Image cytometry analysis of circulating tumor cells.

The majority of cancer-related deaths are as a result of metastatic disease, which has been correlated with the presence of circulating tumor cells (CTCs) in the bloodstream. Therefore the ability to reliably enumerate and characterize these cells could provide useful information about the biology of the metastatic cascade; facilitate patient prognosis; act as a marker of therapeutic response; and/or aid in novel anticancer drug development. Several different techniques have been utilized for the enrichment and detection of these rare CTCs, each having their own unique advantages and disadvantages. In this chapter we will briefly discuss each of these techniques as well as the pros and cons of each approach. In particular, we will provide a comprehensive examination of two image cytometry approaches for CTC analysis that are in routine use in our laboratory; the iCys Laser Scanning Cytometer (Compucyte, Cambridge, MA), and the CellSearch® system (Veridex, North Raritan, NJ). The ability to detect, enumerate, and characterize CTCs is an important tool for the study of the metastatic cascade and the improved clinical management of cancer patients. These rare cells could shed light on the basic biology behind this highly lethal process and ultimately change current patient treatment guidelines.