Translational Epidemiology: An Integrative Approach to Determine the Interplay Between Genetic Ancestry and Neighborhood Socioeconomic Status on Triple Negative Breast Cancer.

OBJECTIVE: To investigate the impact of global and local genetic ancestry and neighborhood socioeconomic status (nSES), on breast cancer (BC) subtype, and gene expression. BACKGROUND: Higher rates of aggressive BC subtypes [triple negative breast cancer (TNBC)] and worse overall BC survival are seen in black women [Hispanic Black (HB) and non-Hispanic Black (NHB)] and women from low nSES. However, the complex relationship between genetic ancestry, nSES, and BC subtype etiology remains unknown. METHODS: Genomic analysis was performed on the peripheral blood from a cohort of 308 stage I to IV non-Hispanic White (NHW), Hispanic White (HW), HB, and NHB women with BC. Patient and tumor characteristics were collected. Global and local ancestral estimates were calculated. Multinomial logistic regression was performed to determine associations between age, stage, genetic ancestry, and nSES on rates of TNBC compared to estrogen receptor (ER+)/epidermal growth factor receptor 2 (HER2-), ER+/HER2+, and ER-/HER2+ disease. RESULTS: Among 308 women, we identified a significant association between increasing West African (WA) ancestry and odds of TNBC [odds ratio (OR): 1.06, 95% confidence interval (95% CI): 1.001-1.126, P =0.046] as well as an inverse relationship between higher nSES and TNBC (OR: 0.343, 95% CI: 0.151-0.781, P =0.011). WA ancestry remained significantly associated with TNBC when adjusting for patient age and tumor stage, but not when adjusting for nSES (OR: 1.049, 95% CI: -0.987-1.116, P =0.120). Local ancestry analysis, however, still revealed nSES-independent enriched WA ancestral segment centered at χ 2 =42004914 ( p =3.70×10 -5 ) in patients with TNBC. CONCLUSIONS: In this translational epidemiologic study of genetic ancestry and nSES on BC subtype, we discovered associations between increasing WA ancestry, low nSES, and higher rates of TNBC compared to other BC subtypes. Moreover, on admixture mapping, specific chromosomal segments were associated with WA ancestry and TNBC, independent of nSES. However, on multinomial logistic regression adjusting for WA ancestry, women from low nSES were more likely to have TNBC, independent of genetic ancestry. These findings highlight the complex nature of TNBC and the importance of studying potential gene-environment interactions as drivers of TNBC.

Factors contributing to delays in initiation of front-line cervical cancer therapy: disparities in a diverse south Florida population.

OBJECTIVE: Delay in initiating cervical cancer treatment may impact outcomes. In a cohort of patients initially treated by surgery, chemoradiation, chemotherapy, or in a clinical trial, we aim to define factors contributing to prolonged time to treatment initiation. METHODS: Data from patients initiating treatment for cervical cancer at a single institution was abstracted. Time to treatment initiation was defined as the interval from the date of cancer diagnosis to the date of treatment initiation. Poisson regression model was used for analysis. RESULTS: Of 274 patients studied, the median time to treatment initiation was 60 days (range 0-551). The median times to initiate surgery (54 days, range 3-96) and chemoradiation (58 days, range 4-187) were not significantly different (relative risk (RR) 1.01, 95% CI 0.98 to 1.04, p=0.54). The shortest median initiation time was for chemotherapy (47 days; RR 1.13, 95% CI 1.08 to 1.19, p<0.0001) and the longest was for clinical trial (62 days; RR 1.18, 95% CI 1.12 to 1.24, p<0.0001). Charity care (RR 1.09, 95% CI 1.05 to 1.14, p<0.0001), Medicare or Medicaid (RR 1.10, 95% CI 1.06 to 1.14, p<0.0001), and self-pay (RR 1.38, 95% CI 1.32 to 1.45, p<0.0001) delayed treatment initiation more than private insurance. Hispanic White women (RR 0.69, 95% CI 0.66 to 0.73, p<0.0001) had a shorter treatment initiation time compared with non-Hispanic White patients, while Afro-Caribbean/Afro-Latina women (RR 0.86, 95% CI 0.81 to 0.90, p<0.0001) and African-American patients (RR 1.13, 95% CI 1.07 to 1.19, p<0.0001) had longer initiation times. Spanish speaking patients did not have a prolonged treatment initiation (RR 0.68, 95% CI 0.66 to 0.71, p<0.0001), though Haitian-Creole speaking patients did (RR 1.07, 95% CI 1.01 to 1.13, p<0.002). Diagnosis at an outside institution delayed treatment initiation time (RR 1.24, 95% CI 1.18 to 1.30, p<0.0001) compared with diagnosis at the cancer center. CONCLUSION: Factors associated with prolonged time to treatment initiation include treatment modality, insurance status, language spoken, and institution of diagnosis. By closely examining each of these factors, barriers to treatment can be identified and modified to shorten treatment initiation time.

