Platinum Priority – Kidney Cancer Editorial by XXX on pp. x–y of this issue Survival Prediction of Clear Cell Renal Cell Carcinoma Based on Gene Expression Similarity to the Proximal Tubule of the Nephron Florian Bu ¨ ttner a,b,c , Stefan Winter a,b , Steffen Rausch d , Anna Reustle a,b , Stephan Kruck d , Kerstin Junker e , Arnulf Stenzl d , Abbas Agaimy f , Arndt Hartmann f , Jens Bedke c,d , Matthias Schwab a,b,c,g,y, *, Elke Schaeffeler a,b,y a Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany; b University of Tuebingen, Tuebingen, Germany; c German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany; d Department of Urology, University Hospital Tuebingen, Tuebingen, Germany; e Department of Urology and Pediatric Urology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg/Saar, Germany; f Institute of Pathology, University Hospital Erlangen, Erlangen, Germany; g Department of Clinical Pharmacology, University Hospital Tuebingen, Tuebingen, Germany E U R O P E A N U R O L O G Y X X X ( 2 0 1 5 ) X X X – X X X ava ilable at www.sciencedirect.com journa l homepage: www.europea nurology.com Article info Article history: Accepted May 26, 2015 Associate Editor: James Catto Keywords: Renal cell carcinoma ccRCC Nephron Personalised medicine Biomarker Abstract There is evidence that molecular features support subclassification of tumours, thereby improving prediction of patient outcome. Currently, two gene expression signatures (ccA/ccB and ClearCode34) have been established to classify clear cell renal cell carci- noma (ccRCC). Because RCC arises from nephron cell types, we aimed to explore its heterogeneity on a molecular level by comparing gene expression between tumour tissue and nephron regions. Based on genes that differ in expression between nephron regions, expression data of 479 ccRCCs and 212 papillary and 66 chromophobe RCCs from The Cancer Genome Atlas were correlated to those of nephron cell types. Cancer- specific survival (CSS) of ccRCC patients was significantly associated with gene expres- sion similarity to the proximal tubules. Subsequently, a ccRCC risk score (S3-score) was established. Survival analyses indicated that the S3-score was significantly associated with CSS considering all cases of ccRCC, as well as metastatic and nonmetastatic ccRCC. Results could be validated in an independent cohort. The S3-score significantly improved the predictive ability of the ccA/ccB and ClearCode34 signatures, and the clinicopathologic-based stage, size, grade, and necrosis score (p [chi-square] = 1.56E-04). Intratumour heterogeneity of the S3-score was observed in 6 of 10 ccRCCs. In summary, the nephron-based S3-score enables prognostic risk stratification for ccRCC. Further studies are needed to evaluate its clinical utility. Patient summary: We developed a novel risk score for clear cell renal cell carcinoma to identify patients at risk of worse outcome that may improve patient care in the future. # 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved. y These authors contributed equally. * Corresponding author. Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstrasse 112, 70376 Stuttgart, Germany. Tel. +49 711 8101 3701; Fax: +49 711 859295. E-mail address: matthias.schwab@ikp-stuttgart.de (M. Schwab). EURURO-6242; No. of Pages 5 Please cite this article in press as: Bu ¨ ttner F, et al. Survival Prediction of Clear Cell Renal Cell Carcinoma Based on Gene Expression Similarity to the Proximal Tubule of the Nephron. Eur Urol (2015), http://dx.doi.org/10.1016/j.eururo.2015.05.045 http://dx.doi.org/10.1016/j.eururo.2015.05.045 0302-2838/# 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.