This is an article derived from a longer conversation Dr. Ali Kasraeian had with Dr. Matt Cooperberg, a urologic oncologist at the University of California San Francisco. In this episode of the The Conversation, the doctors discuss prostate cancer, the need for PSA screening and why AUA’s study on PSA screening isn’t all that accurate.
It’s probably just the next chapter in an ongoing, longstanding controversy about what should be done with prostate cancer and PSA screening. At the root of the problem is the fact that – in United States – the word cancer is used for a lot of different things in life. At one end of the spectrum are things like pancreatic cancer and lung cancer that move very quickly. Prostate cancer is at the other end. Men diagnosed with prostate cancer typically live for decades and many of the prostate cancers that we find never come to any sort of clinically meaningful state. So if you live long enough in the U.S., you’re almost guaranteed to grow a couple of prostate cancer cells somewhere in your prostate, but the majority of these never amount to anything. They never cause any symptoms, they never kill anybody. They never cause any loss of life.
The flip side though, is that because it is so common, there are a minority of prostate cancers that are branded ‘high risk’. Even though it is a minority of prostate cancers, because it is so common, those high-risk prostate cancers still kill more men than any cancer, except lung cancer in the United States. So the challenge now is really finding the ones that need to be treated and treating them appropriately and aggressively while trying to minimize over-treating low-risk prostate cancers that really don’t need to be treated.
Now, one of the proposed solutions to that, which is the one that the U.S. task force has been advocating, is to just stop PSA screening. Most urologists that actually understand the data and understand the disease all agree that it would be a public health disaster. And the folks on the task force are well-intentioned epidemiologists, who have no real experience in prostate cancer research, frankly just don’t understand the disease. So their guideline that came out last year said to stop PSA screening all together — and that is clearly the wrong thing to do to.
What AUA‘s new guideline really tried to do was to be more evidence-based. They really wanted to only make statements they could base on high level evidence, basically coming from randomized trials. And most of those randomized trials, those are situations where you take men and really split them in to those who get screened and those who don’t. Those trials were really only done well in Europe and they only looked at men in their 50s and 60s at the time of diagnosis. So the AUA’s new guideline really focuses on men between ages of 55 and 69. It makes a statement that these are the men who most clearly stand to benefit and should be discussed the option of PSA screening during their primary care visits.
The controversy was when AUA then said that for men under 55, between the ages of 45 and 55, they cannot recommend screening. And that’s based on the fact that there is really no high-level evidence. The randomized trials didn’t include younger men. It doesn’t mean AUA said don’t screen, they said they can’t recommend screening. And it may sound like a semantic difference, but it is an important difference.
The main motivation for that statement was based on the trials to stop the screening. The European trial that they really focused on, that was what was done in that trial. It is well-known there is a lot of over-screening in older men. There was a great VA study done where they saw that 30% of men in their 80s were getting PSA screening even when they had multiple other health problems. These patients had heart disease and all these other things that were going to kill them long, long before prostate cancer ever would. However, we need to be careful because men diagnosed with high-risk prostate cancer, even at older ages, will die of prostate cancer quite a significant proportion of the time when they are not treated.
So when you talk about someone who is over 70, you absolutely have to think about life expectancy. There are men that are 60 going on 70 and there are men that are 70 and are lucky to have made it that far because they’ve got diabetes, heart disease, obesity, and all the rest of it. So you really need to look at the person’s health, not just their age. And the other thing is their prior PSA history. So the assumption from the way the AUA kind of phrased the guideline, is that if your PSA has been low the whole time from 55 to 69, you can probably stop if your PSA is still 1 or whatever at that point. But if you have never been screened before and you are 70 years old and healthy, it absolutely makes sense to screen with the understanding that you are being screened for is high-risk prostate cancer. And that’s probably the most important point that none of the guidelines are stressing sufficiently. The reason to screen, the reason to do PSAs is not to find more prostate cancer. The point is to find high-risk prostate cancers, high-grade prostate cancers.
Listen to the full episode of The Conversation here.