ORIGINAL ARTICLE Prognostic value of alpha-methyl CoA racemase (AMACR) expression in renal cell carcinoma Christian Eichelberg • Sarah Minner • Hendrik Isbarn • Eike Burandt • Luigi Terracciano • Holger Moch • Alexandra Kell • Roman Heuer • Felix K. Chun • Guido Sauter • Margit Fisch • Pierre Tennstedt Received: 16 August 2011 / Accepted: 4 October 2011 / Published online: 19 October 2011 Ó Springer-Verlag 2011 Abstract Purpose Alpha-methyl CoA racemase (AMACR) is used as an immunohistochemical marker for renal cell carci- noma (RCC) subtyping to distinguish papillary (pap) RCC. Expression of AMACR in other renal tumor subtypes is inhomogeneous, and the clinical and prognostic value of AMACR is unknown. The aim of this study was to asses AMACR protein expression in different RCC subtypes and to investigate its prognostic significance. Methods Protein expression of AMACR was analyzed in 1,088 renal tumor samples, among them 809 clear cell RCC and 151 papRCC, by immunohistochemistry using tissue microarry (TMA) technique. Results were correlated with clinicopathological data and to follow-up data [overall (OS)/cancer-specific survival (CSS)]. Results Frequency of AMACR expression was signifi- cantly higher in papRCC compared to other tumor subtypes (83% vs. 15–35%, p \ 0.0001). Presence of AMACR did not correlate with stage or nodal metastases in papRCC. In a dichotomized scoring (negative vs. positive expression), an inverse correlation between higher grade (p = 0.03) and presence of distant metastasis (p = 0.014) was observed in papRCC. AMACR expression correlated with the presence of nodal metastasis in ccRCC (p = 0.02). Both in ccRCC and in papRCC, OS and CSS did not correlate with the AMACR expression status. Conclusions The high expression in papRCC confirms AMACR to be a marker for subtype differentiation in RCC, while a missing expression in this subtype seems to be associated with negative pathological features. However, in contrast to other tumor entities, AMACR expression seems to have a limited prognostic impact in renal carcinoma, especially with regard to survival. Keywords Renal carcinoma subtyping Á Alpha-methyl CoA racemase (AMACR) Á P504 s Á Prognosis Á Papillary renal carcinoma Introduction Approximately 88,000 patients are newly diagnosed with renal cell carcinoma (RCC), and more than 39,000 patients die from their disease in Europe every year [1]. Three major RCC subtypes count for more than 95% of all RCC: clear cell (ccRCC), papillary (papRCC), and chromophobe RCC (chromRCC) [2]. These tumor types diverge in biology, therapeutic options and clinical disease outcome [3, 4]. Sometimes the histological subtyping of RCC can be challenging. This is especially true if biopsy cylinders are analyzed [5]. Therefore, immunohistochemical methods C. Eichelberg (&) Á H. Isbarn Á A. Kell Á R. Heuer Á F. K. Chun Á M. Fisch Department of Urology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany e-mail: c.eichelberg@uke.de S. Minner Á E. Burandt Á G. Sauter Á P. Tennstedt Institute of Pathology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany L. Terracciano Department of Molecular Pathology, University Hospital Basel, Hebelstr. 32, 4031 Basel, Switzerland H. Moch Institute for Surgical Pathology, University Hospital Zurich, Ra ¨mistr. 100, 8091 Zu ¨rich, Switzerland 123 World J Urol (2013) 31:847–853 DOI 10.1007/s00345-011-0783-z