Wednesday, October 25, 2006

New Scans Could Prevent Many Lung Cancer Deaths

October 25, 2006

New Scans Could Prevent Many Lung Cancer Deaths
By GINA KOLATA
The New York Times

Researchers at New York-Presbyterian Hospital/Weill Cornell Medical Center report that they can save the lives of millions of people by detecting lung cancer early and treating it immediately, when it can still be cured.

The stakes are high — lung cancer is the leading cause of cancer deaths in this country, killing more than 160,000 people a year, which is more than 95 percent of patients. And while the death rates for other cancers have fallen, the rate for lung cancer remains stubbornly high, possibly because the cancers are often caught too late. For years, doctors have thought there was very little they could do for lung cancer, but now with more sensitive scans for screening, many are rethinking that view.

“You could prevent 80 percent of deaths,” said the study’s lead author, Dr. Claudia Henschke, a professor of radiology and cardiothoracic surgery at Weill Cornell Medical College.

Her study, being published in Friday’s New England Journal of Medicine, involved more than 31,000 people in seven countries. The participants included smokers and former smokers, as well as people in Japan who had never smoked but had the scans as part of their annual physical exams.

The scans found 484 lung cancers, 412 of which were at a very early stage. Then the researchers kept track of those cancer patients, following them for an average of about three years after the cancer was found. After three years, most were still alive. The researchers projected that more than 80 percent of those with early stage cancer would live at least 10 years after their cancer was detected.

But the report is engendering controversy. Some medical experts and a patient advocacy group saying that because this study is so much bigger than previous studies and so carefully done, it should change the testing landscape. Others are saying that the study did not include comparison groups to clearly demonstrate that there is any benefit from annual CT exams.

Supporters include Dr. James Mulshine, a professor of internal medicine at Rush University Medical Center in Chicago. The study design may not have been perfect, he said, and there is more to be learned from other studies that are now under way, but the data from the new study convinced him.

“This is a profoundly important report,” Dr. Mulshine said. “It is a remarkable result.”

An advocacy group for lung cancer patients, the Lung Cancer Alliance, agreed.

“This is the most important breakthrough for the lung cancer community that has ever happened,” Laurie Fenton, the group’s president, said in a press release.

And, says Dr. Henschke’s colleague, Dr. David Yankelevitz, it makes sense that early detection of lung cancer could save lives. Lung cancer screening is analogous to screening for breast cancer, he said. In both situations, he added, “treatment is easier and the outcomes are better when the tumor is small.”

But mammograms are advocated by many national groups, whereas lung cancer screening is not. And while praising the new study’s careful accumulation of data, representatives of groups like the American Cancer Society, the Society of Clinical Oncology, the International Association for the Study of Lung Cancer, and the U.S. Preventive Services Task Force say the study is unlikely to persuade them to recommend lung cancer screening as a public policy at this time.

One reason is that everyone in Dr. Henschke’s study had CT scans. And so, researchers say, with no comparison group of people who did not have scans, they are left with a pressing question: Does screening, in the end, save lives or cost lives?

“Intuitively, it makes sense —if you have a cancer, take it out,” says Dr. Stephen Swensen, a professor of radiology at the Mayo Clinic who conducted a study that was similar to Dr Henschke’s but smaller. “It makes sense that if you find a cancer earlier you will save lives,” he added. But Dr. Swensen said, “The science hasn’t backed that up yet.”

Cancer specialists have long known that all cancers - and lung cancers are no exception - include ones that stop growing and never kill or that grow so slowly that they never cause problems if they are simply left alone. So, some of them ask, how many of the people said to be cured were never in danger? And how often will people have operations that can involve removing part of a lung, and that can themselves kill a patient, when their cancer was not lethal? The problem, as with other cancer scans, is that science today cannot always tell the difference between cancers that will stop and those that will go on to kill.

The other question that researchers ask is slightly different: How often did the scans find cancers early but without affecting the person’s life expectancy?

“Everyone knows we can pick up things better with screening,” said Dr. Elliott Fishman, a professor of radiology and oncology at Johns Hopkins Hospital in Baltimore. “But is picking up the same thing as curing? If I pick up a tumor that is one centimeter today and you live five years or I pick it up four years later and you live one year, it’s the same thing.”

Even evaluating patients with suspicious CT scan results can be risky, much more dangerous than, say, evaluating women with suspicious lumps on a mammogram, said Dr. David Johnson, deputy director of the cancer center at Vanderbilt University and a past president of the American Society of Clinical Oncology. In Dr. Henschke’s study, doctors investigated more than 4,000 nodules in patients, finding about 400 cancers.

“This is not sticking a needle in a breast,” Dr. Johnson said. “It is sticking a needle in the chest where it can collapse a lung.” In some cases, that is followed by surgery to further evaluate a lump. The issues become pressing with the uncertainty about whether the screening can save lives.

“How many people do we subject to needless evaluations?” Dr. Johnson asked.

It is not even clear, some researchers said, whether the patients in Dr. Henschke’s study really did survive 10 years on average. The investigators used a statistical model to estimate how long patients would be expected to live after most had survived about three years.

“Ten years should be 10 years,” Dr. Fishman said. “It’s being guesstimated out. Let’s look in 10 years and see what happens.”

More definitive answers about the value of CT testing may come in a few years when another study, being conducted by the National Cancer Institutes of Health, is completed. It randomly assigned its nearly 55,000 participants, all smokers or former smokers, to have annual CT scans or, for comparison, a chest X-ray. Based on previous studies, many researchers consider chest X-rays largely ineffective for the early diagnosis of lung cancer so it can serve as a placebo control in this study.

Another cancer institute study is rigorously assessing chest X-rays by randomly assigning participants to have an annual chest X-ray or to have no lung cancer screening.

In the meantime, cancer specialists say doctors and their patients must decide what to do on an individual basis. They could wait for the clinical trials to be completed. Or they could decide to have scans now, even though the data may not be ideal.

The scans can be expensive. Dr. Howard Forman, a professor of diagnostic radiology at Yale, says that Yale charges a total of $802.39 for the scan and the doctor’s interpretation. And many insurers have not paid for CT lung cancer screening tests.

That may change, Dr. Forman said. He himself is not convinced by the new study — like others, he says he needs to see data from a control group. But Dr. Forman, who is on the Medical Policy and Technology Assessment Committee for Wellpoint, a health insurance company, said it will be difficult to deny paying for the test now that the data were published in the New England Journal of Medicine.

“The New England Journal of Medicine is a de facto Good Housekeeping seal of approval,” Dr. Forman said. “This is a big step toward public acceptance. It’s not proof that screening saves lives,” he said. But, he added, “Proof for a lot of medicine is not there.”

For now, says Dr. Robert Smith, director of cancer screening at the American Cancer Society, it might make sense for smokers or former smokers to have CT scans for early lung cancer detection.

Patients, he added, should thoroughly discuss the test with their doctors first, going over what is currently known and not known about the testing, including potential benefits and potential harms. And they should be careful to go to a center that has the expertise and experience to do the scans and any follow-up medical procedures properly.

But, Dr. Smith said, the new study adds to the information that CT scans might save lives.

“There is a lot of promise here,” he said. And so, he said, “it is not at all unreasonable for individuals at high risk of lung cancer to seek testing on their own.”

Others, like Dr. Ned Patz, a professor of radiology, pharmacology, and cancer biology at Duke University Medical Center, say that they suspect patients’ ardor for the testing might cool if they hear the full story about the uncertainties and risks.

“A lot of patients ask about it,” he said. “We counsel them and tell them what the data are. Then they are not interested.”

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