CT screening programs generate cash, controversy
Ads encourage patients to demand expensive tests
They’ve appeared in almost every major newspaper in the country. Serious, slick notices featuring warnings such as: "What you don’t know may be killing you." Or, "A simple exam can save your life."
The ads are for screening computed tomography (CT) scans, radiologic scans of the heart, lungs, or entire body designed to detect early indications of cancer or other deadly disease. Unlike diagnostic CTs, which are performed when a physician suspects a problem, these tests are marketed toward healthy people who just want peace of mind — and can afford the $600-$1,000 out-of-pocket price tag.
Although the practice started at freestanding, boutique radiology centers in California, the programs are spreading quickly nationwide, says Bill Black, MD, professor of radiology at Dartmouth-Hitchcock Medical Center in Lebanon, NH.
"It is even happening in some of the major academic medical centers or affiliated with the major medical centers," Black notes. "There is this tremendous pressure for the hospitals to do these things because it is so lucrative. You can charge out-of-pocket. You don’t have to deal with insurance. And people are demanding it because has been extensively promoted."
But CT screenings in healthy people who don’t have significant risk factors for disease are likely to do more harm than good, many radiologists and disease specialists warn. Patients who receive vague results or false-positives will worry needlessly, often spending thousands of dollars on expensive follow-up tests or procedures.
The screenings have a high false-positive rate, as well as a tendency to overdiagnose problems, Black explains. Sometimes, a minor disease process may be present, but not in a way that would cause health problems.
"Now that screening tests have gotten so sensitive, you find all of the stuff there," he says. "And, even if it looks bad under the microscope, it may never cause a problem for that person if it had never been found."
For example, in cancer screening, the smaller lesions are when they are found, the more vague the histologies and pathologies, Black continues.
"Pathologists are very accurate and very confident in diagnosing a mass that is a couple centimeters in diameter. When you get down to all these places that are a few millimeters in size, even a pathologist cannot tell what is cancer and what is not," he says. "And if they are going to err on a side, it is going to be on the positive’ side because they are sure there are worse repercussions for them for overdiagnosing than underdiagnosing."
Such a problem exists to some extent with all screening tests, including well-accepted ones like mammography, but CT screenings have not been studied as extensively, so little is known about their true potential for predicting serious disease, Black adds.
In fact, the Food and Drug Administration (FDA) is now warning consumers that computed tomography has never been approved as screening tool, only as a diagnostic test, though it is legal for physicians to recommend and perform it for any use they feel appropriate. And no professional society, including the American College of Radiology, recommends full-body CT screening.
"Unlike breast-cancer screening, which has undergone rigorous evaluation, there has been no evaluation of CT screening at all," Black says. "Even if it is possible that it could work, no one really has a good idea of how it should be done. There are no standards at all for how it should be performed, how the results should be interpreted, how you should manage people with specific findings. The chances are so much greater that it is going to cause harm rather than benefit."
Targeted screens are more beneficial
But it is a mistake to lump all screening CT tests in with the increasingly popular "body scan," says James Ehrlich, MD, medical director for the clinics Colorado Heart and Body Imaging in Denver and Heartscan in Washington, DC.
CT scans of certain areas, such as the heart or the lungs, have been shown to be effective in patients who already exhibit certain risk factors, he says.
Clinical studies have shown that a CT scan of the heart to detect the quantity of plaque in the coronary arteries helps predict a patient’s risk for future heart attacks.
In patients older than 45, the question is not whether there is plaque present in the coronary arteries, but how much and whether it poses a threat, Ehrlich explains.
"There are no false-positives for plaque," he notes. Still, it is important to present that information in context — not merely as a positive or negative result.
"We look at how fast the plaque is growing, or how do you compare to the thousands of people your age," he says. "If you are in the top 25th percentile for the amount of plaque you have in your coronary arteries, you are at 22 times the risk of somebody in the bottom 25th percentile."
That information can be used to initiate therapy with certain cholesterol-lowering drugs and talk to the patient about lifestyle changes that need to be made before the patient has their first heart attack, not after.
"The heart scan is an extremely well-validated procedure, with more than 500 articles in the medical literature," Ehrlich states. "It is a test that, when used correctly as a screen in certain age groups or used for a targeted decision by a doctor, is very, very valuable."
Likewise, targeted scans of the lungs have been shown to be beneficial in detecting early cancer in patients who are or have been heavy smokers or who are already showing altered lung function.
But, no well-constructed study has yet shown that an early diagnosis leads to a better overall outcome for these patients, Ehrlich cautions. Patients may get the early diagnosis and initiate treatment, which gives them a better chance of surviving five years compared to a patient who is diagnosed later. But, there is no evidence that the early-diagnosed patient lives longer.
