麻豆传媒

While the vast majority of persons who undergo low-dose CT (LDCT) screening for lung cancer have met U.S. Preventive Services Task Force (USPSTF) eligibility criteria, adherence to subsequent screening recommendations is low, according to a population cohort study.

Of the 1,159,092 persons who were entered into the American College of Radiology's Lung Cancer Screening Registry (LCSR) and received a baseline LDCT scan between 2015 and 2019, 90.8% met USPSTF criteria, reported Gerard A. Silvestri, MD, of the Medical University of South Carolina in Charleston, and colleagues in the .

However, adherence to subsequent screening was "suboptimal," with just 22.3% of those screened having a follow-up scan 12 months later, as recommended in the USPSTF guidelines.

Even extending the window to 24 months or more than 24 months, only 34.3% and 40.3% of individuals were adherent, respectively, to a subsequent screening -- significantly lower than the 94% adherence rate reported in the National Lung Screening Trial, on which the USPSTF recommendations were based.

"We are encouraged that people being screened largely meet the eligibility requirements," the authors wrote. Nevertheless, they added, "adherence is essential -- decreased adherence reduces cost-effectiveness and diminishes mortality benefits. Providers should emphasize that LDCT is not a 'one and done' test."

Considering that an estimated 8 million people in the U.S. were initially eligible for lung cancer screening when the USPSTF recommendations were first published in 2013, Silvestri and colleagues pointed out, "adherence to annual screening is low, which may limit its mortality benefit."

Silvestri's group focused on the first 1 million persons receiving lung cancer screening in data submitted from the 3,625 facilities reporting to the LCSR.

The authors compiled statistics on the smoking history and sociodemographic factors of these screening recipients and compared them with those of 1,257 respondents to the 2015 National Health Interview Survey (NHIS) who met the 2013 USPSTF screening criteria, and who were calculated to be an accurate representation of the population eligible for screening in the U.S.

Compared with the individuals in the NHIS, screening recipients in the LCSR were older (34.7% vs 44.8% were ages 65-74 years; prevalence ratio [PR] 1.29, 95% CI 1.20-1.39), more likely to be female (41.8% vs 48.1%; PR 1.15, 95% CI 1.08-1.23), and more likely to currently smoke (52.3% vs 61.4%; PR 1.17, 95% CI 1.11-1.23).

This meant screening recipients were less likely to be former smokers. "People who formerly smoked may be less likely to have their smoking status recorded in the electronic health record and may not be readily identified as eligible for screening," they suggested. "Screening may not be top of mind for patients or their practitioners during an office visit if they quit smoking years ago."

The authors also pointed out that while that vast majority of individuals screened were USPSTF eligible under the 2013 criteria, this still left 9.2% (n=106,501) who were not.

(lowering the age criterion from 55 to 50 years and the smoking criterion from 30 pack-years to 20) increased the number of individuals eligible for screening to an estimated 15 million. That means, according to the authors' calculations, that 38.0% (n=40,426) of those who had baseline screening while ineligible under the 2013 criteria would have been eligible with the current recommendations.

In an , Karina W. Davidson, PhD, of the Feinstein Institutes for Medical Research at Northwell Health in Manhasset, New York, pointed out that still leaves about 6% of individuals who were inappropriately screened, and she suggested that as screening increases across the country, "many patients could be exposed to harm without potential benefit."

Davidson suggested that clinicians should work with their healthcare systems to ensure that adherence to annual follow-up screening is adequate.

Whether centralized or decentralized approaches are better is still under investigation, she wrote. "More work is needed to establish whether dedicated nurse navigators, central databases, or other tools are required to improve on the 22% rate of annual follow-up screening reported in this sobering real-world registry."

Finally, Davidson noted that the 2021 updated recommendations approximately doubles eligibility among those who identify as American Indian, Alaska Native, Black, or Latino. "Attaining smoking histories and referring and following up with this important, large, and typically medically underserved population segment could dramatically decrease lung cancer deaths," she wrote.

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