Histopathological data, PD-L1 analysis and comparison of PD-L1 clones in clear cell renal cell carcinomas

Renal cell carcinoma (RCC) accounts for 2-3% of adult cancers and 80-90% of renal malignancies. 20-30% of RCC patients have metastatic disease during the time of diagnosis and the 5-year survival rate is 11-20%. Clear cell renal cell carcinoma (CCRCC) is the most common histologic type of RCC. PD-L1 produced by tumor cells inhibits tumor-specific T lymphocyte-mediated immunity by binding to PD-1 on the surface of T lymphocytes, thus allowing tumor cells to escape the host immune system. Enhanced antitumoral response has been observed after the use of monoclonal antibodies targeting PD-L1. There are numerous studies investigating the role of PD-L1 as a prognostic marker and a possible therapeutic target. A total of 107 cases diagnosed with CCRCC from partial or radical nephrectomy materials between 2020 and 2023 belonging to the archives of the Karadeniz Technical University Faculty of Medicine, Department of Medical Pathology were included in this study. PD-L1 expression status of the cases was evaluated with PD-L1 SP263 and 22C3 clones immunohistochemically, and the relationship between expression and clinicopathological parameters was examined. In this study, moderate agreement was found between the expression values of PD-L1 SP263 and 22C3 clones. In cases with lymph node metastasis, the PD-L1 positivity rate was found to be both higher and statistically significant. In the analyses performed with both clones, the PD-L1 positivity rate was higher in cases under the age of 58, with sarcomatoid/rhabdoid differentiation and tumor necrosis, but this difference was not found to be statistically significant. This study supports that there may be a significant correlation between PD-L1 expression and adverse prognostic factors such as lymph node metastasis. Our findings are partially consistent with the literature. Larger-scale studies with different PD-L1 clones and platforms are needed to obtain more reliable results.