Ancestral links of Chesapeake Bay region African Americans to specific Bight of Bonny (West Africa) microethnic groups and increased frequency of aggressive breast cancer in both regions

Doctors’ Perceptions of Multiracial Adolescents

Perceptions of race influence the way health care is delivered to minority populations, particularly multiracial people. Currently only 11% of American physicians are Black or Latinx, making the chances slim that Black and Latinx patients will be treated by a co-ethnic. White supremacy is well documented in the medical literature—along with efforts to combat it—yet medical education and health care are still largely based on studies by and about white people. This privileging of whiteness is increasingly evident as the COVID-19 pandemic has shone a renewed spotlight on disparities in health and care in the U.S. The current study considers how doctors perceive race and use it to make healthcare decisions. Among the (N = 509) doctors in this sample, few said they considered the patient’s race. Of those who did, many determined race by some method other than asking the patient directly. The most common methods were observing skin tone and observing cultural cues. Doctors perceived nearly half the multiracial targets as monoracial. Targets who followed the norm of hypodescent were significantly more likely to be identified congruently by doctors. Targets who identified at the extremes of the color spectrum (black and white) were easier to identify, while the beige tones in the middle of the spectrum were more challenging. Patient ancestry was the most relevant criterion in explaining the congruence of racial identification between patients and doctors, while characteristics of the doctors were nearly irrelevant.

So many Nigerians: why is Nigeria overrepresented as the ancestral genetic homeland of Legacy African North Americans?

The genetics of African North Americans are complex amalgamations of various West and Central African peoples with modest gene flow from specific European and Amerindian peoples. A comprehensive understanding of African North American biohistory is a prerequisite for accurate interpretations of the ancestral genetics of this population. Too often, genetic interpretations falter with ahistorical reconstructions. The recently reported overrepresentation of Nigerian lineages in African North Americans reflects pronounced limitations in the African genomic database, the artificiality of the colonial maps of Africa, the contributions of multiple African empires and kingdoms into the transatlantic trade in enslaved Africans, and the overrepresentation of Yoruba peoples in the existing limited representation of West Africans in public genomic databases. This Matters Arising paper is in response to Micheletti et al. (2020), published in The American Journal of Human Genetics. See also the response by Micheletti et al. (2020), published in this issue.

Kaiso is highly expressed in TNBC tissues of women of African ancestry compared to Caucasian women

Purpose

Triple-negative breast cancer (TNBC) is most prevalent in young women of African ancestry (WAA) compared to women of other ethnicities. Recent studies found a correlation between high expression of the transcription factor Kaiso, TNBC aggressiveness, and ethnicity. However, little is known about Kaiso expression and localization patterns in TNBC tissues of WAA. Herein, we analyze Kaiso expression patterns in TNBC tissues of African (Nigerian), Caribbean (Barbados), African American (AA), and Caucasian American (CA) women.

Methods

Formalin-fixed and paraffin embedded (FFPE) TNBC tissue blocks from Nigeria and Barbados were utilized to construct a Nigerian/Barbadian tissue microarray (NB-TMA). This NB-TMA and a commercially available TMA comprising AA and CA TNBC tissues (AA-CA-YTMA) were subjected to immunohistochemistry to assess Kaiso expression and subcellular localization patterns, and correlate Kaiso expression with TNBC clinical features.

Results

Nigerian and Barbadian women in our study were diagnosed with TNBC at a younger age than AA and CA women. Nuclear and cytoplasmic Kaiso expression was observed in all tissues analyzed. Analysis of Kaiso expression in the NB-TMA and AA-CA-YTMA revealed that nuclear Kaiso H scores were significantly higher in Nigerian, Barbadian, and AA women compared with CA women. However, there was no statistically significant difference in nuclear Kaiso expression between Nigerian versus Barbadian women, or Barbadian versus AA women.

Conclusions

High levels of nuclear Kaiso expression were detected in patients with a higher degree of African heritage compared to their Caucasian counterparts, suggesting a role for Kaiso in TNBC racial disparity.

Electronic supplementary material

The online version of this article (doi:10.1007/s10552-017-0955-2) contains supplementary material, which is available to authorized users.

Molecular characteristics and prognostic features of breast cancer in Nigerian compared with UK women

Although breast cancer (BC) incidence is lower in African-American women compared with White-American, in African countries such as Nigeria, BC is a common disease. Nigerian women have a higher risk for early-onset, with a high mortality rate from BC, prompting speculation that risk factors could be genetic and the molecular portrait of these tumours are different to those of western women. In this study, 308 BC samples from Nigerian women with complete clinical history and tumour characteristics were included and compared with a large series of BC from the UK as a control group. Immunoprofile of these tumours was characterised using a panel of 11 biomarkers of known relevance to BC. The immunoprofile and patients' outcome were compared with tumour grade-matched UK control group. Nigerian women presenting with BC were more frequently premenopausal, and their tumours were characterised by large primary tumour size, high tumour grade, advanced lymph node stage, and a higher rate of vascular invasion compared with UK women. In the grade-matched groups, Nigerian BC showed over representation of triple-negative and basal phenotypes and BRCA1 deficiency BC compared with UK women, but no difference was found regarding HER2 expression between the two series. Nigerian women showed significantly poorer outcome after development of BC compared with UK women. This study demonstrates that there are possible genetic and molecular differences between an indigenous Black population and a UK-based series. The basal-like, triple negative and BRCA1 dysfunction groups of tumours identified in this study may have implications in the development of screening programs and therapies for African patients and families that are likely to have a BRCA1 dysfunction, basal like and triple negative.

