Medically Reviewed by Gary D. Vogin, MD From the WebMD Archives
April 9, 2001 — An ultra-fast CT scan is being advertised on billboards and in newspapers across the country, with claims it can diagnose lung cancer early and, therefore, save the lives of people stricken by the world’s No. 1 cancer killer. Now mobile trucks are making the rounds, much like mobile mammography vehicles. Just climb inside for $200 to get screened for lung cancer. Well, is it really worth it?
Two prestigious medical groups — the American College of Cardiology and American Heart Association — issued a consensus statement last year after a thorough review of scientific literature on the usefulness of ultra-fast CT scans in diagnosing heart disease. The test overstates the risk of heart disease, the statement said.
If you are at risk for lung cancer, should you do it?
On the “pro” side: In one study involving two centers — New York Presbyterian Hospital and New York University Medical Center — 1,000 people over age 60, all of whom had been smoking for more than 10 years, received the ultra-fast CT scan. More than 80% of the tumors identified in that study were early-stage tumors, which can be curable if they are surgically removed.
On the “con” side: A 20-year study from the National Cancer Institute last year found that male smokers who underwent intense screening were somewhat more likely to die from lung cancer than those who went for the more standard, yearly exams. Conducted between 1971 and 1983, the trial compared the death rate from lung cancer in more than 9,000 male smokers who received either intense or standard lung cancer screening. Those in one group had a chest X-ray and sputum tests every four months for six years. Another group got a single recommendation at the start of the study: to have the same screening once a year.
Results: Although the men in the frequent-screening group survived longer with cancer, there was no difference in the number of deaths from cancer between the two groups.
Shouldn’t early detection reduce the number of lung cancer deaths? Not necessarily, says Pamela M. Marcus, MS, PhD, a cancer prevention specialist at the NCI who led the institute’s 20-year study.
As with heart disease, ultra-fast CT scan overstates the risk of lung cancer, Marcus tells WebMD.
Intense CT screening picks up both slow- and fast-growing tumors — as well as those that are benign, Marcus tells WebMD. “Some tumors are so slow-growing that they don’t need to be treated; people will die of other causes before dying of those tumors.”
But when something shows up on a scan, something must be done. The first step is surgery to remove the tumor, to correctly determine if it is cancer.
“The surgery is not without risks,” Marcus says. “There’s actually a fairly high risk of death — of people dying on the table or from complications.”
Cancer treatment also is not innocuous; it has side effects, she says.
Many doctors are taking the wait-and-see approach, Marcus tells WebMD. Wait until symptoms appear before putting people through unnecessary surgery.
Marcus acknowledges that not everyone agrees with that approach.
“Some say that there’s no such thing as an unimportant lung cancer lesion, because the fatality rate for lung cancer is so high,” she tells WebMD. “But there may be a difference between tumors that cause symptoms and those that don’t. Those that cause symptoms seem to be those that need treatment, that are fast-growing. These are caveats that have to be considered. I can’t advocate these scans unless I think they can do more benefit than harm.
“My personal opinion is that it’s too premature to advocate mass screenings in … people who are at elevated risk for lung cancer” but have no symptoms of the disease, Marcus says. “We don’t know enough yet. If somebody is on the fence, the best thing is talk to their doctor.”
The American Lung Association is similarly unsold on the need for mobile CT scanners.
“There’s a lot more research that needs to be done to determine whether there truly is an increase in survival from cancer,” says Norman Edelman, MD, scientific consultant to the American Lung Association and dean of the school of medicine at State University of New York at Stony Brook. In fact, a multicenter study in New York City is attempting to answer that question, Edelman tells WebMD.
“The ALA is not yet recommending this to the American public,” Edelman says. “We’re not saying it’s not good; we’re simply saying more research needs to be done.”
