When prostate cancer spreads to other parts of your body, doctors say it is "metastatic" or that it has "metastasized." Metastasis is the medical term for cancer that has spread beyond the place where it started.
Most often, prostate cancer spreads to the bones. It's also common for it to spread to the liver or lungs. It's rarer for it to spread to other organs, such as the brain.
It's still prostate cancer, even when it spreads. For example, metastatic prostate cancer in a bone in your hip is not bone cancer. It has the same prostate cancer cells the original tumor had, and your treatment options are the same as when cancer was only in your prostate gland.
Metastatic prostate cancer is an advanced form of cancer. Although it can't be cured, it can be treated and controlled.
Most men with advanced prostate cancer live a normal life for many years.
The goals of treatment are to:
- Manage symptoms
- Slow the rate your cancer grows
- Shrink the tumor
Some cancers are called "locally advanced." That means the cancer has spread from the prostate to nearby tissue. This is not metastatic cancer, which is cancer that has spread to other parts of the body. Many locally advanced prostate cancers are curable.
How Prostate Cancer Spreads
Metastasis happens when cancer cells break away from the original tumor and move to a blood or lymph vessel. Once there, they circulate through the body. The cells stop in capillaries -- tiny blood vessels -- at some distant location.
The cells then break through the wall of the blood vessel and attach to whatever tissue they find. They multiply and grow new blood vessels to bring nutrients to the new tumor. Prostate cancer prefers to grow in specific areas, such as lymph nodes or in the ribs, pelvic bones, and spine.
Most cancer cells that break away form new tumors. Many others don't survive in the bloodstream. Some die at the site of the new tissue. Others may lie inactive for years or never become active.
Chances of Developing Metastatic Prostate Cancer
About 50% of men diagnosed with local prostate cancer will develop metastatic cancer during their lifetime. Finding cancer early and treating it can lower that rate.
A small percentage of men aren't diagnosed with prostate cancer until it has become metastatic. Doctors can tell it's metastatic cancer by taking a small sample of the tissue and studying the cells.
How Doctors Find Metastatic Prostate Cancer
When you are diagnosed with prostate cancer, your doctor will order tests such as:
- CT scans
- MRI scans
These tests may focus on your skeleton and in your belly and pelvic areas. That way doctors can check for signs of the cancer's spread.
If you have symptoms such as bone pain and bone breaks for no reason, your doctor may order a bone scan. It can show if you have metastatic cancer in your bones.
Your doctor will also ask for blood tests, including a check of PSA levels, to look for other signs of the cancer's progression.
PSA is a protein made by the prostate gland. A rise in PSA is one of the first signs of the progression of prostate cancer. PSA levels can be high without there being cancer, such as if you have an enlarged prostate or a prostate infection.
But if you've been treated, especially if you’ve had your prostate surgically removed, your PSA levels should become undetectable. The presence of any PSA after surgery is a concern. Any rise in PSA after radiation or hormone treatment suggests the possibility of the cancer spreading. In that case, the doctor will order the same tests used to diagnose the original cancer, including a CT scan, MRI, or bone scan.
Though very rare, it's possible to have metastatic prostate cancer without a higher than normal PSA level. On average, 8 years pass from the time a man is first diagnosed with prostate cancer to the discovery that it has become metastatic. If you have had prostate cancer, work with your doctor to check your risk and set a schedule for routine PSA checks.