In the context of cancer immunotherapy, PD-1 as well as PD-L1 has been widely studied in renal cell carcinoma (RCC). PD-1 and PD-L1 play a significant role as prognostic markers in clear cell renal cell carcinoma. In contrast, little is known about PD-L2 expression patterns in RCC, especially in rarer subtypes. The aim of this study was to evaluate the prevalence, distribution and prognostic impact of PD-L2 expression in chromophobe (ch)RCC. Eighty-one patients who underwent renal surgery due to chRCC were retrospectively evaluated. Tumor specimens were analyzed for PD-L2 expression by immunohistochemistry. Expression data were associated with clinicopathological parameters and overall survival (OS). Twenty-three (28.4%) patients showed a PD-L2 > median (PD-L2 high) staining intensity. No significant association between clinicopathological parameters and PD-L2 expression was identified. A significant difference between 5- and 10-year OS in dependence of PD-L2 expression was found (PD-L2 low 96.4 and 87.7% vs. PD-L2 high 87.1 and 56%; log rank, p = 0.029). However, in multivariate analysis PD-L2 expression failed to be proofed as an independent prognostic factor. In conclusion, to our knowledge this is the first study evaluating the prognostic impact of PD-L2 in a considerably large cohort of chRCC. Our results showed a significant diminished OS in dependence of PD-L2 expression. This implicates that PD-L2 might play a role as prognostic marker in chRCC demanding further evaluation.
Medical oncology (Northwood, London, England). 2017 Mar 28 [Epub]
Franziska Erlmeier, Wilko Weichert, Michael Autenrieth, Max Wiedemann, Andres Jan Schrader, Arndt Hartmann, Philipp Ivanyi, Sandra Steffens
Institute of Pathology, Technical University Munich (TUM), Trogerstraße 18, 81675, Munich, Germany. ., Institute of Pathology, Technical University Munich (TUM), Trogerstraße 18, 81675, Munich, Germany., Department of Urology, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany., The Munich Cancer Registry of the Tumorzentrum Munich, Institute of Medical Information Processing, Biometry and Epidemiology, Ludwig-Maximilians-University Munich, Munich, Germany., Member of the German Renal Cell Tumor Consortium, Jena, Germany., Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany.