HomeNewsTo PSA or not to PSA … that is the question -by Dr. Alan Laird, Chief Medical Officer

To PSA or not to PSA … that is the question -by Dr. Alan Laird, Chief Medical Officer

Since June is Men’s Health Month, I will try to tackle a complicated question. Should a man (or more specifically you or me) undergo PSA screening? Let’s begin with what PSA is. PSA stands for Prostatic Specific Antigen. This protein (antigen) was identified in the 1970s and can be detected and measured with a blood test. It has become a popular test to detect prostate cancer in an early stage. Detecting and measuring it have become relatively easy, deciding when to test and what to do with those results is complicated. There are several reasons for this. First, PSA can be affected by a number of things not just cancer. This means if you have a high PSA you may or may not have prostate cancer. For most men, the prostate gland grows with age. A larger prostate gland releases more PSA into the blood. Therefore an elevated PSA may simply mean an enlarged prostate gland and nothing more. To determine if cancer is present, biopsies (sampling) of the prostate must be done. This is not as simple as a blood test (insert your joke of choice about understatement here). Secondly, prostate cancer is common in men. Prostate cancer is the second leading cause of cancer death in men (behind lung cancer). It has been found at autopsy on up to 60% of men age 80 and above. Many of those men were not having any symptoms or problems from the prostate cancer. That means while cancer was present in their prostate gland, another disease caused their death. Last but not least, is the difficulty in deciding what makes an abnormal test level. I am sorry that this gets a bit technical. Ideally it would be a “yes or no” proposition. A PSA above 10, you have prostate cancer. PSA below 10, you don’t. But like most things in nature, it is not black and white; it is gray. The positive predictive value (portion of men with an elevated PSA who have cancer) is 30% for levels above 4. Between 4 and 10 it is 25% and above ten is 42-64%. So even above 10, you have a 58-36% chance of NOT having cancer. And for those with a PSA of less than 4, they still have a 15% chance of having prostate cancer (negative predictive value of 85% at a PSA of less than 4). Confused yet? And remember the only way to definitely prove the presence of prostate cancer is a biopsy (sampling). Even that is not 100% guaranteed to give you a definite answer. So what’s a guy to do? As you can see there is no easy answer. There are a lot of guidelines out there from many different professional societies and they don’t necessarily agree with each other. This is one or those times it’s really important to have a conversation with your family health provider. There are websites that provide decision support tools including the American Cancer Society, the CDC (Center for Disease Control) and the Mayo Clinic. But even these won’t replace having a conversation with a trained health professional. After all, we can talk about a risk of 30% or 64% at a certain PSA level, but your risk is really either 0% (you don’t have cancer) or 100% (you do have cancer). Trying to figure out which of those you are is the trick. Since I referenced Hamlet in my title for this article, indulge me a bit further. To PSA or not to PSA that is the question! Whether it is nobler to forego screening and therefore avoid the slings and arrows of biopsies and invasive tests; Or to take up screening and the sea of further testing that may be caused by it, to find a cancer and end it. Fortunately for you fair Ophelia, you do not have to think upon such things. Forgive me, William Shakespeare. You could not have guessed what foul topics your words would be used to lighten.