What are our AIMs? Interdisciplinary Perspectives on the Use of Ancestry Estimation in Disease Research

BACKGROUND

Ancestry estimation serves as a tool to identify genetic contributions to disease but may contribute to racial discrimination and stigmatization. We sought to understand user perspectives on the benefits and harms of ancestry estimation to inform research practice and contribute to debates about the use of race and ancestry in genetics.

METHODS

Key informant interviews with 22 scientists were conducted to examine scientists' understandings of the benefits and harms of ancestry estimation.

RESULTS

Three main perspectives were observed among key informant scientists who use ancestry estimation in genetic epidemiology research. Population geneticists self identified as educators who controlled the meaning and application of ancestry estimation in research. Clinician-researchers were optimistic about the application of ancestry estimation to individualized risk assessment and personalized medicine. Epidemiologists remained ambivalent toward ancestry estimation and suggested a continued role for race in their research.

CONCLUSIONS

We observed an imbalance of control over the meaning and application of ancestry estimation among disciplines that may result in unwarranted or premature translation of ancestry estimation into medicine and public health. Differences in disciplinary perspectives need to be addressed if translational benefits of genetic ancestry estimation are to be realized.

Differences in the tumor microenvironment between African-American and European-American breast cancer patients

Background

African-American breast cancer patients experience higher mortality rates than European-American patients despite having a lower incidence of the disease. We tested the hypothesis that intrinsic differences in the tumor biology may contribute to this cancer health disparity.

Methods and Results

Using laser capture microdissection, we examined genome-wide mRNA expression specific to tumor epithelium and tumor stroma in 18 African-American and 17 European-American patients. Numerous genes were differentially expressed between these two patient groups and a two-gene signature in the tumor epithelium distinguished between them. To identify the biological processes in tumors that are different by race/ethnicity, Gene Ontology and disease association analyses were performed. Several biological processes were identified which may contribute to enhanced disease aggressiveness in African-American patients, including angiogenesis and chemotaxis. African-American tumors also contained a prominent interferon signature. The role of angiogenesis in the tumor biology of African-Americans was further investigated by examining the extent of vascularization and macrophage infiltration in an expanded set of 248 breast tumors. Immunohistochemistry revealed that microvessel density and macrophage infiltration is higher in tumors of African-Americans than in tumors of European-Americans. Lastly, using an in silico approach, we explored the potential of tailored treatment options for African-American patients based on their gene expression profile. This exploratory approach generated lists of therapeutics that may have specific antagonistic activity against tumors of African-American patients, e.g., sirolimus, resveratrol, and chlorpromazine in estrogen receptor-negative tumors.

Conclusions

The gene expression profiles of breast tumors indicate that differences in tumor biology may exist between African-American and European-American patients beyond the knowledge of current markers. Notably, pathways related to tumor angiogenesis and chemotaxis could be functionally different in these two patient groups.

Ethnogenetic layering (EL): an alternative to the traditional race model in human variation and health disparity studies

BACKGROUND

Traditionally, studies in human biodiversity, disease risk, and health disparities have defined populations in the context of typological racial models. However, such racial models are often imprecise generalizations that fail to capture important local patterns of human biodiversity.

AIM

More explicit, detailed, and integrated information on relevant geographic, environmental, cultural, genetic, historical, and demographic variables are needed to understand local group expressions of disease inequities. This paper details the methods used in ethnogenetic layering (EL), a non-typological alternative to the current reliance of the biological racial paradigm in public health, epidemiology, and biomedicine.

SUBJECTS AND METHODS

EL is focused on geographically identified microethnic groups or MEGs, a more nuanced and sensitive level of analysis than race. Using the MEG level of analysis, EL reveals clinical variations, details the causes of health disparities, and provides a foundation for bioculturally effective intervention strategies. EL relies on computational approaches by using GIS-facilitated maps to produce horizontally stratified geographical regional profiles which are then stacked and evaluated vertically. Each horizontal digital map details local geographic variation in the attributes of a particular database; usually this includes data on local historical demography, genetic diversity, cultural patterns, and specific chronic disease risks (e.g. dietary and toxicological exposures). Horizontal visual display of these layered maps permits vertical analysis at various geographic hot spots.

RESULTS AND CONCLUSIONS

From these analyses, geographical areas and their associated MEGs with highly correlated chronic disease risk factors can be identified and targeted for further study.