Prostate cancer represents the second most common cancer in men following lung cancer. Prostate cancer will be diagnosed in nearly 250,000 men annually and causes nearly 40,000 deaths each year. If you already have had prostate cancer treatment, changes in PSA levels can tell whether treatment is working.
After surgical removal of your prostate, your PSA levels should be undetectable. After radiation therapy, the PSA levels should drop and remain at low levels.
Signs that your cancer has returned may include one of these:
Three consecutive PSA rises above the lowest level over time
Confirmed rise of more than 2 ng/mL from your lowest level
The key is monitoring your PSA levels over time. A rapid rise suggests rapid cancer growth and the need for treatment. A very slow rise of the PSA can often be watched.
But PSA levels can also be somewhat confusing. For example, they can go up and down a bit for no reason. The PSA test is not precise, and minor changes from test to test are to be expected.
Low rises of PSA levels can’t predict your longevity or symptoms when you have cancer. But high or rapidly rising PSA levels can suggest future problems.
That’s why doctors take other factors into account when evaluating your situation. Talk with your doctor to get a better idea of what to expect, so the numbers don’t add to your anxiety.
Advanced Prostate Cancer and PSA Levels Over Time
If you have advanced prostate cancer that has spread outside the prostate, your doctor will be looking less at your actual PSA levels than at whether and how quickly PSA levels change.
Doctors use changes in PSA levels over time (called PSA velocity) to tell how extensive and aggressive your cancer is.
Your doctor won’t just look at one PSA reading at a time. He or she will confirm it with multiple tests over many months, especially after any radiation therapy. That’s because you can have a temporary bump in PSA levels for about one to two years after radiation treatment.
To determine how aggressive your cancer is and whether further treatment makes sense, your doctor may also consider your:
PSA levels before cancer
Grade of cancer or the Gleason score. The higher the Gleason score, the more aggressive the cancer.
Overall health and life expectancy
PSA Levels and Treatment for Advanced Prostate Cancer
Your symptoms and how long it takes for your PSA levels to double (PSA doubling time) affect decisions about how soon to try treatment such as hormone therapy.
Your doctor will look at how quickly or slowly PSA rises before deciding on which treatment to suggest. You may need continued monitoring before moving to a new treatment. Your doctor may suggest waiting for a while to delay the appearance of treatment-related side effects. Discuss with your doctor how to weigh these considerations.
PSA levels may also be useful in checking if your treatment for advanced prostate cancer is working after you have had:
Treatment should lower PSA levels, keep them from rising, or slow the rise, at least for a while.
Doctors monitor PSA regularly based on the type of treatment you had first. For example, after hormone therapy, PSA should drop to a lower level quickly, i.e., within weeks. It may fall further over time as you continue hormone therapy.
Combined with symptoms and other tests, PSA tests can also show if it’s time to try another type of treatment.
Bottom Line: PSA is an imprecise test for diagnosing and monitoring prostate cancer. If the PSA rises quickly after treatment, whether it is surgery, radiation, or hormone treatment, this is of concern and you may need to have additional treatment. Speak to your doctor if you have any questions.