PSA Test: How to Properly Interpret and Avoid Misuse

There is a great scene in the movie “Back to School” in which Rodney Dangerfield’s character hires Kurt Vonnegut to write a critical essay on the works of, yes, you guessed it, Kurt Vonnegut. The resulting paper receives an F grade from the professor and a comment that “you clearly do not know the first thing about Vonnegut!”

On certain days, Richard Ablin, a research professor of immunobiology and pathology at the University of Arizona College of Medicine, must feel like a cross between Vonnegut and Dangerfield.

Dr. Ablin discovered PSA in 1970 and has since been fighting the good fight to prevent its misinterpretation and misuse. In a NY Times Op-Ed published on March 10, 2010, Dr. Ablin explains what the PSA test actually detects, how it should be used, and as importantly how it should not be used.

All kidding intended, considering how PSA is being used by the medical community, Dr. Ablin clearly does not know the first thing about PSA!

To quote Dr. Ablin:

“As I’ve been trying to make clear for many years now, P.S.A. testing can’t detect prostate cancer and, more important, it can’t distinguish between the two types of prostate cancer — the one that will kill you and the one that won’t.”

He continues:

“… the test simply reveals how much of the prostate antigen a man has in his blood. … Men with low readings might still harbor dangerous cancers, while those with high readings might be completely healthy.”

He argues that the result of the inappropriate uses of PSA as either a screening tool or proxy for the amount or aggressiveness of prostate cancer is billions of dollars annually in unnecessary tests and invasive prostate cancer treatments.  

Dr. Ablin goes on to argue that the PSA does have its place:

“After treatment for prostate cancer, for instance, a rapidly rising score indicates a return of the disease. And men with a family history of prostate cancer should probably get tested regularly. If their score starts skyrocketing, it could mean cancer.”

The Takeaway

Although we are fortunate to have a tool like PSA, we need to avoid projecting value onto it that is not inherent in the test itself. Placing too much weight in modest fluctuations in PSA score will either inflict unnecessary duress or inject delusory confidence. You want neither. Talk to your healthcare practitioner to ensure that both of you view PSA for what it is and for what it is not. Thoughtful diagnosis and treatment require properly profiling and monitoring your condition, and this requires that you do not misuse the PSA test. 

All the Best,

David, CEO & Co-founder