Abstract B064: Investigation of the breast microbiome and mucosal immune system in African American and non-Hispanic White women with and without breast cancer: A pilot study

Abstract

Abstract Growing evidence shows that an imbalance in the breast microbiome due to inflammation may give rise to cancer development, particularly in non-Hispanic white women. However, there is a lack of data on the role of the breast microbiome among African American women. Since African American women are more likely to develop aggressive forms of breast cancer and die from the disease, we hypothesize that distinct microbial signatures exist in the breast and these signatures differ between normal and breast cancer tissues by race. Using 16S rDNA hypervariable tag sequencing, we identified distinct microbial signatures between normal (n = 40) and breast tumor (n = 61) tissues samples from African American and non-Hispanic white women. Women with breast cancer had a higher abundance of Enterobacteriaceae, Bifidobacteriaceae, Bacteroides, and Streptococcus when compared to women without breast cancer. African American breast tumors (n = 27) had lower abundance of the phyla Proteobacteria, Firmicutes, and Actinobacteria compared to non-Hispanic white breast tumors (n = 34). We further evaluated expression of genes involved in immune response using the Innate and Adaptive RT2 Profiler PCR microarray in breast cancer tissues and adjacent normal tissues from the same donor. Expression of several inflammatory response genes, including CD8, TLR8, and GATA3, were significantly increased in breast tumors compared to adjacent normal breast tissues from the same donor. This study provides preliminary evidence of a breast microbiome in African American women and supports further investigation to identify a microbial risk signature for breast cancer and potential microbial-based prevention therapies. Citation Format: Alana Smith, Breia Reed, Joseph F. Pierre, Beverly Lyn-Cook, Athena Starlard-Davenport. Investigation of the breast microbiome and mucosal immune system in African American and non-Hispanic White women with and without breast cancer: A pilot study [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B064.