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

Novel neutrophil biology insights underlying atypical chemokine receptor-1/Duffy antigen receptor of chemokines-associated neutropenia

PURPOSE OF REVIEW

Atypical chemokine receptor-1 (ACKR1)/Duffy antigen receptor of chemokines (DARC)-associated neutropenia (ADAN; OMIM 611862), previously named benign ethnic neutropenia, and present in two-thirds of individuals identifying as Black in the USA, is associated with mild to moderate decreases in peripheral neutrophil counts that nevertheless do not lead to increased infections. Consequently, recent initiatives have sought to establish normal neutrophil count reference ranges for ADAN, considering it a normal variant rather than a clinical disorder requiring medical intervention.

RECENT FINDINGS

A limited number of studies elucidating the mechanism of neutropenia in ADAN has suggested that neutrophils may redistribute from peripheral blood to the tissues including the spleen: this might explain why ADAN is not associated with increased risks of infection since the total number of neutrophils in the body remains normal. In this review, we critically examine the research underlying the molecular basis of ADAN.

SUMMARY

Insights into the biology of neutrophils and their trafficking may inform the clinical interpretation of neutropenia in ADAN. The bulk of research suggests that ADAN does not lead to a diminished host defense as do other forms of neutropenia. However, ADAN may lead to increased proinflammatory signaling, with possible implications for senescence of the immune system and predisposition to autoimmunity and cancer.

The 30th Annual Prostate Cancer Foundation Scientific Retreat Report

BACKGROUND

The 30th Annual Prostate Cancer Foundation (PCF) Scientific Retreat was held at the Omni La Costa Resort in Carlsbad, CA, from October 26 to 28, 2023. A hybrid component was included for virtual attendees.

METHODS

The Annual PCF Scientific Retreat is a leading international scientific conference focused on pioneering, unpublished, and impactful studies across the spectrum of basic through clinical prostate cancer research, as well as research from related fields with significant potential for improving prostate cancer research and patient outcomes.

RESULTS

The 2023 PCF Retreat concentrated on key areas of research, including: (i) the biology of cancer stem cells and prostate cancer lineage plasticity; (ii) mechanisms of treatment resistance; (iii) emerging AI applications in diagnostic medicine; (iv) analytical and computational biology approaches in cancer research; (v) the role of nerves in prostate cancer; (vi) the biology of prostate cancer bone metastases; (vii) the contribution of ancestry and genomics to prostate cancer disparities; (viii) prostate cancer 3D genomics; (ix) progress in new targets and treatments for prostate cancer; (x) the biology and translational applications of tumor extracellular vesicles; (xi) updates from PCF TACTICAL Award teams; (xii) novel platforms for small molecule molecular glues and binding inhibitors; and (xiii) diversity, equity and inclusion strategies for advancing cancer care equity.

CONCLUSIONS

This meeting report summarizes the presentations and discussions from the 2023 PCF Scientific Retreat. We hope that sharing this information will deepen our understanding of current and emerging research and drive future advancements in prostate cancer patient care.

The DARC side of genetics in cancer: Breast cancer disparities

Highlighting the Distinguished Speakers Symposium on "The Future of Human Genetics and Genomics," this collection of articles is based on presentations at the ASHG 2023 Annual Meeting in Washington, DC, in celebration of all our field has accomplished in the past 75 years, since the founding of ASHG in 1948.

Ethnic disparities in breast cancer patterns in Brazil: examining findings from population-based registries

PURPOSE

To investigate breast cancer (BC) incidence and mortality rates among specific racial groups in Brazil.

METHODS

BC incidence was evaluated from 2010 to 2015, using Brazilian Population-Based Cancer Registries, incorporating crude ratios and annual average percentage change (AAPC). Clinical and sociodemographic data from 2000 to 2019 were obtained from Hospital-Based Cancer Registries. Mortality data from 2000 to 2020 were sourced from the National Mortality Information System, comparing White women and Black women.

RESULTS

Across 13 Brazilian registries, 70,896 new BC cases were reported from 2010 to 2015. The median BC incidence rate was notably higher for White women (101.3 per 100,000) compared to Black women (59.7 per 100,000). In the general population, non-significant decrease in annual BC incidence was observed (AAPC = - 1.2; p = 0.474). Black women were more likely to live in underdeveloped areas, have lower education levels, live without a partner, and have higher alcohol consumption as compared to White women. A higher proportion of Black women received advanced-stage diagnoses (60.1% versus 50.6%, p < 0.001). BC-related mortality analysis showed 271,002 recorded deaths, with significant increase in BC-specific mortality rates in both racial groups. Black women displayed an AAPC of 2.3% (p < 0.001), while White women demonstrated a moderately elevated AAPC of 0.6% (p < 0.001).

CONCLUSION

This study underscores the need for targeted policies to address disparities in access to early detection and proper treatment, particularly for Black women in underprivileged regions, aiming to improve the survival rates of Brazilian women grappling with BC.

Genetic ancestry is related to potential sources of breast cancer health disparities among Colombian women

Breast cancer health disparities are linked to clinical-pathological determinants, socioeconomic inequities, and biological factors such as genetic ancestry. These factors collectively interact in complex ways, influencing disease behavior, especially among highly admixed populations like Colombians. In this study, we assessed contributing factors to breast cancer health disparities according to genetic ancestry in Colombian patients from a national cancer reference center. We collected non-tumoral paraffin embedded (FFPE) blocks from 361 women diagnosed with breast cancer at the National Cancer Institute (NCI) to estimate genetic ancestry using a 106-ancestry informative marker (AIM) panel. Differences in European, Indigenous American (IA) and African ancestry fractions were analyzed according to potential sources of breast cancer health disparities, like etiology, tumor-biology, treatment administration, and socioeconomic-related factors using a Kruskal-Wallis test. Our analysis revealed a significantly higher IA ancestry among overweight patients with larger tumors and those covered by a subsidized health insurance. Conversely, we found a significantly higher European ancestry among patients with smaller tumors, residing in middle-income households, and affiliated to the contributory health regime, whereas a higher median of African ancestry was observed among patients with either a clinical, pathological, or stable response to neoadjuvant treatment. Altogether, our results suggest that the genetic legacy among Colombian patients, measured as genetic ancestry fractions, may be reflected in many of the clinical-pathological variables and socioeconomic factors that end up contributing to health disparities for this disease.

Cancer Screening in Low- and Middle-Income Countries

The worldwide cancer burden is growing, and populations residing in low- and middle-income countries (LMICs) are experiencing a disproportionate extent of this growth. Breast, colorectal, and cervical cancers are among the top 10 most frequently diagnosed malignancies, and they also account for a substantial degree of cancer mortality internationally. Effective screening strategies are available for all three of these cancers. Individuals from LMICs face substantial cost and access barriers to early detection programs, and late stage at diagnosis continues to be a major cause for cancer mortality in these communities. This chapter will review the epidemiology of breast, colorectal, and cervical cancers, and will explore prospects for improving global control through novel approaches to screening in cost-constrained environments.

Tumor-Associated Lymphocytes and Breast Cancer Survival in Black and White Women

This case series evaluates whether differences in immune filtration are associated with breast cancer risk in Black vs White women.

Genetic Ancestry-specific Molecular and Survival Differences in Admixed Patients With Breast Cancer

OBJECTIVE

We aim to determine whether incremental changes in genetic ancestry percentages influence molecular and clinical outcome characteristics of breast cancer in an admixed population.

BACKGROUND

Patients with breast cancer are predominantly characterized as "Black" or "White" based on self-identified race/ethnicity or arbitrary genetic ancestry cutoffs. This limits scientific discovery in populations that are admixed or of mixed race/ethnicity as they cannot be classified based on historical race/ethnicity boxes or genetic ancestry cutoffs.

