Grant Number:	5R01CA255318-04 Interpret this number
Primary Investigator:	Warren Andersen, Shaneda
Organization:	University Of Wisconsin-Madison
Project Title:	Understanding the Contribution of Colorectal Cancer Tumor Characteristics to Disparities in Colorectal Cancer Survival
Fiscal Year:	2024

PROJECT ABSTRACT Colorectal cancer (CRC) is the second leading cause of cancer death among U.S. men and women. Racial disparities in CRC survival exist, where the CRC mortality rate for African Americans is 40% higher than the mortality rate for non-Hispanic white Americans. Evidence suggests there may be racial differences in intrinsic CRC tumor biology. We hypothesize that the molecular profile of CRC tumors is more aggressive on average for African Americans than white Americans, and that these tumor differences contribute to the racial disparity in survival. The overarching goal of the project is to define how the CRC survival disparity experienced by African Americans may be influenced by complex biologic differences in tumor characteristics, measured by molecular subtypes, driver gene status, and clinicopathologic markers. The research plan uses molecular epidemiologic and cancer biology approaches to achieve our study aims by leveraging resources from three established research studies, including CRC tumor tissue data from approximately 420 African American CRC patients and 404 non-Hispanic white CRC patients from the Southern Community Cohort Study, the Black Women’s Health Study, and The Cancer Genome Atlas (TCGA). To fulfill Aim 1, we will characterize CRC tumors from white and African American CRC patients for clinicopathologic markers (anatomic site, stage), microsatellite instability, driver gene status (BRAF, and RAS mutation status), and the recently-defined CRC consensus molecular subtypes. The proposed project will be the first study to define CRC consensus molecular subtypes in African Americans. Bioinformatics approaches will identify novel gene- expression molecular subtypes, measured using RNA-seq, to explore the possibility of detecting molecular subtypes that are more prevalent among African American tumors and that may be linked to CRC prognosis. (Aim 2). Lastly, to fulfill Aim 3, associations will be determined between the abovementioned tumor characteristics and CRC survival, and assessed for differences by race. The scientific impact of the proposed study will be to determine the biological mechanisms contributing to CRC survival disparities experienced by African Americans by uncovering the molecular attributes of the tumors themselves. The results of the study will establish the essential foundation for future interventional studies. Currently, CRC treatment is determined by a combination of molecular factors including stage and the presence of somatic mutations. Emerging CRC therapies may be guided by additional tumor factors such as tumor gene-expression or the presence of other targetable features. The existing limited knowledge of the biologic properties of African American CRCs reduces the prospect that precision medicine will be effective. The proposed study aims to provide data on African American CRC tumor molecular profiles to support subtype-specific treatments and precision health strategies to decrease mortality and reduce racial disparities.





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