The Emerging Role of Circulating Tumor Cell Detection in Genitourinary Cancer

Purpose: Circulating tumor cells are malignant cells in peripheral blood that originate from primary tumors or metastatic sites. The heterogeneous natural history and propensity for recurrence in prostate, bladder and kidney cancers are well suited for improved individualization of care using circulating tumor cells. The potential clinical applications of circulating tumor cells include early diagnosis, disease prediction and prognosis, and selection of appropriate therapies. Materials and Methods: The PubMed (R) and Web of Science (R) databases were searched using the key words circulating tumor cells, CTC, prostate, kidney, bladder, renal cell carcinoma and transitional cell carcinoma. Relevant articles and references from 1994 to 2011 were reviewed for data on the detection and significance of circulating tumor cells in genitourinary cancer. Results: Technical challenges have previously limited the widespread introduction of circulating tumor cell detection in routine clinical care. Recently novel platforms were introduced to detect these cells that offer the promise of overcoming these limitations. We reviewed the current state of circulating tumor cell capture technologies and their clinical applications for genitourinary cancers. Conclusions: In genitourinary cancer circulating tumor cell enumeration has been useful for prognosis in patients with castration resistant prostate cancer. Soon characterizing individual circulating tumor cells in blood will serve as a noninvasive real-time liquid biopsy to monitor molecular changes in cancer, allowing clinicians to custom tailor treatment strategies. Circulating tumor cells will serve as a treatment response biomarker. Finally, circulating tumor cell detection promises to assist in the early detection of clinically localized cancers, facilitating curative therapy