METHODS

We used The Cancer Genome Atlas cohort and focused on genetically admixed patients that had less than 90% European, African, Asian, or Native American ancestry.

RESULTS

Genetically admixed patients with breast cancer exhibited improved 10-year overall survival relative to those with >90% European ancestry. Within the luminal A subtype, patients with lower African ancestry had longer 10-year overall survival compared to those with higher African ancestry. The correlation of genetic ancestry with gene expression and DNA methylation in the admixed cohort revealed novel ancestry-specific intrinsic PAM50 subtype patterns. In luminal A tumors, genetic ancestry was correlated with both the expression and methylation of signaling genes, while in basal-like tumors, genetic ancestry was correlated with stemness genes. In addition, we took a machine-learning approach to estimate genetic ancestry from gene expression or DNA methylation and were able to accurately calculate ancestry values from a reduced set of 10 genes or 50 methylation sites that were specific for each molecular subtype.

CONCLUSIONS

Our results suggest that incremental changes in genetic ancestry percentages result in ancestry-specific molecular differences even between well-established PAM50 subtypes which may influence disparities in breast cancer survival outcomes. Accounting for incremental changes in ancestry will be important in future research, prognostication, and risk stratification, particularly in ancestrally diverse populations.

Germline testing of BRCA1, BRCA2, PALB2 and CHEK2 c.1100delC in 1514 triple negative familial and isolated breast cancers from a single centre, with extended testing of ATM, RAD51C and RAD51D in over 400

BACKGROUND

The identification of germline pathogenic gene variants (PGVs) in triple negative breast cancer (TNBC) is important to inform further primary cancer risk reduction and TNBC treatment strategies. We therefore investigated the contribution of breast cancer associated PGVs to familial and isolated invasive TNBC.

METHODS

Outcomes of germline BRCA1, BRCA2 and CHEK2_c.1100delC testing were recorded in 1514 women (743-isolated, 771-familial), and for PALB2 in 846 women (541-isolated, 305-familial), with TNBC and smaller numbers for additional genes. Breast cancer free controls were identified from Predicting Risk Of Cancer At Screening and BRIDGES (Breast cancer RIsk after Diagnostic GEne Sequencing) studies.

RESULTS

BRCA1_PGVs were detected in 52 isolated (7.0%) and 195 (25.3%) familial cases (isolated-OR=58.9, 95% CI: 16.6 to 247.0), BRCA2_PGVs in 21 (2.8%) isolated and 67 (8.7%) familial cases (isolated-OR=5.0, 95% CI: 2.3 to 11.2), PALB2_PGVs in 9 (1.7%) isolated and 12 (3.9%) familial cases (isolated-OR=8.8, 95% CI: 2.5 to 30.4) and CHEK2_c.1100delC in 0 isolated and 3 (0.45%) familial cases (isolated-OR=0.0, 95% CI: 0.00 to 2.11). BRCA1_PGV detection rate was >10% for all familial TNBC age groups and significantly higher for younger diagnoses (familial: <50 years, n=165/538 (30.7%); ≥50 years, n=30/233 (12.9%); p<0.0001). Women with a G3_TNBC were more likely to have a BRCA1_PGV as compared with a BRCA2 or PALB2_PGV (p<0.0001). 0/743 isolated TNBC had the CHEK2_c.1100delC PGV and 0/305 any ATM_PGV, but 2/240 (0.83%) had a RAD51D_PGV.

CONCLUSION

PGVs in BRCA1 are associated with G3_TNBCs. Familial TNBCs and isolated TNBCs <30 years have a >10% likelihood of a PGV in BRCA1. BRCA1_PGVs are associated with younger age of familial TNBC. There was no evidence for any increased risk of TNBC with CHEK2 or ATM PGVs.

Patient-derived tumor organoids with p53 mutations, and not wild-type p53, are sensitive to synergistic combination PARP inhibitor treatment

Poly (ADP-ribose) polymerase inhibitors (PARPi) are used for patients with BRCA1/2 mutations, but patients with other mutations may benefit from PARPi treatment. Another mutation that is present in more cancers than BRCA1/2 is mutation to the TP53 gene. In 2D breast cancer cell lines, mutant p53 (mtp53) proteins tightly associate with replicating DNA and Poly (ADP-ribose) polymerase (PARP) protein. Combination drug treatment with the alkylating agent temozolomide and the PARPi talazoparib kills mtp53 expressing 2D grown breast cancer cell lines. We evaluated the sensitivity to the combination of temozolomide plus PARPi talazoparib treatment to breast and lung cancer patient-derived tumor organoids (PDTOs). The combination of the two drugs was synergistic for a cytotoxic response in PDTOs with mtp53 but not for PDTOs with wtp53. The combination of talazoparib and temozolomide induced more DNA double-strand breaks in mtp53 expressing organoids than in wild-type p53 expressing organoids as shown by increased γ-H2AX protein expression. Moreover, breast cancer tissue microarrays (TMAs) showed a positive correlation between stable p53 and high PARP1 expression in sub-groups of breast cancers, which may indicate sub-classes of breast cancers sensitive to PARPi therapy. These results suggest that mtp53 could be a biomarker to predict response to the combination of PARPi talazoparib-temozolomide treatment.

Clinical and immunological features in ACKR1/DARC-associated neutropenia

ABSTRACT

ACKR1/DARC-associated neutropenia (NP; ADAN; Online Mendelian Inheritance in Man 611862), caused by a variation in the ACKR1/DARC gene (rs2814778), is common in persons of African or Middle Eastern descent. In a cohort of 66 genetically confirmed subjects with ADAN, we show that absolute neutrophil counts (ANCs) may occasionally be lower than previously recognized (0.1 × 109-0.49 × 109/L for 9% of the subjects), which is similar to ANCs in severe congenital NP (SCNP). ANCs often normalized during inflammation, even mild. Individuals with ADAN (of 327 observed person-years) showed no cases of myelodysplastic syndrome (MDS), which is frequently encountered in SCNP. Unexpectedly, 22% presented with autoantibodies to neutrophils, compared with <1% in controls. Compared with healthy donors, subjects with ADAN demonstrated significantly lower human cationic antimicrobial protein-18/pro-leucin leucin-37 plasma levels; higher levels of nonclassical, proinflammatory, 6-sulfo LacNac-expressing monocytes; and differentially expressed plasma levels of 28 of the 239 analyzed cytokines related to immunity/inflammation, cell signaling, neutrophil activation, and angiogenesis. Collectively, more severe neutropenia in ADAN than previously assumed may complicate differential diagnoses compared with other SCNPs, and various (auto)immune/inflammatory reactions with a distinct profile may be a cause or consequence of this hereditary neutropenia.

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.

Low Hospital Volume Is Associated with Higher All-Cause Mortality in Black Women with Triple Negative Breast Cancer

INTRODUCTION

This study examines the association between hospital volume and all-cause mortality in Black women with triple negative breast cancer (TNBC) who received surgery and chemotherapy.

METHODS

Black women ages 18+ with stage I-III TNBC who received both surgery and chemotherapy were identified in the National Cancer Database (NCDB). Hospital volume was determined using the number of annual breast cancer cases divided by the number of years the hospital participated in the NCDB. Hospital annual volume quartiles ranged from Q1 (lowest) to Q4 (highest). Univariable analysis and multivariable logistic regression modeling with restricted cubic splines examined the effect of hospital volume on all-cause mortality.

