631 Circulating Tumor Cells Are Associated With More Advanced Disease in Cholangiocarcinoma

Abstract

Background/Aims: Detection of circulating tumor cells (CTC) is associated with poor progression free and overall survival in patients with breast, prostate, and colon cancer. There is limited information about the prognostic value of CTC in patients with cholangiocarcinoma (CCA). The aim of this study are (1) to quantify circulating tumor cells in the peripheral blood of patients with CCA; and (2) to test the hypothesis that the presence of circulating tumor cells is associated with larger tumor burden of CCA and poor overall survival. Methods: A total of 45 patients with CCA seen at Mayo Clinic Rochester were prospectively enrolled between June 2010 and September 2012. 10 ml peripheral blood was drawn into CellSave Preservative Tubes. Blood samples were processed within 96 hours after the blood draw. The CellSearch system by Veridex was used for the capture, enrichment, identification and enumeration of CTC of epithelial origin in 7.5 ml of peripheral blood from the patients. The CellSearch system has an estimated sensitivity of approximately 20-30% for detecting CTC at a prognostic level . The association between baseline characteristics and detection of CTC was analyzed. Overall survival was estimated by the Kaplan Meier method and compared using the Log Rank test. Results: The mean age of patients was 61 and 29 (64%) patients were male. CTC were detected in 13 (28%) patients. Patients with CTC tended to have larger tumor size, more tumor nodules, a higher CA19-9 level, increased CEA, lymph node involvement, and metastatic disease compared to patients without CTC. (Table) There was no significant association between CTC and demography (age, gender, and race) or underlying liver dysfunction . There was a trend towards poorer survival in patients with CTC compared to patients without CTC (p=0.09). Conclusion: CTC are detectable in patients with cholangiocarcinoma. The presence of CTC was associated with tumor burden and metastatic cancer. The prognostic implications of CTC in patients with CCA need further validation in a larger patient group.