Unraveling Ethnic Disparities in Triple-Negative Breast Cancer (TNBC): Exploring The Impact of Metabolic, Reproductive, Environmental, and Social Factors on the Disease Course in African-American (AA) Women Population

Triple-negative breast cancer (TNBC) is a particularly aggressive subtype of breast cancer (BC) in which the expression of the estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor (HER2) is absent or very low. TNBC consists of approximately 15-30% of the invasive BC cases in the United States (US) Women with TNBC represent a heterogeneous population with regard to their ethnicity and biology including the genetic make-up metabolic or hormonal profile as well as the socioeconomic status (SES) cultural behavioral educational levels. Notably African-American (AA) women usually have a higher prevalence of TNBC and a worse prognosis compared to European-American (EA) or Non-Hispanic White (NHW) women. The goal of this chapter is to elucidate the possible interplay of inherited and acquired, often lifestyle-related risk factors which can stimulate the initiation and development of the most aggressive subtypes of TNBC in AA women compared to their EA (or NHW) counterparts. In particular this chapter explores some ethnic disparities in TNBC mainly in the example of the US where such disparities have been studied in clinical research. This chapter also focuses on differences in TNBC risk factors healthcare patterns clinical outcomes between AA and EA (or NHW) women. It briefly discusses the multi-factorial etiology of these disparities e.g genetic, hormonal, metabolic, behavioral, cultural, socio-economical and environmental. Presented short analysis of a dynamic blend of inherited and acquired variables also provides some directions for the reduction of these disparities, to improve TNBC outcomes, among women from ethnic groups, such as AA. 

Keywords: Acquired, Ethnic groups, Healthcare disparities, Inherited, Risk factors, Triple-negative breast cancer (TNBC).