Abstract PO-258: Disparities in eligibility for low-dose CT (LDCT) lung cancer screening among a multiethnic population

Abstract

Abstract Introduction: African Americans and Native Hawaiians have a higher risk of lung cancer and greater mortality rate than other racial/ethnic groups in the US. The guidelines for lung cancer screening by low-dose CT scan were derived from clinical trial data conducted primarily in white men. In 2021, to address the underlying ethnic/racial disparities in eligibility for lung cancer screening the United States Preventive Services Task Force (USPSTF) updated the 2013 guidelines from 55-80 years of age, current or former smokers (quit ≤15 years) with a 30 pack-year smoking history to include ever smokers ≥50 years of age and with a ≥20 pack-year history. We hypothesize that the disparities in eligibility across race/ethnicity will remain due to the greater age-specific risk and lower pack-years among African Americans and Native Hawaiians. Methods: We used the Multiethnic Cohort study (MEC) data to examine ineligibility to both USPSTF guidelines by sex and race/ethnicity among 1,761 incident lung cancer cases diagnosed within 7 years of study entry. This analysis included African and Japanese Americans, Latino, Native Hawaiians and whites. Smoking history was collected by a self-administered questionnaire at cohort entry. The difference in proportion of ineligible for each group compared to whites were assessed. Results: Among the 1,042 men and 719 women with incident lung cancer, under the 2013 guidelines, 54% of men and 70% of women would have been ineligible for lung cancer screening. Under the 2021 guidelines, 41% of men and 59% of women would have been eligible. For the 2013 guidelines, in men, the disparity was highest in Latinos (19% difference compared to whites), followed by Native Hawaiians (18%), and African (17%) and Japanese (9%) Americans. In women, the disparity was highest in African Americans (33%), followed by Latinas (25%), Japanese Americans (25%), and Native Hawaiians (13%). While an additional ~12% of overall lung cancer cases would have been eligible for screening using the updated guidelines, the disparity in eligibility compared to whites for each racial/ethnic group remained similar (range: 9% in Japanese American men to 33% in African American women). Eleven percent of men and 28% of women would have been ineligible for never smoking. Among ineligible ever smokers, more non-whites than whites were ineligible due to the 20 pack-year threshold (men: 77% vs 64% and women: 90% vs 76%). Also, while an overall 8% of both men and women would have been ineligible due to the age threshold, >20% of Native Hawaiian cases were ineligible due to age. Conclusions: Our findings demonstrate that despite the lower thresholds in the smoking history and age criteria in the updated USPSTF guidelines, racial/ethnic disparities in lung cancer screening eligibility remains. Reasons for these differences include a lower smoking pack-year history and greater age-specific risk among ever smokers, and a higher proportion of never smoker lung cancer cases. Additional analyses with cumulative smoking history are in progress. Citation Format: S. Lani Park, Kyla Yamashita, Lenora Loo, Daniel Stram, Yurii Shvetsov, Loic Le Marchand. Disparities in eligibility for low-dose CT (LDCT) lung cancer screening among a multiethnic population [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-258.