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Blood Test for Prostate Cancer – Risks and Benefits

Overview of Prostate Cancer

PSA test is a cancer blood test used primarily for the screening of prostate cancer. It measures the amount of protein generated by the prostate’s non-cancerous and cancerous tissues; this is usually referred to as a prostate-specific antigen. PSA is typically found in male semen, but is also detectable via a blood test.

The PSA test is able to detect higher PSA levels easily. In other words, high levels of PSA in the blood indicates the traces of prostate cancer in the body; to know more, visit blood tests London Clinic for more information on prostate cancer.

Why is a PSA test carried out?

Prostate cancer is becoming a major health concern among men in the UK, with more than 40,000 new prostate cancer cases which are diagnosed annually. Whilst some prostate cancer may require minimal or no intervention, some prostate cancer may result in death, if prompt and adequate action is not taken. This is why early detection is an important tool in getting appropriate and timely treatment.

The PSA test can be carried out for the following reasons:

  1. For detecting increased PSA levels in the blood
  2. The PSA test is easily used to screen for early signs of prostate cancer.
  3. To judge the effectiveness of a treatment
  4. Detect for recurring cancer

The test is not needed when:

  1. there is an enlarged prostate gland
  2. When you have a prostate infection
  3. Strenuous activity
  4. Recent sexual activity


Recommendations regarding who should, and who shouldn’t get a PSA screening test may vary within organisations. A discussion with your doctor is often advised on the possible risks, limitations and of the test, to help you make an informed decision.

Possible Benefits of the test

  1. The PSA test helps to detect early-stage prostate cancer easily.
  2. You may feel more reassured if the test result is normal
  3. Since it helps to detect early signs of prostate cancer, your cancer can be diagnosed and treated earlier to avoid any form of complications arising from late diagnosis.
  4. If further tests depict that you have early faster-growing prostate cancer, treatment can help you live longer, or help you cure it completely.

Possible limitations of the test

The limitations of the test include:

  1. Misleading results: sometimes, the test does not provide an accurate result. This is because a high PSA level doesn’t necessarily indicate the presence of this cancer in the blood. A lot of men that have been diagnosed with prostate cancer in the past have a normal PSA level.
  2. PSA-raising factors: asides from prostate cancer, several factors can increase the PSA levels; this may include: enlarged prostate and inflamed or infected prostate. Sometimes, an increase in a patient’s age can also increase the PSA levels.
  3. PSA-lowering factors: medications and drugs for some certain illness are known to lower the PSA levels. Examples of such drugs include drugs for treating urinary conditions.
  4. Over diagnosis: research suggests that about 23-42% of men with prostate cancer detected, using PSA tests have tumours that rarely result in any symptoms during their lifetime. These symptom-free tumours can easily result inoverdiagnosis.

What to expect?

During an appointment with your doctor, your doctor will insert a needle into your vein to draw out some blood sample.  This blood sample is then analysed in the lab, to test for prostate cancer; to know more, visit our website for information on prostate cancer.


After your blood sample is taken, your doctor will use a different method to interpret the results before deciding on a biopsy to examine cancerous tissue. These other methods will help to improve the accuracy of the PSA test as a screening tool. Varieties of studies have been carried out to investigate the PSA test variations to determine if they provide a measurable benefit.

Some of the variations of the PSA test may include:

  • PSA velocity: PSA velocity involves the change in PSA levels over time. Increases in PSA levels indicate the presence of cancer while the reverse is the case for low PSA velocity. Some studies have shown inefficiencies in its value to predict the trace of the prostate cancer in the body
  • PSA density: prostate cancers are known to produce more PSA per volume of tissue when compared to benign prostate conditions. To effectively measure the PSA density, it is advised that you use an MRI or transrectal ultrasound.

When to talk to your doctor

Before getting a PSA test, it is important to talk to your doctor regarding the benefits and risk of carrying out a PSA test. This will help you make appropriate decisions afterwards.

To know more, contact our blood tests in London Clinic on information regarding prostate cancer.