Racial and Ethnic Disparities in Breast Cancer Survival: Emergence of a Clinically Distinct Hispanic Black Population.

OBJECTIVE: To understand the impact of Black race on breast cancer (BC) presentation, treatment, and survival among Hispanics. SUMMARY OF BACKGROUND DATA: It is well-documented that non-Hispanic Blacks (NHB) present with late-stage disease, are less likely to complete treatment, and have worse survival compared to their non-Hispanic White (NHW) counterparts. However, no data evaluates whether this disparity extends to Hispanic Blacks (HB) and Hispanic Whites (HW). Given our location in Miami, gateway to Latin America and the Caribbean, we have the diversity to evaluate BC outcomes in HB and HW. METHODS: Retrospective cohort study of stage I-IV BC patients treated at our institution from 2005-2017. Kaplan-Meier survival curves were generated and compared using the log-rank test. Multivariable survival models were computed using Cox proportional hazards regression. RESULTS: Race/ethnicity distribution of 5951 patients: 28% NHW, 51% HW, 3% HB, and 18% NHB. HB were more economically disadvantaged, had more aggressive disease, and less treatment compliant compared to HW. 5-year OS by race/ethnicity was: 85% NHW, 84.8% HW, 79.4% HB, and 72.7% NHB (P < 0.001). After adjusting for covariates, NHB was an independent predictor of worse OS [hazard ratio:1.25 (95% confidence interval: 1.01-1.52), P < 0.041)]. CONCLUSIONS: In this first comprehensive analysis of HB and HW, HB have worse OS compared to HW, suggesting that race/ethnicity is a complex variable acting as a proxy for tumor and host biology, as well as individual and neighborhood-level factors impacted by structural racism. This study identifies markers of vulnerability associated with Black race and markers of resiliency associated with Hispanic ethnicity to narrow a persistent BC survival gap.

Overcoming disparities: Multidisciplinary breast cancer care at a public safety net hospital.

PURPOSE: Public safety net hospitals (SNH) serve a disparate patient population; however, little is known about long-term oncologic outcomes of patients receiving care at these facilities. This study is the first to examine overall survival (OS) and the initiation of treatment in breast cancer patients treated at a SNH. METHODS: Patients presenting to a SNH with stage I-IV breast cancer from 2005 to 2017 were identified from the local tumor registry. The hospital has a weekly breast tumor board and a multidisciplinary approach to breast cancer care. Kaplan-Meier survival analysis was performed to identify patient, tumor, and treatment characteristics associated with OS. Factors with a p < 0.1 were included in the Cox proportional hazards model. RESULTS: 2709 breast cancer patients were evaluated from 2005 to 2017. The patient demographics, tumor characteristics, and treatments received were analyzed. Five-year OS was 78.4% (93.9%, 87.4%, 70.9%, and 23.5% for stages I, II, III, and IV, respectively). On multivariable analysis, higher stage, age > 70 years, higher grade, and non-Hispanic ethnicity were associated with worse OS. Patients receiving surgery (HR = 0.33, p < 0.0001), chemotherapy (HR = 0.71, p = 0.006), and endocrine therapy (HR = 0.61, p < 0.0001) had better OS compared to those who did not receive these treatments. CONCLUSION: Despite serving a vulnerable minority population that is largely poor, uninsured, and presenting with more advanced disease, OS at our SNH approaches national averages. This novel finding indicates that in the setting of multidisciplinary cancer care and with appropriate initiation of treatment, SNHs can overcome socioeconomic barriers to achieve equitable outcomes in breast cancer care.

Axillary response rates to neoadjuvant chemotherapy in breast cancer patients with advanced nodal disease.

