Abstract 5215: Detection of circulating tumor cells in peripheral blood of patients with renal cell carcinoma

Abstract

Abstract Detection of circulating tumor cells in peripheral blood of patients with renal cell carcinoma The aim of this study was to evaluate the clinical relevance of the presence of disseminated tumor cells in peripheral blood, so called circulating tumor cells (CTCs), for renal cell carcinoma (RCC) patients. 233 peripheral blood samples from 154 RCC patients were investigated for the presence of disseminated tumor cells (DTCs) by autoMACS technique and immunocytochemical (ICC) staining of cytokeratin. The frequency of CTCs was analyzed statistically for correlation with relevant clinical data. Two kinds of tumor cells were detected: those with expression of cytokeratin 8/18 (CK+), but also cells without a detectable CK+ expression, which we called large blue stained (Bl+) cells with a tumor-like morphology. After following the CD45 autoMACS depletion protocol, we identified CTCs in 96 out of 233 peripheral blood samples (41%), which originated from 81 out of 154 (53%) RCC patients. A significant correlation between the detection of CTCs and positive lymph node status (p < 0.001; Chi-square test) and the presence of synchronous metastases at the time of primary tumor resection (p < 0.02; Chi-square test) was found. In a multivariate Cox's regression hazard model, presence of CK+ CTCs was significantly correlated with poor overall survival for RCC patients (RR=2.3; p < 0.05). The presence of CTCs correlated to lymph node status and presence of synchronous metastases in RCC. It is important to evaluate CK+ and Bl+ tumor cells together to determine the role of CTCs in tumor behavior and disease progression. Detection of CK+ CTCs in peripheral blood is a significant and independent prognostic factor for RCC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5215. doi:10.1158/1538-7445.AM2011-5215