Abstract C110: Mobile low dose computerized tomographic (LDCT) scanning program identifies pre-malignant lung cancer lesions in a Native American population: A study of Indian Health Service and Levine Cancer Institute
Authors: Dungan Kia , Reed Hollis , Doege Darcy , Carrizosa Daniel , Wheeler Melissa , Raghavan Derek 
Published: December 2023

Abstract
BACKGROUND: Native Americans (NA) are an under-served population for healthcare, including lung cancer screening. Randomized trials have shown LDCT screening for lung cancer improves survival but with severe under-representation of NA due to financial and insurance constraints, geography and lack of access. They are over-represented in national statistics of presentation with advanced disease and lung cancer deaths. In our region, the Indian Health Service (IHS) has recorded less than 5% of eligible heavy smokers from the Catawba and other tribes have undergone LDCT lung screening. We previously reported that a free, mobile LDCT unit achieved a shift to earlier diagnosis in African Americans (AAs) and other under-served groups with improved 4 year survival and reduced costs of care (1).We adapted our initial trial to include a structured evaluation of efficacy and utility of mobile LDCT in heavy smokers in our NA population. We hypothesized that mobile LDCT would overcome key obstructions to lung cancer screening in NA. METHODS: We used a coach fitted with a portable 32 slice low-dose CT scanner; all films were reviewed by a central panel via the LUNGRADS protocol (1). Eligible subjects were invited to participate by IHS staff. Levine Cancer Institute committed to treat any identified cancers, irrespective of insurance status to avoid delay. Technical details of the unit have been reported (1). RESULTS: 91 heavy smokers have been screened, representing 60% participation rate, with the following characteristics: M:F=1:1; median age 61 years (44-77 years); 68% had some form of health insurance which did not cover lung cancer screening (termed "under-insured") and 32% were uninsured; 73% still smoking; median pack year history 48 (range 22-98). No lung cancers were identified but 10% had LUNGRADS 3-4 (moderate-high risk) lesions, 36% had LUNGRADS 2 lesions and 20% had scattered, non-diagnostic lung lesions; patients with LUNGRADS 4 lesions were offered biopsy to define whether cancer was present. All subjects have been recruited into ongoing follow up LDCT and smoking cessation programs. DISCUSSION: NA traditionally have had the highest level of advanced lung cancer at presentation with high mortality rate from lung cancer. We have increased participation in LDCT lung cancer screening from 5% to 60% of eligible heavy smokers, and have identified a unique sub-population of 10% with potentially premalignant disease that will require meticulous follow-up to achieve early diagnosis of lung cancer. Our previous studies in impoverished AAs and other under-served groups have identified a shift from 20% to 60% early stage cancer at diagnosis; similar benefits are expected in NAs. This is the first such study in NAs and suggests mobile LDCT should be considered by health services responsible for their care. Studies of the science of cancer in the under-served should also focus on pragmatic solutions with potential for early improvement in outcome. REFERENCES: 1. Raghavan D et al, The Oncologist, 2020, 25: e777-e781.
Citation Format: Kia Dungan, Hollis Reed, Darcy Doege, Daniel Carrizosa, Melissa Wheeler, Derek Raghavan. Mobile low dose computerized tomographic (LDCT) scanning program identifies pre-malignant lung cancer lesions in a Native American population: A study of Indian Health Service and Levine Cancer Institute [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr C110.