Detection of circulating tumor cells in cancers of biliary origin.

Abstract

Circulating Tumor Cells (CTCs) have been described in malignancies of epithelial origin. In this study we examined the detection of CTCs using CellSearch assay in cholangiocarcinoma and gallbladder cancer. The clinical outcomes and detection of CTCs were examined in sixteen patients with biliary cancer using the CellSearch assay. Stages of cancer, baseline demographic data and overall survival were evaluated. Thirteen patients had cholangiocarcinoma and three had gallbladder cancer. Using a cut off of two or more CTCs per 7.5 mL of blood, 3/13 cholangiocarcinoma and 1/3 gallbladder cancer patients had detectable CTCs. At 12 months of follow up from time CTC is drawn; 1/4(25%) of patients with positive CTC were alive while 6/12 (50%) of patients with negative CTC remained alive without a significant difference in survival between the two groups. Our finding that 25% of patients with cholangiocarcinoma and gallbladder cancer have two or more detectable CTCs/7.5 mL is the first report to our knowledge in this disease. Larger patient numbers are needed to determine the prognostic significance of finding CTCs in biliary cancer. Prospective validation of the role of CTC in advanced biliary cancer patients is on going.