For Smokers, a Tough Call
Tuesday, November 14, 2006
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 at 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, experts from the American Cancer Society and other groups say.
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 percent 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 in the Washington area offer tests that range from $175 to $800 and are rarely covered by insurance. About 60 percent 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 he thinks 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" and that people over 40 who have smoked the equivalent of a half-pack a day for 15 years should consider being screened. Washington Radiology charges $686 for the non-invasive test, which takes about 30 seconds; a physician's order is required.
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 percent 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 percent, 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.
Claudia I. Henschke, the researcher who headed the I-ELCAP study, said the study shows that early diagnosis means that a cure is possible. She has said she does not think that a randomized controlled trial, the gold standard in medicine, is necessary to prove the effectiveness of lung CT scans, as do officials at the National Cancer Institute and the American Cancer Society.