🌸 Get a 10% discount, enter code: MIDSOMMAR10 at checkout 🇸🇪
PSF

Fraction of prostate-specific antigen

PSA free

Free PSA can be crucial in the investigation of prostate cancer. It represents the portion of PSA that is not bound to proteins in the blood. By measuring free PSA, doctors can be assisted in distinguishing between prostate cancer and other conditions. Read more about how free PSA is used in medical diagnostics to provide more accurate assessments and avoid unnecessary medical procedures.

What is Free PSA?

Free PSA generally refers to the fraction of prostate-specific antigen (PSA) circulating in the blood unbound to other proteins. Free PSA is utilized in the investigation of prostate cancer. PSA is a protein primarily produced by the prostate gland, and lower concentrations naturally occur in the blood. Elevated levels of PSA may indicate prostate cancer but can also result from benign prostate enlargement or prostate inflammation. Analysis of free PSA is employed to enhance specificity in prostate cancer diagnostics, particularly in borderline cases where total PSA is moderately elevated.

Analysis of Free PSA

In the blood analysis of free PSA, the amount of PSA in the blood that is not bound to other proteins is measured. The result from a free PSA test is then compared with total PSA to evaluate the proportion between them. This analysis helps reduce the number of unnecessary biopsies in men with elevated PSA levels by providing more specific information about the risk of prostate cancer.

Significance of Free PSA in Diagnosis

Free PSA is primarily used to distinguish between prostate cancer and other benign conditions such as prostate hyperplasia. A lower ratio of free PSA to total PSA is often associated with a higher risk of prostate cancer. This information can be crucial for urologists when deciding whether further diagnostic tests or a biopsy are necessary. Levels of free PSA can also be influenced by other factors such as age, family history, and the use of certain medications.

Use of Free PSA in Clinical Practice

In clinical practice, free PSA is often measured when PSA levels are in the so-called gray zone, usually between 4 and 10 ng/ml. A high proportion of free PSA may indicate a lower risk for prostate cancer, while a low proportion may suggest a higher risk. It is important to remember that no single test can provide complete certainty, and results from free PSA tests are recommended to always be used in conjunction with other diagnostic methods and the patient’s clinical history. This approach enhances diagnostic precision and reduces the likelihood of performing invasive procedures on patients with a low risk of prostate cancer, thereby contributing to more targeted and effective care for men being evaluated for this disease.

Normal Values for Free PSA

Normal values for free PSA can vary between different laboratories and depend on the methods of analysis used. Generally, a higher value of free PSA is considered better as it suggests a lower risk for prostate cancer. Typically, a free to total PSA ratio above 25% usually indicates a lower risk. It is important to be aware that there is no uniform "normal value" for free PSA as it must be assessed in relation to total PSA and individual factors. It is important to discuss your PSA results with a doctor who can help interpret them in the context of your overall health.

Free PSA is often used together with total PSA to increase the precision in prostate cancer diagnostics and to avoid unnecessary biopsies. This is especially important for those with moderately elevated PSA levels but no other signs of cancer. This can help identify those who need more thorough investigation and avoid unnecessary treatment for those at lower risk.