Public health screening guidelines for lung cancer followed by the U.S. Preventive Services Task Force (USPSTF) and the Centers for Medicare & Medicaid Services (CMS) undercount eligible Black individuals, according to a study by Mary Pasquinelli, DNP, FNP-BC, and colleagues in press at the Journal of Thoracic Oncology. This may contribute to disparities in lung cancer screening and treatment.
Current Guidelines
Current USPSTF and CMS guidelines, established by results from the National Lung Cancer Screening Trial, recommend low-dose computed tomography (CT) screening for individuals that meet the following criteria: age 55–80 or 55–77 years, respectively; a 30 or more pack-year cigarette smoking history; and, in former smokers, having quit smoking within the past 15 years.
“We found that the PLCOm2012 model was significantly more sensitive in selecting patients with lung cancer as being eligible for screening for the entire cohort. Broader use of this model in racially diverse populations may help overcome disparities in lung cancer screening and outcomes.”— Mary Pasquinelli, DNP, FNP-BC
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However, Black individuals are more likely to start smoking at a later age, smoke fewer cigarettes per day, and smoke for a longer duration; they are less likely to quit smoking and tend to be diagnosed with lung cancer at an earlier age. Previous research including 48,364 ever-smokers in the Southern Community Cohort Study showed that a smaller proportion of Black individuals would have met the current USPSTF criteria compared to White individuals—17% vs 31%, respectively.
Black ever-smokers are at increased risk for lung cancer compared to White ever-smokers, after adjusting for age and smoking history. Even among Black or Hispanic patients who are appropriately screened, access to treatment and participation in clinical trials is limited.
Study Methods
To follow up on the Southern Community Cohort Study, researchers from the University of Illinois at Chicago performed a retrospective analysis of 1,050 patients with thoracic cancer from their cancer registry. The cohort was assessed for whether each case would have been eligible by USPSTF criteria for screening based on age, pack-years, and quit time. After some exclusions, the cohort of 883 ever-smokers comprised the following racial/ethnic makeup: 258 (29.2%) White patients, 497 (56.3%) Black patients, 69 (7.8%) Hispanic patients, 24 (2.7%) Asian patients, and 35 (4.0%) patients of another race or ethnicity.
The researchers analyzed this cohort using the PLCOm2012 lung cancer risk prediction screening model, based on data collected from the control arm of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO), a randomized controlled trial studying screening to reduce cancer mortality. The PLCOm2012 model incorporates 11 predictors, which include sociodemographic factors, medical history, and four smoking exposure variables.
USPSTF vs PLCOm2012
Compared to the USPSTF criteria, the PLCOm2012 model increased the sensitivity for the Black patient cohort at lung cancer risk thresholds of 1.51%, 1.70%, and 2.00% per 6-years. The USPSTF criteria and the PLCOm2012 model with 1.70% risk threshold identified 62.4% and 66.0% of White patient cases, respectively, and 50.3% and 71.3% of Black patient cases, respectively. Thus, the PLCOm2012 model improved sensitivity in both White and Black ever-smokers and eliminated the eligibility disparity.
Of the 64 Black ever-smokers who were USPSTF-ineligible because they were younger than 55, 23.4% would have qualified by the PLCOm2012 with a risk threshold of 1.7%. Of 53 Black ever-smokers who were USPSTF-ineligible because they had quit smoking more than 15 years ago, 49.1% would have qualified by the PLCOm2012. Of the 193 of Black ever-smokers who were USPSTF-ineligible because they had less than 30 pack-years, 40.4% would have qualified by the PLCOm2012.
“We found that the PLCOm2012 model was significantly more sensitive in selecting patients with lung cancer as being eligible for screening for the entire cohort,” said lead author Dr. Pasquinelli, Director of the Lung Screening Program at the University of Illinois Hospital and Health Science System. “Broader use of this model in racially diverse populations may help overcome disparities in lung cancer screening and outcomes.”
Disclosure: For full disclosures of the study authors, visit jto.org.
