Dr. Len Lichtenfeld’s blog is having technical issues, so we are happily hosting his latest post here. –djs
By: Len Lichtenfeld, M.D., Deputy Chief Medical Officer, American Cancer Society
To screen or not to screen for prostate cancer, that is the question. Or is it?
A report from the venerable United States Preventive Services Task Force made it to the media yesterday–a bit ahead of schedule–and it not only says we aren’t certain whether a man should get a PSA test to find prostate cancer early, it came flat out and proposed, effectively, “Don’t do it!”
That proposed recommendation is going to create a good deal of discussion, I would think.
Whether PSA testing to find prostate cancer early really saves lives is not certain. The test has been around for over two decades, but it wasn’t until recently that there were any scientific studies that could provide evidence whether or not the test actually worked. And those two studies produced conflicting results, or so it seemed.
One study done in several European countries found that PSA screening reduced deaths from prostate cancer by about 20%. Another study done in the United States concluded that PSA screening did no such thing. In fact, in the US study, the deaths from prostate cancer were greater during the period of the study in men who were screened vs. those who were not, but that difference was not found to be statistically significant.
Basically, what has happened is that the Task Force reviewed all of the evidence as to whether or not PSA screening decreased death rates from prostate cancer, and whether or not the harms from early diagnosis and treatment outweighed the benefits.
In reviewing the available studies, they found studies that tried to answer the question, but didn’t find any that were really well done. So they had to rely on a lesser level of evidence, and among that evidence were the two studies noted above.
In the European study, they pointed out that for ALL of the men included in the study, ages 50-74, there was no reduction in deaths in the group with PSA testing. They also pointed out that the European study was in fact a “compilation” of trials in several centers in several countries, and that the frequency of PSA testing differed considerably from center to center (every 2-7 years, not every year as is commonly done in the United States).
The USPSTF researchers also pointed out that the group where the reduced death rates were found was in fact a “select” group of men ages 55-69. Furthermore, not all men in that study were treated equally: men who were in the “PSA testing arm” were treated in academic centers, where they would have arguably received better care, compared to the untested control group who were treated in community hospitals.
Another wrinkle was highlighted by the researchers who pointed out that one of the Swedish centers that participated in the trial had exceptionally good results (in fact the only center in the study that had such great results). Take that center out of the analysis, and voila! the benefits of screening in the European study miraculously vanishes.
Then there was the United States study, where many of the men in the “untested” control arm had PSA tests anyway, thus making the results of “no benefit” less than clear cut.
I could go on, but I think you can begin to understand the dilemmas all of us have faced in trying to figure out whether or not PSA testing really works. And let’s not ignore the question of what happens to men after they receive treatment for their prostate cancer, problems that are not insignificant such as incontinence of urine, difficulty with bowel movements, impotence and more. These are not minor issues.
So here is a test that has strong advocates, not the least of whom are the truly well-meaning men and their loved ones, friends and colleagues who truly believe that PSA testing saved their lives. And not a few of those men are in positions of influence, including a number of Congressmen and Senators, senior executives, celebrities, you name it. They were told that PSA testing saved their lives and I would expect they would take that advice to heart. Hear it often enough, and you believe it.
But just saying something often enough, loud enough and clear enough does not make it so. Just ask the women who took all those hormones for all those years, and all those doctors who thought they were doing the right thing for their patients by prescribing those medications. They too thought hormones were good for their health, until the evidence proved it wasn’t so. (Hormone therapy remains a useful treatment, but only with a clear understanding of the risks and benefits of those treatments.)
So, now the horns of the dilemma. The Task Force is now on record as proposing a recommendation that men NOT get PSA testing. They conclude there is no real proof of benefit, and real proof of harms. Too many men go through too many treatments with too many long -lasting complications without a clear expectation that it will save their lives.
That’s pretty radical, and is certain to raise a firestorm of criticism among those who believe that PSA testing saves lives.
The American Cancer Society went through the same evidence a couple of years ago and had the same discussions. We elected to say to men that we did not know whether or not PSA testing saved lives, but thought the best approach was for men and their health professionals to have a clear discussion, outlining the benefits and risks before embarking on a program of PSA testing. And that remains our recommendation today.
But I will say that even then, the evidence of benefit from PSA screening was certainly not overwhelming, if it existed at all. We knew then about the issues with the United States trial; there were whispers about some problems with the European study that are now more clearly discussed in the Task Force report. But the bottom line remains for both organizations that the evidence is not firm that the test makes a real difference.
After all this, you know what really gets me upset?
We have invested over 20 years of belief that PSA testing works. Catch it early, treat it early, and get it out. Save a life. That’s the mantra many of us–including me, as a practicing physician–believed. And here we are all of these years later, and we don’t know for sure. That is not an acceptable situation. Plain and simple, we have not done our homework to prove our point. And the chickens are coming home to roost.
Unfortunately, those “chickens” are men like me who dutifully get our blood tested every year. We have been poked and probed, we have been operated on by doctors and robots, we have been radiated with fancy machines, we have spent literally billions of dollars. And what do we have? A mess of false hope?
Back in the early part of this decade, researchers came to the conclusion that although there were some benefits to hormone therapies for post-menopausal women, there were more harms that outweighed their routine use. Almost a decade later, there has been a significant decline in hormone usage, we are more aware of the risks, we counsel our patients carefully about the use of these medicines, and we recommend the lowest dose for the shortest period of time.
Now we are about to face similar issues with prostate cancer screening. We will argue, we will refute the other persons science, yet I suspect we will come to an understanding that just because experts, doctors and grateful patients and their families say it often enough and loud enough does not make it so.
As someone reminded me recently, anecdote is not a form of evidence. And for PSA screening, unfortunately, according to the Preventive Services Task Force, the evidence just isn’t there.
It’s always hard to learn that the emperor in fact has no clothes. The sad reality, however, is that this debate is not about a fairy tale. It’s real life, my friends. And people have been hurt, and doctors have been deceived. At least, that’s what the Task Force is saying.
Maybe it’s time to listen to evidence instead of hope. Sometimes that’s hard to do.