Prostate cancer occurs when the cells within the prostate gland start to multiply out of control. It is the second most common cancer in American men, after skin cancer.

When prostate cancer has not spread beyond the prostate, treatment may first involve surgery or radiation to remove the cancer. Initial treatment may also involve medication that aims to keep levels of the male sex hormones low. This is because prostate cancer growth is often driven by male sex hormones, including testosterone.

Metastatic castration sensitive prostate cancer occurs when the cancer spreads to other parts of the body, or if the cancer is first diagnosed when it has already spread. This type of prostate cancer is still responsive to hormone therapy.

If hormone therapy no longer stops or slows the cancer, the condition is known as metastatic castration resistant prostate cancer.