[The early steps of the metastatic process]

Metastasis is the main cause of cancer-related death. While the development of clinically detectable metastases occurs only at late time points, recent data obtained in mice and humans indicate that cancer cell dissemination is an early event in the progression of several types of cancer. However, disseminated cancer cells can remain dormant for prolonged periods of time. Then, how do cancer cells acquire the ability to disseminate so early? What are the selective pressures driving their dissemination? What are the signals controlling dormancy and why do some cancer cells eventually escape these controls? The present review presents our current understanding on these questions and how this novel paradigm could be translated to the clinic.