The story of prostate cancer screening for more than 30 years has centered on the prostate specific antigen or PSA test. In more recent years, scientists have become concerned that an elevated PSA test may have led to over-diagnosis and over-treatment of non-lethal cancers--with devastating side effects. New developments in PSA testing are an effort to fine-tune results and identify slow-growing cancers eligible for active surveillance.

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Prostate screening traditionally has focused on two methods: the digital rectal exam (DRE) and prostate specific antigen, or PSA testing. Researchers have always worked toward improving the accuracy and reliability of both modalities. Along the way, PSA test options have been surfacing.

New methods seek to clarify diagnoses in men whose PSA is considered “borderline”—i.e., a range of between 4 nanograms per milliliter (ng/ml) and 10 ng/ml. The idea is to have these “fine-tuned” PSA tests help identify encapsulated, slow-growing cancers that may be eligible for a so-called “watchful waiting” treatment plan.

This does not mean that you and your doctor are ignoring any symptoms of prostate cancer you may be manifesting. If you receive a prostate cancer diagnosis, “active surveillance” will mean periodic checks using the following PSA test variations, and may also include biopsy.

• PCA3: This is a genetic urine test that provides a PCA3 score. Men with a higher PCA3 score are more likely to have prostate cancer cells detected on biopsy than men with a low PCA3 score. The U.S. Food and Drug Administration (FDA) has approved this test for men 50 or older who have had one negative prostate biopsy and for whom a repeat biopsy is recommended based on current standard of care.

• PSA velocity: This test determines the rate at which your PSA changes over time and is reported as ng/ml per year.

• PSA doubling time: This is the amount of time elapsed while your PSA level doubles.

Variations on the traditional prostate specific antigen (PSA) test are improving diagnoses and limiting unnecessarily aggressive treatments that can have devastating side effects.

• Free vs. total PSA: PSA in the blood can be circulating independently (“free”) or attached to other proteins. Men with a high total PSA but low free PSA are more likely to have prostate cancer.

• PSA density: This test divides the PSA level by the volume of the part of the prostate gland that surrounds the urethra. There is some evidence that this value can be useful in detecting prostate cancer.

• Pro-PSA: Having a form of free PSA called pro-PSA has been linked to an increased risk of aggressive prostate cancer.

For further reading on related topics, see the following University Health News posts:

• “Are You Keeping Tabs on Your PSA Levels?“
• “An Abnormal PSA Result: What Comes Next?“
• “Prostate Cancer Stages“
• “Prostate Cancer Symptoms? PSA Test Is Only Part of the Story“

Originally published in May 2016 and updated.