Breast Tumor Microenvironment: Differences in Black Women?
Posted: Monday, May 24, 2021
Christine B. Ambrosone, PhD, of the Roswell Park Comprehensive Cancer Center, Buffalo, New York, and colleagues investigated how host immunity may differ between races and how that may affect the tumor microenvironment. Published in the Journal of the National Cancer Institute, the research team discovered weaker antitumor activity of immune cells in Black patients with breast cancer, suggesting a potential immunobiologic basis for aggressive disease.
“We observed in the tumor microenvironment of breast cancer in patients of African descent a distinct signature of exhausted versus total CD8-positive T cells and noted further that this immune cell profile is associated with poorer breast cancer survival,” stated study coauthor Song Yao, PhD, in a Roswell Park press release. Dr. Ambrosone added: “...These findings may suggest an opportunity to enlist host immunity through immune checkpoint inhibitors in patients whose breast cancers fit this immune profile.”
Tumor tissue and data from 1,315 patients were obtained from the Women’s Circle of Health Study and clinicopathologic data from the New Jersey State Cancer Registry. Of this population, 920 patients were Black, and 395 were White. Other publicly available data were utilized for further comparison.
Tumors from Black patients demonstrated a more robust overall immune response, but the quality and composition of immune cells varied, regardless of the tumor subtype. Individuals of African American descent had higher pathologic tumor-infiltrating lymphocyte scores than those of European descent. A stronger CD4-positive and B-cell–positive response was observed in Black patients, along with a more exhausted CD8-positive T-cell profile.
Among all patients with hormone receptor–positive disease, a higher ratio of exhausted CD8-positive T cells to total CD8-positive T cells (ExCD8-r) correlated with poorer survival. Additionally, in those with hormone receptor–negative disease, CD8-positive T cells and ExCD8-r absolute fraction combinations were identified in a low-CD8, high–ExCD8-r subgroup—the most common among Black patients with the worst survival.
Disclosure: For disclosures of the study authors, visit academicoup.com.