Asynchronous growth of prostate cancer is reflected by circulating tumor cells delivered from distinct, even small foci, harboring loss of heterozygosity of the PTEN gene.

The clinical value of prostate-specific antigen (PSA)-positive circulating tumor cells (CTCs) is still a matter of debate and it is also still unclear if these CTCs actually represent the primary tumor. Therefore, we isolated PSA-positive CTCs from the peripheral blood of patients suffering from multifocal cancers and did genetic profiling of each cancer focus by a multiplex PCR-based microsatellite analysis (D7S522, D8S522, NEFL, D10S541, D13S153, D16S400, D16S402, D16S422, and D17S855). In 17 of 20 prostate cancer cases, the loss of heterozygosity (LOH) pattern of the CTCs was identical with only one focus of the primary tumor.