Abstract Background: Colorectal cancer (CRC) remains a significant public health concern in the United States, with substantial disparities observed in survival rates and age at diagnosis among different racial and ethnic groups. In Texas counties bordering Mexico, which have predominantly Hispanic populations, show higher CRC diagnoses. Hispanic patients generally exhibit lower screening rates, higher mortality, and late-stage diagnosis compared to non- Hispanic counterparts. Understanding the factors behind these disparities is crucial for developing targeted interventions to improve outcomes and reduce the burden of CRC. Methods: Using data from the Texas Cancer Registry, a retrospective study examined CRC survival rates and age at diagnosis among 235,076 patients of various racial and ethnic groups in Texas from 1995 to 2016. The association between Race and ethnicity and survival time over two periods (1995-2005 and 2006-2016) was analyzed using Kaplan-Meier survival analysis and pairwise comparisons. Additionally, the effects of Race and ethnicity on age at diagnosis were examined for the same periods using Welch ANOVA and posthoc comparisons. Results: Persistent survival disparities were observed, with Black patients facing the lowest median survival times across both periods (1995-2005 and 2006-2016). Hispanic patients showed significantly lower median survival rates compared to their non-Hispanic counterparts. Comparisons between races showed significant differences in median survival time between the two periods (1995-2005 and 2006-2016). Black: Hispanic patients showed no significant improvement in survival time between the periods. Significant improvements in survival time were observed in Black: non-Hispanic, White: Hispanic, and White: non-Hispanic patients. Lastly, the mean age at diagnosis depended on the ethnicity of the patient, with Hispanic patients displaying an earlier onset of CRC compared to non-Hispanic equivalents. Hispanic ethnicity was associated with an earlier onset of CRC compared to non-Hispanic counterparts. Conclusion: Geographic and ethnic disparities significantly influence CRC outcomes in Texas. Hispanic populations in border counties face increased risks due to lower screening and socioeconomic challenges. The rising incidence of early-onset CRC, particularly among younger, socioeconomically disadvantaged, and minority populations, necessitates targeted public health interventions to improve screening, early detection, and treatment access. Addressing these disparities is crucial to enhancing CRC survival rates and reducing mortality across diverse demographic groups. Citation Format: Tyler J Torres, Elias Arellano Villanueva, Yossef Alsabawi, Manish Tripathi. Unraveling Early Onset Disparities and Determinants: A Two-decade Analysis of Colorectal Cancer Trends in Texas [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C157.