A smoking-duration cutoff may be a better measure for determining lung cancer screening eligibility compared with smoking pack-years.
Changing the current United States Preventive Services Task Force (USPSTF) lung cancer guidelines to a 2-year smoking duration cutoff vs a 20 pack-year cutoff would significantly improve the rate of cancer detection and reduce racial disparities with screenings, according to findings presented at the International Associated for the Study of Lung Cancer (IASLC) North American Conference on Lung Cancer in Chicago.
Using the Southern Community Cohort Study (SCCS) and the Black Women’s Health Study (BWHS), investigators looked at individuals with a smoking history. A total of 49,703 and 22,126 individuals from the SCCS and BWHS, respectively, qualified for analysis.
Investigators looked at these individuals’ data to determine who would qualify for lung cancer screening under the current USPSTF guidelines and compared those findings against who would qualify if the “20 pack-year” requirement was replaced with a “20-year smoking duration” criterion.
Under the current 2021 USPSTF guidelines, the percentage of Black patients with lung cancer who would have qualified for screening in the SCCC group was 57.6%. A significantly higher proportion of White patients in this group would have met the criteria (74.0%) with the current guideline (P < .001).
However, in looking at this same population, the proportion of Black and White patients who would have been eligible for screening with the proposed guideline change was 85.3% and 82.0%, effectively eliminating the screening disparities between the 2 groups.
Importantly, approximately all patients with lung cancer between the ages of 50 and 59 would have qualified for screening under the proposed guidelines—including Black and White patients.
When investigators evaluated the 486 Black women with lung cancer in the BWHS group, their calculations found that changing the 20 pack-year cutoff to a 20-year smoking duration cutoff would increase the percentage of women eligible for screening from 42.5% to 63.8%.
Lung cancer screening with low-dose CT has reduced the incidence of death by 20%, but qualifying best practices for screening eligibility continues to be an ongoing challenge. Currently, patients are eligible for screening if they have a 20 pack-year smoking history, are between the ages of 50 and 80, and either currently smoke or have quit within the past 15 years.
Yet, the study authors maintain that the pack-year smoking history is a biased measure that severely underestimates the lung cancer risk that faces individuals who smoke less intensely.
According to the study authors, the current “pack-year” parameter used to determine lung cancer screening eligibility since the 2021 USPSTF guideline is based on historic and not epidemiologic evidence. They argue that it excludes many individuals who are at high risk for lung cancer.
“Our research challenges current lung cancer screening practices and highlights the need for a reevaluation of screening criteria to ensure equitable access for all individuals at risk. We anticipate that these findings will contribute to ongoing discussions within the medical community regarding the refinement of lung cancer screening guidelines,” they reported.
Potter A. Pack-Year Smoking History: an inadequate and biased measure to determine lung cancer screening eligibility. Presented at the 2023 North America Conference on Lung Cancer. December 1-3; 2023; Chicago, IL.