USPSTF lung cancer screening guidelines ‘woefully inadequate’ for African American smokers
Race-specific modifications to U.S. Preventive Services Task Force lung cancer screening guidelines could reduce large disparities in sensitivity and specificity between African American and white smokers, according to study results published in JAMA Oncology.
“Among smokers diagnosed with lung cancer, 32% of African Americans vs. 56% of whites were eligible for screening, so it’s a striking disparity in eligibility,” Melinda Aldrich, PhD, MPH, assistant professor of thoracic surgery at Vanderbilt University Medical Center, said in a press release.
The USPSTF guidelines for lung cancer screening with low-dose CT fail to consider racial differences in smoking patterns and were based on a study population of only 4% African American smokers, according to study background.
Aldrich and colleagues investigated the diagnostic accuracy of the USPSTF screening eligibility criteria among 48,364 current or former adult smokers (67% African American, 33% white) in the prospective, observational Southern Community Cohort Study, which enrolled patients from March 2002 to September 2009. Median age at cohort entry was 50 years (interquartile range [IQR], 45-57). About half of the participants (51%) were women, and 32% had not attained a high school education. A larger proportion of African American vs. white ever-smokers were current smokers (63% vs. 54%).
Among the entire study population, 17.4% of African American smokers (n = 5,654 of 32,463) and 31.4% of white smokers (n = 4,992 of 15,901) met eligibility requirements for USPSTF screening (P < .001).
With follow-up through 2014, researchers identified 1,269 incident lung cancer cases. Among those diagnosed with lung cancer, a significantly lower proportion of African American smokers (32%; n = 255 of 791) met the criteria for screening than white smokers (56%; n = 270 of 478; P < .001). The lower rate of screening eligibility appeared largely associated with fewer smoking pack-years among African American vs. white smokers (median pack-years, 25.8 vs. 48; P < .001).
Researchers observed racial disparities in sensitivity and specificity of USPSTF guidelines between African American and white smokers across age groups. They estimated that lowering the smoking pack-year eligibility requirement from a minimum 30-pack-year history to 20 pack-years for African Americans would increase the percentage of African Americans who meet eligibility criteria from 17.4% to 28.5% and, among those diagnosed with lung cancer, from 32.2% to 48.9%, rates comparable to those of white smokers. It also would result in similar sensitivity and specificity compared with white smokers across all ages.
The researchers cited self-reporting of smoking data, a lack of information about lung screening utilization, and missing data on smoking and race for 5,566 patients as the study’s main limitations.
“This is a proposal for the first step, acknowledging that the guidelines are inadequate, woefully inadequate, actually, as they exist right now, with a suggested change that would largely correct the disparity,” William Blot, PhD, associate director for population science research at Vanderbilt Ingram Cancer Center, research professor of medicine and Ingram professor of cancer research, said in the press release.
The researchers also found that African Americans tend to be diagnosed with lung cancer at an earlier age than whites, and estimated that reducing the minimum age for screening for African Americans from 55 years to 50 years, in addition to lowering the pack-year requirement, would increase eligibility among those diagnosed with lung cancer to 57.8%, even closer to that of white smokers.
– by Jennifer Byrne
Disclosures: Aldrich reports grants from the NIH/NCI during the conduct of the study. Blot and the other authors report no relevant financial disclosures.