The prognostic impact of Claudin 6 in papillary renal cell carcinoma.

Claudins are promising biomarkers for diagnosis and prognosis or targets for treatment. They play a major role in signal transduction and are important in nearly all aspects of tumorigenesis. Claudin 6 is a member of the claudin family and is part of the tight junction molecule. It is reactivated in several cancer types and serves as prognostic marker in, for example, gastric, breast or non small cell lung cancer. The prognostic role of Claudin 6 in renal cell carcinoma (RCC), especially in papillary RCC (pRCC), is still unclear.

The patients' sample collection was a joint collaboration of the PANZAR consortium. Patients' medical history and tumor specimens were collected from n = 240 and n = 128 patients with type 1 and 2 pRCC, respectively. Expression of Claudin 6 was determined by immunohistochemistry.

In total, Claudin 6 staining was positive in 55 of 240 type 1 and 30 of 128 type 2 pRCC cases. Kaplan-Meier analysis disclosed an overall survival of 84% for Claudin 6- compared to 78% for Claudin 6 + in pRCC type 1 tumors (p = 0.449, log-rank) and 68% for Claudin 6- compared to 65.4% for Claudin 6 + in pRCC type 2 tumors (p = 0.364, log-rank).

In this study, claudin 6 expression showed no significant association regarding overall survival (OS) and therefore did not qualify as a prognostic marker in pRCC. Future studies will have to determine, whether Claudin 6 plays a prognostic role in other RCC entities. In addition, the function of Claudin 6 as a predictive marker for therapeutic approaches has to be evaluated in future studies.

Pathology, research and practice. 2022 Feb 11 [Epub ahead of print]

Marie Mikuteit, Stefanie Zschäbitz, Christine Stöhr, Edwin Herrmann, Iris Polifka, Abbas Agaimy, Lutz Trojan, Philipp Ströbel, Frank Becker, Christian Wülfing, Peter Barth, Michael Stöckle, Michael Staehler, Christian Stief, Axel Haferkamp, Markus Hohenfellner, Stephan Macher-Göppinger, Bernd Wullich, Joachim Noldus, Walburgis Brenner, Frederik C Roos, Bernhard Walter, Wolfgang Otto, Maximilian Burger, Andres Jan Schrader, Arndt Hartmann, Sandra Steffens, Franziska Erlmeier

Department of Rheumatology and Immunology, Hannover Medical School, 30625 Hannover, Germany; Department of Medical Oncology, National Center of Tumor Diseases, University Hospital Heidelberg, 69120 Heidelberg, Germany; Institute of Pathology, University Hospital Erlangen-Nuernberg, Friedrich Alexander University (FAU), 91054 Erlangen, Germany; Department of Urology, University Hospital Münster, 48149 Münster, Germany; Department of Urology, University Hospital Göttingen, 37075 Göttingen, Germany; Department of Pathology, University Hospital Göttingen, 37075 Göttingen, Germany; Department of Urology and Pediatric Urology, University Hospital Saarland (UKS), 66421 Homburg, Germany; Department of Urology, University Hospital Marburg, 35037 Marburg, Germany; Department of Urology, University Hospital Heidelberg, 69120 Heidelberg, Germany; Institute of Pathology, University Hospital Mainz, 55131 Mainz, Germany; Department of Urology and Pediatric Urology, University Hospital Erlangen, 91058 Erlangen, Germany; Department of Urology, Marien-Hospital Herne, Ruhr University Bochum, 44625 Herne, Germany; Department of Urology, University Hospital Mainz, 55131 Mainz, Germany; Department of Urology, University Hospital Frankfurt, 60590 Frankfurt/Main, Germany; Department of Urology, University Hospital Regensburg, 93053 Regensburg, Germany; Department for Rheumatology and Immunology, Hannover Medical School, 30625 Hannover, Germany., Department of Medical Oncology, National Center of Tumor Diseases, University Hospital Heidelberg, 69120 Heidelberg, Germany., Institute of Pathology, University Hospital Erlangen-Nuernberg, Friedrich Alexander University (FAU), 91054 Erlangen, Germany., Department of Urology, University Hospital Münster, 48149 Münster, Germany., Department of Urology, University Hospital Göttingen, 37075 Göttingen, Germany., Department of Pathology, University Hospital Göttingen, 37075 Göttingen, Germany., Department of Urology and Pediatric Urology, University Hospital Saarland (UKS), 66421 Homburg, Germany., Department of Urology, University Hospital Marburg, 35037 Marburg, Germany., Department of Urology, University Hospital Munich, 81337 Munich, Germany., Department of Urology, University Hospital Heidelberg, 69120 Heidelberg, Germany., Institute of Pathology, University Hospital Mainz, 55131 Mainz, Germany., Department of Urology and Pediatric Urology, University Hospital Erlangen, 91058 Erlangen, Germany., Department of Urology, Marien-Hospital Herne, Ruhr University Bochum, 44625 Herne, Germany., Department of Urology, University Hospital Mainz, 55131 Mainz, Germany., Department of Urology, University Hospital Frankfurt, 60590 Frankfurt/Main, Germany., Department of Urology, University Hospital Regensburg, 93053 Regensburg, Germany., Department of Urology, University Hospital Münster, 48149 Münster, Germany; Department for Rheumatology and Immunology, Hannover Medical School, 30625 Hannover, Germany., Institute of Pathology, University Hospital Erlangen-Nuernberg, Friedrich Alexander University (FAU), 91054 Erlangen, Germany. Electronic address: .