Ask Dr. Hallberg: New prostate cancer screening guidelinesby Dr. Jon Hallberg, Minnesota Public Radio
St. Paul, Minn. — The recommendations by a government panel against prostate screening using the Prostate-Specific Antigen test in healthy men have been out for a few days now. They are likely to be the most definitive and influential to date. Evidence has been building for years that the PSA blood test was simply not saving lives.
But these new guidelines are still meeting some resistance, especially by groups of doctors. MPR's regular medical analyst Dr. Jon Hallberg spoke to MPR's All Things Considered about the new guidelines.
Tom Crann: These guidelines are going to be taken pretty seriously, but they're not exactly new.
Dr. Jon Hallberg: That's right. The momentum has been building and we greeted these recommendations not as ho-hum, but it wasn't really changing the conversations we've been having with our patients.
Crann: These recommendations are about the PSA blood test. What does it show?
Hallberg: The PSA stands for Prostate-Specific Antigen. I think people can think of it as a marker or a protein that's associated with the prostate gland that only men have. The trouble is, though, that as specific as it is, it's really non-specific. It doesn't tell us the difference between inflammation, aging, prostate cancer, infection, and so it's just a number. We know roughly where it should be on a scale of 0 to 4, but what does it mean when it's 7 or when it's 3. This has been an ongoing debate for years and years.
Crann: The idea that you can detect cancer with a blood test seems like a great idea. What's wrong with that?
Hallberg: It's fantastic. If there really was a test that could tell us with assuredness, you have cancer — you know certain blood-born cancers you can tell basically by how the blood looks. But with something like this it just looks so promising. We really want to put all our eggs in this basket, but unfortunately it's just the wrong test. It just isn't that specific.
Crann: What's the reaction been in the clinic? I imagine that some patients say they still want it?
Hallberg: Since this latest set of recommendations were published, the patients I've talked to — they too are not that surprised by it. The guys I've talked to are older and they're taking it kind of with a grain of salt. They say, I'm old enough, let's forget the testing, I don't need to do it at this point. We'll still have conversations. It's informed decision making that needs to occur.
Crann: Prostate cancer is still a fairly common form of cancer, so these new guidelines can't mean that there's no more worry about prostate cancer, right?
Hallberg: It's the second most common cancer in men besides skin cancer, so it's a very common cancer. Yet the lifetime risk of dying from it is 2.9 percent. So we have to look at that. People listening are going to know people who have had prostate cancer or died from it, so it's a huge problem, we just don't have the right test yet to detect it.
Crann: Is there a middle ground where the test will be useful for some patients?
Hallberg: It's important to note that the new guidelines are in kind of the conversation phase. People who have strong opinions about it are weighing in, so these are not the final, definitive recommendations. Once they go into place, some insurance plans might stop paying for the PSA test. But despite that, I think people who believe that as bad as this test is —, it's the best we've got — will still do it. People may pay for it out of pocket — it's not that expensive of a test. I don't think it's going to go away anytime soon. It will still be offered. And the important point about this test is that the guidelines only deal with screening people who have no symptoms. Those who have a strong family history of prostate cancer, those who are having symptoms, those who have had prostate cancer, that's entirely different. That's not what we're talking about. I think we're going to see more focused testing if we use this test.
Crann: And the hope here is there might be another blood test that is more accurate that will be available at some point?
Hallberg: I have to imagine that there are labs around the world where researchers are looking for what is the marker that tells the difference. Prostate cancer is not prostate cancer is not prostate cancer. If you have it under the microscope there's no way of looking at those cells and knowing if it will be slow growing — which is what most of them are — or fast-growing and aggressive. So if they can find the protein or the marker that can tell us the difference, that's where we need to be looking.
(Interview transcribed by MPR reporter Elizabeth Dunbar.)
- All Things Considered, 10/12/2011, 5:19 p.m.
Assistant professor in family medicine at the University of Minnesota, and medical director at Mill City Clinic.