TUESDAY, Jan. 14, 2003 (HealthDayNews) -- It sounds like a great idea: Go to the doctor's office, spend a few hundred dollars on a CAT scan, and find out if you have lung cancer from smoking.
But if you're not suffering from any symptoms, researchers say you should just stay home and save your money.
While the scans may save lives, a computer simulation shows that regular scans would be too expensive for American society to bear, says Dr. Parthiv J. Mahadevia, a research scientist who studied the potential use of the technology. False alarms could also lead to unnecessary surgeries for healthy people, he says.
"There are negative consequences as well as high costs," says Mahadevia, who works at MEDTAP International in Bethesda, Md.
Computed tomography (known as CT or CAT scans) allows doctors to see three-dimensional views of the inside of the body. Scientists improved the technology in the 1990s by developing a type of CAT scan known as helical or spiral. The scans -- which cost as much as $450 each -- can detect tumors smaller than one centimeter, and doctors routinely use them on patients who show signs of lung cancer.
But some doctors also advocate their use on smokers who don't otherwise appear to be sick.
The U.S. government recently started an eight-year study of the use of the CAT technology to detect lung cancer. The National Cancer Institute is recruiting 50,000 smokers and ex-smokers to determine if regular CAT scans and traditional X-rays would reduce death rates.
For now, though, the worth of the scans isn't clear, Mahadevia says. "The question is: What do we do in the interim? How can we guide decision-making?"
So he and colleagues designed a computer model to estimate how many lives would be saved if hypothetical groups of 60-year-old smokers and former smokers got annual CAT scans.
Out of 100,000 current smokers in the hypothetical scenario, the scans would save an estimated 553 lives. But more than 1,100 people would undergo unnecessary biopsies and other types of surgery that pose risks of their own, according to the study.
Using a common measurement of the value of medical tests, the researchers estimate that it would cost U.S. society an estimated $116,000 for each extra year of "high-quality" life for current smokers who would otherwise have died. (Lives defined as "high-quality" would not be hindered by major health problems.)
According to the researchers, it's not cost-effective to spend more than $100,000 to add an extra year of "high-quality" life.
The results, which are published in today's issue of the Journal of the American Medical Association, show that CAT scans are best used when a person already shows symptoms of lung cancer, Mahadevia says. "When you know there's something going on, you need to find out what it is," he says.
But even a firm diagnosis of lung cancer doesn't guarantee a rosy future, says Dr. Victor Grann, a clinical professor of
medicine at Columbia University who wrote an editorial accompanying Mahadevia's study.
"The problem with lung cancer patients who smoke is that not only are they prone to get lung cancer once, but they're also at risk to get it again or get other cancers," he says.
Also, lung cancer is difficult to detect in its early stages and difficult to treat later on. "The majority of lung cancer patients are in more advanced stages when the disease is picked up, and they end up dying from it," Grann says.
However, Grann does say that it may be cost-effective to give the CAT scans to smokers who seem healthy if their level of worry about cancer is so high that it may affect their quality of life.
More information
Find out more about CAT scans from Brigham and Women's Hospital or the Minnesota State Health Technology Advisory Committee.
