The sense and nonsense of CT screening for lung cancer

Supporters of evidence-based preventive medicine cheered when the Affordable Care Act required Medicare and private health insurers to provide first-dollar coverage for all preventive services assigned an "A" or "B" recommendation grade by the U.S. Preventive Services Task Force. However, editorials published in JAMA and BMJ earlier this year expressed concerns that explicitly linking Task Force determinations with coverage decisions would politicize the guideline development process. Also, since the USPSTF is permitted to consider only clinical effectiveness, not cost effectiveness, it could potentially put taxpayers on the hook for cost-prohibitive screenings.

In this context, our August 2013 Georgetown University Health Policy Seminar debated the USPSTF's recent draft recommendation statement that endorsed annual low-dose CT screening for lung cancer in longtime smokers. This Grade "B" recommendation applies to "healthy persons with a 30 pack-year or more history of smoking who are ages 55 to 79 years and have smoked within the past 15 years," a population that includes up to 8 million persons in the U.S. Using data from the National Lung Screening Trial and five modeling studies, the Task Force estimated that implementation of their recommendation could prevent up to 20,000 lung cancer deaths each year. They downplayed the potential harms of false positive screens (which affected 1 in 4 participants in the NLST), overdiagnosis, and radiation-induced cancers.

Images from the Lung Cancer Foundation's Demand A CT Scan campaign.

Lung cancer screening advocacy groups, which had been pressing for years for patients at high risk of lung cancer to "demand a CT scan," were quick to praise the USPSTF's decision. Notably, the American Cancer Society's guideline for lung cancer screening, also released this year, advocates a more conservative approach: initiating a shared decision-making discussion about benefits and harms of lung cancer screening in high-risk persons in otherwise good health, rather than simply recommending screening. The USPSTF's approach is certain to be far more costly, and may discourage clinicians from explaining the many downsides of this screening test to their patients.

- Kenny Lin, MD, MPH
  Director, Robert L. Phillips, Jr. Health Policy Fellowship
  Department of Family Medicine
  Georgetown University School of Medicine