patients with RCC.