EpCam expression and detection of circulating tumor cells in neuroendocrine tumors

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Introduction: Using the CellSearchTM system, circulating tumor cells (CTCs) can be reproducibly enumerated according to expression of EpCAM and cytokeratins 8, 18 or 19 and the absence of the haemopoietic marker CD45. The number of CTCs detected in 7.5 mls blood has been shown to correlate with prognosis in breast, colon and prostate cancer and can predict response to therapy. Neuroendocrine tumors (NETs) have not previously been reported to express EpCAM and have not been systematically assessed for presence of CTCs. We have therefore explored the expression of EpCAM in NETs and the detection of NET cells in the circulation.

Aim(s): To detect circulating tumor cells in patients with neuroendocrine tumors

Materials and methods: EpCAM expression was evaluated by standard immunohistochemistry in a consecutive series of NET patients for whom formalin-fixed paraffin-embedded tumor tissue was available. For CTC analysis, consenting patients with a histological diagnosis of NET, who had received no treatment other than somataostatin analogues for the previous two months, were recruited. 7.5 mls of blood was collected and CTCs enumerated using the Veridex CellSearchTM. All evaluations of CTCs were performed without knowledge of clinical status of patients. Clinicopathological data including tumor grade, serum chromogranin A (CgA), 24-hour urinary 5HIAA and tumor burden was also recorded.

Conference: 7th Annual ENETSConcerence (2010)

Presenting Author: Khan M

Authors: Khan M, Tsigani T, Rashid M, Luong T, Caplin M,

Keywords: neuroendocrine tumor, circulating tumor cells, carcinoid, EpCAM,