Genomic Disparities in Breast Cancer among Latinas

Abstract

Background Breast cancer is the most common cancer diagnosed among Latinas in the United States and the leading cause of cancer-related death among this population. Latinas tend to be diagnosed at a later stage and have worse prognostic features than their non-Hispanic white counterparts. Genetic and genomic factors may contribute to observed breast cancer health disparities in Latinas. Methods We provide a landscape of our current understanding and the existing gaps that need to be filled across the cancer prevention and control continuum. Results We summarize available data on mutations in high and moderate penetrance genes for inherited risk of breast cancer and the associated literature on disparities in awareness of and uptake of genetic counseling and testing in Latina populations. We also discuss common genetic polymorphisms and risk of breast cancer in Latinas. In the treatment setting, we examine tumor genomics and pharmacogenomics in Latina patients with breast cancer. Conclusions As the US population continues to diversify, extending genetic and genomic research into this underserved and understudied population is critical. By understanding the risk of breast cancer among ethnically diverse populations, we will be better positioned to make treatment advancements for earlier stages of cancer, identify more effective and ideally less toxic treatment regimens, and increase rates of survival.

Insights into BRCA1/2 Genetic Counseling from Ethnically Diverse Latina Breast Cancer Survivors

“…We identified facilitators and barriers to the use of BRCA genetic counseling among Latinas, none of whom reported that they had previously undergone this service, despite the fact that about 35% of the sample had undergone BRCA testing. These factors are important to consider given that there are significant disparities in the use of genetic services among this underserved group (Dean et al 2015;Gammon et al 2011;Levy et al 2011;Lynce et al 2016;Pagán et al 2009). Consistent with prior research, we found that the majority of participants demonstrated very low levels of awareness and knowledge about the benefits of genetic counseling, BRCA mutations, and increased risk associated with HBOC (Gammon et al 2011;Kinney et al 2010;Lynce et al 2016;Mai et al 2014;Sussner et al 2010Sussner et al , 2013Sussner et al , 2015Vadaparampil et al 2010a, b).…”

“…Latinas are diagnosed with breast cancer at younger ages and present with more advanced stages of the disease, manifesting larger and more poorly differentiated tumors than non-Latina white women. (Chen and Li 2015;Banegas and Li 2012;Banegas et al 2014;Lantz et al 2006;Lynce et al 2016;Ooi et al 2011). Latinas are also diagnosed with more triple negative disease (Lara-Medina et al 2011) and more hormone receptor negative tumors (Lagos-Jaramillo et al 2011;Ooi et al 2011), both of which are associated with a poorer prognosis and a greater risk of mortality regardless of stage of disease (Dunnwald et al 2007).…”

“…Likewise, despite the benefits of genetic counseling and testing for hereditary breast and ovarian cancer (HBOC) risk, significant disparities exist in the use of these services between women of non-Latina and Latina descent. While statistics are not available for genetic counseling alone, many studies indicate that awareness and use of genetic testing among Latinas is low (Dean et al 2015;Gammon et al 2011;Levy et al 2011;Lynce et al 2016;Mai et al 2014;Pagán et al 2009). In a recent study among at-risk Latina and non-Latina participants who had not previously undergone genetic counseling/testing, 57% of Latinas were unaware of the availability of BRCA testing, with Latina ethnicity the only notable factor associated with lack of awareness (Gammon et al 2011).…”

Exome Sequencing Reveals a High Prevalence ofBRCA1andBRCA2Founder Variants in a Diverse Population-Based Biobank

“…Understanding of the prevalence and contribution to cancer risk of BRCA1/2 variants in non-European populations has been limited by racial and ethnic disparities in genetic research (14). In addition to reduced uptake of genetic testing in diverse populations (15)(16)(17)(18), there is a higher rate of detection of variants of uncertain significance in non-European populations (19)(20)(21). Here, we evaluated the range of BRCA1/2 variants in a diverse patient population from the BioMe Biobank in New York City, and explored clinical characteristics of individuals harboring expected pathogenic variants in BRCA1/2.…”

Genetic Cancer Risk Assessment for Breast Cancer in Latin America

“…As we have shown, cancer genetics is largely underdeveloped in Latin America (63, 64), and Latin American populations are poorly represented in genomic studies. Therefore, there is a great need to develop policies aimed at increasing the availability of clinical cancer genetics, as well as of research to better understand the prevalence, risks and outcomes of hereditary cancer in the region.…”