Study Looks at Potential Impact of Expanded Eligibility for Low-Dose CT Lung Cancer Screening

Modifications to pack-year history and smoking quit duration thresholds beyond those recommended in the 2021 United States Preventative Services Task Force (USPSTF) criteria for low-dose computed tomography lung cancer screening may more than double the number of increased lung cancer cases physicians would see with application of the 2021 USPSTF screening criteria.

Did the United States Preventative Services Task Force (USPSTF) go far enough in 2021 with modification of its criteria recommendations for low-dose computed tomography (LDCT) lung cancer screening to help address disparities in screening access?

In a recently published study assessing data from 17,421 people diagnosed with a lung nodule, researchers compared the 2013 USPSTF criteria (> 30 pack-year history of cigarette smoking and active smoking or quit duration < 15 years in people 55 to 80 years of age) versus 2021 USPSTF criteria, which expanded the initial age criteria to 50 and reduced the pack-year history to > 20. The study authors also examined the potential impact of increasing the quit duration to 25 years (USPSTF2021-QD25), reducing the pack-year history to > 10 years (USPSTF2021-PY10), and the combination of those two criteria modifications (USPSTF2021-QD25-PY10).

The expanded LDCT screening criteria of the 2021 USPSTF criteria led to an 11 percent increase in the number of people diagnosed with lung cancer in comparison to the 2013 USPSTF criteria, according to the study, which was published in the Journal of Thoracic Oncology. However, the study authors found the USPSTF2021-PY10 criteria, the USPSTF2021-QD25 criteria and the USPSTF2021-QD25-PY10 criteria led to 26 percent, 28 percent, and 37 percent increases, respectively, in the number of diagnosed lung cancer cases in comparison to 2013 USPSTF criteria.

Out of the 501 people diagnosed with lung cancer in the USPSTF2013 cohort, 48 percent were women and 20 percent were Black. Out of the 588 patients diagnosed with lung cancer in the USPSTF2021cohort, 66 percent were female, and 21 percent were Black. In regard to the 184 additional people who were diagnosed with lung cancer in the USPSTF2021-CD25-PY10 group (but not eligible for screening with the 2013 USPSTF criteria), the researchers pointed out that 57 percent were female, and 24 percent were Black.

“LDCT screening, as currently implemented, exacerbates racial and sex-based disparities because women and racial minorities develop lung cancer at a younger age and with less intense cigarette tobacco exposure than White men, upon whose risk the eligibility criteria are mostly based. This inequitable access is particularly unfortunate because lung cancer screening seems to be disproportionately more effective in Black persons and women,” wrote study co-author Raymond U. Osarogiagbon, MBBS, FACP, the director of the Multidisciplinary Thoracic Oncology Program and the Thoracic Oncology Research (ThOR) Group at Baptist Cancer Center in Memphis, Tn., and colleagues.

Noting a higher risk of lung cancer among Black and female populations with lower than 20 pack-years of tobacco exposure, the study authors emphasized the importance of a lower pack-year threshold for LDCT screening.

“When we reduced the pack-year requirement to 10 years, overall eligibility increased an additional 13% and the percentages of eligible persons who were Black or female increased further beyond that seen when moving from USPSTF2013 to USPSTF2021,” pointed out Osarogiagbon and colleagues. “This pack-year reduction also showed a minimal drop in the proportion of individuals with lung cancers identified.”

Noting study limitations inherent to retrospective analysis, the study authors also said the inclusion criteria of pulmonary nodule identification suggests a higher-risk population with Lung-RADS 3 and 4. Accordingly, Osarogiagbon and colleagues said extrapolation of these findings to general populations may be limited.