What is PSA? Should I see a Urologist? Do I need a prostate biopsy?
PSA, or Prostate Specific Antigen, is a protein made by the prostate. A PSA test is a blood test that simply measures the level of PSA protein in the blood.
PSA levels rise for many reasons
- Prostate size
- Prostate infection or inflammation (prostatitis)
- Sometimes ejaculation
- Bike riding
- Viral illnesses (significant cold and flu with fever and body aches)
- Recent prostate examination
- Recent catheter placement
- Prostate cancer
It has been found that the higher the PSA level, the higher the risk of cancer. There is no level so low that means you do not have prostate cancer, and no level so high that means you certainly have cancer. It is a bit like saying “the more you weigh, the more likely you are obese” and then asking what number of pounds means you have a problem. PSA, like your bathroom scale, is a very good test to monitor your health, but the number alone does not tell the whole story.
The PSA level is an excellent indicator for who needs an evaluation by an urologist. Unfortunately, too many urologists are too quick to recommend a biopsy on any man with an elevated PSA, and then too quick to recommend aggressive treatment for any prostate cancer that is found. Both approaches, I believe, are incorrect. Please refer to my lecture on Active Surveillance of Low Risk Prostate Cancer for more details on this subject.
You should see an urologist if your PSA is over 4.0 or if the PSA is increasing. A rising PSA is usually defined as increasing more than 0.75 in a year. It is important to then see an urologist who will consider many factors before recommending a biopsy vs. monitoring of the PSA over time. It is unusual to recommend a biopsy after a single high PSA reading. PSA should usually be repeated to be sure that the level is truly high. Percent free PSA can also be helpful. Percent free PSA less than 10% indicates high risk of cancer and biopsy should be considered. Percent free PSA greater than 25% indicates low risk of cancer and biopsy can often be avoided. Also, men with very large prostates and mild to moderately high PSA tests are less likely to have cancer. On the other hand, a family history of prostate cancer, any sign that the PSA is consistently rising, or a prostate that is asymmetrical or has any firm areas or nodules should make the urologist and the prostate owner more strongly consider a prostate biopsy.
Matthew Greenberger, MD