PURPOSE: Utilization of sentinel lymph node biopsy (SLNB) in breast cancer patients with positive nodes after neoadjuvant chemotherapy (NAC) has increased. We examine axillary response rates after NAC in patients with clinical N2-3 disease to determine whether SLNB should be considered. METHODS: Breast cancer patients with clinical N2-3 (AJCC 7th Edition) disease who received NAC followed by surgery were selected from our institutional tumor registry (2009-2018). Axillary response rates were assessed. RESULTS: Ninety-nine patients with 100 breast cancers were identified: 59 N2 (59.0%) and 41 (41.0%) N3 disease; 82 (82.0%) treated with axillary lymph node dissection (ALND) and 18 (18.0%) SLNB. The majority (99.0%) received multiagent NAC. In patients undergoing ALND, cCR was observed in 20/82 patients (24.4%), pathologic complete response (pCR) in 15 patients (18.3%), and axillary pCR in 17 patients (20.7%). In patients with a cCR, pCR was identified in 60.0% and was most common in HER2+ patients (34.6%). CONCLUSION: In this analysis of patients with clinical N2-3 disease receiving NAC, 79.3% of patients had residual nodal disease at surgery. However, 60.0% of patients with a cCR also had a pCR. This provides the foundation to consider evaluating SLNB and less extensive axillary surgery in this select group.

Phosphoinositide 3-kinase inhibitors induce DNA damage through nucleoside depletion.

We previously reported that combining a phosphoinositide 3-kinase (PI3K) inhibitor with a poly-ADP Rib polymerase (PARP)-inhibitor enhanced DNA damage and cell death in breast cancers that have genetic aberrations in BRCA1 and TP53. Here, we show that enhanced DNA damage induced by PI3K inhibitors in this mutational background is a consequence of impaired production of nucleotides needed for DNA synthesis and DNA repair. Inhibition of PI3K causes a reduction in all four nucleotide triphosphates, whereas inhibition of the protein kinase AKT is less effective than inhibition of PI3K in suppressing nucleotide synthesis and inducing DNA damage. Carbon flux studies reveal that PI3K inhibition disproportionately affects the nonoxidative pentose phosphate pathway that delivers Rib-5-phosphate required for base ribosylation. In vivo in a mouse model of BRCA1-linked triple-negative breast cancer (K14-Cre BRCA1(f/f)p53(f/f)), the PI3K inhibitor BKM120 led to a precipitous drop in DNA synthesis within 8 h of drug treatment, whereas DNA synthesis in normal tissues was less affected. In this mouse model, combined PI3K and PARP inhibition was superior to either agent alone to induce durable remissions of established tumors.

Spatial organization of dendritic cells within tumor draining lymph nodes impacts clinical outcome in breast cancer patients.

BACKGROUND: Dendritic cells (DCs) are important mediators of anti-tumor immune responses. We hypothesized that an in-depth analysis of dendritic cells and their spatial relationships to each other as well as to other immune cells within tumor draining lymph nodes (TDLNs) could provide a better understanding of immune function and dysregulation in cancer. METHODS: We analyzed immune cells within TDLNs from 59 breast cancer patients with at least 5 years of clinical follow-up using immunohistochemical staining with a novel quantitative image analysis system. We developed algorithms to analyze spatial distribution patterns of immune cells in cancer versus healthy intra-mammary lymph nodes (HLNs) to derive information about possible mechanisms underlying immune-dysregulation in breast cancer. We used the non-parametric Mann-Whitney test for inter-group comparisons, Wilcoxon Matched-Pairs Signed Ranks test for intra-group comparisons and log-rank (Mantel-Cox) test for Kaplan Maier analyses. RESULTS: Degree of clustering of DCs (in terms of spatial proximity of the cells to each other) was reduced in TDLNs compared to HLNs. While there were more numerous DC clusters in TDLNs compared to HLNs,DC clusters within TDLNs tended to have fewer member DCs and also consisted of fewer cells displaying the DC maturity marker CD83. The average number of T cells within a standardized radius of a clustered DC was increased compared to that of an unclustered DC, suggesting that DC clustering was associated with T cell interaction. Furthermore, the number of T cells within the radius of a clustered DC was reduced in tumor-positive TDLNs compared to HLNs. Importantly, clinical outcome analysis revealed that DC clustering in tumor-positive TDLNs correlated with the duration of disease-free survival in breast cancer patients. CONCLUSIONS: These findings are the first to describe the spatial organization of DCs within TDLNs and their association with survival outcome. In addition, we characterized specific changes in number, size, maturity, and T cell co-localization of such clusters. Strategies to enhance DC function in-vivo, including maturation and clustering, may provide additional tools for developing more efficacious DC cancer vaccines.

