In a new study of tumor microenvironment led by Yale Cancer Center, researchers showed that triple-negative breast cancer (TNBC) which has a worse overall outcome in African American compared to Caucasian patients actually has a different Tumor Microenvironment in the two mentioned groups. The findings were reported on June 22 at the American Association for Cancer Research (AACR) virtual annual meeting II.
“The goal of this study was to compare the Tumor Microenvironment in TNBC of the two groups to look for differences between African American and non-African American TNBC patients,” said Vesal Yaghoobi, a postdoctoral associate at Yale Cancer Center and lead author of the study. David Rimm, M.D., Ph.D., is senior author of the research.
Yale Scientists compared CD45, CD3, CD8, CD20, CD14, CD68, PD-L1, THY1, aSMA and Fibroblast Activation Protein (FAP) expression level and the activation status of CD3-positive cells between African American and Caucasian TNBC cases. Researchers discovered African American patient tumors contained a significantly higher CD45-positive cells and a significantly higher level of lymphocytes, measured by assessment of CD45+ CD14- cells. Even though researchers could not find any differences in CD3 expression between the two groups, tumors in African American patients contained a significantly higher level of activated T-cell. Finally, African American patient tumors showed a significantly higher level of CD68+ cells and PD-L1 expression in CD68+ cells. All other markers showed no difference between the two groups.
“Significant differences do exist in the Tumor Microenvironment of African American tumors versus Caucasian TNBC tumors,” said Yaghoobi. “Further testing of macrophages, fibroblasts, regulatory T-cells is underway for better defining the differences.”