RESULTS

Sixteen thousand five hundred fifty-six patients met the study criteria. All-cause mortality incidence was lower at higher volume compared to lower volume hospitals Q1 24.1% (95% CI: 22.8 to 25.4), Q2 21.8% (95% CI: 20.5 to 23.1), Q3 20.9% (95% CI: 19.6 to 22.1), Q4 19.0% (95% CI: 17.7 to 20.1), p<0.001. On multivariable analysis, treatment at the highest hospital volume quartile was associated with a 21% reduction in the odds of death compared to the lowest quartile [Q4 Vs. Q1, OR=0.79 (95% CI: 0.67 to 0.92)]. For every 100-patient increase in annual volume, all-cause mortality was reduced by 4% [OR=0.96 (95% CI: 0.94 to 0.98)]. There was a significant linear dose-dependent relationship between increasing hospital volume and all-cause mortality.

CONCLUSION

Black women treated at high-volume hospitals have lower all-cause mortality than those at low-volume hospitals. Future studies should examine the characteristics of high-volume hospitals associated with improved outcomes.

Population-specific Mutation Patterns in Breast Tumors from African American, European American, and Kenyan Patients

Women of African descent have the highest breast cancer mortality in the United States and are more likely than women from other population groups to develop an aggressive disease. It remains uncertain to what extent breast cancer in Africa is reminiscent of breast cancer in African American or European American patients. Here, we performed whole-exome sequencing of genomic DNA from 191 breast tumor and non-cancerous adjacent tissue pairs obtained from 97 African American, 69 European American, 2 Asian American, and 23 Kenyan patients. Our analysis of the sequencing data revealed an elevated tumor mutational burden in both Kenyan and African American patients, when compared with European American patients. TP53 mutations were most prevalent, particularly in African American patients, followed by PIK3CA mutations, which showed similar frequencies in European American, African American, and the Kenyan patients. Mutations targeting TBX3 were confined to European Americans and those targeting the FBXW7 tumor suppressor to African American patients whereas mutations in the ARID1A gene that are known to confer resistance to endocrine therapy were distinctively enriched among Kenyan patients. A Kyoto Encyclopedia of Genes and Genomes pathway analysis could link FBXW7 mutations to an increased mitochondrial oxidative phosphorylation capacity in tumors carrying these mutations. Finally, Catalogue of Somatic Mutations in Cancer (COSMIC) mutational signatures in tumors correlated with the occurrence of driver mutations, immune cell profiles, and neighborhood deprivation with associations ranging from being mostly modest to occasionally robust. To conclude, we found mutational profiles that were different between these patient groups. The differences concentrated among genes with low mutation frequencies in breast cancer.

SIGNIFICANCE

The study describes differences in tumor mutational profiles between African American, European American, and Kenyan breast cancer patients. It also investigates how these profiles may relate to the tumor immune environment and the neighborhood environment in which the patients had residence. Finally, it describes an overrepresentation of ARID1A gene mutations in breast tumors of the Kenyan patients.

From Race to Racism and Disparities to Equity: An Actionable Biopsychosocial Approach to Breast Cancer Outcomes

PURPOSE

Racial disparities in outcomes of breast cancer in the United States have widened over more than 3 decades, driven by complex biologic and social factors. In this review, we summarize the biological and social narratives that have shaped breast cancer disparities research across different scientific disciplines in the past, explore the underappreciated but crucial ways in which these 2 strands of the breast cancer story are interwoven, and present 5 key strategies for creating transformative interdisciplinary research to achieve equity in breast cancer treatment and outcomes.

DESIGN

We first review the key differences in tumor biology in the United States between patients racialized as Black versus White, including the overrepresentation of triple-negative breast cancer and differences in tumor histologic and molecular features by race for hormone-sensitive disease. We then summarize key social factors at the interpersonal, institutional, and social structural levels that drive inequitable treatment. Next, we explore how biologic and social determinants are interwoven and interactive, including historical and contemporary structural factors that shape the overrepresentation of triple-negative breast cancer among Black Americans, racial differences in tumor microenvironment, and the complex interplay of biologic and social drivers of difference in outcomes of hormone receptor positive disease, including utilization and effectiveness of endocrine therapies and the role of obesity. Finally, we present 5 principles to increase the impact and productivity of breast cancer equity research.

RESULTS

We find that social and biologic drivers of breast cancer disparities are often cyclical and are found at all levels of scientific investigation from cells to society. To break the cycle and effect change, we must acknowledge and measure the role of structural racism in breast cancer outcomes; frame biologic, psychosocial, and access factors as interwoven via mechanisms of cumulative stress, inflammation, and immune modulation; take responsibility for the impact of representativeness (or the lack thereof) in genomic and decision modeling on the ability to accurately predict the outcomes of Black patients; create research that incorporates the perspectives of people of color from inception to implementation; and rigorously evaluate innovations in equitable cancer care delivery and health policies.

CONCLUSIONS

Innovative, cross-disciplinary research across the biologic and social sciences is crucial to understanding and eliminating disparities in breast cancer outcomes.

Oncologic anthropology: Global variations in breast cancer risk, biology, and outcome

The global breast cancer burden is growing. Of 19.3 million new cancers diagnosed in 2020, 2.26 million were breast, surpassing lung as the most commonly diagnosed worldwide. Breast cancer is the fourth most common cause of cancer deaths worldwide, and the leading cause of death in females. Incidence and mortality rates are projected to rise disproportionately in low and middle-income countries, a consequence of socioeconomic factors and differences in tumor biology related to genetic ancestry.

Survival of Filipino women with breast cancer in the United States

BACKGROUND

The survival of women with early-stage breast cancer varies by racial group. Filipino women with breast cancer are an understudied group and are often combined with other Asian groups. We compared clinical presentations and survival rates for Filipino and White women with breast cancer diagnosed in the United States.

METHODS

We conducted a retrospective cohort study of women with breast cancer diagnosed between 2004 and 2015 in the SEER18 registries database. We compared crude survival between Filipino and White women. We then calculated adjusted hazard ratios (HR) in a propensity-matched design using the Cox proportional hazards model.

RESULTS

There were 10,834 Filipino (2.5%) and 414,618 White women (97.5%) with Stage I-IV breast cancer in the SEER database. The mean age at diagnosis was 57.5 years for Filipino women and 60.8 years for White women (p < 0.0001). Filipino women had more high-grade and larger tumors than White women and were more likely to have node-positive disease. Among women with Stage I-IIIC breast cancer, the crude 10-year breast cancer-specific survival rate was 91.0% for Filipino and 88.9% for White women (HR 0.81, 95% CI 0.74-0.88, p < 0.01). In a propensity-matched analysis, the HR was 0.73 (95% CI 0.66-0.81). The survival advantage for Filipino women was present in subgroups defined by age of diagnosis, nodal status, estrogen receptor status, and HER2 receptor status.

CONCLUSION

In the United States, Filipino women often present with more advanced breast cancers than White women, but experience better breast cancer-specific survival.

Addressing Inequalities in Breast Cancer Care Delivery

Breast cancer treatment, timeliness of care, and clinical outcomes are inferior for patients of Black race and Hispanic ethnicity, and the origin of these inequities is multifactorial. Owing to aggregate reporting of data in the United States for patients of Asian, Native Hawaiian, and Pacific Islander ancestry, disparities within and across these groups are difficult to appreciate. In large part due to low prevalence, male breast cancer remains understudied, and treatment algorithms are primarily extrapolated from research conducted in female patients.

Breast Cancer Phenotypes in Africa: A Scoping Review and Meta-Analysis

PURPOSE

Africans have been associated with more aggressive forms of breast cancer (BC). However, there is a lack of data regarding the incidence and distribution of different subtypes on the basis of phenotypic classification. This scoping review and meta-analysis was undertaken to determine the distribution pattern of BC phenotypes (luminal, human epidermal growth factor receptor 2 [HER2]+, and triple-negative breast cancer [TNBC]) across the African region.