Clinical Outcomes for Primary and Radiation-Associated Angiosarcoma of the Breast with Multimodal Treatment: Long-Term Survival Is Achievable.

BACKGROUND: The optimal management of primary angiosarcoma (PAS) and radiation-associated angiosarcoma (RAAS) of the breast remains undefined. Available data show persistently poor survival outcomes following treatment with surgery or chemotherapy alone. The objective of this study was to evaluate long-term outcomes in patients treated with multimodality therapy. METHODS: Patients diagnosed with stage I-III PAS or RAAS of the breast were identified from our local tumor registry (2010-2020). Patient demographics, tumor characteristics, and treatment were collected. Primary outcomes were local recurrence (LR), distant recurrence (DR), and median overall survival (OS). A secondary outcome was pathologic complete response (pCR) following neoadjuvant chemotherapy (NAC). Mann-Whitney U, chi-squared, or Fisher exact tests were used to analyze data. Kaplan-Meier curves compared OS for PAS and RAAS. RESULTS: Twenty-two patients met inclusion criteria, including 11 (50%) with RAAS and 11 (50%) with PAS. Compared to PAS patients, RAAS patients were older and had more comorbidities. For RAAS patients, median time from radiation to diagnosis was 6 years (IQR: 5-11). RAAS patients were more likely to have a pCR to NAC (40% vs. 20%, p = 0.72). RAAS patients had a higher LR rate (43% vs. 38%, p = 0.83), and PAS patients were more likely to develop a DR (38% vs. 0%, p = 0.07). Median OS was 81 months in PAS patients and 90 months in RAAS patients (p = 1.00). DISCUSSION: Long-term survival can be achieved in patients with PAS and RAAS who undergo multimodality treatment. NAC can result in pCR. The long-term clinical implications of pCR warrant further investigation.

Epstein-Barr Virus Infection of Mammary Epithelial Cells Promotes Malignant Transformation.

Whether the human tumor virus, Epstein-Barr Virus (EBV), promotes breast cancer remains controversial and a potential mechanism has remained elusive. Here we show that EBV can infect primary mammary epithelial cells (MECs) that express the receptor CD21. EBV infection leads to the expansion of early MEC progenitor cells with a stem cell phenotype, activates MET signaling and enforces a differentiation block. When MECs were implanted as xenografts, EBV infection cooperated with activated Ras and accelerated the formation of breast cancer. Infection in EBV-related tumors was of a latency type II pattern, similar to nasopharyngeal carcinoma (NPC). A human gene expression signature for MECs infected with EBV, termed EBVness, was associated with high grade, estrogen-receptor-negative status, p53 mutation and poor survival. In 11/33 EBVness-positive tumors, EBV-DNA was detected by fluorescent in situ hybridization for the viral LMP1 and BXLF2 genes. In an analysis of the TCGA breast cancer data EBVness correlated with the presence of the APOBEC mutational signature. We conclude that a contribution of EBV to breast cancer etiology is plausible, through a mechanism in which EBV infection predisposes mammary epithelial cells to malignant transformation, but is no longer required once malignant transformation has occurred.

Profiling flavonoid cytotoxicity in human breast cancer cell lines: determination of structure-function relationships.

