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Abstract: although only about 5% of thyroid nodules are cancerous, the rising prevalence of both thyroid nodules and cancers is largely attributed to increased use of improved diagnostic and screening modalities. Evidence suggests that early detection of small thyroid cancers through screening only partly explains the increased incidence of thyroid nodules and cancers. Some of this increased incidence is possibly driven by environmental, occupational, or dietary exposures, which remain largely unknown to date. We aimed to identify potential risk factors of thyroid abnormalities in a uniquely exposed population of U.S. nuclear weapons’ industry (Department of Energy, DOE), enrolled in a low-dose CT (LDCT) lung cancer screening program. Methods: We conducted a matched case-control study and identified participants with incidentally found non-cancer thyroid abnormalities (cases) and controls without any thyroid abnormality on LDCT. Results: We identified 638 cases and 1927 controls from the lung cancer screening program database between January 1, 2006, and June 30, 2023. In the adjusted analysis, radiation exposure (medium exposure OR: 1.6 (1.1, 2.3) and high exposure OR: 1.5 (1.0, 2.3), versus low exposure), female sex (OR: 2.7 (2.0, 3.5), African-American race (OR: 2.5 (1.8, 3.4), versus White), obesity (BMI 30-39.9 OR: 1.5 (1.1, 2.1), BMI >40 OR: 2.4 (1.5, 3.8) versus BMI <25) and engineering (OR: 1.5 (1.0, 2.3) and operations (OR: 1.5 (1.0, 2.2), versus administrative) job categories were significantly associated with any thyroid abnormality. Discussion: Our study corroborates earlier data that female sex, and higher BMI are predictors of incidental non-cancerous thyroid abnormalities in a large national occupationally exposed cohort.
Co-authors: Khaula Khatlani MD, MSc, Steven Markowitz MD, DrPH, Amy Manowitz, Jennifer Stuckey, Yan Guo, Maaike Vangerwen MD, PhD