Later, cells can break away from the main cancer and get into the lymphatic system or bloodstream. They can then travel to other areas of the body and start growing there. These cancers are called secondary cancers or metastases.

If prostate cancer spreads, it is usually to the bones. It may also spread to the liver, lungs or brain, but this is very uncommon. If prostate cancer spreads to the bones it can cause pain there. Back pain is quite a common sign of advanced prostate cancer, but remember that back pain is a common problem and it can have many other causes.