New research suggests that proposed lung cancer screening guidelines could inadvertently increase racial and ethnic disparities, but adding in a risk prediction model could reduce some of these disparities by identifying people with high predicted benefit, regardless of race or ethnicity.
The draft United States Preventive Services Task Force (USPSTF) 2020 guidelines recommend annual lung cancer screening for individuals aged 50-80 who currently smoke or quit in the last 15 years, and who have a smoking history equivalent to at least one pack of cigarettes per day for 20 years or more.
This expands the age range and smoking history requirement compared to the 2013 USPSTF recommendations in an attempt to partially ameliorate racial disparities in screening eligibility. The 2013 guidelines recommend screening ever-smokers aged 55-80 with 30 or more pack-years and 15 or fewer quit-years.
However, neither the 2013 nor the 2020 USPSTF recommendations consider the higher risk of lung cancer and younger ages at diagnosis among African Americans, despite their smoking less than Whites, according to Rebecca Landy, PhD, of the National Cancer Institute in Bethesda, Md.
“For the same age and smoking history as Whites, minorities have substantially different lung cancer risk,” Dr. Landy said. “Incorporating individualized prediction models into USPSTF guidelines may reduce racial/ethnic disparities in lung cancer screening eligibility.”
Dr. Landy and colleagues set out to test that theory, and she presented the results at the 2020 World Congress on Lung Cancer (Abstract 3564), which was rescheduled for January 2021. The results were published in the Journal of the National Cancer Institute.
Study details
Dr. Landy and colleagues modeled the performance of National Lung Screening Trial–like screening (three annual CT screens, 5 years of follow-up) among three cohorts of ever-smokers aged 50-80 using the 2015 National Health Interview Survey.
One group was eligible by USPSTF 2013 guidelines, another by draft USPSTF 2020 guidelines, and yet another by augmenting the USPSTF 2020 guidelines using risk prediction to include individuals with 12 or more days of life gained according to the Life-Years From Screening–CT (LYFS-CT) model.
“Among each race/ethnicity, we calculated the number eligible for screening, proportion of preventable lung cancer deaths prevented, proportion of gainable life-years gained, and screening effectiveness, as well as the relative disparities in lung cancer deaths prevented and life-years gained,” Dr. Landy said.
Results
Under the 2013 guidelines, 8 million ever-smokers were eligible. The disparities in lung cancer death sensitivity, compared to Whites, were 15% for African Americans, 15% for Asian Americans, and 24% for Hispanic Americans. Disparities for life-year gained sensitivity were 15%, 13%, and 24%, respectively.
Under the 2020 draft guidelines, 14.5 million ever-smokers were eligible, but racial/ethnic disparities persisted. Disparities in lung cancer death sensitivity were 13% for African Americans, 19% for Asian Americans, and 27% for Hispanic Americans. Disparities for life-year gained sensitivity were 16%, 19%, and 27%, respectively.
Using the LYFS-CT predictive-risk model added an additional 3.5 million people and “nearly eliminated” disparities for African Americans, Dr. Landy noted. However, disparities persisted for Asian Americans and Hispanic Americans.
Disparities in lung cancer death sensitivity were 0% for African Americans, 19% for Asian Americans, and 23% for Hispanic Americans. Disparities for life-year gained sensitivity were 1%, 19%, and 24%, respectively.
