[MOL] new way of detecting lung cancer [01170] Medicine On Line


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[MOL] new way of detecting lung cancer



By GINA KOLATA 
AITHERSBURG, Md. -- Doctors and scientists urged the Federal Government on 
Tuesday to start a large study of a new way of detecting lung cancer as soon 
as possible, seizing what they see as a small window of time to discover if 
the method works before it becomes so widely used that no one will question 
it. 
If the study is begun, it would be one of the fastest movements in medical 
history from the discovery of a method to its large-scale testing. Dr. Peter 
Greenwald, director of division of cancer prevention at the National Cancer 
Institute, said he did not know of another example in diagnostic imaging of a 
large study's starting so soon after a discovery. 

The lung cancer screening method, known as spiral CT scanning, is so new that 
doctors are still learning its capabilities. It can find lung cancers when 
they are as small in diameter as a soda straw, as compared with chest X-rays 
that find them when they are about the size of a quarter. 

But the question is, Does finding a lung cancer so early mean that patients 
will live longer? The first major papers on the spiral CT scanning were 
published in April 1998 and last July. Ordinarily, a period of years would 
follow during which the method would be studied in groups of patients to 
learn if the early results were easily replicated. 

But medical experts at a workshop held in a hotel here said the usual languid 
period of waiting to start a clinical study would not suffice. A large study 
in which possibly tens of thousands of patients are randomly assigned to have 
the screening test or not must start immediately, they said, or it will be 
too late. Already, they said, patients are lining up to have the scan and 
hospitals are advertising that they will provide it. 

Dr. Christine Berg, the acting chief of the lung and upper aerodigestive 
cancer research group at the National Cancer Institute, who oversaw the 
meeting, said the institute's advisory board had already urged that a large 
study be undertaken. 

And now, with most of the participants at the meeting on Tuesday saying the 
same, she said she would urge that planning begin. 

"We need to convey to decision makers that a study should be moved on as 
quickly as possible so that we can understand the benefits and risks of this 
technology," Dr. Berg said. 

Some advocates of the technology, however, said it would be unjustified to 
deny it to people at high risk of lung cancer. 

Dr. Claudia I. Henschke of the Weill Medical College of Cornell University in 
Manhattan, said a study that randomly assigned people to be screened with the 
new technology or to forgo such screening would be unacceptable. 

"You're condemning the control arm," Dr. Henschke said. 

And Margaret McCarthy, executive director of the Alliance for Lung Cancer 
Advocacy, said she was sure that every person in the room would seek out the 
new test for themselves if they were at risk of lung cancer. Who, then, she 
asked, would be willing to be in a study where they might not get the 
screening test? 

The two studies so far of spiral CT scanning tested it on smokers and former 
smokers, documenting the test's ability to find tumors when they are very 
small. 

Dr. Henschke, who directed one study, estimated that the method could allow 
as many as 80 percent of lung cancer patients to survive at least five years. 
Just 15 percent live that long now. 

But neither her study nor one conducted by Japanese scientists included a 
group of patients who, for comparison, did not have the test, raising 
questions of whether the patients really lived longer than they would have if 
they had not taken part in the study. 

Now, Dr. Henschke said, she and her colleagues are planning to enroll 10,000 
patients in the New York area for additional study of the method's efficacy. 
That study would not include a control group of patients who did not get the 
screening test. 

Some participants at the meeting warned that though it sounded logical that 
if cancers were detected very early, patients who would otherwise die would 
be cured, the history of lung cancer screening provided a cautionary tale. 

A few decades ago, it was widely believed that chest X-rays could save lives 
by finding lung cancers before people had symptoms. The American Cancer 
Society recommended that smokers have annual chest X-rays and doctors urged 
the tests upon their patients. 

But in 1971, the Mayo Clinic in Rochester, Minn., began a study of 9,211 
smokers who were randomly assigned to have regular chest X-rays or not. 

The results were startling. Cancers were found earlier, but the men who were 
screened lived no longer than those who were not -- their cancers killed them 
at the same time, but they lived a longer time beforehand knowing that they 
had cancer and being treated for it. As a result, the cancer society withdrew 
its recommendation that people at high risk for lung cancer be screened with 
chest X-rays. 

Spiral CT scanning is much more sensitive than chest X-rays, and it is 
possible that it is picking up cancers when they are really curable. On the 
other hand, cancer experts said, it is also possible that it is picking up 
tumors that would never have caused a problem, and that patients would have 
died with them, not of them. 

It is also possible that, like chest X-rays, spiral CT finds cancers early 
but does not save lives. 

Dr. Barnett Kramer, deputy director of the division of cancer prevention at 
the cancer institute, said more was at stake than medical certainty that 
patients would be helped. Spiral CT scanning would be enormously expensive. 

It costs anywhere from $250 to $1,000 for a scan, depending on the hospital 
offering it, Dr. Kramer said in an interview before today's meeting. He 
calculated that it would cost $39 billion to screen all smokers and former 
smokers in the country. And, he added, that does not include the cost of 
doing biopsies for people whose tumors turn out to be benign and those whose 
tumors are so indolent that they would never have been life-threatening. 

John Fletcher, an ethicist, said it was the uncertainty about the value of 
spiral CT scanning that made him want a randomized clinical trial. 

"We're in a situation that the experts call equipoise, where we really don't 
know if spiral CT scanning is better than usual care," Dr. Fletcher said. 

But, Dr. Fletcher, an emeritus professor at the University of Virginia, told 
participants at the meeting, "There is a window of opportunity here that you 
will lose when the pressure to do the test is so high that you can't resist 
it and it becomes a de facto standard of care." 

For that reason, Dr. Anthony B. Miller of the German Cancer Research 
Institute in Heidelberg said, "the message we're getting is, let's get on 
with it." 
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