METHODS

Four online databases (PubMed, Scopus, ProQuest, and EBSCOhost) were accessed to identify studies published between 2000 and 2022 reporting the representation of receptor status (estrogen receptor, progesterone receptor, and HER2) in African patients with BC. Furthermore, the meta-analysis was carried out using a random-effects model and pooled using the inverse variance method and logit transformation. 95% CI and I2 statistics were calculated using the Clopper-Pearson method to estimate between-study heterogeneity.

RESULTS

A total of 2,734 records were retrieved, of which 2,133 were retained for further screening. After the screening, 63 studies were finally selected for the scoping review and meta-analysis. The pooled frequency of luminal, HER2-positive (HER2+), and TNBC was estimated at 56.30%, 12.61%, and 28.10%, respectively. Northern Africa had the highest frequency of the luminal subtype, while West Africa showed higher frequencies of HER2+ and TNBC subtypes. The review also had a representation of only 24 countries in Africa.

CONCLUSION

Our results highlight the disparity in the representation of molecular subtypes among the people in different regions of Africa. There is a need to incorporate routine molecular subtyping into the management of African patients with BC.

Breast Cancer Germline Genetic Counseling and Testing for Populations of African Heritage Globally: A Scoping Review on Research, Practice, and Bioethical Considerations

PURPOSE

Despite the disproportionately high risk of breast cancer among women of African heritage, little is known about the facilitators and barriers to implementing germline genetic testing and counseling (GT/C).

METHODS

This scoping review followed guidelines recommended by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews. Published manuscripts from database inception through 2021 were sourced from PubMed, Cumulative Index to Nursing and Allied Health Literature via EBSCO, Embase, Cochrane Library, and Scopus. Search terms were used to retrieve articles addressing (1) African heritage, (2) breast cancer, and (3) GT or GC. The screening involved abstract and title review and full-text review. Data were extracted for all articles meeting the inclusion criteria.

RESULTS

A total of 154 studies were included. Most studies that took place were conducted in the United States (71.4%), and most first authors (76.9%) were from the United States. GT was conducted in 73 (49.7%) studies. BRCA1/BRCA2 were the most commonly studied genes for germline mutations. GC was conducted in 49 studies (33.3%), and perspectives on GC were evaluated in 43 (29.3%). The use of racial/ethnic categories varied broadly, although African American was most common (40.1%). Racism was mentioned in three studies (2.0%).

CONCLUSION

There is a growing body of literature on GT/C for breast cancer in women of African heritage. Future studies on GT/C of African populations should consider increased clarity around racial/ethnic categorizations, continued community engagement, and intentional processes for informed consent.

Patient-derived tumor organoids with p53 mutations, and not wild-type p53, are sensitive to synergistic combination PARP inhibitor treatment

Poly (ADP-ribose) polymerase inhibitors (PARPi) are used for patients with BRCA1/2 mutations, but patients with other mutations may benefit from PARPi treatment. Another mutation that is present in more cancers than BRCA1/2 is mutation to the TP53 gene. In 2D breast cancer cell lines, mutant p53 (mtp53) proteins tightly associate with replicating DNA and Poly (ADP-ribose) polymerase (PARP) protein. Combination drug treatment with the alkylating agent temozolomide and the PARPi talazoparib kills mtp53 expressing 2D grown breast cancer cell lines. We evaluated the sensitivity to the combination of temozolomide plus PARPi talazoparib treatment to breast and lung cancer patient-derived tumor organoids (PDTOs). The combination of the two drugs was synergistic for a cytotoxic response in PDTOs with mtp53 but not for PDTOs with wtp53. The combination of talazoparib and temozolomide induced more DNA double-strand breaks in mtp53 expressing organoids than in wild-type p53 expressing organoids as shown by increased γ-H2AX protein expression. Moreover, breast cancer tissue microarrays (TMAs) showed a positive correlation between stable p53 and high PARP1 expression in sub-groups of breast cancers, which may indicate sub-classes of breast cancers sensitive to PARPi therapy. These results suggest that mtp53 could be a biomarker to predict response to the combination of PARPi talazoparib-temozolomide treatment.

Outcomes in breast cancer-does ethnicity matter?

Ethnic or racial differences in breast cancer (BC) survival outcomes have been reported, but current data are largely restricted to comparisons between African Americans and non-Hispanic whites. Most analyses have traditionally been based on self-reported race which may not always be accurate, or are oversimplified in their classification. With increasing globalization, quantification of the genetic ancestry from genomic data may offer a solution to infer the complex makeup from admixture of races. Focusing on the larger and the latest studies, we will discuss recent findings on the differing host and tumor biology that may be driving these disparities, in addition to the extrinsic environmental or lifestyle factors. Socioeconomic disparities with lower cancer literacy may lead to late presentation, poorer adherence to treatment, and other lifestyle factors such as unhealthy diet, obesity, and inadequate physical activity. These hardships may also result in greater allostatic load, which is in turn associated with aggressive BC features in disadvantaged populations. Epigenetic reprogramming may mediate the effects of the environment or lifestyle factors on gene expression, with ensuing differences in BC characteristics and outcome. There is increasing evidence that germline genetics can influence somatic gene alterations or expression, as well as modulate the tumor or immune microenvironment. Although the precise mechanisms remain elusive, this may account for the varying distribution of different BC subtypes across ethnicities. These gaps in our knowledge highlight the need to interrogate the multiomics landscape of BC in diverse populations, ideally in large-scale collaborative settings with standardized methodology for the comparisons to be statistically robust. Together with improving BC awareness and access to good quality health care, a holistic approach with insights of the biological underpinnings is much needed to eradicate ethnic disparities in BC outcomes.

State Variation in Racial and Ethnic Disparities in Incidence of Triple-Negative Breast Cancer Among US Women

Importance

There are few data on state variation in racial and ethnic disparities in incidence of triple-negative breast cancer (TNBC) in the US, limiting the ability to inform state-level health policy developments toward breast cancer equity.

Objective

To quantify between and within racial and ethnic disparities in TNBC incidence rates (IRs) among US women across states.

Design, Setting, and Participants

This cohort study using population-based cancer registry data included data for all women with TNBC diagnosed from January 1, 2015, to December 31, 2019, identified in the US Cancer Statistics Public Use Research Database. Data were analyzed from July through November 2022.

Exposures

State and race and ethnicity (Hispanic, non-Hispanic American Indian or Alaska Native, non-Hispanic Asian or Pacific Islander, non-Hispanic Black, or non-Hispanic White) abstracted from medical records.

Main Outcomes and Measures

The main outcomes were diagnosis of TNBC, age-standardized IR per 100 000 women, state-specific incidence rate ratios (IRRs) using the rate among White women in each state as a reference for between-population disparities, and state-specific IRRs using the race and ethnicity-specific national rate as a reference for within-population disparities.

