Breast Cancer Statistics, 2022.

This article is the American Cancer Society's update on female breast cancer statistics in the United States, including population-based data on incidence, mortality, survival, and mammography screening. Breast cancer incidence rates have risen in most of the past four decades; during the most recent data years (2010-2019), the rate increased by 0.5% annually, largely driven by localized-stage and hormone receptor-positive disease. In contrast, breast cancer mortality rates have declined steadily since their peak in 1989, albeit at a slower pace in recent years (1.3% annually from 2011 to 2020) than in the previous decade (1.9% annually from 2002 to 2011). In total, the death rate dropped by 43% during 1989-2020, translating to 460,000 fewer breast cancer deaths during that time. The death rate declined similarly for women of all racial/ethnic groups except American Indians/Alaska Natives, among whom the rates were stable. However, despite a lower incidence rate in Black versus White women (127.8 vs. 133.7 per 100,000), the racial disparity in breast cancer mortality remained unwavering, with the death rate 40% higher in Black women overall (27.6 vs. 19.7 deaths per 100,000 in 2016-2020) and two-fold higher among adult women younger than 50 years (12.1 vs. 6.5 deaths per 100,000). Black women have the lowest 5-year relative survival of any racial/ethnic group for every molecular subtype and stage of disease (except stage I), with the largest Black-White gaps in absolute terms for hormone receptor-positive/human epidermal growth factor receptor 2-negative disease (88% vs. 96%), hormone receptor-negative/human epidermal growth factor receptor 2-positive disease (78% vs. 86%), and stage III disease (64% vs. 77%). Progress against breast cancer mortality could be accelerated by mitigating racial disparities through increased access to high-quality screening and treatment via nationwide Medicaid expansion and partnerships between community stakeholders, advocacy organizations, and health systems.

Breast cancer statistics, 2019.

This article is the American Cancer Society's biennial update on female breast cancer statistics in the United States, including data on incidence, mortality, survival, and screening. Over the most recent 5-year period (2012-2016), the breast cancer incidence rate increased slightly by 0.3% per year, largely because of rising rates of local stage and hormone receptor-positive disease. In contrast, the breast cancer death rate continues to decline, dropping 40% from 1989 to 2017 and translating to 375,900 breast cancer deaths averted. Notably, the pace of the decline has slowed from an annual decrease of 1.9% during 1998 through 2011 to 1.3% during 2011 through 2017, largely driven by the trend in white women. Consequently, the black-white disparity in breast cancer mortality has remained stable since 2011 after widening over the past 3 decades. Nevertheless, the death rate remains 40% higher in blacks (28.4 vs 20.3 deaths per 100,000) despite a lower incidence rate (126.7 vs 130.8); this disparity is magnified among black women aged <50 years, who have a death rate double that of whites. In the most recent 5-year period (2013-2017), the death rate declined in Hispanics (2.1% per year), blacks (1.5%), whites (1.0%), and Asians/Pacific Islanders (0.8%) but was stable in American Indians/Alaska Natives. However, by state, breast cancer mortality rates are no longer declining in Nebraska overall; in Colorado and Wisconsin in black women; and in Nebraska, Texas, and Virginia in white women. Breast cancer was the leading cause of cancer death in women (surpassing lung cancer) in four Southern and two Midwestern states among blacks and in Utah among whites during 2016-2017. Declines in breast cancer mortality could be accelerated by expanding access to high-quality prevention, early detection, and treatment services to all women.

Breast Cancer Incidence Among Asian American Women in New York City: Disparities in Screening and Presentation.

