THE PROGNOSTIC AND DETECTION FEATURES OF CIRCULATING TUMOR CELLS
The presence of circulating tumor cells (CTC) in solid tumors might be associated with stem cell-like tumor cells which have been suggested to be the active source of metastatic spread in primary tumors. Furthermore, to be able to disseminate and metastasize, CTC must be able to perform epithelial-mesenchymal transition. The prognostic significance of CTC counts is now well documented in multiple indications by the CellSearch assay, where CTC counts above a threshold define an unfavorable prognostic group. The ability to capture and study CTCs is an emerging field with implications for early detection, diagnosis, determining prognosis and monitoring of cancer, as well as for understanding the fundamental biology of the process of metastasis. The development of tumor-specific markers to select targeted therapies and to assess clinical outcome remains a significant area of modern science. In this review an association of baseline CTC number with clinical characteristics and survival in solid tumor patients has been evaluated.