Lung Cancer Screening Recommended for Heavy Smokers

New guidelines from the U.S. Preventive Services Task Force (USPSTF) recommend that smokers between the ages of 55 and 80 who have smoked for at least 30 pack-years, or former smokers who meet the age and pack-year criteria but quit less than 15 years ago, undergo annual screenings for lung cancer using low-dose computed tomography (CT) scans. Pack-years are calculated by multiplying the number of packs smoked daily by the number of years.

Published December 31 in the Annals of Internal Medicine, the guidelines update those released in 2004, which concluded that the evidence was insufficient to recommend screening.

Lung cancer is the leading cause of cancer death in the United States, and the vast majority of people who develop the disease ultimately die from it, no matter how it's detected, notes Michael LeFevre, MD, MSPH, a family physician at the University of Missouri School of Medicine in Columbia and the co-vice chair of the USPSTF.

“Even without screening, other cancers have a much better prognosis than lung cancer,” he adds.

The recommendations were based largely on results from the National Lung Screening Trial, a randomized trial involving more than 50,000 current and former smokers between 55 and 74 years old. The results, published in 2011 in the New England Journal of Medicine, suggested screening could prevent as many as 20,000 of the 160,000 annual lung cancer deaths.

The USPSTF assigned the guidelines a B recommendation, meaning the task force is moderately certain the benefit from screening outweighs the harms by at least a moderate amount. However, LeFevre cautions that the balance between risk and harm is delicate in this case.

“There is meaningful harm associated with lung cancer screening,” including a 95% false-positive rate and an increased cancer risk from radiation associated with screening, he says. The guidelines do not extend to other combinations of age groups and smoking history. “The further you stray from the target group, the greater the likelihood that the harm will outweigh the benefit.”

Frank Detterbeck, MD, surgical director of thoracic oncology at Yale University School of Medicine in New Haven, CT, calls the guidelines an important step in the ongoing process of using screening wisely. But like LeFevre, he cautions against extrapolating to other patients.

“I think we need to stick to what we know. We have something that can do a lot of good if we pay attention,” he says. “I'm for screening but if we do it haphazardly, then it could end up being cast in a bad light and won't really take hold. I think people need to be careful about how they do screening.”