Abstract 6134: The Latino Colorectal Cancer Consortium: A resource for colorectal cancer disparities research
Authors: Loroña Nicole C. , Matejcic Marco , Sobieski Daniel , Nguyen Nathalie T. , Hoehn Hannah J. , Diaz Diana B. , Shankar Kritika , Jean-Baptiste Esther , Coppola Domenico , Fulmer Clifton , Saglam Ozlen , Jiang Kun , Muñoz-Antonia Teresita , Flores Idhaliz , Gordian Edna , Torres José A. Oliveras , Felder Seth I. , Sanchez Julian A. , Fleming Jason , Siegel Erin M. , Cress Douglas , Stern Mariana C. , Teer Jamie K. , Schmit Stephanie L. , Figueiredo Jane C. 
Published: March 2024

Abstract
Purpose: The Latino Colorectal Cancer Consortium (LC3) was established to fill a gap in representation of the diverse Hispanic/Latino/a/x community in cancer genomic research and to enhance understanding of determinants of disparities in the burden of colorectal cancer (CRC).
Methods: The LC3 joins together three established studies with deeply-annotated clinical, epidemiologic, and biologic data available for a heterogenous group of Hispanic/Latino/a/x men and women diagnosed with primary colorectal adenocarcinoma: the Hispanic Colorectal Cancer Study (California), the Total Cancer Care Protocol at Moffitt Cancer Center (Florida), and the Puerto Rico Biobank (southern Puerto Rico). Each contributing study collected data on demographics, medical history, family history, and lifestyle factors. Vital status, cause of death, treatment, and clinical characteristics were obtained through medical chart abstraction and/or linkage to cancer registries. Blood, saliva, or normal colonic tissues were used to extract and genotype germline DNA for a subset of participants. Tumor tissues (snap frozen or formalin-fixed paraffin-embedded) were evaluated by pathologists for diagnosis, tissue content, tumor cellularity, necrosis, immune infiltration, and additional histopathologic characteristics.
Results: The LC3 has assembled 2,041 participants across the three studies to date, with recruitment ongoing. Median age at diagnosis is 57 (range: 19-93), 54% of participants are male, and 63% are colon cancer cases (vs. rectal cancer). Participants were diagnosed between 1999 and 2022. The target is to generate comprehensive multi-omic data on 600 LC3 participants. To date, 243 have genome-wide germline genotyping, 323 have paired tumor/normal whole exome sequencing, and 257 have T cell receptor immunosequencing (immunoSEQ, Adaptive Biotechnologies). Further, 206 cases are represented on a set of tissue microarray blocks (target N=281). Bulk RNA-seq data are to be generated on 250 tumors.
Conclusions: The LC3 fills an important gap in research infrastructure for the scientific community. Key strengths of this unique consortium are its ability to capture a diversity of Latino CRC patients with respect to nativity and cultural heritage and to represent the spectrum of stages from early to metastatic. Ultimately, research from the LC3 will inform development of equitable precision medicine approaches and predictive models to improve the health of the rapidly-growing, heterogeneous Hispanic/Latino/a population.
Citation Format: Nicole C. Loroña, Marco Matejcic, Daniel Sobieski, Nathalie T. Nguyen, Hannah J. Hoehn, Diana B. Diaz, Kritika Shankar, Esther Jean-Baptiste, Domenico Coppola, Clifton Fulmer, Ozlen Saglam, Kun Jiang, Teresita Muñoz-Antonia, Idhaliz Flores, Edna Gordian, José A. Oliveras Torres, Seth I. Felder, Julian A. Sanchez, Jason Fleming, Erin M. Siegel, Douglas Cress, Mariana C. Stern, Jamie K. Teer, Stephanie L. Schmit, Jane C. Figueiredo. The Latino Colorectal Cancer Consortium: A resource for colorectal cancer disparities research [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 6134.