The PSA test has become controversial. To understand why, you first need to understand what a PSA test is and what it tells you.
The PSA Test
Your prostate produces a substance called protein specific antigen (PSA). A PSA blood test measures the amount of this substance in your blood.
Under normal conditions, only a small amount of the PSA ends up your blood steam. So, your PSA level will be very low – maybe as low as 1 or even less.
However, prostate cancer or a benign condition such as prostatitis can cause the prostate gland to produce more PSA than normal, giving you a higher PSA level.
Why The PSA Test Is Controversial
There are several reasons why the PSA test has become controversial.
First, the results it provides are not definitive as to whether a man has prostate cancer. There have been many men whose tests showed high PSA levels but did not have prostate cancer. This is called a false positive. Unfortunately, there have also been false negatives - men who tested low but were later found to have prostate cancer.
Some of this is because a PSA test cannot tell the difference between protein specific antigens produced as a result of prostate cancer and PSAs produced as a result of a prostate condition such as benign prostatic hyperplasia.
Sometimes doctors are able to rule out prostate cancer in men with a high PSA level using non-invasive tests such as a urinalysis. However, in other cases, men have had an invasive procedure called a biopsy or other unnecessary tests before learning he does not have prostate cancer.
Research On PSA Screening
Perhaps the biggest argument against annual PSA screening is that it hasn’t been found to save many lives. There have been studies both here and in Europe about the wisdom of widespread prostate cancer screening. One of the results found by the European study was that there were 48 men who were told they had prostate cancer and were needlessly treated for it, for every man whose death was prevented.
The New England Journal of Medicine recently reported the results of a study of 182,000 men in seven European countries and of 77,000 men at 10 medical centers in the U.S. In both studies, men were divided into two equal groups. One of the groups received annual PSA screening and the other half was not screened yearly.
The European data involved a group of studies with different designs. However, taken together, these studies showed that the group that was screened saw only a 20% relative reduction in deaths from prostate cancer. The results showed seven fewer prostate cancer deaths for every 10,000 men screened for the nine-year period.
The American study has only a single design. It found no reduction in deaths from prostate cancer after most of the screened participants had been followed for 10 years.
In other words, the research seems to indicate that widespread PSA testing does not prevent deaths from prostate cancer.
The PSA Test And You
And if you’re over 50 (or over 40 for African-Americans), your doctor will probably suggest you have annual PSA tests. This test may not be infallible but it’s one of the only two tests available at this point for spotting prostate cancer while it’s still in an early stage. The other is what’s known as a prostate exam or digital rectal examination or DRE.
If your PSA test shows a level of 4 or higher, there is reason to be concerned. But don’t let a doctor rush you off for unnecessary treatments such as a biopsy. Instead, if you haven’t had a DRE, be sure to ask for one. You could also ask for a second opinion or that you be given one or more of the non-invasive tests such as a transrectal ultrasound – to prove or disprove any diagnosis.
The PSA test may not give a definitive answer on prostate cancer, it is the only game in down. The good news is that knowing what you now know will help you better understand the PSA test, how to evaluate its results and how to react if you have an elevated PSA level.