A recent study led by Dr. Alina M. Hamilton at the University of North Carolina at Chapel Hill analyzed how breast cancer immune microenvironments differ by race and tumor subtype. Hamilton’s work recognizes the importance of the immune microenvironment in breast cancer survival. She sheds light on how this research could be of particular benefit to Black women, who suffer 40% higher mortality from breast cancer than do non-Hispanic white women.
The study participants included 1,957 women, 53% of whom were Black and all of whom had invasive breast cancer and were 50 years old or younger. The participants contributed tumor tissue samples to the Carolina Breast Cancer Study. Gene analysis was performed on these samples for a 48-gene immune panel. Statistical analysis was adjusted for participant age and tumor stage.
The study ultimately found that breast cancer could be classified into three immune phenotypes: an adaptive-enriched, innate-enriched or quiet immune microenvironment. Both adaptive-enriched and innate-enriched tumors were associated with high risk of recurrence scores. (Relative frequency differences (RFD) for adaptive-enriched: 24.1%; 95% CI: 19.3 to 28.8 | RFD for innate-enriched: 13.1%; 95% CI: 9.1 to 17).
After adjusting for tumor subtype, the adaptive-enriched microenvironment was found to be associated with Black race (RFD: 7.5%; 95% CI: 1.4 to 13.6). Black women were also found to have decreased CD8 T cell scores (p = 0.05) and increased Treg cell scores (p = 0.02).
The study concludes that immune response seems to be related to tumor subtype and race.
A call to action is made advocating for further research on how breast cancer immune microenvironments and race impact breast cancer disparities. With more research, targeted interventions by immune response differences and tumor subtype could be developed to improve treatment response and prognosis, particularly for Black women .
Source: Racial differences in breast cancer immune microenvironments. 2020. https://www.sabcs.org