Results

The study included data for 133 579 women; 768 (0.6%) were American Indian or Alaska Native; 4969 (3.7%), Asian or Pacific Islander; 28 710 (21.5%), Black; 12 937 (9.7%), Hispanic; and 86 195 (64.5%), White. The TNBC IR was highest among Black women (25.2 per 100 000 women), followed by White (12.9 per 100 000 women), American Indian or Alaska Native (11.2 per 100 000 women), Hispanic (11.1 per 100 000 women), and Asian or Pacific Islander (9.0 per 100 000 women) women. Racial and ethnic group-specific and state-specific rates substantially varied, ranging from less than 7 per 100 000 women among Asian or Pacific Islander women in Oregon and Pennsylvania to greater than 29 per 100 000 women among Black women in Delaware, Missouri, Louisiana, and Mississippi. Compared with White women, IRRs were statistically significantly higher in 38 of 38 states among Black women, ranging from 1.38 (95% CI, 1.10-1.70; IR, 17.4 per 100 000 women) in Colorado to 2.32 (95% CI, 1.90-2.81; IR, 32.0 per 100 000 women) in Delaware; lower in 22 of 22 states among Asian or Pacific Islander women, varying from 0.50 (95% CI, 0.34-0.70; IR, 5.7 per 100 000 women) in Oregon to 0.82 (95% CI, 0.75-0.90; IR, 10.5 per 100 000 women) in New York; and did not differ among Hispanic and American Indian or Alaska Native women in 22 of 35 states and 5 of 8 states, respectively. State variations within each racial and ethnic population were smaller but still substantial. For example, among White women, compared with the national rate, IRRs varied from 0.72 (95% CI, 0.66-0.78; IR, 9.2 per 100 000 women) in Utah to 1.18 (95% CI, 1.11-1.25; IR, 15.2 per 100 000 women) in Iowa, 1.15 (95% CI, 1.07-1.24; IR, 14.8 per 100 000 women) in Mississippi, and 1.15 (95% CI, 1.07-1.24; IR, 14.8 per 100 000 women) in West Virginia.

Conclusions and Relevance

In this cohort study, there were substantial state variations in racial and ethnic disparities in TNBC incidence, with Black women in Delaware, Missouri, Louisiana, and Mississippi having the highest rates among all states and racial and ethnic populations. The findings suggest that more research is needed to identify factors contributing to the substantial geographic variations in racial and ethnic disparities in TNBC incidence to develop effective preventive measures and that social determinants of health contribute to the geographic disparities in TNBC risk.

Prospects for targeting ACKR1 in cancer and other diseases

The chemokine network is comprised of a family of signal proteins that encode messages for cells displaying chemokine G-protein coupled receptors (GPCRs). The diversity of effects on cellular functions, particularly directed migration of different cell types to sites of inflammation, is enabled by different combinations of chemokines activating signal transduction cascades on cells displaying a combination of receptors. These signals can contribute to autoimmune disease or be hijacked in cancer to stimulate cancer progression and metastatic migration. Thus far, three chemokine receptor-targeting drugs have been approved for clinical use: Maraviroc for HIV, Plerixafor for hematopoietic stem cell mobilization, and Mogalizumab for cutaneous T-cell lymphoma. Numerous compounds have been developed to inhibit specific chemokine GPCRs, but the complexity of the chemokine network has precluded more widespread clinical implementation, particularly as anti-neoplastic and anti-metastatic agents. Drugs that block a single signaling axis may be rendered ineffective or cause adverse reactions because each chemokine and receptor often have multiple context-specific functions. The chemokine network is tightly regulated at multiple levels, including by atypical chemokine receptors (ACKRs) that control chemokine gradients independently of G-proteins. ACKRs have numerous functions linked to chemokine immobilization, movement through and within cells, and recruitment of alternate effectors like β-arrestins. Atypical chemokine receptor 1 (ACKR1), previously known as the Duffy antigen receptor for chemokines (DARC), is a key regulator that binds chemokines involved in inflammatory responses and cancer proliferation, angiogenesis, and metastasis. Understanding more about ACKR1 in different diseases and populations may contribute to the development of therapeutic strategies targeting the chemokine network.

Annual report to the nation on the status of cancer, part 1: National cancer statistics

BACKGROUND

The American Cancer Society, the Centers for Disease Control and Prevention, the National Cancer Institute, and the North American Association of Central Cancer Registries collaborate to provide annual updates on cancer occurrence and trends in the United States.

METHODS

Data on new cancer diagnoses during 2001-2018 were obtained from the North American Association of Central Cancer Registries' Cancer in North America Incidence file, which is comprised of data from Centers for Disease Control and Prevention-funded and National Cancer Institute-funded, population-based cancer registry programs. Data on cancer deaths during 2001-2019 were obtained from the National Center for Health Statistics' National Vital Statistics System. Five-year average incidence and death rates along with trends for all cancers combined and for the leading cancer types are reported by sex, racial/ethnic group, and age.

RESULTS

Overall cancer incidence rates were 497 per 100,000 among males (ranging from 306 among Asian/Pacific Islander males to 544 among Black males) and 431 per 100,000 among females (ranging from 309 among Asian/Pacific Islander females to 473 among American Indian/Alaska Native females) during 2014-2018. The trend during the corresponding period was stable among males and increased 0.2% on average per year among females, with differing trends by sex, racial/ethnic group, and cancer type. Among males, incidence rates increased for three cancers (including pancreas and kidney), were stable for seven cancers (including prostate), and decreased for eight (including lung and larynx) of the 18 most common cancers considered in this analysis. Among females, incidence rates increased for seven cancers (including melanoma, liver, and breast), were stable for four cancers (including uterus), and decreased for seven (including thyroid and ovary) of the 18 most common cancers. Overall cancer death rates decreased by 2.3% per year among males and by 1.9% per year among females during 2015-2019, with the sex-specific declining trend reflected in every major racial/ethnic group. During 2015-2019, death rates decreased for 11 of the 19 most common cancers among males and for 14 of the 20 most common cancers among females, with the steepest declines (>4% per year) reported for lung cancer and melanoma. Five-year survival for adenocarcinoma and neuroendocrine pancreatic cancer improved between 2001 and 2018; however, overall incidence (2001-2018) and mortality (2001-2019) continued to increase for this site. Among children (younger than 15 years), recent trends were stable for incidence and decreased for mortality; and among, adolescents and young adults (aged 15-39 years), recent trends increased for incidence and declined for mortality.

CONCLUSIONS

Cancer death rates continued to decline overall, for children, and for adolescents and young adults, and treatment advances have led to accelerated declines in death rates for several sites, such as lung and melanoma. The increases in incidence rates for several common cancers in part reflect changes in risk factors, screening test use, and diagnostic practice. Racial/ethnic differences exist in cancer incidence and mortality, highlighting the need to understand and address inequities. Population-based incidence and mortality data inform prevention, early detection, and treatment efforts to help reduce the cancer burden in the United States.

Ethnic and racial-specific differences in levels of centrosome-associated mitotic kinases, proliferative and epithelial-to-mesenchymal markers in breast cancers

Molecular epidemiology evidence indicates racial and ethnic differences in the aggressiveness and survival of breast cancer. Hispanics/Latinas (H/Ls) and non-Hispanic Black women (NHB) are at higher risk of breast cancer (BC)-related death relative to non-Hispanic white (NHW) women in part because they are diagnosed with hormone receptor-negative (HR) subtype and at higher stages. Since the cell cycle is one of the most commonly deregulated cellular processes in cancer, we propose that the mitotic kinases TTK (or Mps1), TBK1, and Nek2 could be novel targets to prevent breast cancer progression among NHBs and H/Ls. In this study, we calculated levels of TTK, p-TBK1, epithelial (E-cadherin), mesenchymal (Vimentin), and proliferation (Ki67) markers through immunohistochemical (IHC) staining of breast cancer tissue microarrays (TMAs) that includes samples from 6 regions in the Southeast of the United States and Puerto Rico -regions enriched with NHB and H/L breast cancer patients. IHC analysis showed that TTK, Ki67, and Vimentin were significantly expressed in triple-negative (TNBC) tumors relative to other subtypes, while E-cadherin showed decreased expression. TTK correlated with all of the clinical variables but p-TBK1 did not correlate with any of them. TCGA analysis revealed that the mRNA levels of multiple mitotic kinases, including TTK, Nek2, Plk1, Bub1, and Aurora kinases A and B, and transcription factors that are known to control the expression of these kinases (e.g. FoxM1 and E2F1-3) were upregulated in NHBs versus NHWs and correlated with higher aneuploidy indexes in NHB, suggesting that these mitotic kinases may be future novel targets for breast cancer treatment in NHB women.

