Grant Number:	3R03CA293127-02S1 Interpret this number
Primary Investigator:	Ping, Jie
Organization:	University Of Miami School Of Medicine
Project Title:	Racial Disparities in Breast Cancer Risk and Gene Expression-Roles of Genetics and Lifestyle Factors
Fiscal Year:	2026

PROJECT SUMMARY African American (AA) women have 40% higher breast cancer mortality and are more likely to be diagnosed with aggressive subtypes, such as triple negative breast cancer, than European American (EA) women. Exact reasons for these disparities remain unclear – but genetics and lifestyle may both play a role. However, it is unclear how genetic and lifestyle factors contribute to racial differences in molecular profiles of breast cancer. Our collaboration with Zambian cancer researchers presents a unique opportunity to include African Zambian (AZ) breast cancer patients to help reveal the underlying mechanisms for breast cancer racial disparities in the United States. Given the drastic differences in lifestyle and environmental exposures, yet relatively small genetic differences between AA and AZ, including AZ, AA, and EA breast cancer patients in one study will offer an excellent opportunity to disentangle the contribution of genetic predispositions from lifestyle exposures on the molecular profiles and tumor characteristics of breast cancer. We propose to recruit 250 incident AZ breast cancer patients, collect clinical and lifestyle data, obtain tumor tissues, and performing RNA sequencing (RNA-Seq). These data will be compared with existing data from the Southern Community Cohort Study. Specially, this study has the following aims: 1) to recruit 250 African Zambian women with pathologically confirmed breast cancer at the Cancer Disease Hospital in Lusaka, Zambia; 2) to derive molecular profiles of breast cancer in AZ women and compare with those from AA and EA women. We will perform RNA-Seq on breast tumor tissue samples from AZ patients to characterize gene expression, molecular intrinsic subtypes of breast cancer, and PAM50-based risk of recurrence scores (ROR-S). Demographic, clinical, and molecular data will be summarized and compared across these three racial/ethnic groups, and expression of known breast cancer susceptibility genes, molecular intrinsic subtypes, and ROR-S will be used to distinguish the differential contributions of genetic ancestry versus lifestyle on breast cancer molecular phenotype. This will be the first epidemiologic study to compare breast cancer molecular profiles across AZ, AA, and EA women. This foreign collaboration is directly useful and beneficial to the United States because it leverages unique environmental and ancestral contrasts unattainable within the U.S. alone to identify the biological drivers of breast cancer disparities disproportionately affecting AA women. Findings from this cross-continental comparison will generate critical preliminary data for full-scale etiological investigations and provide translational insights to improve risk stratification, prevention, and precision treatment strategies for underserved U.S. populations





None. See parent grant details.