Using the "free" PSA test (PSA-f) to help see
if you need to undergo biopsy for prostate cancer

The PSA-f blood test measures the percentage of free PSA (PSA-f) compared to bound PSA (PSA-ACT) out of the total PSA circulating in your blood. PSA-f circulates in the blood "unbound," without a carrier protein.

The "free" PSA test can help your urologist decide whether an elevated or rising PSA is caused by benign prostate growth (BPH), which is a common condition, or is caused by prostate cancer.

Patients with free PSA (PSA-f) over 25% usually have benign prostate hyperplasia.

Most patients with prostate cancer have a free PSA below 15%.

If your free PSA is below 7% the likelihood of prostrate cancer is high. You should undergo biopsy.

If biopsy is negative but free PSA remains low, you will need repeat biopsy.

You might might also want to look into color doppler ultrasound from an "artist."

Another factor your doctor should consider is the rate (velocity) of any PSA rise.

One PSA test result is not enough, usually, to point you towards a biopsy. According to a study published in JAMA (May 28, 2003), "An isolated elevation in PSA level should be confirmed several weeks later before proceeding with further testing, including prostate biopsy."

Prostate cancer detection flow chart showing use of precent "free" PSA test score Do you have an elevated PSA and ...     Signs of prostate inflammation such as urinary frequency, urgency, burning? YES Treat with antibiotics and repeat PSA before deciding if biopsy is necessary. Is the digital rectal exam (DRE) normal?   NO YES     Biopsy How high is the PSA? PSA 10 Biopsy   PSA 2.5 to 10 Biopsy or free-PSA test % free PSA is low % free PSA is high PSA under 2.5 but more than .75 ng/ml higher than last year's Biopsy   Biopsy         Repeat tests in a year

last updated December 22, 2005

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