What is the PSA test and why is it performed to screen for prostate cancer?

The prostate-specific antigen (PSA) test is one of the most important laboratory tests used in men's health to detect potential signs of prostate cancer at an early stage. The prostate is a walnut-sized gland located directly below the bladder, responsible for producing the fluid that makes up part of semen. The primary goal of the PSA test is to screen men who do not have any obvious symptoms of cancer, in the hope of detecting any abnormalities early, as cancer treatment may be more effective and easier in the initial stages before it begins to spread to other areas of the body [1].

What is the role of the PSA test in early screening?

The PSA test measures the amount of a specific protein produced by the prostate in a patient's blood sample. It is essential to understand that having elevated levels of this protein in the blood does not necessarily mean the presence of cancer. The prostate may produce higher amounts of this protein due to many non-cancerous reasons, such as benign prostatic hyperplasia (BPH), which becomes more common as men age, or due to inflammation or infection of the prostate [2]. Therefore, the PSA test is not considered a definitive diagnostic tool; rather, it is an indicator that requires further examination to accurately assess the condition [1].

When and why is the screening performed?

There is no universal approach to prostate cancer screening for everyone. Instead, the decision should be based on a shared dialogue between the patient and the treating physician. When making this decision, a set of personal factors that increase the level of risk are evaluated, the most important of which is age; the risk of infection increases significantly after the age of fifty. Family medical history is also taken into account, as the probability of developing the disease increases if first-degree relatives have been affected, in addition to ethnic factors, as data indicates that men of African descent may be more susceptible to infection at a younger age and with more aggressive forms of the disease [1], [2]. You can read more details about the timing of the screening in our article on prostate cancer screening, its timing, and PSA results (Arabic).

Risks associated with screening and diagnosis

It is necessary for the patient to be aware that the screening may carry potential risks. One of these risks is obtaining a false-positive result, which may cause undue anxiety and prompt the patient to undergo additional diagnostic procedures such as a prostate biopsy. The biopsy, which is the only procedure capable of confirming the presence of cancer, carries its own risks, including pain, fever, urinary tract infections, and the appearance of blood in the urine or semen [1], [2]. Physicians also face the challenge of over-diagnosis, where slow-growing cancers that would not cause any harm throughout the patient's life may be discovered, yet subsequent treatment may lead to permanent side effects such as erectile dysfunction or urinary incontinence [2]. Therefore, balancing the benefits of early detection with the risks of unnecessary treatment is the cornerstone of making the appropriate health decision.

Medical references

• Prostate Cancer Screening
• Prostate Cancer Screening (PDQ®)–Patient Version