Recent improvement have been done in detection and characterization of blood circulating tumoral DNA (ctDNA). ctDNA reach regularly the blood stream after tumoral cell apoptosis or necrosis and could be extract and sequenced by some molecular biology technics such as real time PCR (rtPCR), digital PCR (dPCR) or next generation sequencing (NGS). Interesting, Several studies demonstrate that some genomic alterations of solid cancer can be characterized after sequencing of ctDNA. Other experiments pointed that ctDNA level could be linked to tumor stage and patient prognostic.