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Doctors Propose New Cancer Definition to Avoid Unnecessary Treatments

July 30, 2013 at 12:00 AM EDT
A panel of doctors and scientists proposed a change to the definition of cancer, in hopes of shifting the way we think about and treat the disease. Gwen Ifill discusses the recommendation with Dr. Barnett Kramer of the National Cancer Institute and Dr. Larry Norton of the Memorial Sloan-Kettering Cancer Center.
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GWEN IFILL: Now we turn to changes in how we think about cancer and how we choose to treat it. It comes from a panel of doctors advising the National Cancer Institute.

In a paper in “The Journal of the American Medical Association,” the doctors recommended changing the very definition of what’s often seen as the earliest signs of cancer. For example, a diagnosis of noninvasive abnormal cells in the breast would be renamed so that the words cancer or carcinoma are not part of the description. The idea is to avoid unnecessary treatment.

The recommendations were published on the same day another medical panel recommended annual CAT scans for people at higher risk of developing lung cancer.

For more on these findings, we turn to Dr. Barnett Kramer of the National Cancer Institute and Dr. Larry Norton of the Memorial Sloan-Kettering Cancer Center.

Welcome to you both, gentlemen.

Why change definitions, Dr. Kramer?

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DR. BARNETT KRAMER, National Cancer Institute: Well, the meeting that you mentioned achieved a strong consensus. I should point out that it wasn’t an official advisory panel to the federal government or to the National Cancer Institute.

But it was one of the workshops that the National Cancer Institute often convenes to gather the opinions of outside experts. At that meeting, there was a consensus that it’s time to bring the terminology related to cancer into the 21st century. And that is to identify cancer by how it acts and not to restrict ourselves to how it simply looks like under a microscope to a pathologist.

GWEN IFILL: Let me follow up on that. How do you know how it acts if it’s in the early stages? How can you tell?

BARNETT KRAMER: In some cases, we have the luxury of following cancers.

For example, there’s a growing recognition that not all prostate cancers need to be treated immediately, and we’re able to follow them with periodic X-rays and biopsies and get an idea of the pace of the progression of the disease. In many other cases, we unfortunately don’t have that luxury and so we have to rely on molecular studies that identify the underlying behavior of the tumor.

GWEN IFILL: Dr. Norton, what do you think about this? Do you think it’s a good idea to change the way we look at these early cancers?

DR. LARRY NORTON, Memorial Sloan-Kettering Cancer Center: Well, Dr. Kramer said something very important, which is that there’s an expanding knowledge of the molecules that make cancers cancerous.

And if we really understood that, and if we’re all doing research at the National Cancer Institute, Memorial Sloan-Kettering, Breast Cancer Research Foundation — it’s a major topic of research — to figure out how, by measuring those molecules, we can tell which molecular changes are going to lead to a problem and which are not.

But we’re not quite there yet. And I’m totally in favor of changing terminology once we can be absolutely sure that when we tell a patient that this is an indolent thing that is not going to cause any trouble that we can have great confidence that we’re telling them the truth.

Until that time, we have to be very, very careful that we’re not giving people false confidence that what they have let’s say in their breast or their prostate is totally benign and is not going to cause trouble, because if we don’t treat it and it does cause trouble, well, that’s not going to be a good result.

GWEN IFILL: Well, let me ask you this, Dr. Norton. So, say somebody comes to you and you discover an early — something — a lesion that could be cancerous, could be very early. In this case, what would you do about that? How would you treat it?

LARRY NORTON: Well, mostly, we’re talking not about actually things that we would call cancer, but things that may predispose to the development of true cancer.

And some of these do have the word carcinoma in them, and it is a source of confusion. So you have to explain very carefully that something, let’s say ductal carcinoma in situ of the breast, DCIS, is like a criminal before the criminal has done a crime. It hasn’t actually done anything bad yet, but it sure has all the signs that it very well might. Now, in some cases we can tell relative odds that it’s going to cause trouble, like turn into a real cancer that could spread and threaten life. 

In some cases, we can really specify that this is very likely to do that or less likely to do it. But in no case yet can we say that it’s not going to do that. So then the patient really has to make a choice of what they can do to try to minimize their risks if they wish to minimize their risks. It’s a very individual decision. A lot of explanation has to go into it, so that what we really need now is good communication. I’m not so sure just changing terminology is going to accomplish that.

