Free PSA percentage is the ratio of free (unbound) PSA to total PSA in the blood. It helps distinguish between prostate cancer and benign prostate conditions when total PSA is mildly elevated.
A high free PSA percentage (above 25%) suggests the PSA elevation is more likely due to benign prostatic hyperplasia (BPH) rather than cancer.
Low values may indicate
A low free PSA percentage (below 10%) suggests a higher probability of prostate cancer, and further evaluation such as a prostate biopsy may be recommended.