Restricting lung cancer screening to only high-risk former smokers makes economic sense, a new study shows.
The study, “Performance and Cost-Effectiveness of Computed Tomography Lung Cancer Screening Scenarios in a Population-Based Setting: A Microsimulation Modeling Analysis in Ontario, Canada,” appeared in the journal PLoS Medicine.
U.S. guidelines recommend lung cancer screening with computed tomography (CT) for current and former smokers aged 55 through 80 who smoked at least 30 pack-years and who have quit within the past 15 years. Other countries are thinking about implementing similar lung cancer screening policies.
Yet even though many organizations support these programs, their cost effectiveness is debatable. Kevin ten Haaf of the Erasmus MC University Medical Center, in the Dutch city of Rotterdam, wanted to find out if it made sense to screen for lung cancer in a population-based setting and evaluate the effects of screening eligibility criteria.
To do so, he and his colleagues applied a mathematical model to examine 576 lung cancer screening strategies for people born in the Canadian province of Ontario between 1940 and 1969. They found that screening with rigorous smoking eligibility criteria (more years of heavy smoking required for screening) was more cost-effective than a less strict criteria, and that screening annually can be more cost-effective than screening once every two years.
The sweet spot appeared to be annual screening for those 55 to 75 years old who had smoked more than 40 pack-years and were current smokers or had quit less than 10 years ago.
This scenario would screen 9.56 percent (499,261 individuals) of the total population at least once, which would require 4,788,523 CT examinations, and reduce overall lung cancer mortality by 9.05 percent (preventing 13,108 lung cancer deaths), compared to no screening at all. Researchers estimated that this strategy would result in an incremental cost-effectiveness ratio equivalent to US$31,298 per life-year gained.
The U.S. National Lung Screening Trial (NLST), which compared two ways of detecting lung cancer — low-dose helical CT and standard chest X-ray — found that CT lung cancer screening for current and former smokers with three annual screens can be cost-effective in a trial setting. However, this latest study shows that stricter criteria would require fewer CT scans, leading to fewer false positives and fewer lung cancer diagnoses.
This analysis did not study what impact increased frequency of lung cancer screening and follow-up would have on the quality of life of those who were screened.
“Quality of life was not incorporated in the analyses, and assumptions for follow-up procedures were based on data from the NLST, which may not be generalizable to a population-based setting,” the researchers wrote. Even so, they added, results indicate “that lung cancer screening can be cost-effective in a population-based setting if stringent smoking eligibility criteria are applied.”