The diagnostic accuracy of federal screening guidelines for lung cancer was put to the test in a recent study, published in JAMA Oncology. Researchers observed several racial disparities in the guidelines that could put African Americans at risk.
The study suggests current lung cancer screening guidelines may be too conservative for African American smokers.
Researchers from Vanderbilt University Medical Center focused on U.S. Preventative Services Task Force (USPSTF) guidelines designed to identify adults at risk of lung cancer, who may benefit from low-dose computed tomography (CT) screening.
The current guidelines recommend CT screening for smokers age 55 to 80 with a 30 pack-year history and who still smoke—or have quit only within the past 15 years.
“These guidelines were derived from a study population including only four percent African American smokers.”
“These guidelines were derived from a study population including only four percent African American smokers,” said lead author Melinda Aldrich, Ph.D., assistant professor of thoracic surgery at Vanderbilt. “We wanted to determine if they are a clinically valid approach to identifying at-risk African Americans.”
Focusing on African Americans
The study zeroed in on specific smoking patterns among African Americans, and how this influences eligibility for lung cancer screening.
Said Aldrich, “African Americans tend to smoke fewer cigarettes overall as compared to whites, but their risk of lung cancer remains high. The current guidelines don’t address this discrepancy.”
Aldrich and a team of Vanderbilt researchers analyzed data from 48,364 “ever-smokers” enrolled in the Southern Community Cohort Study, including 1,269 who developed lung cancer. Sixty seven percent of the overall cohort identified as African American. The study was one of the largest comprehensive evaluations of the USPSTF lung cancer screening guidelines in African Americans to date.
Researchers collected demographic information and analyzed smoking patterns among African American and white study participants. They calculated daily cigarette use and total smoking pack-years. Then, they applied the current USPSTF screening guidelines.
“Among smokers diagnosed with lung cancer, 32 percent of African Americans versus 56 percent of whites were eligible for screening, so it’s a striking disparity in eligibility,” Aldrich said. Nearly half of African American smokers did not meet the minimum 30 pack-year requirement for screening.
Across both groups, large proportions of smokers who later developed lung cancer did not meet age requirements for screening (36 percent of African Americans and 44 percent of whites). The researchers suggest that lowering the age requirement could have widespread benefits—particularly for African Americans who often develop lung cancer at an earlier age than other groups.
“If we don’t shift the age, then we are still going to potentially diagnose African Americans at late stage.”
“Shifting the age at which we can diagnose African Americans may allow the diagnosis to occur at an earlier cancer stage when there is better potential for curative treatment,” Aldrich said. “If we don’t shift the age, then we are still going to potentially diagnose African Americans at late stage.”
Narrowing the Gap
The authors also wrote that adjusting the smoking pack-year requirement—from 30 to 20 pack-years—for African Americans “would increase the number of eligible African American smokers for screening from 17.4 percent to 28.5 percent.”
Guideline revisions could help level the playing field for African Americans, especially since insurance companies use the USPSTF guidelines to determine coverage of costly CT scans.
Said Aldrich, “Overall, our goal is to equalize the performance of lung cancer screening for African American smokers and narrow the gap in health disparities between them and other groups. Screening guidelines should be equitable.”