Abstract 37: Bone metastases in renal cell carcinoma are predicted by characteristics of the primary tumor

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Introduction: The poor prognosis of renal cell carcinoma (RCC) is caused by a high risk of metastasis. 30 % of all RCC patients develop bone metastases during course of disease. The outcome of RCC patients with bone metastases is poor so that a prediction would be of advantage. The aim of this study was to elucidate the mechanisms that lead to an organ specific metastasis of RCC in bones and probably predict bone metastasis. Methods: In 30 RCC tissue specimens and 9 RCC primary cell lines collected from patients who had developed no metastases, lung or bone metastases within 5 years after nephrectomy (each 10 RCC tissue specimens, each 3 RCC cell lines) expression and/or activity of 46 cellular signalling molecules were quantified by a phospho kinase array and Western blot analyses. As steps of metastasis, migration of the primary RCC cells was analysed in a Boyden chamber with 10 µg/ml fibronectin as chemotaxin, adhesion to extracellular matrix compounds fibronectin, collagen I and IV was determined after cell staining with crystal violet. Results: In RCC tissue specimens and primary cells from patients who developed bone metastases a higher expression of alpha5 integrins, higher activity of Akt and FAK as well as a lower expression of PTEN was detected, compared to those from patients without or with lung metastases. According to these results we observed an enhanced chemotactic migration (13-fold) of bone metastatic RCC cells and adhesion to fibronectin (6-fold) or collagen type I (8-fold) - both components of the bone matrix. Conclusion: These results show that specific characteristics like the expression and activity of cell signalling mediators and the cellular behaviour of the primary tumor determine the location of the subsequent metastasis in RCC and could be used as prognostic marker for bone metastasis. This should be considered during follow-up care. Funded by the Wilhelm Sander Foundation Citation Format: Elke Schneider, Tobias Haber, Frederick C. Roos, Christian Hampel, Kerstin Junker, Joachim W. Thuroff, Walburgis Brenner. Bone metastases in renal cell carcinoma are predicted by characteristics of the primary tumor. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 37. doi:10.1158/1538-7445.AM2014-37