The National Lung Screening Trial (NSLT) showed a 20% reduction in death from lung cancer, but with a number needed to screen of 320 to prevent one death, a false-positive rate of 96% and each abnormal scan generating costs of ~$45,000, the risk / benefit / cost accounts are far from settled. Few insurers (e.g. Wellpoint) are paying for CT scans as screening in asymptomatic smokers; Medicare is not, yet, but may do so along with many other insurers if the U.S. Preventive Services Task Force (USPSTF) revises its lung cancer screening recommendations (last updated in 2004).
Results from recently conducted surveys show that well before the NSLT was published, primary care doctors have been ordering a lot of lung cancer screening tests on asymptomatic smokers -- but usually, its a "placebo" chest X-ray they choose:
In 2006-2007, Carrie Klabunde et al surveyed about 1,250 physicians by mail, 962 of whom responded (77%):
- 62% had ordered lung cancer screening tests in the past 12 months (2005-2006)
- 55% had ordered chest radiographs;
- 22% had ordered chest CT;
- <5% had ordered sputum cytology.
What made doctors more likely to order lung cancer screening tests? Physicians ordered more screening if they believed that expert groups recommend lung cancer screening (they don't) or that screening tests are effective, and if their patients had asked them about screening.
The best available data from the PLCO trial strongly suggest that chest X-rays are not useful in detecting lung cancer at an early enough stage to improve survival.
These numbers are impressively high. The real question is how high have they gone now after the publication of the National Lung Screening Trial, and in an environment of $99 (cash-only) lung cancer screening CT scans advertised by otherwise reputable academic and community health centers, in an attempt to get patients in the door to get a piece of that $45,000 in downstream revenue, excuse me, I meant "costs of care."
Klabunde CL et al. Lung Cancer Screening Practices of Primary Care Physicians: Results From a National Survey. Ann Family Med 2012;10:102-110.