The Shortcomings of PSA Density

Calculating PSA density can help your doctor analyze your prostate-specific antigen (PSA) score and determine whether or not your results are abnormal. PSA is produced by prostate cells—whether the cells are normal or cancerous. Men with larger prostates, logically, have more prostate cells and, in general, produce more PSA regardless of whether they have cancer or not. So your PSA score alone can't be used to determine whether or not you have prostate cancer.

To account for different prostate sizes, your prostate’s volume is measured via transrectal prostate ultrasound. Your PSA level is then divided by the size of your prostate to calculate your PSA density.

A high PSA density means that a relatively small volume of prostate tissue is making a lot of PSA, while a low PSA density means that a large volume of prostate tissue is making relatively little PSA.

In the past, physicians relied heavily on the absolute PSA level to help determine whether or not your prostate cancer had been eliminated as well as if returned after treatment, how extensive the disease was, and other factors.

However, it became apparent that just looking at the absolute PSA level failed in some important ways. For one, some men with normal or even low absolute PSA levels have been found to have prostate cancer. Second, many men with very high absolute PSA levels do not have prostate cancer and, have instead, a benign, less dangerous condition known as benign prostatic hyperplasia (BPH).

Your absolute PSA level will not always tell the whole story. That is why doctors began using other PSA values such as PSA velocity, PSA density, and percent-free PSA, to get a more accurate idea of what's happening in the prostate.

On one hand, a high PSA density could indicate you have a higher risk of prostate cancer. However, the evidence for this likely higher risk of prostate cancer does not really change your diagnosis or treatment if you have a high PSA density.

Not all experts agree that PSA density should change the way your physician diagnoses, monitors, or treats prostate cancer. Some doctors feel that PSA density is simply not helpful when making decisions and choose to ignore it.

If you're worried about your PSA density, discuss your concerns with your doctor or see a different doctor for a second opinion. If you're unsure about your doctor's views on PSA density or levels generally, ask them to share their understanding of the issue and if their views on the matter change how they treat their patients.

Overall, men with a higher PSA density should be more vigilantly monitored for prostate cancer. If you have a higher PSA density, your physician may be more suspicious about any abnormalities found on your digital rectal exam or if your PSA level increases.