BOSTON — A new study published in JAMA Internal Medicine suggests that using smoking duration thresholds could identify more high-benefit candidates for lung cancer screening compared to current U.S. Preventive Services Task Force (USPSTF) criteria. The observational study analyzed 2024 National Health Interview Survey data from 57 million individuals aged 40 to 80 years who had ever smoked.

Researchers at Boston University School of Medicine, including Dr. Lauren Kearney, categorized individuals based on expected benefit using the Life-Years from Screening–CT model. They found that while smoking duration thresholds identify more potential beneficiaries, they involve trade-offs. "Smoke duration thresholds are simple to apply and identify more people who may benefit from [lung cancer screening] than USPSTF criteria," Kearney said. "However, they entail trade-offs between effectiveness and efficiency and population size."

The USPSTF criteria captured 77% of individuals who would benefit most from screening. A smoking duration threshold of at least 40 years identified 85% of this group, while a 30-year threshold captured 97%. A 20-year threshold identified 99% of those in the highest-benefit category.

Regarding efficiency, current USPSTF criteria excluded 98% of individuals expected to receive the least benefit. A 40-year threshold excluded 100% of the lowest-benefit individuals. In contrast, a 30-year threshold excluded 69% of the lowest-benefit group, and a 20-year threshold excluded 96%. Among those selected by a 40-year criterion, 68.8% were in the highest-benefit category and 0.1% were in the lowest-benefit category.

"Decision-makers must weigh these trade-offs according to priorities such as resource availability and the imperative to avoid missing those who may gain the most," Kearney stated. Iakovos Toumazis, a researcher at the University of Texas MD Anderson Cancer Center in Houston, noted that "no single simplified eligibility rule can fully capture the heterogeneity of lung cancer risk among individuals who ever smoked." He added, "As screening programs continue to evolve, policies that balance simplicity, efficiency, and precision will be essential to maximizing the benefits of [lung cancer screening] while minimizing potential harms."

The mean age of the study population was 59.1 years, with men making up 55% of the group. The average number of years smoked was 26. The USPSTF expanded eligibility in 2021 by lowering the pack-year threshold to 20 years and the screening initiation age to 50 years. Estimates indicate fewer than 20% of eligible individuals undergo low-dose CT screening. One study found that increasing screening uptake to 100% of eligible individuals could more than quadruple the number of lung cancer deaths prevented over a 5-year period.