BACKGROUND: Asian American (AsAm) women have some of the lowest rates of up-to-date breast cancer screening, and lack of disaggregated racial/ethnic data can mask disparities. We evaluated presentation patterns among AsAms at two hospitals with distinct communities: New York Presbyterian-Queens (NYPQ), in Flushing, Queens and Weill Cornell Medical Center (WCM), on the Upper East Side (UES) neighborhood of Manhattan. PATIENTS AND METHODS: Patients with newly diagnosed breast cancer between January 2019 and December 2022 were identified using a prospective database and clinical data collected. Patients were categorized as self-reported Asian versus Non-Asian. The Asian group was disaggregated as Chinese-Asian versus Other-Asian. Physician workforce data were obtained from public records. RESULTS: A total of 3546 patients (1162 NYPQ, 2384 WCM) were included. More NYPQ patients identified as Asian compared with WCM (49 vs. 14%, p < 0.001). Asian patients were mostly East Asian Chinese (NYPQ 61%, WCM 53%). More Chinese patients at NYPQ reported Chinese as their preferred language (81 vs. 33%, p < 0.001). Greatest differences of screen-detected disease frequency were seen between NYPQ and WCM Chinese patients (75 vs. 59%, p < 0.001). Eighty percent of NYPQ Chinese patients presented with stage 0/I disease versus 69% at WCM (p = 0.007), a difference not observed between Other-Asian patients (75% NYPQ, 68% WCM, p = 0.095). 3% of UES physicians versus 16% in Flushing reported speaking Chinese. CONCLUSIONS: Chinese patients residing in a neighborhood with more Chinese-speaking physicians more frequently presented with screen-detected, early-stage breast cancer. Stage distribution differences were not apparent among the aggregated pool of Other-Asian patients, suggesting cancer disparities may be masked when ethnic groups are studied in aggregate.

Disaggregating the Asian-American Breast Cancer Population: Disparities in Reconstruction Rates.

INTRODUCTION: Breast cancer (BC) incidence has been increasing among Asian-Americans (AsAms); recent data suggest these patients are less likely to undergo postmastectomy breast reconstruction (PMBR) compared to non-Asian women. Historically, AsAm BC patients are reported in aggregate, masking heterogeneity within this population. We aim to identify patterns of postmastectomy reconstruction among disaggregated AsAm BC patients at our institution. METHODS: A retrospective chart review was performed for BC patients who underwent mastectomy between 2017 and 2021. Patient demographic and clinical information was collected including self-reported race/ethnicity and reconstruction at time of mastectomy. Self-identified Asian patients were disaggregated into East Asian, Southeast Asian, South Asian, and 'Asian Other.' We examined rates of reconstruction between the different races and the disaggregated Asian subgroups. Univariable and multivariable analysis was performed to examine patient factors associated with PMBR. RESULTS: Six hundred and five patients met inclusion criteria. Forty seven percent of patients identified as Asian, 36% of which as East Asian. Forty four percent of all patients underwent PMBR. Southeast Asian and South Asian women were least likely to undergo reconstruction, while Hispanic and non-Hispanic Black women were most likely to pursue PMBR (P = 0.020). On multivariable analysis, Hispanic, non-Hispanic White, and non-Hispanic Black women were more likely to undergo reconstruction compared to Asian women. Other factors associated with reconstruction were coverage with private insurance and diagnosis of noninvasive disease. CONCLUSIONS: Rates of PMBR are lower among AsAms than non-Asian patients and vary between Asian ethnic subgroups. Further investigation is needed to identify patterns of reconstruction among the disaggregated AsAm population to address disparities.

Breast cancer statistics, 2017, racial disparity in mortality by state.

In this article, the American Cancer Society provides an overview of female breast cancer statistics in the United States, including data on incidence, mortality, survival, and screening. Approximately 252,710 new cases of invasive breast cancer and 40,610 breast cancer deaths are expected to occur among US women in 2017. From 2005 to 2014, overall breast cancer incidence rates increased among Asian/Pacific Islander (1.7% per year), non-Hispanic black (NHB) (0.4% per year), and Hispanic (0.3% per year) women but were stable in non-Hispanic white (NHW) and American Indian/Alaska Native (AI/AN) women. The increasing trends were driven by increases in hormone receptor-positive breast cancer, which increased among all racial/ethnic groups, whereas rates of hormone receptor-negative breast cancers decreased. From 1989 to 2015, breast cancer death rates decreased by 39%, which translates to 322,600 averted breast cancer deaths in the United States. During 2006 to 2015, death rates decreased in all racial/ethnic groups, including AI/ANs. However, NHB women continued to have higher breast cancer death rates than NHW women, with rates 39% higher (mortality rate ratio [MRR], 1.39; 95% confidence interval [CI], 1.35-1.43) in NHB women in 2015, although the disparity has ceased to widen since 2011. By state, excess death rates in black women ranged from 20% in Nevada (MRR, 1.20; 95% CI, 1.01-1.42) to 66% in Louisiana (MRR, 1.66; 95% CI, 1.54, 1.79). Notably, breast cancer death rates were not significantly different in NHB and NHW women in 7 states, perhaps reflecting an elimination of disparities and/or a lack of statistical power. Improving access to care for all populations could eliminate the racial disparity in breast cancer mortality and accelerate the reduction in deaths from this malignancy nationwide. CA Cancer J Clin 2017;67:439-448. © 2017 American Cancer Society.

