Many High-Risk Individuals Not Eligible For Lung-Cancer Screening By US Guidelines

Many individuals, especially Blacks, at high risk of lung cancer are not eligible for screening by US Preventive Services Task Force (USPSTF) guidelines, according to a new study.

"Current national screening guidelines for lung cancer can induce disparities related to race, socioeconomic status, and comorbidity, and hence a more comprehensive screening approach such as risk-based screening should be considered," Dr. Summer S. Han of Stanford University School of Medicine, in Stanford, California, told Reuters Health by email.

Current USPSTF guidelines recommend annual low-dose CT screening of people aged 55-80 years who have at least 30 pack-years of smoking and are within 15 years since smoking cessation. Individuals with other risk factors—race, low education, history of chronic obstructive pulmonary disease, or family history of lung cancer—could be missed by these guidelines.

To characterize the profiles of those eligible for lung cancer screening by risk-based criteria but not by USPSTF criteria, Dr. Han and colleagues used data from the National Health Interview Survey (NHIS) and the Cancer Intervention and Surveillance Modeling Network (CISNET) Lung Working Group Smoking History Generator and the US Census Bureau.

Overall, 5.4% of individuals aged 50-54 years and 10.4% of those aged 71-80 years would be eligible for lung cancer screening by risk-based criteria but ineligible by USPSTF criteria.

In the younger age group, significantly more blacks (15.6%) than whites (4.8%) would be missed for screening by USPSTF criteria, the researchers report in the Journal of the National Cancer Institute.

Higher risk thresholds would select fewer individuals for screening and would decrease the gap between the two screening criteria, but the proportion of individuals ineligible for screening by USPSTF is consistently higher in blacks than in whites, independently of the risk threshold.

Racial disparities in screening eligibility were larger among males than females, which largely reflects racial differences in smoking behavior.

Education level also affects the disparities between the two criteria: In the 50-54-year age group eligible for screening by risk-based criteria, 6.4% of those who have a high school education or less would be ineligible for screening by USPSTF criteria, compared with only 2.4% of those with a college education and 1.5% of those with postgraduate or professional degrees.

"Personalized screening based on risk prediction models has the potential to reduce disparities in screening compared to national lung screening guidelines that recommend uniform screening criteria, which are likely to exclude high-risk individuals from disadvantaged groups," the authors conclude.

Dr. Kim L. Sandler, co-director of Vanderbilt University Medical Center's Lung Cancer Screening Program, in Nashville, TN, told Reuters Health by email, "This publication contributes to the growing body of literature that supports modification of the existing USPSTF guidelines for lung screening to address racial disparities. Whether this will be based on adjustments in age and/or pack-years or implementation of a risk-prediction model is yet to be seen, but hopefully we will see some change in screening recommendations."

"This study again shows that a significantly higher proportion of black individuals as compared to whites with lung cancer are ineligible for lung screening," she said. "Physicians should be aware of this disparity and consider how personalized screening based on risk models could affect their patients and practice."

Dr. Sandler added, "The authors point out that this article addresses eligibility but not screening rates. Even if we modify the screening guidelines, we must also address the currently low uptake of lung screening so that we can improve survival."

—Will Boggs MD

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