Circulating Tumor Cells - a Promising Multifunctional Biomarker

Circulating tumor cells are most often released into the blood or lymph from the primary tumor. They are distributed by circulation to other tissues, where they can form metastases. In clinical practice, these cells have a high potential because their collection is non-invasive and, in addition, their early detection and molecular characterization allow the choice of appropriate therapy and continuous monitoring of the effectiveness of anticancer treatment. This paper describes the mechanisms of penetration of tumor cells into the circulation, the possibilities of their survival in the bloodstream and ways of settling in the new organ microenvironment. It also focuses on various ways of separating these cells from the sample and the possibility of their subsequent detection.