A Prospective Evaluation of the Quality of Life and Mental Health Implications of Mastectomy Alone on Women in sub-Saharan Africa.

OBJECTIVE: Assess quality of life and mental health implications of mastectomy for breast cancer on sub-Saharan African women. BACKGROUND: Mortality rates amongst women diagnosed with breast cancer in sub-Saharan Africa (SSA) are high, with disparities in survival relative to women in high income countries partly attributed to advanced disease at presentation. Fears of the sequelae of mastectomy are a prominent reason for presentation delays. There is a critical need to better understand the effects of mastectomy on women in SSA to inform preoperative counseling and education for women with breast cancer. METHODS: Women with breast cancer in Ghana and Ethiopia undergoing mastectomy were followed prospectively. Breast related quality-of-life and mental health measures were evaluated preoperatively, 3 and 6 months postoperatively, using BREAST-Q, PHQ-9, and GAD-7. Bivariate and logistic regression analyses evaluated changes in these measures for the total cohort and between sites. RESULTS: A total of 133 women from Ghana and Ethiopia were recruited. The majority of women presented with unilateral disease (99%) and underwent unilateral mastectomy (98%) with axillary lymph node dissection. Radiation was more common in Ghana ( P <0.001). Across most BREAST-Q subscales, women from both countries reported significantly decreased scores at 3 months postoperative. At 6 months, the combined cohort reported decreased scores for breast satisfaction (mean difference, -3.4). Women in both countries reported similar improvements in anxiety and depression scores postoperatively. CONCLUSIONS: Women from Ghana and Ethiopia who underwent mastectomy experienced a decline in breast-related body image while also experiencing decreased levels of depression and anxiety.

Top Breast Oncology Articles from 2021 to Inform Your Cancer Practice.

Breast oncology generates extensive literature and widespread media attention every year because of the high worldwide burden of this disease and also because of the rapid pace at which treatment advances have progressed. The year 2021 was no different, and this review will summarize some of the practice-changing, practice-validating, and practice-challenging publications of that year. These studies cover a broad range of topics including multidisciplinary care with gene expression profiling; breast cancer disparities; breast cancer screening; and prophylactic mastectomy surgery.

Landmark Series: The Cancer Genome Atlas and the Study of Breast Cancer Disparities.

Race-related variation in breast cancer incidence and mortality are well-documented in the United States. The effect of genetic ancestry on disparities in tumor genomics, risk factors, treatment, and outcomes of breast cancer is less understood. The Cancer Genome Atlas (TCGA) is a publicly available resource that has allowed for the recent emergence of genome analysis research seeking to characterize tumor DNA and protein expression by ancestry as well as the social construction of race and ethnicity. Results from TCGA based studies support previous clinical evidence that demonstrates that American women with African ancestry are more likely to be afflicted with breast cancers featuring aggressive biology and poorer outcomes compared with women with other backgrounds. Data from TCGA based studies suggest that Asian women have tumors with favorable immune microenvironments and may experience better disease-free survival compared with white Americans. TCGA contains limited data on Hispanic/Latinx patients due to small sample size. Overall, TCGA provides important opportunities to define the molecular, biologic, and germline genetic factors that contribute to breast cancer disparities.

Social Determinants of Cancer Disparities.

Cancer is a major public health issue that is associated with significant morbidity and mortality across the globe. At its root, cancer represents a genetic aberration, but socioeconomic, environmental, and geographic factors contribute to different cancer outcomes for selected population subsets. The disparities in the delivery of healthcare affect all aspects of cancer management from early prevention to end-of-life care. In an effort to address the inequality in the delivery of healthcare among socioeconomically disadvantaged populations, the World Health Organization defined social determinants of health (SDOH) as conditions in which people are born, live, work, and age. These factors play a significant role in the disproportionate cancer burden among different population groups. SDOH are associated with disparities in risk factor burden, screening modalities, diagnostic testing, treatment options, and quality of life of patients with cancer. The purpose of this article is to describe a more holistic and integrated approach to patients with cancer and address the disparities that are derived from their socioeconomic background.

