Dr. Tom Miller: Screening for prostate cancer.
Dr. Blake Hamilton: Oh my.
Dr. Tom Miller: Why the oh my?
Dr. Blake Hamilton: This is a very controversial subject.
Dr. Tom Miller: This is Dr. Tom Miller. We are going to be talking about prostate cancer screening next on The Scope.
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Prostate Screening with P.S.A.
Dr. Tom Miller: Hi, I'm here with Dr. Blake Hamilton. He's the medical director for the urology clinic, and he's also associate director for the division of urology. Let's talk about it. Is prostate cancer screening with P.S.A. testing something that's time has come and gone?
Dr. Blake Hamilton: No, I don't think so. It's a shifting environment to be sure, but I think it still has relevance.
Dr. Tom Miller: You know, the national guidelines, or a couple of the guidelines out there now say that you really don't need to screen men for prostate cancer using the blood test, the P.S.A., prostate specific antigen test. That's based on a couple of large studies, I believe. The outcomes of those studies, one in Europe, one in the United States, didn't back up the idea that using this test could save lives best that the studies showed.
What is P.S.A.?
Dr. Blake Hamilton: We have to go back and understand the history of P.S.A. P.S.A. is a protein that's produced by the prostate. It has a role. It has a function. We learned many years ago, three decades ago, that it goes up in prostate cancer, and when you treat prostate cancer it goes down. It became used as a marker for recurrence of treated prostate cancer. It continues to be very reliable. It's one of the best blood markers that we have for cancer.
Dr. Tom Miller: No question. I think we all know that we find more prostate cancer using this test. The question is does it save lives in the long run.
Is a P.S.A. Test Worth It?
Dr. Blake Hamilton: The two studies that you refer to, depending on how you interpret them, show that there was not enough difference between the group that was screened and the group that was not screened. There are several problems with those studies. One is that they may not be mature enough. They had an average follow up of eight, nine, ten years, and the arms are separating. If we get to 15 years I think we'll see a difference. I think we'll see a clear separation between those two arms. The other problem is there are some methodological problems in how the patients were accrued. It's complicated. I think the real issue is that some people with prostate cancer will suffer immensely and die, and many will not. What we really need to do is do a better job of trying to predict who needs treatment and who doesn't. I think that what's happened over the last couple of decades is when men are diagnosed with prostate cancer based on P.S.A. screening they automatically have gotten treatment. So, in a sense as a community we've over-treated men with prostate cancer.
Dr. Tom Miller: I think part of the concern is also the potential complications of the surgery or the other treatments available for prostate cancer. I mean it's not a benign procedure, and there are outcomes that are difficult for the patient. I think that is coloring the judgment of some of the task force groups that are looking at screening guidelines currently.
Dr. Blake Hamilton: The problem is you still have some 250,000 men who will be diagnosed with prostate cancer this year in the United States. There will be some 35,000 of those who will die from prostate cancer. To say that prostate cancer screening with P.S.A. has come and gone would be throwing the baby out with the bathwater. What we need to do is keep the screening but make better decisions about when to biopsy and when to treat prostate cancer. Already we're seeing a significant decline in the number of men who are being treated, and that's appropriate. But, we've got to keep looking for the ones that are going to be lethal cancers, because they're real.
P.S.A. Test Alternatives
Dr. Tom Miller: Let's talk practicalities. Are you saying that we should continue to follow the past guidelines which say begin screening in men at the age of 50, and then continue screening every year with P.S.A. testing?
Dr. Blake Hamilton: There are now many alternatives to that.
Dr. Tom Miller: Right.
Dr. Blake Hamilton: One alternative, which comes from the U.S. preventive services task force, is to not screen at all. The American Urological Association has modified their guidelines to suggest that we screen maybe not every year but every two years in men between the ages of 55 and 70 where we think that we'll find the highest yield in the patients for whom it will really matter. Screening in 80 year olds, not important. Screening in the younger generation, not enough data to show evidence that it helps or makes a difference.
Who Should Get Screened for Prostate Cancer?
Dr. Tom Miller: Younger generation meaning 50 years old and above?
Dr. Blake Hamilton: Less than 55.
Dr. Tom Miller: Less than 55.
Dr. Blake Hamilton: Although there are many researchers who would argue that between 45 and 55 should be included. The guidelines as we have them now would be that those men in that 15 year window, and screening not as intensely as we have in the past, but not to give it up.
Dr. Tom Miller: Let's say that your P.S.A. is elevated. What should the patient do? Should they go then to a urologist who specializes in prostate cancer? A lot of this, as you say, is going to depend on the expertise of the specialist taking care of this type of problem.
Dr. Blake Hamilton: I think most urologists have the ability to evaluate an elevated P.S.A. and make a decision on a biopsy. There continue to be a variety of opinions out there. If you have a single elevation in the P.S.A. I think it's reasonable to wait some time and repeat it and think about what that means.
Dr. Tom Miller: So, screening is something that you believe we should continue. You think it's a good idea.
Dr. Blake Hamilton: Yes, I think we should continue screening but do it judiciously and appropriately, and then think carefully without automatic treatment of those who are diagnosed with prostate cancer.
Dr. Tom Miller: A final thought. What about that time honored rectal exam? Do we still have to do that on patients? It's the brunt of so many jokes.
Dr. Blake Hamilton: Yes, it is. Unfortunately, there are some bad prostate cancers that have low P.S.A.s and are only found on physical examination, so we're going to continue doing that exam, Tom.
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