Weighing lung-cancer test
To screen or not to screen?
That is the question patients -- most of them current or former smokers -- are asking doctors following the publication of a large international study that found that spiral CT scans can detect lung cancer at its earliest and most curable stage.
The results, published last month in the New England Journal of Medicine, have fueled hope that the technology can lead to early treatment of the most common cause of cancer death, as mammography has done for breast cancer.
But the study involving more than 31,000 current and former smokers headed by researchers at Weill Medical College of Cornell University failed to answer a fundamental question: Does screening extend lives or merely find cancer earlier?
Because the study did not use a control group, there is no way to tell whether the risks of screening, which include repeated radiation exposure and the possibility of aggressive follow-up treatment, outweigh the benefits of early detection, say experts from the American Cancer Society and other groups.
Therein lies the rub -- and the reason doctors are sharply divided about testing people who don’t have symptoms, even for a cancer that kills 85% of the 174,000 Americans found to have the disease annually within five years of diagnosis.
Interest in lung cancer screening is growing, experts agree. Some hospitals and radiology clinics offer tests that range from $175 to $800 and are rarely covered by insurance. About 60% of hospitals and clinics own CT scanners, which were developed in the 1990s and can detect tumors as small as a grain of rice.
“I think the answer is pretty clear: no,” said Ned Patz, a professor of radiology, cancer biology and pharmacology at Duke University Medical Center, when asked about screening. “I’m not saying it won’t work, just that there’s no solid proof yet that it does.”
That’s what Patz told his 74-year-old father, a former smoker who has no symptoms but worries about the consequences of his 20-year pack-a-day habit. A more definitive answer, Patz said, must await the outcome of a National Cancer Institute study involving 53,000 current and former smokers. That study, launched in the mid-1990s, is comparing the death rates of patients who received spiral CT scans with those screened with chest X-rays. Results are expected by about 2010.
Radiologist Alex Kladakis says there’s no need to wait.
One of 22 physicians at Washington Radiology Associates, among the area’s largest radiology practices, Kladakis said that the recent study shows “the proof is really there.” To Kladakis, the most persuasive finding in the study, dubbed I-ELCAP (International Early Lung Cancer Action Project), is the survival data. Of the 412 people in the study found to have Stage 1 cancer who underwent surgery, 85% were alive five years later; the eight patients who declined treatment were dead. The average five-year survival rate for Stage 1 lung cancer is about 70%, according to federal statistics.
“It seems to me those eight are kind of a mini-control group,” Kladakis said, adding that requests for lung screenings have increased since the study was published. “Lung cancer is a very, very bad disease,” he said. And by the time a patient has symptoms, such as a persistent cough, it usually means the disease is advanced, Kladakis said, citing the example of ABC anchorman Peter Jennings, who died of lung cancer last year.
Dennis Barry, 51, underwent the scan last year as part of the study -- and was stunned that it turned up a suspicious nodule. An executive vice president of Donohoe Construction Co., he enrolled in the study at the suggestion of a relative who works at the hospital.
He said he smoked a pack a day from age 15 to age 40, when he quit. Last summer, weeks after the scan, Barry had part of his lung removed, followed by chemotherapy.
“I’m a lucky guy,” said Barry, whose father died of lung cancer at 65 after years of smoking. “I think this test saved my life.”
But consumers in general currently don’t have enough information to decide whether screening is a wise choice, said Arthur Levin, director of the New York-based Center for Medical Consumers.
“One study is not sufficient. The problem is that in this country we let the marketplace decide this. And because lung cancer is such a major killer, there’s going to be a lot of interest in moving this down the road,” and many people who say they want the test but may not understand the pitfalls.
CT scans, routinely used to stage lung cancer once it has been diagnosed, often pick up nodules, clumps of potentially cancerous tissue, during screening. Their size matters: Smaller nodules are less likely to be malignant than larger ones, experts say. Thoracic experts estimate that as many as 60% of smokers and former smokers have lung nodules, Patz said, but people who never smoked also can have them.
Finding a nodule usually triggers a cascade of interventions, starting with a biopsy, which can cause infection, scarring and a collapsed lung. A cancer diagnosis typically results in surgery, often followed by chemotherapy or radiation or both. Doctors have no accurate way of determining which tumors are fast-growing and aggressive and which grow so slowly that patients are likely to die with and not of them, as with some types of prostate cancer.
But Laurie Fenton, president of the Lung Cancer Alliance, a Washington-based advocacy group, said the findings of the study are so persuasive that her group is advocating screening scans for people older than 50 who are current smokers or who smoked the equivalent of a pack a day for 10 years and those with significant exposure to secondhand smoke.
“We have to educate doctors” about the benefits of screening, Fenton said.