Assessing the Complex General Surgical Oncology Pipeline: Trends in Race and Ethnicity Among US Medical Students, General Surgery Residents, and Complex General Surgical Oncology Trainees.

BACKGROUND: Cancer incidence is expected to increase in coming decades, disproportionately so among minoritized communities. Racially and ethnically concordant care is essential to addressing disparities in cancer outcomes within at-risk groups. Here, we assess trends in racial and ethnic representation of medical students (MS), general surgery (GS) residents, and complex general surgical oncology (CGSO) fellows. METHODS: This is a retrospective review of data from the American Association of Medical Colleges and the Accreditation Council of Medical Education (ACGME) from 2015 to 2020. Self-reported race and ethnicity was obtained for MS, GS, and CGSO trainees. Race and ethnicity proportions were compared with respective representation in the 2020 US Census. Mann-Kendall, Wilcoxon rank sum, and linear regression were used to assess trends, as appropriate. RESULTS: A total of 316,448 MS applicants, 128,729 MS matriculants, 27,574 GS applicants, 46,927 active GS residents, 710 CGSO applicants, and 659 active CGSO fellows were included. With every progressive stage in training, there was a smaller proportion of URM active trainees than applicants. Further, URM, Hispanic/Latino, and Black/African American trainees were significantly underrepresented compared with 2020 Census data. While the proportion of White CGSO fellows increased over time (54.5-69.2%, p = 0.009), the proportion of Black/African American and Hispanic/Latino (URM) CGSO fellows did not significantly change over the study period, though URM representation was lower in 2020 as compared with 2015. DISCUSSION: From 2015 to 2020, minority representation decreased at every advancing stage in surgical oncology training. Efforts to address barriers for URM applicants to CGSO fellowships are needed.

Racial and Ethnic Disparities in Outcomes After Breast-Conserving Therapy and Endocrine Therapy for DCIS: A Post-Hoc Analysis of the NSABP B-35 Randomized Clinical Trial.

BACKGROUND: Racial and ethnic disparities in outcomes after treatment for ductal carcinoma in situ (DCIS) are largely unknown. The objective of this study was to examine breast cancer outcomes by race and ethnicity in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-35 clinical trial. PATIENTS AND METHODS: The NSABP B-35 trial randomized postmenopausal women with hormone receptor-positive DCIS treated with breast-conserving therapy to 5 years of tamoxifen or anastrozole. In total, 3104 women were enrolled between 2003 and 2006. For this analysis, patients without complete self-reported race and ethnicity or with immediate trial dropout were excluded. Kaplan-Meier curves and adjusted Cox-proportional hazards models were used for analyses. RESULTS: Of the 3061 women included, 2614 (85.4%) were non-Hispanic white (NHW), 255 (8.3%) were non-Hispanic Black (NHB), 95 (3.1%) were Hispanic, and 96 (3.1%) were Asian or Pacific Islander (API). Endocrine therapy assignment and duration were well balanced between racial and ethnic groups. Median follow-up was 9 years; unadjusted Kaplan-Meier curves did not show any racial differences in disease events. Adjusted Cox-proportional hazards models found API (versus NHW) race to be associated with higher local recurrence [hazard ratio (HzR) 2.45, p = 0.035] and NHB race to be associated with higher distant recurrence (HzR 5.03, p = 0.020) and breast cancer mortality (HzR 3.83, p = 0.046). CONCLUSIONS: Despite similar locoregional treatments and standard endocrine therapy in a clinical trial population, racial and ethnic disparities exist in long-term outcomes for hormone-receptor-positive DCIS. These findings suggest that factors outside of access and treatment may impact DCIS outcomes by race and ethnicity.

Unmet Needs in Oncology Clinical Research and Treatment in Africa: Focus on Ghana.