The patient may live longer after the diagnosis, but if he or she just got the diagnosis earlier than the other patient, it just may mean that he or she lived longer knowing that he or she had the disease, not longer overall.
"That issue is still controversial. Some doctors do feel that finding it earlier means the patient is going to live longer," Ehrlich says.
But, that still doesn’t mean that a lung scan is a good idea for all patients.
"Since the prevalence of lung cancer is so small in any population that doesn’t get exposed to lung carcinogens, this is not a test the normal person should have unless they are a heavy smoker. Even if they are, it is preferable to do a simple pulmonary function test to see if they already have changes in the lungs as well," he says. "If we look only at that group — what we call the high-risk group — in about 40% of them, we will find hidden lung cancer, and that is high enough that you should screen in those patients."
The full-body scans — which are scans of the heart, lungs, and abdomen — present more of a problem, say both Ehrlich and Black.
Performed in people who have no symptoms or risk factors for disease, these are often mere hunting expeditions for anything that may appear amiss, and something frequently does.
"There is a basic principle in medicine that when you are looking for problems in a population where it is statistically unlikely that someone is walking around with a major problem, you will find false-positives and you will find them frequently," says Black.
There have been some cases where a scan turned up a major problem — kidney cancer, for example — in patients who had no symptoms or reasons to suspect they were ill. But the intense coverage of these cases in the media aside, these situations are extremely rare and don’t begin to balance out the number of patients who get a false-positive or an undetermined diagnosis, then suffer anxiety and pursue other medical treatments that aren’t necessary, say both doctors.
"That comprises a big part of the controversy over CT screening," says Black. "Should the public have access on a self-referral basis to a screening test that could be very profitable for a radiology imaging center, but will lead to downstream medical costs as you work up these problems and lead to an excessively anxious public who are being told, You have a nodule and we better find out what it is.’ Then, $10,000 later, they find out it is nothing?"
Education, disclosure is important
It’s OK to provide the scan that people are demanding as long as you make a strong effort to ensure that patients understand the true risks and benefits of undergoing the procedure, says Ehrlich.
The imaging centers that he leads do offer body scans in addition to targeted scans of the heart and lungs, but all of their advertising and the educational materials they provide to prospective clients specifically mentions the potential for overdiagnosis, for false positives, and that they only recommend screening CTs for people with specific risk factors.
"Our policy is that we ethically feel that patients in all of our procedures should understand whether the test is really worth their money and whether they fit the profile of someone who should have the test," he says. "We are proud to mention that about 20 patients a week we discourage from having any of our tests, and a much higher percentage of people from having the body scan because it is so oversold nationwide. And to undergo the test they have to sign an extensive consent."
Facilities face enormous economic pressures
Imaging centers and hospitals face enormous economic pressures, and it is very tempting to just maximize the use of the expensive imaging equipment, especially when patients are demanding the tests and willing to pay for it up front, Erlich continues.
So, it is vital that centers have policies in place that ensure they make every effort to encourage only those patients who are appropriate candidates for the procedure, and to make sure that patients who choose the screen despite a recommendation not to understand how to put the information they receive into the appropriate context.
"We actually prefer physician referral because when you have a bad result, you have somebody to take care of these patients," he explains. "I call about 50 patients a day only to make sure they have a doctor who will see them. It is a lot of responsibility on an imaging center, with so many people coming in proactively without their doctor’s knowledge. If you find a problem, how do you make sure the patient is not just putting it in the closet and forgetting about it?"
Unfortunately, the advertising and promotion that many centers are doing not only overstates the benefits that patients may receive from screening, but also contributes to an erroneous perception that the average person’s risk for developing cancer or another disease is much higher than it actually is, adds Black.
For example, large studies of women living in different areas of the country have found that most believe they are at much higher risk of dying from breast cancer than they actually are, he says.
Misperceptions are widespread
This overestimation of risk coupled with advertising that seems to guarantee that cancer will be detected early and will then be curable, sets the stage for problems, he adds.
"Because there are such wide misperceptions, overestimations of risk, and overestimations of benefit, it is very hard to use this technology appropriately," Erlich says. "Not only do people overreact to the screenings, they overreact to the screening findings. If there is a finding that might be managed better by monitoring for a while, rather than surgery, the patient may be very uncomfortable with that and the specialist may rush in to more drastic treatment. There is a lot of potential for harm."
If people were aware of how to take the information and put it into the proper context, then the screenings would have more benefit, he believes. "These are simple, noninvasive procedures. The real harm comes in when you do not know what to do with the information that you find. It’s not that screening can’t possibly be beneficial, but under the current conditions there is too much of a tendency to overact and, consequently, a higher potential for harm."
Sources
- James Ehrlich, MD, 2490 W. 26th Ave., No. 110-A, Denver, CO 80211.
- Bill Black, MD, Department of Radiology, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756.
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