Free PSA measures the amount of unbound prostate-specific antigen circulating in the blood. It is used alongside total PSA to help distinguish prostate cancer from benign prostate conditions.
Category: Tumor Markers
Also known as: fpsa, free psa abs, free psa value, psa free value
Reference range: 0–0 ng/mL (Source: ABIM)
Standard unit: ng/mL
High values may indicate
A higher proportion of free PSA relative to total PSA is generally associated with benign prostatic hyperplasia rather than cancer.
Low values may indicate
A lower proportion of free PSA relative to total PSA may indicate a higher risk of prostate cancer, prompting further evaluation such as a biopsy.