African Ancestry-Associated Gene Expression Profiles in Triple-Negative Breast Cancer Underlie Altered Tumor Biology and Clinical Outcome in Women of African Descent

Women of sub-Saharan African descent have disproportionately higher incidence of triple-negative breast cancer (TNBC) and TNBC-specific mortality across all populations. Population studies show racial differences in TNBC biology, including higher prevalence of basal-like and quadruple-negative subtypes in African Americans (AA). However, previous investigations relied on self-reported race (SRR) of primarily U.S. populations. Due to heterogeneous genetic admixture and biological consequences of social determinants, the true association of African ancestry with TNBC biology is unclear. To address this, we conducted RNA sequencing on an international cohort of AAs, as well as West and East Africans with TNBC. Using comprehensive genetic ancestry estimation in this African-enriched cohort, we found expression of 613 genes associated with African ancestry and 2,000+ associated with regional African ancestry. A subset of African-associated genes also showed differences in normal breast tissue. Pathway enrichment and deconvolution of tumor cellular composition revealed that tumor-associated immunologic profiles are distinct in patients of African descent.

SIGNIFICANCE

Our comprehensive ancestry quantification process revealed that ancestry-associated gene expression profiles in TNBC include population-level distinctions in immunologic landscapes. These differences may explain some differences in race-group clinical outcomes. This study shows the first definitive link between African ancestry and the TNBC immunologic landscape, from an African-enriched international multiethnic cohort. See related commentary by Hamilton et al., p. 2496. This article is highlighted in the In This Issue feature, p. 2483.

Risk of Presenting with Poor-Prognosis Metastatic Cancer in Adolescents and Young Adults: A Population-Based Study

Having metastatic disease at diagnosis poses the great risk of death among AYAs with cancer from all sociodemographic subgroups. This “landscape” study utilized United States Surveillance, Epidemiology, and End Results Program data from 2000−2016 to identify subgroups of AYAs at highest risk for presenting with metastases across twelve cancer sites having a poor-prognosis (5-year survival <50% with metastases). Adjusted odds ratios for risk of metastatic disease presentation were compared for AYAs in aggregate and by sociodemographic subgroup (race/ethnicity, sex, socioeconomic status [SES]). In general, AYAs who were male, racial/ethnic minorities, or low SES were at consistently greatest risk of metastases. Strikingly, having metastatic melanoma was independently associated with multiple AYA sociodemographic subgroups, including males (aOR 3.11 [95% CI 2.64−3.66]), non-Hispanic Blacks (4.04 [2.32−7.04]), Asian Pacific Islanders (2.99 [1.75−5.12]), Hispanics (2.37 [1.85−3.04]), and low SES (2.30 [1.89−2.80]). Non-Hispanic Blacks were more likely to present with metastatic cancer in all sites, except for bone, rhabdomyosarcoma, and stomach. Low SES AYAs are more likely to present with metastatic melanoma, bone tumors, soft tissue sarcomas, breast, cervical, lung, and stomach carcinomas. Building on these results, future cancer-specific studies should investigate the connection between sociodemographic risk factors and biological drivers of metastases. This line of research has potential to inform targeted public health and screening efforts to facilitate risk reduction and earlier detection of these deadly diseases.

Racial Disparity in Quadruple Negative Breast Cancer: Aggressive Biology and Potential Therapeutic Targeting and Prevention

Simple Summary

Quadruple negative breast cancer (QNBC), a subgroup of triple negative BC, has emerged as a highly aggressive BC subtype that disproportionately afflicts and impacts Black/African-American (AA) women. In this article, we review molecular distinctions in Black/AA and White/European-American (EA) QNBC biology as well as address potential non-genetic risk factors that could be underlying this racially disparate burden. We aim to provide deeper insight and provide a framework for novel discovery of actionable therapeutic targets and identify lifestyle changes to improve outcomes for Black/AA QNBC patients.

Abstract

Black/African-American (AA) women, relative to their White/European-American (EA) counterparts, experience disproportionately high breast cancer mortality. Central to this survival disparity, Black/AA women have an unequal burden of aggressive breast cancer subtypes, such as triple-negative breast cancer (ER/PR-, HER2-wild type; TNBC). While TNBC has been well characterized, recent studies have identified a highly aggressive androgen receptor (AR)-negative subtype of TNBC, quadruple-negative breast cancer (ER/PR-, HER2-wildtype, AR-; QNBC). Similar to TNBC, QNBC disproportionately impacts Black/AA women and likely plays an important role in the breast cancer survival disparities experienced by Black/AA women. Here, we discuss the racial disparities of QNBC and molecular signaling pathways that may contribute to the aggressive biology of QNBC in Black/AA women. Our immediate goal is to spotlight potential prevention and therapeutic targets for Black/AA QNBC; ultimately our goal is to provide greater insight into reducing the breast cancer survival burden experienced by Black/AA women.

Association of lipid profile biomarkers with breast cancer by molecular subtype: analysis of the MEND study

There is conflicting evidence on the role of lipid biomarkers in breast cancer (BC), and no study to our knowledge has examined this association among African women. We estimated odds ratios (ORs) and 95% confidence intervals (95% CI) for the association of lipid biomarkers-total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides-with odds of BC overall and by subtype (Luminal A, Luminal B, HER2-enriched and triple-negative or TNBC) for 296 newly diagnosed BC cases and 116 healthy controls in Nigeria. Each unit standard deviation (SD) increase in triglycerides was associated with 39% increased odds of BC in fully adjusted models (aOR: 1.39; 95% CI: 1.03, 1.86). Among post-menopausal women, higher total cholesterol (aOR: 1.65; 95% CI: 1.06, 2.57), LDL cholesterol (aOR: 1.59; 95% CI: 1.04, 2.41), and triglycerides (aOR: 1.91; 95% CI: 1.21, 3.01) were associated with increased odds of BC. Additionally, each unit SD increase in LDL was associated with 64% increased odds of Luminal B BC (aOR 1.64; 95% CI: 1.06, 2.55). Clinically low HDL was associated with 2.7 times increased odds of TNBC (aOR 2.67; 95% CI: 1.10, 6.49). Among post-menopausal women, higher LDL cholesterol and triglycerides were significantly associated with increased odds of Luminal B BC and HER2 BC, respectively. In conclusion, low HDL and high LDL are associated with increased odds of TN and Luminal B BC, respectively, among African women. Future prospective studies can definitively characterize this association and inform clinical approaches targeting HDL as a BC prevention strategy.

Analysis of the genomic landscapes of Barbadian and Nigerian women with triple negative breast cancer

PURPOSE

Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype that disproportionately affects women of African ancestry (WAA) and is often associated with poor survival. Although there is a high prevalence of TNBC across West Africa and in women of the African diaspora, there has been no comprehensive genomics study to investigate the mutational profile of ancestrally related women across the Caribbean and West Africa.

METHODS

This multisite cross-sectional study used 31 formalin-fixed paraffin-embedded (FFPE) samples from Barbadian and Nigerian TNBC participants. High-resolution whole exome sequencing (WES) was performed on the Barbadian and Nigerian TNBC samples to identify their mutational profiles and comparisons were made to African American, European American and Asian American sequencing data obtained from The Cancer Genome Atlas (TCGA). Whole exome sequencing was conducted on tumors with an average of 382 × coverage and 4335 × coverage for pooled germline non-tumor samples.

