[Metastatic potential: a generic characteristic of the primary tumor]

How do metastases arise from the primary tumor? To address this important question at both cognitive and clinical levels, the somatic genetic of cancers has proposed two models based on our knowledge of genes underlying tumor progression through the use of both patients' tumors and experimental models. The first model proposes the emergence of a subpopulation of rare and variant highly metastatic cells. The second model suggests the occurrence of a pre-malignant state of all the tumor cells which further metastasize without additional transitions in gene expression. Today, the science of functional genomic allows revisiting this debatted concern.