ABSTRACT
Tumor cells observed in peripheral blood are believed to be the means for the spread of the disease to metastatic sites. These circulating tumor cells (CTCs) could provide up-to-date assessment of disease status. Peripheral blood is a particularly attractive body •uid for assessing the disease as its collection is a minimally invasive procedure that can be repeated throughout the course of disease progression and treatment. Consequently, the enumeration and characterization of CTCs are being explored for their role as prognostic and predictive diagnostic tools in cancer.
