Free prostate-specific antigen (free PSA) is a form of PSA, a protein produced primarily by the epithelial cells of the prostate gland, that circulates in the bloodstream unbound to other proteins. PSA exists in two main forms in blood: free (unbound) and complexed (bound to protease inhibitors). Measuring the ratio of free to total PSA helps improve the specificity of prostate cancer screening, as lower free PSA percentages are more often associated with prostate cancer, whereas higher ratios tend to indicate benign prostate conditions such as benign prostatic hyperplasia (BPH).
In clinical and research settings, free PSA is used alongside total PSA to enhance the accuracy of prostate cancer detection and reduce unnecessary biopsies. The free-to-total PSA ratio helps distinguish between malignant and non-malignant prostate diseases, particularly in men with intermediate total PSA levels (typically 4-10 ng/mL). Additionally, free PSA measurement assists in monitoring prostate cancer progression and response to treatment. In research, studying free PSA contributes to understanding prostate cancer biology and improving diagnostic tools for early detection and risk stratification.
This product is manufactured in USA by Eagle Biosciences.