FISH Probe Counting in Circulating Tumor Cells

Presence of tumor cells in blood of patients with metastatic carcinomas has been associated with poor progression free and overall survival (Cohen et al., 2008; Cristofanilli et al., 2004; de Bono et al., 2008). Assessment of treatment targets on circulating tumor cells (CTC) before initiation of therapy may provide a means to guide therapy (Attard et al., 2009; de Bono et al., 2007; Hayes et al., 2002; Meng et al., 2006; Meng et al., 2004; Smirnov et al., 2005; Swennenhuis et al., 2009). Characterization of CTC can be performed by Fluorescence In Situ Hybridization (FISH) which has been used to prove that CTC are indeed malignant (Fehm et al., 2002; Swennenhuis, et al., 2009), and that gene amplifications, deletions and translocations related to certain therapies can be detected (Attard, et al., 2009; Meng, et al., 2006; Meng, et al., 2004).