Prostate cancer is estimated to have been the most commonly diagnosed cancer for men in 2010. If the cancer goes undetected for long enough, it may begin to spread from the prostate gland to other areas of the body, a process known as metastasis. Once metastasis occurs, the prostate cancer has reached stage IV. This is the most severe diagnosis possible and generally offers a less than ideal prognosis.  At stage IV, treatment options often have to be combined in a joint effort to try and rid the body of metastasized prostate cancer.

According to the American Joint Committee on Cancer, metastasis is caused by the process known as angiogenesis. As new blood vessels are created, cancerous cells break away from the original tumor and use the blood vessels to travel throughout the body. More often than not, those cells find homes in the lymph nodes or bones. Once well enough entrenched in the new location, the cancerous cells begin to grow and divide. These new cancers stemming from the original one are sometimes referred to as secondary cancers.