Flavonoids have been shown to be cytotoxic to cancer cells. However, the mechanism of cytotoxicity has not been clearly defined. It has previously been reported that HER2/ERBB2, the estrogen receptor, progesterone receptor, and p53 were required for flavonoid induced cytotoxicity in breast cancer cell lines. We have used a panel of breast cancer cell lines, known to contain as well as be deficient in these signaling pathways, to screen fourteen different flavonoids. Comparing the cytotoxicity for all flavonoids allows us to determine if a structure-functional relationship exists between cytotoxicity and flavonoid, and if a particular signaling pathway is required for cytotoxicity. We show that several flavonoids are cytotoxic to all cell lines including primary mammary epithelial cells tested. The cytotoxic flavonoids are also able to inhibit Mitochondrial Outer Membrane Permeability while at the same time stimulate ATP levels whereas the non-cytotoxic flavonoids are not able to do this. We also show that both cytotoxic and non-cytotoxic flavonoids can transverse the cell membrane to enter MDA-MB-231 cells at different levels. Finally, all flavonoids regardless of their cytotoxicity were able to induce some form of cell cycle arrest. We conclude that for flavonoids to be strongly cytotoxic, they must possess the 2,3-double bond in the C-ring and we believe the cytotoxicity occurs through mitochondrial poisoning in both cancer and normal cells.

Some natural flavonoids are competitive inhibitors of Caspase-1, -3 and -7 despite their cellular toxicity.

A common feature of both apoptosis and inflammation is the activation of caspases. Caspases are aspartate-directed cysteine proteases that have numerous cellular targets. It has been discovered that several flavonoids are inhibitors of caspases. Flavonoids are members of a family of polyphenolic compounds from plants that have many biological properties, one of which is the ability to induce cell death. Some flavonoids are selective inhibitors of particular caspases. Since some of the inhibitory flavonoids are nevertheless cytotoxic, these results suggest that flavonoid-induced cell death may be occurring through a non-classical apoptosis pathway that is not dependent on caspase activity.

Profiling flavonoid cytotoxicity in human breast cancer cell lines: determination of structure-function relationships.

Flavonoids have been shown to be cytotoxic to cancer cells. However, the mechanism of cytotoxicity has not been clearly defined. It has previously been reported that HER2/ERBB2, the estrogen receptor, progesterone receptor, and p53 were required for flavonoid induced cytotoxicity in breast cancer cell lines. We have used a panel of breast cancer cell lines, known to contain as well as be deficient in these signaling pathways, to screen fourteen different flavonoids. Comparing the cytotoxicity for all flavonoids allows us to determine if a structure-functional relationship exists between cytotoxicity and flavonoid, and if a particular signaling pathway is required for cytotoxicity. We show that several flavonoids are cytotoxic to all cell lines including primary mammary epithelial cells tested. The cytotoxic flavonoids are also able to inhibit Mitochondrial Outer Membrane Permeability while at the same time stimulate ATP levels whereas the non-cytotoxic flavonoids are not able to do this. We also show that both cytotoxic and non-cytotoxic flavonoids can transverse the cell membrane to enter MDA-MB-231 cells at different levels. Finally, all flavonoids regardless of their cytotoxicity were able to induce some form of cell cycle arrest. We conclude that for flavonoids to be strongly cytotoxic, they must possess the 2,3-double bond in the C-ring and we believe the cytotoxicity occurs through mitochondrial poisoning in both cancer and normal cells.

Quantitative, architectural analysis of immune cell subsets in tumor-draining lymph nodes from breast cancer patients and healthy lymph nodes.

BACKGROUND: To date, pathological examination of specimens remains largely qualitative. Quantitative measures of tissue spatial features are generally not captured. To gain additional mechanistic and prognostic insights, a need for quantitative architectural analysis arises in studying immune cell-cancer interactions within the tumor microenvironment and tumor-draining lymph nodes (TDLNs). METHODOLOGY/PRINCIPAL FINDINGS: We present a novel, quantitative image analysis approach incorporating 1) multi-color tissue staining, 2) high-resolution, automated whole-section imaging, 3) custom image analysis software that identifies cell types and locations, and 4) spatial statistical analysis. As a proof of concept, we applied this approach to study the architectural patterns of T and B cells within tumor-draining lymph nodes from breast cancer patients versus healthy lymph nodes. We found that the spatial grouping patterns of T and B cells differed between healthy and breast cancer lymph nodes, and this could be attributed to the lack of B cell localization in the extrafollicular region of the TDLNs. CONCLUSIONS/SIGNIFICANCE: Our integrative approach has made quantitative analysis of complex visual data possible. Our results highlight spatial alterations of immune cells within lymph nodes from breast cancer patients as an independent variable from numerical changes. This opens up new areas of investigations in research and medicine. Future application of this approach will lead to a better understanding of immune changes in the tumor microenvironment and TDLNs, and how they affect clinical outcomes.