The purpose of this study is to investigate the role of circulating tumor cells (CTCs) in patients with prostate cancer. Patients who have prostate cancer can develop metastases where the cancer spreads outside the prostate into other organs. It is believed that this occurs from tumor cells that circulate in the bloodstream.

This study aims to isolate these CTC cells and investigate their molecular and genetic makeup in order to better understand why certain therapies may be effective in advanced or metastatic prostate cancer.
   
In addition to looking at the molecular characteristics of these cells, this study is also investigating new ways to isolate these cells from the bloodstream. Currently, these cells can be isolated by a machine called CellSearch that captures prostate cancer cells by a technique that uses a magnetic technique (termed “immunomagnetic capture”).

Circulating tumor cells will be collected via blood draws at various time points throughout the study. These blood draws will take place at the same time as blood draws for participants regular labs as part of their standard of care.