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Lung test's value debated

The Baltimore Sun

For doctors at Anne Arundel Medical Center, the common-sense idea was too good to pass up: offer habitual smokers a low-cost CT scan to see if cancer has taken root in their lungs.

CT scans can spot lung nodules as small as a grain of rice. Lung cancer, the deadliest of all cancers, is often caught too late to be cured, long after the first symptoms have appeared.

"If you find [lung cancer] earlier and smaller, you have a better chance of curing it," said Dr. Kenneth Adam Lee, the hospital's chief of thoracic surgery. "This gives us a chance to do some good for these people."

Yet, as with other instances in which medical intuition has led doctors down questionable paths, the notion that finding lung cancer earlier will lead to better outcomes for patients is at the center of a major debate. Insurance companies do not cover lung cancer screening, because no one has proved that it saves lives. No major medical society advocates the practice.

Instead, many doctors argue that screening even the lungs of habitual smokers can lead to unnecessary - and sometimes dangerous - follow-up tests that can harm or even kill patients. Others argue that abnormalities turned up by screenings might be so minor that patients could die of something else before they even realize that they have slow-growing lung cancer.

What lung screening proves, they say, is that the more you look, the more you find, not that there's a lot of value in the results.

"I'm well aware that there is enthusiasm in at least some sectors" for lung screening, said Dr. Barnett S. Kramer, associate director for disease prevention at the National Institutes of Health. "But the evidence doesn't support it. It seems so intuitive that it ought to work. But the history of medicine tells us that even highly intuitive notions that something must be beneficial can be harmful."

Consider hormone replacement therapy (HRT), long employed to ease the symptoms of menopause and widely assumed to help stave off aging by supplying female hormones that the body has stopped making. Many doctors believed that boosting estrogen levels would also ward off heart disease and osteoporosis. But a major study showed that, for many women, HRT could cause more harm than good - including increasing their risk of heart attack.

Another recent failure of conventional wisdom involved diabetes patients. Over the past few years, many doctors have tried to lower diabetics' high blood sugar levels as much as possible - as close to those of normal patients as medication, diet and exercise allowed. But federal health officials this month halted one part of a major study testing this hypothesis after an abnormal number of patients died as they closed in on "normal" blood sugar levels.

So it might be with lung cancer screening. In the 1970s, the practice began to catch on, based on the apparently reasonable notion that chest X-rays would find cancers at a smaller, more curable stage. There was pressure to make such screening routine - just as there is in some circles today with CT scans - until a major Mayo Clinic study showed it did not save lives.

Most lung cancers caught before patients show symptoms are found accidentally when a patient comes into a doctor's office or hospital complaining of something else.

Routine screening has been proved to work for other cancers - such as mammography and colonoscopy - but it's not widely used for lung cancer, which kills more people each year than breast, colon and prostate cancers combined.

The newer, more sensitive technology for screening lungs - called spiral CT, or computed tomography - has been tested but not in the rigorous fashion considered the scientific gold standard: a randomized clinical trial.

The largest study of lung cancer CT scans was conducted by the International Early Lung Cancer Action Program (I-ELCAP). Results published in The New England Journal of Medicine in October 2006 showed that the technology caught a large number of early-stage lung cancers - and found that of those who had surgery within one month of diagnosis, the survival rate was 92 percent.

The eight patients who were diagnosed with early-stage lung cancer and who did not receive treatment died within five years of diagnosis.

But critics don't consider this a definitive test, mainly because there was no control group with which to compare the results. Others criticize the methodology, saying many cancers were "cured" that didn't need to be, and that early diagnoses did not translate into fewer late-stage cancers or deaths.

Critics said some patients appeared to live longer only because they were diagnosed years before they would have been otherwise. Most died of lung cancer anyway.

A smaller study published last year in the Journal of the American Medical Association concluded that CT might catch some early-stage cancers, but fast-moving, late-stage cancers rarely showed up early enough to cure - at times even appearing and killing between annual scans.

"CT screening for lung cancer should be considered an experimental procedure, based on an uncorroborated premise," the authors wrote.

To definitively answer the question, the National Cancer Institute is sponsoring a $200 million, 55,000-participant National Lung Screening Trial.

Half of the volunteers got three annual CT scans; the other half got chest X-rays. Those who urge caution say they are waiting for the NLST results.

"The right thing to do is to show it does or does not work before we promote it to the public," said Edward F. Patz Jr., a radiologist at Duke University Medical Center who is part of the NLST. "We don't know that it actually helps anybody."

What is known is that screening finds more cancer - and more lesions and nodules that might or might not be cancer - spots that doctors sometimes don't know how to treat, or whether to treat them at all.

"One negative is, we find a lot of stuff," said Dr. William C. Waterfield, a medical oncologist at Franklin Square Hospital Center in Essex, which conducted free lung screenings for about a year and now charges $100. "About 2 percent of patients will have lung cancer. Twenty-five percent and maybe higher will have abnormal CAT scans."

Those with abnormal scans are closely monitored and sometimes go through further tests, including needle biopsies, which can lead to surgery. Sometimes, patients return in a few months for repeat scans.

Doctors in Waterfield's hospital are split on the issue, but with so many smokers in the area's blue-collar community and such high rates of lung cancer, he isn't willing to wait.

Dr. Frederic W. Grannis, a thoracic surgeon at City of Hope Hospital near Los Angeles, is an investigator with the I-ELCAP. He notes only 15 percent of patients are alive five years after diagnosis.

"Despite all the potential problems with screening, in the long run it's far better than what we're doing," he said.

Those who take a wait-and-see approach are concerned about the costs of lung screening - and not just the direct ones. They worry that some hospitals are luring in patients who pay next to nothing for the scan, but then charge insurance companies for the expensive and sometimes unnecessary follow-up tests. Some critics refer to a lung scan as a "loss leader" for hospitals.

There are emotional costs as well - including the fear and anxiety of a false positive. Dr. Rex C. Yung, director of pulmonary oncology at Johns Hopkins Hospital, said a recent Mayo Clinic study found abnormalities in 71 percent of scans - that's 19 out of 20 patients enduring false positive tests. "It is a huge additional burden - not just a $150 screening," he said.

Joy Shoemaker doesn't see it that way. The Annapolis breast cancer survivor lost her two older sisters to lung cancer in the past five years. By the time they were diagnosed, it was too late to save them. So when she heard Anne Arundel Medical Center was offering lung screening, she called.

Two years ago, her lungs were scanned, and doctors found a spot. They decided to watch it. When she returned last year, the spot had changed but not enough to do more than wait. Last week, she had another scan and is awaiting the result.

"As long as they will monitor me, I will be monitored," she said. "I'd be foolish not to. After all, I don't want it to be too late."

stephanie.desmon@baltsun.com

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