Prostate Marker Test (PSA, Free PSA & Ratio)

A blood test measuring total prostate-specific antigen (PSA) and free PSA, with calculation of the free-to-total ratio. PSA is a protein made by the prostate; raised total PSA can be associated with prostate conditions including cancer, but is not specific on its own. Adding free PSA and the ratio helps interpret a borderline total PSA — a lower proportion of free PSA is associated with higher prostate-cancer risk, which can help decide whether further investigation is needed. At Onkologie Bona Dea the test is used within the oncologist's individualised risk assessment, typically for men aged 45 and over.

The Prostate Marker Test measures prostate-specific antigen (PSA) in the blood in two forms — total PSA and free PSA — and calculates the ratio between them. PSA is a protein produced by the prostate gland; a small amount normally circulates in the blood, and the level tends to rise with prostate enlargement, inflammation and prostate cancer. Because a raised total PSA can have several benign causes, measuring it alone is not specific. Splitting it into free PSA (the unbound fraction) and bound PSA, and expressing free PSA as a percentage of the total, adds useful information: a lower proportion of free PSA is statistically associated with a higher likelihood of prostate cancer, which helps the oncologist interpret a borderline result and decide whether further investigation such as imaging or referral is warranted. The test requires only a standard venous blood sample and takes a few minutes to draw; there is no special preparation beyond avoiding activities that can transiently raise PSA before the test, which the clinic will advise on. At Onkologie Bona Dea the result is not read in isolation — it is incorporated into the oncologist's overall examination and individual risk assessment, alongside the clinical prostate examination, age and family history. It is most commonly used for men aged 45 and over, and forms part of the tumour-marker selection in the clinic's preventive screening. This targeted marker suits men who want a focused prostate-risk check, those with a family history of prostate cancer, and men following up a previous borderline reading. For those wanting the most refined stratification, the clinic also offers the Prostate Health Index (PHI), a more advanced calculation that adds the [-2]proPSA isoform. As with all the clinic's services this is a preventive screening tool interpreted by an oncologist rather than a stand-alone diagnosis; an abnormal result leads to a discussion of the appropriate next steps. The test is self-pay and conducted in Czech.