Abstract 6528: The role of health behaviors in microbial dysbiosis and lung cancer inequities

Abstract Lung cancer remains the leading cause of cancer-related morbidity and mortality worldwide. African Americans (AA) are disproportionally affected by the disease, and mortality is higher in AA compared to European Americans (EA). The mortality rate among AA is higher than EA even when diagnosed at an early stage, implying biological differences associated with health behaviors such as smoking and its impact on microbial dysbiosis. A higher mortality rate in AA diagnosed at an early stage compared to EA highlights the biological differences in AA are primarily due to health behaviors such as smoking and its impact on microbial dysbiosis, making AA predisposed to higher risk and mortality. Microbial dysbiosis in lung cancer was analyzed using GEO and All of Us data repositories. Our analysis provides compelling evidence of the interplay between microbial dysbiosis, health behaviors, and racial disparities in lung cancer outcomes. Our study shows that smoking exacerbates microbial imbalances, particularly with the prevalence of Streptococcus and its differential impact on AA and EA. Dysbiosis correlates strongly with lung cancer pathogenesis, particularly the abundance of Streptococcus, Haemophilus, Neisseria, and Pseudomonas. AA participants show higher susceptibility to Streptococcus invasion, with detectable levels in the blood at just 7 cigars daily compared to 23 cigars in EAs. Urine samples of AAs smoking only 17 cigars per day are positive for streptococcus, while for EAs the bacteria is detected only when they smoke 20 cigars daily. These findings underscore a biological predisposition that amplifies cancer risk for AAs at lower smoking intensities. The lower thresholds for Streptococcus detection among AA populations suggest a heightened biological vulnerability, emphasizing the need for tailored public health interventions and early screening programs in these communities. These results underscore the importance of integrating microbial profiling in personalized medicine approaches and addressing underlying health inequities to improve lung cancer outcomes across diverse populations. Citation Format: Murugesh Eswaran, Briana A. Brock, Hina Mir, Gabriela Oprea-Ilies, Eric Flenaugh, James W. Lillard, Brian M. Rivers, Rajesh Singh, Shailesh Singh. The role of health behaviors in microbial dysbiosis and lung cancer inequities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6528.