Expression of PD-L1 in renal cancer, prognostic features and clinical utility of its routine staining

Introduction: The expression of PD-L1 in renal cell carcinoma (RCC) is associated with worse survival and prognostic clinical-pathological features. However, they seem to respond better to new therapeutic agents. Knowing the behavior of RCC according to the presence of PD-L1 has implications for medical counseling and therapeutic approaches.

Objective: To identify the presence of PD-L1 in renal tumor cells and analyze its association with patients' prognostic factors, overall survival (OS) and cancer-specific survival (CSS).

Methodology: Retrospective analysis of RCC tissue samples, obtained between 2018 and 2021. Immunohistochemistry analysis with mouse monoclonal Anti PD-L1, clone 22C3. Definition of PD-L1 "positive" as a Tumor Proportion Score ≥1%. Comparison of prognostic factors according to the presence or absence of PD-L1, and univariate analysis for OS and CSS.

Results: 14% (n = 11) of the sample were PD-L1(+). Average age was 59 years. There were no statistically significant differences between PD-L1 status and TNM stages, nuclear grade and histology. PD-L1(+) had worse OS with a HR of 5.27 (CI: 1.1-23.7; P = .03) and CSS showed a unfavorable tendency for PD-L1(+) with a HR of 4.79 (CI: 0.79-28.95; P = .08).

Conclusion: The prevalence of PD-L1 in RCC is considerable. In this study PD-L1(+) was associated with unfavorable OS and CSS. It seems reasonable to incorporate its routine use in RCC.