Prostate cancer (PC) is the most common cancer in men, with about 8,800 deaths by year in France. The metastatic phase of the disease, leading to death remains poorly controlled using existing therapies. In this context, the aim of this project is to identify, at an early stage, the landscape of mutations or/and chromosome alterations that drives progression to a metastatic disease. To this aim, this pilot study is first based on the analysis of metastatic lymph node sample from prostate cancer patients. The whole genome and whole transcriptome sequencing planned for the DNA and RNA extracted from this metastatic tissue will allow characterizing the chromosome alterations present at the metastatic stage of PC, in comparison with the germline DNA from the same patient used as a reference. This project will also allow studying the multifocality and tumor heterogeneity of prostate cancer by comparing the whole genome DNA profile from three different foci from the tumoral prostatic tissue from the same PC case. Indeed, many studies have demonstrated that 60 to 90 % of prostate cancers are multifocal at diagnosis but, actually, the biological basis of this multifocality and histological heterogeneity attributed to prostate cancer has not been fully elucidated. We will also be able to compare the pattern of the chromosome alterations identified during this study with the ones found during the ICGC French prostate cancer program on aggressive cases, that is coordinated by our team.