PROJECT SUMMARY/ABSTRACT – RESEARCH PROJECT Outcomes for cancer patients in low- and middle-income countries (LMIC) like Nigeria are poor compared to high-income countries (HIC). Advances in immuno-oncology (IO) research and the successes of immunotherapy seen in HIC have not been mirrored in LMIC. Colorectal cancer (CRC) outcomes, for example, are poor for Nigerian patients when compared to similarly staged patients in the US. Through our work to understand the biology that underlies this disparity, we have found a higher rate of microsatellite instability (MSI-H) in CRC of Nigerian versus US patients. As MSI-H tumors are immunogenic and potentially sensitive to immune checkpoint blockade, there may be a large proportion of Nigerian patients who may benefit from immunotherapy. However, there are few studies focused on tumor immunology and IO in Nigerian CRC. These investigations are vital as we consider the broad application of immunotherapy in LMIC, such as Nigeria. The Nigerian Immuno-Oncology Research (NOLA) program will integrate our expertise in IO and global cancer disparities to generate preliminary data, resources, and biobanks for larger future studies. Specifically, in this feasibility and planning phase, we will: 1. characterize the tumor immune microenvironment of Nigerian CRC patients and compare to a reference cohort of US patients; 2 create a whole slide image pathology dataset of Nigerian CRC patients and controls; and 3. build a biobank for future single-cell analyses of the tumor microenvironment of Nigerian CRC. The results and resources generated will inform future multi-modal investigations of TME biomarkers associated with tumor immunogenicity/outcome, cost-effective patient stratification for immunotherapy, and rational design of future immunotherapy trials to address the disparate outcomes in Nigerian patients with CRC.