The End of the Beginning: Circulating Tumor Cells As a Biomarker in Castration-Resistant Prostate Cancer

Although circulating tumor cells (CTCs) were first observed from patients with metastatic malignancies more than 100 years ago, only recently has the clinical and research potential of CTCs become widely recognized. Because CTCs are thought to represent cells that are shed by primary or metastatic tumors, significant interest has focused on examining CTCs as prognostic or predictive biomarkers in several malignancies, including breast and...