LAUSR

Introduction: Levonorgestrel-releasing intrauterine system (LNG-IUS) is associated with ~50% risk reduction for uterine cancer incidence and can be an effective primary prevention strategy. We aimed to understand current patterns of LNG-IUS use and identify disparities that could inform implementation strategies for more effective and equitable uterine cancer primary prevention. Methods: We analyzed LNG-IUS use among U.S. women aged 18-50 with the 2017-2019 National Survey of Family Growth. Statistical analysis was stratified by race, sociodemographic, and health factors. Predictors of LNG-IUS use were assessed through weighted multivariable logistic regression using the Wald chi-square test. Results: Current LNG-IUS use was significantly lower in Hispanic women compared to White women (AOR 0.65, P=0.049). Compared to women with up to a high school education, LNG-IUS use was higher for women with a college degree or higher in the overall sample (AOR 1.86, P=0.009), White women (AOR 1.91, P=0.04), and Black women (AOR 4.54, P=0.007), but not for Hispanic women (AOR 0.79, P=0.64). All racial/ethnic subgroups had lower odds of LNG-IUS for non-parous women than parous women (all P<0.002). Although a known uterine cancer risk factor, obesity was not associated with LNG-IUS use. Conclusions: Hispanic women, women with lower educational levels, and nulliparous women have disproportionately low LNG-IUS use despite being at increased uterine cancer risk. Community-based educational interventions for high-risk women and their providers on the benefits of LNG-IUS on uterine cancer prevention are needed to mitigate uterine cancer disparities. Table 1. Logistic Regression on Predictors for LNG-IUS Use in U.S. Women Aged 18-50 OVERALL (N=4107) WHITE (n=1948) HISPANIC (n=1052) BLACK (n=861) AOR (95% CI) AOR (95% CI) AOR (95% CI) AOR (95% CI) Race Ref 0.65* (0.42-0.98) 0.77 (0.46-1.27) Age 18-24 1.16 (0.55-2.46) 1.15 (0.45-2.94) 13.13* (1.42-121.3) 0.55 (0.11-2.83) 25-34 1.65 (0.88-3.10) 1.46 (0.69-3.13) 31.75** (4.04-249.5) 0.63 (0.18-2.14) 35-44 1.07 (0.55-2.10) 1.10 (0.49-2.47) 13.28* (1.51-116.6) 0.54 (0.14-2.02) 45-50 Ref Ref Ref Ref Education ≤High School Ref Ref Ref Ref Some College 1.56* (1.02-2.51) 1.56 (0.83-2.94) 1.05 (0.47-2.32) 3.90* (1.39-10.96) ≥Bachelor’s 1.86** (1.17-2.97) 1.91* (1.03-3.54) 0.79 (0.30-2.12) 4.54** (1.51-13.65) BMI Normal Ref Ref Ref Ref Overweight 1.44 (0.93-3.22) 1.40 (0.81-2.41) 0.96 (0.35-2.62) 1.54 (0.56-4.22) Obese 0.87 (0.57-1.31) 0.86 (0.52-1.43) 0.68 (0.28-1.63) 1.01 (0.35-2.89) Parity Parous 2.85*** (1.89-4.30) 2.21** (1.33-3.67) 7.30*** (2.61-20.38) 5.38*** (2.27-12.76) Nulliparous Ref Ref Ref Ref Abbreviations: AOR, adjusted odds ratio; BMI, body mass index; CI, confidence interval; Ref, reference group. *P<0.05; ** P<0.01; *** P<0.001 aEarly Menarche <12yo; Normal Menarche 12-14yo; Late Menarche >14yo. Citation Format: Paul G. Yeh, Iakovos Toumazis, Charlotte Sun, Karen Lu, Larissa A. Meyer. Disparities in uptake of levonorgestrel-releasing intrauterine system (LNG-IUS): implications for uterine cancer primary prevention. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5769.