Cancer incidence is increasing worldwide and is a major cause of mortality. The relative magnitude of the increase is remarkably high in low human development index (HDI; 95%) and medium HDI (64%) countries. On the African continent, a corresponding increase in cancer burden is predicted, particularly for sub-Saharan Africa. Current epidemiologic data indicate that mortality rates of certain cancers, such as breast and cervical cancers, in sub-Saharan Africa are the highest in the world, and the cancer risks are broadly comparable to the risks in high-income countries, such as the United States and Europe. Although emerging data alludes to the unique genetic profile of cancer in African populations, most cancer therapies are introduced to Africa without confirmatory clinical trials. Therefore, there is an increasing need for clinical trials directed toward prevention, screening, diagnosis, and identification of innovative treatments in the African context. This review will discuss the increasing cancer burden in Africa, with a particular focus on Ghana, unmet clinical needs in cancer, current medical systems, clinical trial regulatory systems, and challenges to clinical trial recruitment.

Breast cancer among African American and sub-Saharan African women: a tale of global inequities.

Breast Cancer is the most common female cancer worldwide with significant global disparities, particularly disadvantaging women of African Ancestry. Though the United States and Sub-Saharan Africa are seemingly very different settings, there are many important parallels between the experience of getting diagnosed and treated for breast cancer in these two geographic regions for women of African ancestry. This commentary explores the parallels and differences and proposes an agenda to move forward to narrow the disparities gaps for some of the worlds most vulnerable women.

The Global Macroeconomic Burden of Breast Cancer: Implications for Oncologic Surgery.

OBJECTIVE: In this study, we quantified the global macroeconomic burden of breast cancer to underscore the critical importance of improving access to oncologic surgical care internationally. SUMMARY BACKGROUND DATA: Breast cancer mortality in many low and middle-income countries (LMICs) is dramatically higher than in high-income countries. Prior to identifying solutions, however, it is important to first define the burden of disease. METHODS: Data from the Institute of Health Metrics and Evaluation (2005-2015) were used to assess epidemiologic trends for 194, middle, and low-income countries. Economic burden defined by Welfare Loss (WL) was calculated by measuring disability-adjusted-life-years lost to breast cancer alongside the dollar equivalent of a value of statistical life year and as a function of each country's gross domestic product (GDP). RESULTS: Annual mortality rates among breast cancer patients were significantly greater in LMICs in South Asia (3.06 per 100 women) and Sub-Saharan Africa (2.76 per 100 women), compared with high-income countries like the United States (1.69 per 100 women). From 2005-2015, mortality in South Asia increased by 8.20% and decreased by 6.45% in Sub-Saharan Africa; mortality rates in 2015 were observed as 27.9 per 100,000 in South Asia and 18.61 per 100,000 in Sub-Saharan Africa. Countries in South Asia demonstrated the greatest rise in WL due to breast cancer, from 0.05% to 0.08% of GDP. CONCLUSIONS: The burden of disease and economic impact of breast cancer is intensifying in LMICs. Global efforts to improve access to surgical care for women with breast cancer could reduce mortality and mitigate the social and financial impact of this disease in LMICs.

Multiethnic PDX models predict a possible immune signature associated with TNBC of African ancestry.

PURPOSE: Triple-negative breast cancer (TNBC) is an aggressive subtype most prevalent among women of Western Sub-Saharan African ancestry. It accounts for 15-25% of African American (AA) breast cancers (BC) and up to 80% of Ghanaian breast cancers, thus contributing to outcome disparities in BC for black women. The aggressive biology of TNBC has been shown to be regulated partially by breast cancer stem cells (BCSC) which mediate tumor recurrence and metastasis and are more abundant in African breast tumors. METHODS: We studied the biological differences between TNBC in women with African ancestry and those of Caucasian women by comparing the gene expression of the BCSC. From low-passage patient derived xenografts (PDX) from Ghanaian (GH), AA, and Caucasian American (CA) TNBCs, we sorted for and sequenced the stem cell populations and analyzed for differential gene enrichment. RESULTS: In our cohort of TNBC tumors, we observed that the ALDH expressing stem cells display distinct ethnic specific gene expression patterns, with the largest difference existing between the GH and AA ALDH+ cells. Furthermore, the tumors from the women of African ancestry [GH/AA] had ALDH stem cell (SC) enrichment for expression of immune related genes and processes. Among the significantly upregulated genes were CD274 (PD-L1), CXCR9, CXCR10 and IFI27, which could serve as potential drug targets. CONCLUSIONS: Further exploration of the role of immune regulated genes and biological processes in BCSC may offer insight into developing novel approaches to treating TNBC to help ameliorate survival disparities in women with African ancestry.

