Abstract Background: Triple-negative breast cancer (TNBC) accounts for about 10-15% of all breast cancers nationwide with disparities of incidence and outcomes among races, geographic locations, and other factors. This study is aimed to analyze the differences in the rate of TNBC, patient conditions at time of diagnosis, and death from TNBC among women in Mississippi. Methods: A retrospective study was conducted to serially review breast cancer cases diagnosed in the University of Mississippi Medical Center during May 2016 to May 2023. The entire breast cancer population was then stratified by race. The rate of TNBC, age and BMI at time of diagnosis, the rate of expiration were compared between African American (AA) and Caucasian American (CA) women with breast cancer. Two-tailed Student’s T-test was used to calculate the difference in mean values, and Chi-Square Test was used to compare the difference in rates or percentages. The significant p value was set at p<0.05. Results: In total 291 women with breast cancer, AA patients were 195 (67.01%), CA patients were 88 (30.24%), and other were 8 (2.75%). The mean age of all patients was 58.3 years-old (ranged 24-97). The mean BMI was 31.19. The patients with TNBC were 109 (37.46%) in entire studied population. A total of 32 (1.6%) patients, including 14 TNBC and 18 non-TNBC were expired with an average age of 61.84 and an average survival time of 20 months from diagnosis to expiration. As compared to CA patient population, AA breast cancer patients had onset at younger age (58.08±0.88 vs. 59.18±1.36), had a higher BMI (31.79±0.62 vs. 28.25±1.05, p=0.017), higher percentage of TNBC (41.54% vs. 30.68%, p=0.082 and OR=1.605), and higher rate of expiration (11.28% vs, 9.1%). Also, as compared to CA expired patients with breast cancer, AA expired patients had higher BMI (29.57 vs. 28.61), shorter survival time (17.5 months vs. 19.4 months), and died at younger age (61.84-year old vs. 66.38-year old) with a higher proportion of TNBC subtype (54.6% vs 12.5%, p=0.045, OR=9.6). Conclusions: Breast cancer is greatly disparate racially between AA and CA and geographically between Mississippi and US national average. The disparities are manifested in the proportion of TNBC subtype, age at onset of breast cancer, BMI at time of diagnosis, and death rate. Citation Format: Navdeep Kaur, Javaria A. Khan, Jinghe Mao, Diva Melvin, Muhammad M. Hassan, Xinchun Zho. Disparities of triple negative breast cancer in Mississippi [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1014.