If you are a white male over the age of 50 or a black male over the age of 40, chances are your doctor has talked with you about a PSA blood test.

What Is Your Prostate Gland?

Your prostate is a gland that stores and secretes a slightly alkaline fluid that is milky or white in appearance.  This fluid usually constitutes 25-30% of the volume of you semen along, with spermatozoa and seminal vesicle fluid.  It's about the size of a walnut and sort of straddles your urethra.

Why Have A PSA Blood Test?

The purpose of a PSA blood test is to determine whether or not you might have prostate cancer.  A PSA blood test measures your prostate-specific antigen (PSA), a protein produced by the cells of your prostate gland.  Protein Specific Antigen (PSA) is produced by both cancerous and noncancerous (benign) prostate tissue.  A small amount of this antigen normally enters your blood stream.  However, cancer cells usually make more PSA than do benign cells, which causes the PSA levels in your blood to rise.

As you might imagine, detecting prostate cancer in its early stages can be critical.  A high PSA could reveal prostate cancer that, if left untreated, is likely to spread to other parts of your body (metastasize).  Or it could reveal a quick-growing cancer that can cause other problems.  In either event, identifying prostate cancer early on reduces your risk of side effects such as erectile dysfunction or incontinence.

How Is The PSA Blood Test Done

You doctor will take a sample of your blood, either from inside your elbow or the back of your hand and then send it to a laboratory for analysis.  The procedure is quick and almost painless.  However, there are always some risks associated with drawing blood.  These include excessive bleeding, fainting or feeling light-headed, hematoma (blood accumulating under your skin) and infection.  There is always a slight risk any time your skin is broken but, it is very unlikely that this blood test will cause you to have any problems.

What A PSA Blood test Can Tell You

Most men have a PSA level that’s under 4 ((ng/ml) and, traditionally, this has been viewed as a sort of cutoff point for the possibility of prostate cancer, though the cancer is a possibility at any PSA level.  There are published reports that men who have a prostate gland that feels normal in a digital rectal examination (DRE) and a PSA lower than 4, have about a 15% chance of having prostate cancer.  However, if you have a PSA between 4 and l0, you have a 25% chance of having prostate cancer and if your PSA is above l0, the risk of prostate cancer increases to 67%.

Most doctors today will look not just at your PSA level but whether it’s changing quickly, either up or down and over what period of time – as a better indicator of prostate cancer.

However, if you are tested and your PSA level is 4 or higher, you might have either prostate cancer or some other condition such as prostatitis or benign prostatatic hyperplasia (BPH).

What Else Will Your Doctor Consider?

In addition to your PSA number, your doctor will use these factors in evaluating your PSA score:

  • You age
  • The size of your prostate
  • When you last ejaculated (you should not have ejaculated for two days before the test)
  • How quickly your PSA levels are changing – either up or down
  • Whether you taking other medications that can affect your PSA measurement such as Propecia, Proscar or Avodart.

PSA Screening

After your first PSA blood test, your doctor may start you on PSA screening.  He or she will most likely recommend that you be retested periodically - for example, every four years.  On the other hand, you or your doctor may suggest a shorter interval such as every other year.

It can be reassuring to learn you have a normal PSA level and a good DRE (digital rectal examination) as this makes it unlikely that you do have prostate cancer.  But it is not necessary for some men to get screened for prostate cancer – especially men 75 and older.

The Problems With PSA Tests

There are two problems with PSA blood tests.  First, the test alone does not provide doctors with enough information to distinguish between a benign (non-cancerous) prostate problem and prostate cancer.  The second problem with PSA tests is that they may not be a reliable indicator of prostate cancer.  There have been many cases where the test returned a false positive, meaning that, despite a high PSA, there was no prostate cancer.  As a result, there have been many men who were unnecessarily treated for this disease.  Conversely, there have been cases of false negatives – where men with low PSA scores did, in fact, have prostate cancer that went undetected.

A Digital Rectal Exam (DRE)

Since PSA tests are not always reliable, many doctors will also perform a digital rectal exam or DRE.  This is a standard examination where the doctor feels your prostate from the rectum, checking for things such as size, lumps and firmness.  Some doctors believe that this examination is a more reliable way to spot prostate cancer than the PSA screening.

Other Tests For Prostate Problems

If your PSA level has been increasing or your doctor finds a suspicious lump during your DRE, he or she may suggest some other tests to determine if you may have cancer or some other problem.  This could be a urine test to see if you have a UTI (urinary tract infection) or blood in your urine.  It could also be a transrectal ultrasound, x-rays or a cystoscopy, a procedure where your doctor looks into your urethra and bladder using a thin, lighted tube.

Prostatitis And Benign Prostate Hyperplasia

A PSA level above 4 may indicate not that you have prostate cancer but that you have prostatitis, benign prostatic hypertrophy (BPH), a prostate infection or a urinary tract infection (UTI).

Prostatitis is an infection of the prostate and BPH is an enlargement that happens to many men, as they grow older.  Prostatitis is relatively easy to cure – usually with an anti-inflammatory medicine or antibiotics in the case of infectious prostatitis.  BPH cannot be prevented but there are now a number of treatments available to help alleviate the problem.

The symptoms of prostatitis and BPH are about the same – trouble starting to urinate; having to urinate frequently, especially at night; a feeling that your bladder is not empty after urinating; sudden urges to urinate; having your urine stop and start repeatedly; and having to strain to urinate.

PSA blood tests alone may or may not be a reliable indicator of prostate cancer.  But regular PSA screening, along with a digital rectal exam, gives you a good chance to catching prostate cancer early on when it can be more easily treated.

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