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.

Abstract P3-12-08: Neighborhood disadvantage predicts worse breast cancer-specific survival

BackgroundAlthough advances in screening, detection, diagnosis, and treatment have reduced overall breast cancer mortality, well-documented socioeconomic and racial/ethnic disparities persist. The objective of this study was to utilize the area deprivation index (ADI), a compositive measure of neighborhood disadvantage, on breast cancer survival in South Florida, predominantly consisting of Miami-Dade County residents. The ADI is based on a measure created by the Health Resources & Services Administration (HRSA) over three decades ago, and has since been refined, adapted, and validated to the Census Block Group neighborhood level. The ADI score (1-10) includes factors from the domains of income/employment (e.g., median family income), education (e.g., % population &gt;25 with &lt;9 years of education), housing (e.g., % occupied housing without complete plumbing), and household characteristics (e.g., % single-parent households with children &lt;18). MethodsPatients treated at our medical campus, comprised of both a safety-net hospital and an adjacent academic cancer center, with stage I-IV breast cancer from 2005-2017 were identified from our local tumor registry. Our main outcome of interest was breast cancer-specific survival (BCSS). The ADI was calculated for each patient at the census block group level using the University of Wisconsin Neighborhood Atlas (https://www.neighborhoodatlas.medicine.wisc.edu/mapping) and categorized into tertiles. Random effects frailty models were conducted, controlling for patient and tumor characteristics [grade, stage, receptor status (ER+/HER-, ER+/HER2+, ER-HER2+, ER-/HER2-)], and NCCN-guideline appropriate treatment. ResultsThe study population was 5,377 breast cancer patients with 55.5% being Hispanic, 27.0% being non-Hispanic White (NHW), and 17.5% being non-Hispanic Black (NHB). The distribution of NHB was highest in the most disadvantaged neighborhoods compared to NHW and Hispanics (p&lt;0.001). In addition, more uninsured patients lived in the most disadvantaged neighborhoods compared to those with any type of insurance. After controlling for multiple covariates including comorbidities, race/ethnicity, insurance status, and tumor subtype, we found that those individuals living in the most disadvantaged neighborhoods (highest ADI tertile) had a significantly increased hazard of breast cancer specific death compared to those living in the most advantaged neighborhoods (T2: HR: 1.27 95% CI: 1.00, 1.63, p&lt;0.05 and T3: HR: 1.5 95% CI 1.17, 1.91, p&lt;0.05). ConclusionThis study is the first to evaluate BCSS through the lens of the ADI, a composite measure of neighborhood advantage and disadvantage using census block group data reflective of social determinants of health domains spanning income, education, employment, and housing quality. Our study suggests that breast cancer survival disparities are partly influenced by neighborhood disadvantage. Even when accounting for sociodemographics, tumor characteristics, and NCCN-guideline appropriate treatment, survival disparities remained, suggesting potential social and environmental factors impacting survival. To address these disparities, effective interventions are. needed that account for the social and environmental contexts in which cancer patients live and are treated.

Table: ADI (Tertiles) and Breast Cancer-Specific SurvivalHR (95% CI)Area Deprivation Index (vs. most advantaged)ADI Tertile 21.27 (1.00, 1.63)ADI Tertile 3 (more disadvantaged)1.50 (1.17, 1.91)Race (vs. NHW)Hispanic0.94 (0.72, 1.22)NHB1.71 (1.27, 2.31)Age1.02 (1.01, 1.02)Insurance (vs. Private)Government1.49 (1.19, 1.86)Insurance, NOS0.97 (0.62, 1.51)Uninsured1.15 (0.87, 1.52)Unknown1.19 (0.78, 1.82)Receptor Status (vs. ER+/HER2-)ER+/HER2+1.40 (1.06, 1.86)ER-/HER2-2.11 (1.70, 2.60)ER-/HER2+1.20 (0.85, 1.69)Unknown0.88 (0.51, 1.51)Body Mass Index (vs. Normal Weight (18.5 – 24.9)Underweight (Less than 18.5)1.40 (0.72, 2.72)Overweight (25.0 – 29.9)0.70 (0.56, 0.88)Obese (&gt; 29.9)0.79 (0.63, 0.98)Hypertension0.84 (0.67, 1.03)Diabetes Mellitus1.02 (0.74, 1.40)NCCN-guideline concordant Treatment0.84 (0.75, 0.94)

Citation Format: Neha Goel, Seraphina Choi, Sina Yadegarynia, Kristin Rojas, Susan Kesmodel, Erin Kobetz, Ashly Westrick. Neighborhood disadvantage predicts worse breast cancer-specific survival [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-12-08.