GWEN IFILL: Dr. Kramer, is this a question of overdiagnosis, overtreatment, or is it that improved technology has told us more than we ever used to know?

BARNETT KRAMER: Yes, it’s a little bit of both.

Overdiagnosis is the term we apply to the detection of tumors that have low malignant potential or very little chance of actually causing the patient’s death. And there are two criteria for overdiagnosis. One, there needs to be a large reservoir of tumors that have a very wide spectrum of behavior, and the more we learn about the biology of cancer, the more we know it’s virtually always there.

And the only other criterion is a sensitive screening test that can dip into that reservoir, and as we focus on more and more sensitive screening tests, we are tapping into that very, very large reservoir, detecting tumors whose natural history we really don’t even understand because traditionally we haven’t observed it.

GWEN IFILL: It sounds like both of these cases — the next one I’m going to ask you about — are about risks vs. benefits. You have this recommendation now that CAT scans be performed on an annual basis on heavy smokers to detect lung cancer early.

What’s the risk/benefit ratio there, Dr. Kramer?

BARNETT KRAMER: Well, that’s a very important point.

I want to put the national lung screening trial, which is the trial of low-dose helical C.T., into context. It was the first trial that ever showed that we could decrease the risk of dying of lung cancer in people who are at very high risk of dying of lung cancer by virtue of their smoking.

On the other hand, stopping smoking has a much, much larger and faster effect. And so no matter what, we need to encourage people who smoke to stop smoking. Nevertheless, about half of all lung cancers in our country are in people who already stopped smoking.

GWEN IFILL: So, Dr. Norton, is this a matter of mortality, of relative risk of mortality, and which is better, this annual screen that may not be covered by insurance, might not be worth the risk to people?

LARRY NORTON: Well, you’re bringing up a lot of topics, just the insurance, but I just want to concentrate on the biology here.

GWEN IFILL: OK.

LARRY NORTON: I think what we’re seeing with the lung cancer screening is very much like what we have seen with mammography screening.

Many, many studies have shown that if you do mammographic screening and you pick up small changes, you can pick up this DCIS that I mentioned and do things to even prevent the development of cancer in the first place or you can pick up very small cancers with a very high cure rate with breast conservation as an option for patient.

So that’s kind of where we are. I mean, I see in the lung cancer screening the very early days of mammographic screening of the breasts. Now, it’s possible, of course, that some of these cancers that we’re picking up on lung screening are also not going to grow. And if we can understand the biology of that and understand the molecules, we may be able to just do a needle biopsy, for example, and say we found the cancer, but it is not going to cause you trouble. You don’t have to do anything about it.

LARRY NORTON: When that day comes, we can call it indolent. But we’re not there yet.

GWEN IFILL: But when you say we’re not there yet, does that mean that both of these things we’re talking about are some ways down the road?

LARRY NORTON: Absolutely.

There’s no definitive test that we can do now to DCIS or lung cancer or anything else that is going to tell us with certainty that this is not getting turn into a dangerous disease that could be life-threatening. We’re moving that direction. It’s a very, very important area of research. And I would applaud the day when we could actually say this is early changes and it’s never going to cause you a problem and you can ignore it.

That is going to be wonderful.

GWEN IFILL: Dr. Kramer?

LARRY NORTON: And I think that day will come, but we’re not there yet.

GWEN IFILL: How far away?

BARNETT KRAMER: Yes. So how far down the road we are depends very heavily on our understanding of the underlying biology of each tumor.

And the better we understand it, the better we can make individualized decisions that help patients choose the best therapy. In the case of prostate cancer, there is a very large reservoir, we already know, of tumors that are so slow-growing that at least many of them are best left observed and not treated.

In the case of lung cancer, on average the tumors grow much faster than with prostate cancer, and so we’re not there. We need to learn more about the biology. And in the meantime, I want to emphasize the national lung screening trial showed that the net benefits outweigh the harms in this case.

GWEN IFILL: OK, Dr. Barnett Kramer of the National Cancer Institute and Dr. Larry Norton of the Memorial Sloan-Kettering Cancer Center, thank you both very much.

LARRY NORTON: Thank you.

BARNETT KRAMER: Thank you.