Current challenges in metastasis: disseminated and circulating tumor cells detection.

Metastatic dissemination of the primary tumor is responsible for the majority of cancer-related morbidity and mortality. Detection of disseminated tumor cells in the bone marrow and circulating tumor cells in the peripheral blood is associated with early metastatic recurrence in cancer. Circulating tumor cells (CTCs) shed from the site of disease in metastatic or primary tumor that can be recognized and enriched in the peripheral blood of cancer patients. The detection of rare circulating tumor cells (CTC) is an objective of numerous oncologists' researches. Circulating tumor cells have the potential to help to detect cancer recurrence at its earlier stage, determine therapy resistance before full blown progression, distinguish molecular changes during treatment, monitor efficacy therapy during treatment, guide therapy choice, and predict clinical outcome. In future perspective, standardization of the different enrichment methods in clinical trial is integrated. Developments in CTC detection methods will improve a wide range of clinical applications, as well as the discovery of biomarkers to predict treatment responses and disease progression. In order to identifying, several techniques have been applied to detect and isolate CTC in a heterogeneous population for management and monitoring response to therapy in clinical course in patients with localized or metastatic disease.