Participants at 33 sites received either a low-dose CT scan or a chest x-ray for three years and were followed for five. The results were compelling enough that researchers stopped the trial early in November and released some information about the study. But the complete statistics and results were not released until Wednesday.
Frank Detterbeck, M.D., surgical director of the Yale Thoracic Oncology Program, says now government groups, such as the U.S. Preventive Services Task Force, and nonprofit cancer groups will delve into the numbers and create guidelines for how doctors should interpret the results.
"We need to take these results very seriously," Detterbeck says, and consider how to "save the thousands of lives that we have the potential to save."
About 7 million Americans fit into the group studied in the trial, but there are 94 million current or former smokers and many more with other risks, such as exposure to secondhand smoke.
Detterbeck chairs a committee of experts working to create guidelines in the next several months to help doctors apply the results of the study to their patients.
While the results are compelling enough to warrant the CT scans, Detterbeck says, at the same time it's crucial to carefully design the recommendations so that doctors understand how to interpret the findings.
The researchers, he points out, also saw a large number of spots on the scans that weren't dangerous, leading to more scans, and even biopsies and surgery. About a quarter of all the scans found some abnormality but nearly all of them turned out to be benign. The scans also found cancers that surgeons then removed that might not have been harmful.
"If everybody who has a little finding on the scan starts to have a biopsy, then we may do a lot of harm," Dedderbeck says.
And as government seeks to reign in rising health cost, even one of the experts who helped design the study says there are hard decisions to be made before the country commits to a new screening that could cost billions of dollars.
"There are not unlimited health care dollars," says Edward Patz Jr., M.D., a professor of radiology at Duke University Medical Center and an investigator who helped design the study. "We have to make some decisions once we have the data whether this is really worth it or not."
Next page: Is this test really necessary? »