Results of PSA tests are reported as nanograms of PSA per milliliter of blood (ng/mL). There's no specific cutoff point between a normal and abnormal PSA level. Your doctor might recommend a prostate biopsy based on results of your PSA test and digital rectal exam, along with other factors.

Variations of the PSA test

Your doctor may use other ways of interpreting PSA results before making decisions about ordering a biopsy to test for cancerous tissue. These other methods are intended to improve the accuracy of the PSA test as a screening tool.

Researchers continue to investigate variations of the PSA test to determine whether they provide a measurable benefit. Variations of the PSA test include:

  • PSA velocity. PSA velocity is the change in PSA levels over time. A rapid rise in PSA may indicate the presence of cancer or an aggressive form of cancer.
  • Percentage of free PSA. PSA circulates in the blood in two forms — either attached to certain blood proteins or unattached (free). If you have a high PSA level but a low percentage of free PSA, it may be more likely that you have prostate cancer. This test is primarily used for men with a PSA level in the borderline range between 4 and 10. It is especially useful when determining the need for re-biopsy rather than in an initial screening state.

Talk to your doctor

Before getting a PSA test, talk to your doctor about the benefits and risks. If you decide that a PSA test is right for you, ask your doctor:

  • When you will discuss the results
  • What kinds of recommendations he or she might make if the results are positive
  • How often you should repeat the test if the results are negative

Discussing these issues beforehand may make it easier for you to learn the results of your test and make appropriate decisions afterward.

May. 07, 2013