Abstract A110: Could use of individualized risk models mitigate health disparities in eligibility for lung cancer screening?
Authors: Katki Hormuzd , Skarzynski Martin , Cheung Li , Berg Christine , Chaturvedi Anil , Landy Rebecca , Young Corey 
Published: September 2020

Abstract
Background: Current US Preventive Services Task Force (USPSTF) lung cancer screening guidelines recommend screening ever-smokers aged 55-80 years with ≥30 pack-years who currently smoke or have quit in the last 15 years. However, USPSTF guidelines could exacerbate health disparities, since they do not account for race/ethnicity, gender or socioeconomic status. In particular, African-Americans have a higher risk of developing lung cancer despite smoking less than their white counterparts, suggesting that current guidelines may eliminate many African Americans from screening despite having equivalent risk to whites. Validated lung cancer risk models, some of which include race/ethnicity, have been proposed for determining screening eligibility, although it is unknown whether these would mitigate any potential disparities. Methods: Using data from the US-representative 2015 National Health Interview Survey, we calculated those eligible for screening (overall and by subpopulations) under USPSTF guidelines, and three prominent validated lung cancer risk models (Bach, PLCOM2012 and LCRAT) at a range of risk thresholds. The PLCOM2012 and LCRAT models include race/ethnicity, and the Bach and LCRAT models include gender. We also calculated the distributions of pack-years, cigarettes per day (cpd) and years smoked by race/ethnicity. Results: Using a 2.3% 6-year lung cancer risk threshold for each model, a higher proportion of those selected by risk models are African-American (PLCOM2012: 10%, LCRAT: 12%, Bach: 9%) compared to USPSTF guidelines (7%). In contrast, a lower proportion of those selected by risk models are Asian-American (PLCOM2012: 1.6%, LCRAT: 1.4%, Bach: 2.1%) compared to USPSTF guidelines (2.7%). The models disagree on the proportion selected who are Hispanic (PLCOM2012: 1.5%, Bach: 5.1%, LCRAT: 2.6%), although the proportion selected by USPSTF guidelines (3.9%) is within their range. Some of the differences between models may occur as a result of how each model assigns risk to smokers with &lt;30 pack-years, which occurs more frequently in racial/ethnic minorities: 82% of African-American ever-smokers aged 50-80, 84% of Hispanic and 80% of Asians had smoked &lt;30 pack-years, compared to 67% of whites. Conclusions: Substantially higher proportions of those selected for lung screening by risk models were African-American than by USPSTF guidelines. However, risk models might select smaller proportions of Asian-Americans than USPSTF guidelines and disagree on the proportion selected who are Hispanic. Given historical lack of equal access to healthcare among minorities, the use of risk models to determine screening eligibility requires careful thought.
Citation Format: Hormuzd Katki, Martin Skarzynski, Li Cheung, Christine Berg, Anil Chaturvedi, Rebecca Landy, Corey Young. Could use of individualized risk models mitigate health disparities in eligibility for lung cancer screening? [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr A110.