RESULTS

Variants detected at high frequency in our WAA cohorts were found in the following genes NBPF12, PLIN4, TP53 and BRCA1. In the TCGA TNBC cases, these genes had a lower mutation rate, except for TP53 (32% in our cohort; 63% in TCGA-African American; 67% in TCGA-European American; 63% in TCGA-Asian). For all altered genes, there were no differences in frequency of mutations between WAA TNBC groups including the TCGA-African American cohort. For copy number variants, high frequency alterations were observed in PIK3CA, TP53, FGFR2 and HIF1AN genes.

CONCLUSION

This study provides novel insights into the underlying genomic alterations in WAA TNBC samples and shines light on the importance of inclusion of under-represented populations in cancer genomics and biomarker studies.

Breast cancer screening in low and middle-income countries

Breast cancer incidence rates are rising in low and middle-income countries (LMIC), and these populations have reduced access to advanced multidisciplinary treatment. Screening and early detection are therefore critical in these regions but must be affordable and sustainable. Mammography screening programs are well established in more affluent countries, but alternative strategies to reduce the breast cancer burden of LMIC (such as clinical breast examination, general breast health awareness, and addressing modifiable lifestyle factors including obesity) are likely to be more realistic at the present time.

Haplotypes of single cancer driver genes and their local ancestry in a highly admixed long-lived population of Northeast Brazil

Admixed populations have not been examined in detail in cancer genetic studies. Here, we inferred the local ancestry of cancer-associated single nucleotide polymorphisms (SNPs) and haplotypes of a highly admixed Brazilian population. SNP array was used to genotype 73 unrelated individuals aged 80-102 years. Local ancestry inference was performed by merging genotyped regions with phase three data from the 1000 Genomes Project Consortium using RFmix. The average ancestry tract length was 9.12-81.71 megabases. Strong linkage disequilibrium was detected in 48 haplotypes containing 35 SNPs in 10 cancer driver genes. All together, 19 risk and eight protective alleles were identified in 23 out of 48 haplotypes. Homozygous individuals were mainly of European ancestry, whereas heterozygotes had at least one Native American and one African ancestry tract. Native-American ancestry for homozygous individuals with risk alleles for HNF1B, CDH1, and BRCA1 was inferred for the first time. Results indicated that analysis of SNP polymorphism in the present admixed population has a high potential to identify new ancestry-associated alleles and haplotypes that modify cancer susceptibility differentially in distinct human populations. Future case-control studies with populations with a complex history of admixture could help elucidate ancestry-associated biological differences in cancer incidence and therapeutic outcomes.

Effect of Diallyl Trisulfide on TNF-α-induced CCL2/MCP-1 Release in Genetically Different Triple-negative Breast Cancer Cells

BACKGROUND/AIM

Diallyl trisulfide (DATS) has been shown to prevent and inhibit breast carcinogenesis. CCL2/MCP-1 has been shown to play a significant role in breast cancer. This study explored DATS efficacy on triple-negative breast cancer (TNBC) cells.

MATERIALS AND METHODS

DATS efficacy on TNF-α induced TNBC cells were examined via trypan blue exclusion test, wound-healing assay, human cytokine arrays, ELISA, and RT-PCR.

RESULTS

DATS significantly induced cell death and inhibited cell migration. Expression of CCL2/MCP-1, IL-6, PDGF-BB, NT-3, and GM-CSF in TNF-α-treated cells increased. However, DATS significantly decreased the expression of CCL2/MCP-1 in TNF-α-treated MDA-MB-231 but not in MDA-MB-468 cells. DATS significantly down-regulated mRNA expression of IKBKE and MAPK8 in both cell lines, indicating a possible effect in genes involved in the NF-κB and MAPK signaling.

CONCLUSION

DATS may have a role in TNBC therapy and prevention by targeting CCL2.

Screening mammography mitigates breast cancer disparities through early detection of triple negative breast cancer

PURPOSE

Screening mammography improves breast cancer survival through early detection, but Triple Negative Breast Cancer (TNBC) is more difficult to detect on mammography and has lower survival compared to non-TNBC, even when detected at early stages. TNBC is twice as common among African American (AA) compared to White American (WA) women, thereby contributing to the 40% higher breast cancer mortality rates observed in AA women. The role of screening mammography in addressing breast cancer disparities is therefore worthy of study.

METHODS

Outcomes were evaluated for TNBC patients treated in the prospectively-maintained databases of academic cancer programs in two metropolitan cities of the Northeast and Midwest, 1998-2018.

RESULTS

Of 756 TNBC cases, 301 (39.8%) were mammographically screen-detected. 46% of 189 AA and 38.5% of 460 WA patients had screen-detected TNBC (p = 0.16). 25.3% of 257 TNBC cases ≤50 years old had screen-detected disease compared to 47.3% of 499 TNBC cases >50 years old (p < 0.0001). 220/301 (73.1%) screen-detected TNBC cases were T1 lesions versus 118/359 (32.9%) non-screen-detected cases (p < 0.0001). Screen-detected TNBC was more likely to be node-negative (51.9% v. 40.4%; p < 0.0001). Five-year overall survival was better in screen-detected TNBC compared to nonscreen-detected TNBC (92.8% v. 81.5%; p < 0.0001) in the entire cohort. The magnitude of this effect was most significant among AA patients (Fig. 1). Screening-related survival patterns were similar among AA and WA patients in both cities.

CONCLUSION

Data from two different cities demonstrates the value of screening mammography to mitigate breast cancer disparities in AA women through the early detection of TNBC.

Cells with Cancer-associated Mutations Overtake Our Tissues as We Age

BACKGROUND

To shed light on the earliest events in oncogenesis, there is growing interest in understanding the mutational landscapes of normal tissues across ages. In the last decade, next-generation sequencing of human tissues has revealed a surprising abundance of cells with what would be considered oncogenic mutations.

AIMS

We performed meta-analysis on previously published sequencing data on normal tissues to categorize mutations based on their presence in cancer and showcase the quantity of cells with cancer-associated mutations in cancer-free individuals.

METHODS AND RESULTS

We analyzed sequencing data from these studies of normal tissues to determine the prevalence of cells with mutations in three different categories across multiple age groups: 1) mutations in genes designated as drivers, 2) mutations that are in the Cancer Gene Census (CGC), and 3) mutations in the CGC that are considered pathogenic. As we age, the percentage of cells in all three levels increase significantly, reaching over 50% of cells having oncogenic mutations for multiple tissues in the older age groups. The clear enrichment for these mutations, particularly at older ages, likely indicates strong selection for the resulting phenotypes. Combined with an estimation of the number of cells in tissues, we calculate that most older, cancer-free individuals possess at least a 100 billion cells that harbor at least one oncogenic mutation, presumably emanating from a fitness advantage conferred by these mutations that promotes clonal expansion.

CONCLUSIONS

These studies of normal tissues have highlighted the specific drivers of clonal expansion and how frequently they appear in us. Their high prevalence throughout cancer-free individuals necessitates reconsideration of the oncogenicity of these mutations, which could shape methods of detection, prevention and treatment of cancer, as well as of the potential impact of these mutations on tissue function and our health.

Patterns of Palliative Radiotherapy Utilization for Patients With Metastatic Breast Cancer in Harare, Zimbabwe

PURPOSE

In sub-Saharan Africa, radiotherapy (RT) utilization and delivery patterns have not been extensively studied in patients with metastatic breast cancer.