Radial Scars and Complex Sclerosing Lesions of the Breast: Prevalence of Malignancy and Natural History Under Active Surveillance.

BACKGROUND: When needle core biopsies (NCBs) of the breast reveal radial scar or complex sclerosing lesions (RSLs), excision is often recommended despite a low risk of malignancy in the modern era. The optimal management of NCBs revealing RSLs is controversial, and understanding of the natural history of unresected RSLs is limited. METHODS: We retrospectively analyzed pathology and imaging data from 148 patients with NCB revealing RSL without atypia from 2015 to 2019 to determine the prevalence of malignancy and the behavior of RSLs undergoing active surveillance (AS). RESULTS: The mean age of patients was 52 years, and most lesions were screen-detected (91%). The median lesion size was 6.0 mm (range 2-39). Most patients (66%, n = 98) underwent immediate surgery, while 34% (n = 50) of patients underwent AS, with a median follow-up of 16 months (range 6-51). Of the excised RSLs, 99% (n = 97) were benign and 1% (n = 1) revealed ductal carcinoma in situ (DCIS). In 17% (n = 17) of cases, additional high-risk lesions were discovered upon excision. Among the 50 patients undergoing AS, no lesions progressed on interval imaging. CONCLUSIONS: In this cohort, 99% of RSLs undergoing excision were benign, 1% revealed DCIS, and there were no invasive cancers. In the first study of patients with RSLs undergoing AS, we found that all lesions either remained stable or resolved. We propose that the vast majority of patients with RSL on NCB can be safely offered AS, and that routine excision is a low-value intervention.

Outcome of African-American compared to White-American patients with early-stage breast cancer, stratified by phenotype.

BACKGROUND: Breast cancer mortality rates are 39% higher in the African-American (AA) women compared to White-American (WA) women despite the advances in overall breast cancer screening and treatments. Several studies have undertaken to identify the factors leading to this disparity in United States with possible effects of lower socioeconomic status and underlying aggressive biology. METHODS: A retrospective analysis was done using a prospectively maintained database of a metropolitan health system. Patients were selected based on diagnosis of early-stage breast cancer between 10/1998 and 02/2017, and included women over age of 18 with clinically node-negative disease. Patients were then stratified by phenotype confirmed by pathology and patient-identified race. RESULTS: A total of 2,298 women were identified in the cohort with 39% AA and 61% WA women. The overall mean age at the time of diagnosis for AA women was slightly younger at 60 years compared to 62 years for WA women (p = 0.003). Follow-up time was longer for the WA women at 95 months vs. 86 months in AA women. The overall 5-year survival was analyzed for the entire cohort, with the lowest survival occurring in patients with triple-negative breast cancer (TNBC). Phenotype distribution revealed a higher incidence of TNBC in AA women compared to WA women (AA 16% vs. WA 10%; p < 0.0001). AA women also had higher incidence of HER2 positive cancers (AA 16.8% vs. WA 15.3%; p < 0.0001). WA women had a significantly higher distribution of Non-TNBC/HER2-negative phenotype (AA 55% vs. WA 65%; p < 0.0001). Furthermore, a subgroup analysis was done for a sentinel lymph node (SLN) negative cohort that showed higher rates of grade 3 tumors in AA (AA 35% vs. WA 23%; p < 0.0001); and higher rates of grade 1 and grade 2 tumors in WA (30% vs. 21% and 44% vs. 40%). Despite higher grade tumors in AA women, five-year overall survival outcomes in SLN-negative cohort did not differ between AA and WA women when stratifying based on tumor subtype. CONCLUSION: Breast cancer survival disparities in AA and WA women with SLN-negative breast cancer are diminished when evaluated at early-stage cancers defined by SLN-negative tumors. Our evaluation suggests that when diagnosed early, phenotype does not contribute to racial survival outcomes. The lower survival rate in AA women with breast cancer may be attributed to later stage biology between the two races, or underlying socioeconomic disparities.

Next-generation sequencing identifies recurrent copy number variations in invasive breast carcinomas from Ghana.

