The free-to-total PSA ratio compares the amount of unbound prostate-specific antigen to your total PSA level.
Total PSA: This measures all the PSA protein in your blood, whether it is attached to other proteins or floating free.
Free PSA: This measures only the PSA that floats freely without attaching to blood proteins.
The Difference: Benign prostate enlargement releases more free PSA. Prostate cancer releases less free PSA and more bound PSA.
The ratio when total PSA level falls into a borderline range between 4.0 and 10.0 ng/mL.
Above 25%: This is a higher ratio. It means your risk of prostate cancer is lower, and the high PSA is likely due to a benign issue.
Between 10% and 25%: This is a moderate ratio. Advised you to consider having a biopsy.
10% or Less: This is a low ratio. It means your risk of prostate cancer is higher, and a biopsy is often recommended.