PSA screening involves having a PSA blood test done on a regular basis to check for signs of prostate cancer. A PSA blood test is usually done about once a year along with a prostate exam or digital rectal examination (DRE). If there is reason to believe you may be at a higher risk for prostate cancer, your doctor may believe PSA screening on a more frequent basis is warranted.
A PSA blood test is very simple. Your doctor or a phlebotomist (one who is trained to draw blood) will draw some blood, probably from either the inside of your elbow or the back of your hand. This blood sample will be sent to a laboratory which will analyze it and report the level of PSA in your blood. Since PSA is produced by your body (prostate gland) and used to detect disease, it is sometimes called a biological or tumor marker. Your doctor should receive the results of your PSA blood test in just a day or two.
What is PSA?
PSA stands for protein specific antigen, a substance produced by your prostate gland. If you have a perfectly healthy prostate, some of this protein will get into your blood stream and you will have a PSA level – even if it’s as low as 0.50.
Prostate cancer tissue and certain kinds of benign (non-cancerous) tissue can cause the prostate to generate more PSA proteins, which will cause a higher or elevated PSA level.
What Is A Normal PSA Level?
Having a low PSA level is no guarantee you do not have cancer. Men with a low PSA have been found to have prostate cancer and men with a high PSA have been found to be cancer free. However, most doctors use a PSA of 4 (ng/mL) as the cutoff for concern about the risk. In other words, if your PSA level is less than 4, your doctor will probably not recommend any other tests.
If your PSA level is between 4 and 10, there is an increased chance you have prostate cancer. In fact, studies have shown that with this PSA level comes a 25% chance that you have prostate cancer. If you have a PSA level above 10, the risk that you have prostate cancer increases to 67%.
As you can see from these statistics, you can have a high PSA reading, but not have prostate cancer.
Limitations Of PSA Screening
There are two problems with PSA screening. The first problem is a PSA blood test is a not definitive indication of whether you have prostate cancer.. You can have a high PSA and no prostate cancer or a low PSA and prostate cancer. Second, PSA screening cannot tell the difference between a high PSA level produced by prostate cancer and one produced by a non-cancerous condition such as prostatitis or benign prostatic hyperplasia. Even if you have a PSA level as high as 10 or 12, there is still a reasonable chance you do not have prostate cancer, as BPH or an enlarged prostate is a normal part of aging.
The Trend Of Your PSA Screenings
Just as important as your level for your last PSA screening is the trend - whether it’s going up or down and how quickly. In fact, many doctors now believe this can be a more reliable way to diagnose prostate cancer than just your level for one PSA screening. For example, if your PSA level has gone from 1 to 4 in a year or less, this may signify the presence of prostate cancer, despite the fact that your PSA level is still at the normal “cut off point”.
A High PSA Level
If your PSA screening shows you have a PSA higher than 4, your doctor will most likely order further tests. This could be a urinalysis – to see if it’s a urinary tract infection – x-rays, a transrectal ultrasound or a procedure called a cystoscopy. If your PSA is higher than 10, the odds are your doctor will order a biopsy which is the only guaranteed way to tell if you have prostate cancer.
How Often Should PSA Screening Be Done?
Most doctors will start PSA screening white males once a year, beginning at age 50 and African-American men at age 40. If there is a family history of prostate cancer, or if you have a high-fat diet or are obese, you might also start annual PSA screening at age 40. This is because these factors put you at a higher risk of developing prostate cancer.
When you reach the age of 75, your doctor will probably stop the PSA screening. This is because men age 75 have about a 10-year life expectancy and most experts believe they will die of something else before they die of prostate cancer. In fact, the U.S. Preventive Services Task Force does not recommend prostate cancer screening in men 75 and older.
As you might guess, PSA screening has become controversial due to its limitations. However, it is still one of the only ways of detecting prostate cancer at an early stage when it is relatively easy to treat. So if you are a man over the age of 50 (or 40 if you’re African-American), you should definitely have a PSA blood test along with a digital rectal exam every year. The old cliché is certainly true when it comes to prostate cancer – better to be safe than sorry.
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