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| DR. ANDREW VON ESCHENBACH | |
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Dr. Andrew von Eschenbach, director of the National Cancer Institute at the National Institutes of Health, talks to Susan Dentzer about his experience as a prostate cancer patient and his research to assess and improve screening for the disease. The NewsHour Health Unit is funded by a grant from The Henry J. Kaiser Family Foundation.
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SUSAN DENTZER: You understood exactly what
decision-making tradeoffs you'd have to make [after you were diagnosed
with prostate cancer.] How did you feel?
Just because I spent my life dealing with the problem as a surgeon and as a researcher didn't change the fact that once I was a prostate cancer patient I had all of those reactions and responses. But at least I knew I had a problem, and then based on that knowledge, I could make some decisions as to what to do about it. Our best weapon today to deal with cancer is to be able to find it early, at a time when we still can effectively apply treatment. And we have a variety of methods of early detection available to us. We have, for example, mammography for breast cancer, and colonoscopy for colon cancer, and PSA, or prostate specific antigen, for prostate cancer. Those tests give us the opportunity to determine whether there may or may not be a problem present, and that gives us the opportunity to make rational decisions as to what we may need to do about that problem. So in my case, having the PSA blood test gave me the opportunity to determine and detect that there was a problem there, and then make decisions about what should be done. | ||||||||||
| Assessing prostate cancer screening | |||||||||||
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SUSAN DENTZER: It seemed very counterintuitive to many people when the U.S. Preventive Services Task Force came out recently and modified what it said from 1996, but still said, in effect, there is no reason to recommend for or against widespread prostate cancer screening. Why is it that it's at least a credible position now on the part of the task force or anyone else to say we just don't know if screening reduces mortality.
So the U.S. Preventive Services Task Force, in looking at that information, and in the absence of that absolutely conclusive proof, did not come forward with a recommendation that emphatically said every man should have a PSA screening. On the other hand, in looking at the evidence and realizing that PSA is a very effective tool at being able to detect prostate cancer and detect it when it's still early in its development, it moved further from its previous position, which was to say you should not do it. And now they recommended that in the consultation with the physician, one should decide whether it was an appropriate thing to do for the individual patient. I guess in a way, that is too long an answer to the question you asked, but the fact of the matter is that their responsibility was to give a recommendation based on the best available proof, and the proof right now is still insufficient to make a categorical, absolute recommendation. On the other hand, the data does support the fact that PSA can be useful. As long as a patient is informed, they have the opportunity to then avail themselves of the PSA test. SUSAN DENTZER: And the task force did assert that it is clear that screening does lead to cancers being detected early. ANDREW VON ESCHENBACH: Yes, it does. And we are having increasing evidence that treatments that are applied early, like radical prostatectomy, can, in fact, improve outcome or survival. And so therefore, although we don't have the kind of proof that's incontrovertible, the prospective randomized trial that is considered to be the gold standard for clinical trials, to be able to decide the difference between doing something or not doing something, the evidence is pointing in that direction. |  | ||||||||||
| New tests on the horizon | |||||||||||
| SUSAN DENTZER: Some people look at this and say there is obviously great uncertainty around [PSA testing], yet we are spending $10 billion a year, perhaps more, on PSA and other forms of prostate cancer screening. Does that make any sense?
The National Cancer Institute is promoting a great deal of research to be able to help define what the best way to apply PSA is, to know and determine how we might improve upon the test, knowing that it's not specific for cancer. At the same time, we realize that because it's not specific for cancer, we have to find an even better tool. So in addition to research to help us decide how we could best apply PSA, and we have a trial that's underway to do that, we also have a great deal of research that's underway to determine and find better tools that are specific for cancer, especially prostate cancer. One more recent advance along those lines has been a blood test that can look at the pattern of proteins that are in the blood, and by looking at not one specific marker like a PSA protein, but a variety of markers, we are able to then detect and determine the presence of cancer. This is very early in its development, but has been very exciting from the point of view of its impact on ovarian cancer, and has just recently been applied to prostate cancer, and appears that it may be beneficial and even perhaps better than PSA. So we are approaching this problem from both sides, doing the research to improve the application of our current tool, but to develop an even better tool for tomorrow. SUSAN DENTZER: What is the name of that test?
SUSAN DENTZER: So it could be quite a significant advance? ANDREW VON ESCHENBACH: It could be quite a significant advance. It's just one of many avenues that we're pursuing. Studying or looking at proteomics, or proteins is one methodology. We're also looking at alterations and changes that may be occurring in gene patterns, in gene profiles. So there are a variety of strategies all intended to find better methods of early detection of cancer. | |||||||||||
| Determining which prostate cancers will spread | |||||||||||
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SUSAN DENTZER: What is the NCI doing to foster research that will help us so that we could look at a cancer in an early stage and say yep, this one's got to come out, it's going to metastasize versus this one we can sit back and wait for a while?
We are approaching that from the point of view of studying the cancer cell itself, learning a great deal about the genes that are responsible for the growth and progression of the cancer cell. We also are recognizing that the behavior of that cancer cell is very much influenced by its interaction with its environment, neighboring cells in the vicinity that can provide growth factors to stimulate the tumor, and provide opportunities for that tumor to spread. So we're also doing a great deal of research to look at the interaction between the cancer cell and its environment. We also recognize that different tumors behave differently in different people, and we need to know much more about the person with cancer and how that can influence the ultimate outcome. So we are approaching our understanding of the behavior of cancer on multiple fronts -- from the tumor, from the interaction of the tumor within its local environment, and within the person itself. | |||||||||||
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ANDREW
VON ESCHENBACH: Well, I think one of the things that was very important
was that it's better to know than to not know. It was very stressful,
it was very anxiety provoking, it was all of the horrible things that
you could imagine, to find out that I had prostate cancer. 
ANDREW
VON ESCHENBACH: Well, the U.S. Preventive Services Task Force, along
with the National Cancer Institute, are really charged and responsible
for providing the absolute best scientific information upon which we
can make decisions. At this point in time, the amount of scientific
information regarding whether men who have their prostate cancer detected
by PSA ultimately then benefit with regard to improved survival, has
not been absolutely conclusively established by what we describe as
prospective, randomized trials where men are chosen at random to be
screened or not screened, and then followed for very, very long periods
of time to decide at the end of that whether there is or isn't a difference.
ANDREW
VON ESCHENBACH: Well, I think it makes sense from the perspective that
we have to use the tools that are available to us today that are the
best tools, and right now PSA is the best tool.
ANDREW
VON ESCHENBACH: This is a blood test that is being developed in terms
of what we describe as this new field of proteomics, and it's a protein
pattern blood test, looking at an array of proteins from one drop of
blood.
ANDREW
VON ESCHENBACH: Well, one of the very important parts of our research
effort at the NCI is to really understand the fundamental biology of
a cancer -- how it begins, and what are the processes that result in
it taking on various forms of behavior -- very benevolent, slow growing
tumors versus the very aggressive, very malignant tumors.