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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