Detection and Characterization of Circulating Tumor Cells by the CellSearch Approach.

Cancer metastasis occurs when cells shed from a primary or metastatic tumor, enter the circulation, and begin to grow in distant locations of the body. With current techniques it is possible to measure the presence of a few circulating tumor cells (CTC) in a blood sample. Detection of even the presence of a very small number (one or more) of these CTC in a 7.5 mL blood sample with the CellSearch system is associated with a significant decrease in survival of patients with metastatic carcinomas. The techniques and definitions used for the detection and enumeration of CTC with the CellSearch system were validated in series of preclinical and prospective multicenter studies. After enumeration of the CTC, the cells can be isolated from the cartridge for the purpose of downstream single-cell analysis. In this chapter, we will describe in detail the sample acquisition, sample preparation, data acquisition, and assignment of CTC used in the CellSearch system.