PSA Test (Prostate spesific antigen)

Prostate spesific antigen (PSA) is a kind of protein that is produced from prostate cells. Cancerous and noncancerous cells both produce PSA. PSA test is a laboratory test that measures the level of prostate spesific antigen in your blood. Prostate is a kind of gland that is found below men’s bladder. PSA test is a tumor indicator, in normal conditions. PSA is found in certain limits in blood but its level increases in some conditions; especially in prostate cancer.

Purpose of  PSA test

Prostate cancer is a commonly seen cancer type in men and in second place in cancer death causes after lung cancer. Today, mortality rate decreases in early diagnosis of prostate cancer  and treatment becomes easier. Especially in older ages PSA test is useful for the diagnosis.

Abnormal PSA levels

PSA level increases in some different conditions other than prostate cancer;

    • Prostate Enlargement (benign prostate hypertrophy): Prostate is a gland that surrounds urethra, in prostate enlargement prostate cells multiply,prostate gland gets larger,it compresses to your urethra and limits the urine flow. Patient usually has urination problems.
    • Prostatitis ( Prostate gland infection): Infections in prostate gland cause high level PSA too. It doesn’t increase the cancer risk. It can be seen at any age. As you see all increased PSA level doesn’t mean that you have prostate cancer, the exact diagnosis can be done with other physical examinations and screening tests. Only PSA test is not enough to diagnose the prostate cancer.
  • Urinary tract infections
  • Medical Procedures: Medical procedures like taking a biopsy or cystoscopy ( checking the bladder with a tube camera)
  • Older age: High age may cause high PSA level too
  • Sexual Intercourse: Ejaculation may affect PSA level, ask your doctor if you must avoid ejaculation for a few days before the PSA test
  • Bike Riding: If you ride bike for long hours in a day this may affect your PSA level.
  • Catheter usage in bladder to drain urine

Prostate cancer diagnosis

  • Your doctor first will listen all your complaints.psa test
  • If your complaints are related with prostate cancer doctor requests PSA test.
  • Your doctor makes a physical examination to your prostate gland.
  • A biopsy may be necessary according to the PSA test result and pyhsical examination.
  • Prostate biopsy result is needed to diagnose the cancer finally.

How the PSA test is done?

A single tube of blood will be colected from your arm vein. 8-10 hours of fasting is necessary before the blood collection.

PSA test normal values

Values under 4 ng/mL (nanograms per mililiter of blood) are normal for PSA test. In some  non-cancer cases higher values than 4 ng/mL are found or lower values than 4 ng/mL are found in cancer patients. For this reason PSA test is preferred for monitoring the treatment rather than diagnosis.

PSA test for post-treatment monitoring

Decreasing of  PSA level is associated with the success of surgical or medical treatment.PSA is produced by prostate gland so if prostate gland is removed completely with surgery, no PSA must be found in blood test. If  all of the prostate gland couldn’t  be removed  by surgical operation PSA level can’t be found zero.

PSA Test: screening test or monitoring for treatment?

Today PSA test is accepted as a monitoring test for post-treatment period like other tumor markers rather than a screening test for diagnosis.


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