African and African-American (AA) women have higher incidence of triple-negative breast cancers (TNBC) with high histological grade and aggressive clinical behavior, but the reasons are not fully understood. We recently found that the oncogenic protein EZH2 is overexpressed in Ghanaian breast cancer patients, with 16% of the tumors expressing cytoplasmic EZH2. Understanding the molecular underpinnings of these aggressive tumors may lead to the identification of potential targetable oncogenic drivers. We characterized the copy number variations of 11 Ghanaian breast tumor patients by targeted multiplexed PCR-based DNA next-generation sequencing (NGS) over 130 cancer-relevant genes. While the DNA quality was not optimal for mutation analysis, 90% of the tumors had frequent recurrent copy number alterations (CNAs) of 17 genes: SDHC, RECQL4, TFE3, BCL11A, BCL2L1, PDGFRA, DEK, SMUG1, AKT3, SMARCA4, VHL, KLF6, CCNE1, G6PD, FGF3, ABL1, and CCND1, with the top oncogenic functions being mitotic G1-G1/S-phase regulation, gene transcription, apoptosis, and PI3K/AKT pathway. The most common recurrent high-level CNAs were gains of RECQL4 and SDHC, in 50% and 60% of cases, respectively. Network analyses revealed a significant predicted interaction among 12 of the 17 (70.6%) genes with high-level CNAs (p = 5.7E-07), which was highly correlated with EZH2 expression (r = 0.4-0.75). By immunohistochemistry, RECQL4 and SDHC proteins were upregulated in 53 of 86 (61.6%) and 48 of 86 (56%) of Ghanaian invasive carcinoma tissue samples. In conclusion, our data show that invasive carcinomas from Ghana exhibit recurrent CNAs in 17 genes, with functions in oncogenic pathways, including PI3K/AKT and G1-G1/S regulation, which may have implications for the biology and treatment of invasive carcinomas in African and AA women.

Hereditary Susceptibility for Triple Negative Breast Cancer Associated With Western Sub-Saharan African Ancestry: Results From an International Surgical Breast Cancer Collaborative.

OBJECTIVE: To investigate subtype-specific risk of germline alleles associated with triple negative breast cancer (TNBC) in African ancestry populations. BACKGROUND: Breast cancer (BC) mortality is higher in African American (AA) compared to White American (WA) women; this disparity is partly explained by 2-fold higher TNBC incidence. METHODS: We used a surgically maintained biospecimen cohort of 2884 BC cases. Subsets of the total (760 AA; 962 WA; 910 West African/Ghanaian; 252 East African/Ethiopian) were analyzed for genotypes of candidate alleles. A subset of 417 healthy controls were also genotyped, to measure associations with overall BC risk and TNBC. RESULTS: TNBC frequency was highest in Ghanaian and AA cases (49% and 44% respectively; P < 0.0001) and lowest in Ethiopian and WA cases (17% and 24% respectively; P < 0.0001). TNBC cases had higher West African ancestry than non-TNBC (P < 0.0001). Frequency of the Duffy-null allele (rs2814778; an African ancestral variant adopted under selective pressure as protection against malaria) was associated with TNBC-specific risk (P < 0.0001), quantified West African Ancestry (P < 0.0001) and was more common in AA, Ghanaians, and TNBC cases. Additionally, rs4849887 was significantly associated with overall BC risk, and both rs2363956 and rs13000023 were associated with TNBC-specific risk, although none as strongly as the Duffy-null variant. CONCLUSIONS: West African ancestry is strongly correlated with TNBC status, as well as germline variants related to BC risk. The Duffy-null allele was associated with TNBC risk in our cohort.

Triple-Negative Breast Cancer, Stem Cells, and African Ancestry.

Triple-negative breast cancers (TNBCs) are more common among African-ancestry populations, such as African Americans and western, sub-Saharan Africans, compared with European-ancestry populations. This phenotype prevalence contributes to disparities in breast cancer outcomes between African Americans and White Americans. Breast cancer stem cells represent the tumor subpopulation involved in metastatic virulence, and ongoing research seeks to characterize the extent to which TNBC versus non-TNBC stem cells may differ. This review summarizes the existing literature regarding TNBCs and stem cells as they pertain to the burden of breast cancer among African-ancestry populations. Additional research related to variations in somatic tumor genomics between the African-American and White-American populations is also summarized. This review furthermore explores the history of insights regarding breast cancer disparities related to racial/ethnic identity, socioeconomic status, and tumor biology.