METHODS

A retrospective cohort study of female patients with metastatic breast cancer seen at Parirenyatwa Radiotherapy Centre in Zimbabwe from 2014 to 2018 was conducted. Demographics, pathology, staging, and treatment data were abstracted through chart review. Fisher's exact test and chi-squared test of independence were used to compare proportions, and independent two-sample t-tests were used to compare means.

RESULTS

Of 351 patients with breast cancer, 152 (43%) had metastatic disease, median age 51 years (interquartile range: 43-61 years). Of those with metastatic disease, 30 patients (20%) received radiation to various metastatic sites: 16 spine; three nonspine bone metastases; six whole brain; and five chest wall or supraclavicular. Patients who received radiation were younger (46 v 52 years; P = .019), but did not differ significantly by performance status than those who did not. The most common dose prescription was 30 Gy in 10 fractions (33%). Five (17%) patients had treatment interruption and two (7%) had treatment noncompletion. Province of origin and clinical tumor stage were significant predictors of RT receipt (P = .002; and P = .018, respectively).

CONCLUSION

A minority of patients with metastatic breast cancer received RT (20%), and these were likely to be younger, with advanced tumor stage, and resided in provinces where RT is available. Conventional courses were generally prescribed. There is a need to strongly consider palliative RT as an option for patients with metastatic breast cancer and use of hypofractionated courses (e.g. 8 Gy in one fraction) may support this goal.

Disparities in Breast Cancer Associated With African American Identity

Persistent disparities in the burden of breast cancer between African Americans and White Americans have been documented over many decades. Features characterizing breast cancer in the African American community include a 40% higher mortality rate, younger age distribution, greater advanced-stage distribution, increased risk of biologically aggressive disease such as the triple-negative phenotype, and increased incidence of male breast cancer. Public health experts, genetics researchers, clinical trialists, multidisciplinary oncology teams, and advocates must collaborate to comprehensively address the multifactorial etiology of and remedies for breast cancer disparities. Efforts to achieve breast health equity through improved access to affordable, high-quality care are especially imperative in the context of the COVID-19 pandemic and its disproportionately high economic toll on African Americans.

Association of high-sensitivity C-reactive protein and odds of breast cancer by molecular subtype: analysis of the MEND study

Breast cancer (BC) in Nigeria is characterized by disproportionately aggressive molecular subtypes. C-reactive protein (CRP) is associated with risk and aggressiveness for several types of cancer. We examined the association of high-sensitivity CRP (hsCRP) with odds of BC by molecular subtype among Nigerian women. Among 296 newly diagnosed BC cases and 259 healthy controls, multivariable logistic regression models were used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for the association between hsCRP and odds of BC overall and by molecular subtype (luminal A, luminal B, HER2-enriched and triple-negative or TNBC). High hsCRP (> 3 mg/L) was observed in 57% of cases and 31% of controls and was associated with 4 times the odds of BC (aOR: 4.43; 95% CI: 2.56, 7.66) after adjusting for socio-demographic, reproductive, and clinical variables. This association persisted regardless of menopausal status and body mass index (BMI) category. High hsCRP was associated with increased odds of TNBC (aOR: 3.32; 95% CI: 1.07, 10.35), luminal A BC (aOR: 4.03; 95% CI: 1.29, 12.64), and HER2-enriched BC (aOR: 6.27; 95% CI: 1.69, 23.25). Future studies are necessary in this population to further evaluate a potential role for CRP as a predictive biomarker for BC.

Cancer microenvironment and genomics: evolution in process

Cancer heterogeneity is a result of genetic mutations within the cancer cells. Their proliferation is not only driven by autocrine functions but also under the influence of cancer microenvironment, which consists of normal stromal cells such as infiltrating immune cells, cancer-associated fibroblasts, endothelial cells, pericytes, vascular and lymphatic channels. The relationship between cancer cells and cancer microenvironment is a critical one and we are just on the verge to understand it on a molecular level. Cancer microenvironment may serve as a selective force to modulate cancer cells to allow them to evolve into more aggressive clones with ability to invade the lymphatic or vascular channels to spread to regional lymph nodes and distant sites. It is important to understand these steps of cancer evolution within the cancer microenvironment towards invasion so that therapeutic strategies can be developed to control or stop these processes.

Breast cancer disparities in outcomes; unmasking biological determinants associated with racial and genetic diversity

Breast cancer (BC) remains a leading cause of death among women today, and mortality among African American women in the US remains 40% higher than that of their White counterparts, despite reporting a similar incidence of disease over recent years. Previous meta-analyses and studies of BC mortality highlight that tumor characteristics, rather than socio-economic factors, drive excess mortality among African American women with BC. This is further complicated by the heterogeneity of BC, where BC can more appropriately be defined as a collection of diseases rather than a single disease. Molecular phenotyping and gene expression profiling distinguish subtypes of BC, and these subtypes have distinct prognostic outcomes. Racial disparities transcend these subtype-specific outcomes, where African American women suffer higher mortality rates among all BC subtypes. The most striking differences are observed among the most aggressive molecular subtype, triple-negative BC (TNBC), where incidence and mortality are significantly higher among African American women compared to all other race/ethnicity groups. We and others have shown that this predisposition for triple-negative disease may be linked to shared west African ancestry, where the highest rates of TNBC are observed among west African nations, and these high frequencies follow into the African diaspora. Genetic and molecular characterization of breast tumors among subtypes and racial/ethnic groups have begun to identify targets with future therapeutic potential, but more work needs to be done to identify targeted treatment options for all women who suffer from BC.

Breast cancer in sub-Saharan Africa: The current state and uncertain future

Breast cancer is the commonest cause of global cancer-related deaths in women and a public health burden in sub-Saharan Africa (SSA). Although the disease incidence in SSA seems lower, mortality rates are disproportionately high in comparison to high-income countries. The global disease burden is growing, with SSA reporting the majority of cases; however, the dearth of information results in insufficient data which is barely representative of the actual disease burden in this population. Future incidence predictions assign the subregion with a majority of the cases and associated deaths. Breast cancer presents with racial and ethnic variations, and available evidence suggests geographical diversity and persistent risk factors that have barely been explored in SSA. Breast cancer is a complex genetic disease, but the genetic risk factors in the extant African population, which is the most genetically diverse population, is scant and of low quality. This review focuses on the burden, prevalence, detection, treatment, survival, biology, as well as risk factors, and reinforces the need for breast cancer-associated risk factor investigation and population-specific studies in SSA.

Investigation of triple-negative breast cancer risk alleles in an International African-enriched cohort

Large-scale efforts to identify breast cancer (BC) risk alleles have historically taken place among women of European ancestry. Recently, there are new efforts to verify if these alleles increase risk in African American (AA) women as well. We investigated the effect of previously reported AA breast cancer and triple-negative breast cancer (TNBC) risk alleles in our African-enriched International Center for the Study of Breast Cancer Subtypes (ICSBCS) cohort. Using case-control, case-series and race-nested approaches, we report that the Duffy-null allele (rs2814778) is associated with TNBC risk (OR = 3.814, p = 0.001), specifically among AA individuals, after adjusting for self-indicated race and west African ancestry (OR = 3.368, p = 0.007). We have also validated the protective effect of the minor allele of the ANKLE1 missense variant rs2363956 among AA for TNBC (OR = 0.420, p = 0.005). Our results suggest that an ancestry-specific Duffy-null allele and differential prevalence of a polymorphic gene variant of ANKLE1 may play a role in TNBC breast cancer outcomes. These findings present opportunities for therapeutic potential and future studies to address race-specific differences in TNBC risk and disease outcome.

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.