If you're a man over age 55, you may have already had a PSA, or prostate-specific antigen test. This test screens for prostate cancer by measuring the amount of a protein in your bloodstream released by cells in your prostate gland.
This test isn't just for screening, though. You'll also have it after a prostatectomy -- surgery to take out all or part of your prostate. This will tell you how well the treatment worked and whether your cancer has come back.
You'll need this test every few months after your operation. But getting tested for cancer many times can cause a lot of anxiety. And because the results aren't always clear, you may worry about them.
A little knowledge can help calm your fears. Before you have this test, find out what to expect. Ask your doctor what your results might mean and what will happen if your PSA level is higher than it should be.
Why You Have the Test
The goal of a prostatectomy is to remove all the cancer, or as much of it as possible. If your cancer hasn't spread, it might cure you.
But no surgery is perfect. It's possible that some of the cancer cells spread outside your prostate before your procedure. Or the operation might have left a few cancer cells behind. Those cells could start to grow in the future.
A regular PSA test after a prostatectomy is a way for your doctor to keep tabs on your treatment. It can help your doctor see how well your surgery worked, and if your cancer has come back.
When to Get Tested
You'll have your first follow-up PSA test 1 to 3 months after your surgery. You need to wait because some PSA stays in your blood after your prostate is removed. If you wait until it has cleared, that will make an accurate result more likely.
Then you'll have repeat PSA tests once every 6 to 12 months for about 5 years. If your doctor says chances are high that your cancer will come back, you may need them once every 3 months. If your PSA levels stay normal, you can switch to once-a-year PSA tests. Ask your doctor how often you'll need a test.
What Your PSA Numbers Mean
The PSA test measures the level of prostate-specific antigen in your blood. The lab will report your results in nanograms of PSA per milliliter (ng/mL) of blood.
Only the prostate gland releases PSA, so your numbers should drop to almost zero within 4 weeks after your surgery. A test result above 0.2 ng/mL a few months after your procedure could be a sign that your prostate cancer has come back. This is called a biochemical recurrence.
If your number is higher than it should be, it doesn't mean you definitely have cancer. Results can vary from person to person and from lab to lab. A more accurate way to find out if you have cancer is to test how quickly your PSA levels rise.
A PSA velocity test measures the change in your PSA levels over time. PSA doubling time tests calculate how long it takes for your PSA levels to double. If they rise quickly, it could be a sign of cancer. Knowing how fast yours is rising can help your doctor predict whether your cancer will spread, and if -- or when -- you'll need treatment.
What to Do Next
Learning that your PSA level is higher than it should be can be very stressful. Talk to your doctor about what your results mean and your next steps. You may need more treatment, or you might be able to wait and have regular PSA tests to watch your cancer.
It's important to remember that your PSA test doesn't tell the whole story. Levels can go up and down, and they're different for each person. Even if you do still have cancer or your cancer has come back, it may not spread for a long time.
If your cancer does come back, treatment options include radiation in the area where your prostate used to be, and hormone therapy. Having these treatments can reduce the risk that your cancer will grow and spread.