Patients at risk for lung cancer who undergo CT screening have about a one-in-five chance that doctors will find--and potentially treat--a tumor that wouldn't lead to illness or death, according to a study published online in the journal JAMA Internal Medicine.
The study was based on data obtained during the National Lung Screening Trial, which found that 20 percent of lung cancer deaths can be prevented if doctors perform CT screening on patients at high risk of developing lung cancer--namely people ages 55 to 79 who are current smokers or quit less than 15 years ago.
This past summer, the United States Preventive Services Task Force issued a draft recommendation supporting the use of lung cancer screening with low-dose CT for persons with a high-risk of developing the disease.
"It doesn't invalidate the initial study, which showed you can decrease lung cancer mortality by 20 percent," Norman Edelman, M.D., senior medical adviser for the American Lung Association, told in HealthDay News. "It adds an interesting caution that clinicians ought to think about--that they will be taking some cancers out that wouldn't go on to kill that patient."
Edward Patz, a professor of radiology at Duke University Medical Center and co-author of the study, said the results highlighted the need for research to detect genetic markers that will help physicians discriminate between aggressive cancers and those that won't need treatment.
The American College of Radiology issued a statement reacting to the study, saying that the benefits accrued from CT lung cancer screening in the reduction of lung cancer deaths in high risk patients "significantly outweigh the comparatively modest rate of overdiagnosis noted in the article."
Added Paul Ellenbogen, M.D., chair of the ACR's Board of Chancellors: "Physicians should certainly discuss the risk and benefits of CT lung cancer screening with patients--including that of overdiagnosis. However, for high-risk patients, the group in which CT lung cancer screening is proposed, the lifesaving benefit outweighs the risks. It is now a matter of incorporating the available information--including this JAMA [Internal Medicine] article--and adjusting protocols to minimize those risks as we move forward."