Abstract P3-13-05: Comprehensive analysis of global genetic ancestry and socioeconomic status on breast cancer outcomes

Purpose: Disparities in breast cancer outcomes have been a long-standing and persistent challenge. Earlier onset, advanced stage at diagnosis, aggressive tumor subtypes [triple negative breast cancer (TNBC)], and worse overall survival (OS) are some of the characteristic features of breast cancer in non-Hispanic Black (NHB) women compared to their non-Hispanic White (NHW) counterparts, denoting one of the most significant examples of racial/ethnic differences in oncology. Given our location in South Florida, gateway to Latin America and the Caribbean, we discovered that these disparities in tumor characteristics and outcomes among NHB and NHW also extend to Hispanic Blacks (HB) compared to Hispanic Whites (HW). Since Hispanics are the second largest ethnic group in the US and have a rich genetic architecture with contributions from European (EU), West African (WA), and Native American (NA) populations, we sought to investigate genomic associations between observed inter and intra-racial/ethnic differences and breast cancer characteristics and outcomes. Methods: Patients with stage I-IV breast cancer were included. Patient socioeconomnic status (SES), tumor and treatment characteristics, and follow-up data were collected for each patient. Genomic analysis was performed on the peripheral blood from a cohort of 309 patients with breast cancer. This breast cancer cohort was comprised of 192 self-reported HW, 12 HB, 46 NHW, 47 NHB, and 12 unknown (declined to report) patients. Leukocyte DNA from each patient was genotyped, generating whole genome single nucleotide polymorphism (SNP) profiles. Global ancestral estimates, using &gt;100,000 SNPs, were calculated against reference samples from EU, WA, NA, and East Asian (EA) ancestral populations. A genomic diversity space was generated via principal component analysis and ADMIXTURE was used to estimate the ancestral proportions among the patients. Results: The genetic structure of individual patient sample revealed a diverse ancestral admixture where average EU, WA, NA, and EA ancestries were 64.5%, 21.8%, 11.2%, and 2.5%, respectively. Multinomial logistic regression revealed a significant association between increasing WA ancestry and aggressive tumor subtypes (ER-/HER2+ and TNBC), p=0.009 and p=0.031, respectively. These findings remained significant when correcting for patient age and tumor stage; however, when adjusting for income, the association between WA ancestry and ER-/HER2+ and TNBC was no longer significant. Kaplan Meier survival curves showed a significant difference in 5-year OS for patients with &gt;70% WA ancestry compared to those with &lt;70% WA ancestry, p=0.023. Conclusions: In this first integrative approach studying genetic ancestry and SES on breast cancer characteristics and outcomes, we found a significant association between increasing WA ancestry and aggressive breast cancer subtypes, even after adjusting for known covariates. More striking, this association was negated when adjusting for income, suggesting potential gene-environment interactions not accounted for by genetic race. We also discovered that Hispanics have a more complex genetic architecture than non-Hispanic patients, which may in-turn drive genetically-associated survival patterns of resiliency with improved survival in HW compared to NHB patients. Furthermore, the OS differences based on quantitative genetic ancestry cut-offs may serve as a future tool in patient prognosis. Collectively, our results show that genetic ancestry and SES influence breast cancer subtypes and survival. This lays a foundation for future studies to investigate complex genomic relationships between race/ethnicity, SES, and breast cancer characteristics and outcomes through the lens of gene-environment interactions.

Citation Format: Daniel A Rodriguez, Sina Yadegarynia, J. William Harbour, Nipun B. Merchant, Erin N. Kobetz, Neha Goel. Comprehensive analysis of global genetic ancestry and socioeconomic status on breast cancer outcomes [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-13-05.

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.

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.

Abstract SS1-01: Where you live matters: Impact of economic, racial/ethnic, and racialized economic residential segregation on breast cancer survival

Background:Racial and economic residential segregation remains a problem within the United States (US). Although advances in screening, detection, diagnosis, and treatment have reduced overall breast cancer mortality, well-documented socioeconomic and racial/ethnic survival disparities persist. The objective of this study was to analyze the effect of economic and racial/ethnic residential segregation as measured by the Index of Concentration at the Extremes (ICE) on breast cancer survival in South Florida.

Methods:Patients treated at our medical campus with stage I-IV breast cancer from 2005-2017 were identified from our local tumor registry. Census tracts were used as neighborhood proxies. Using 5-year estimates from the American Community Survey, 5 ICE variables were computed: economic (high vs. low), race/ethnicity (non-Hispanic White (NHW) vs. non-Hispanic Black (NHB) and NHW vs. Hispanic) and racialized economic (low-income NHB vs high-income NHW and low-income Hispanics vs. high-income NHW) segregation. ICE captures spatial socioeconmic and racial/ethnic segregation by literally mapping a critical dimension of social inequality not otherwise captured by metrics that characterize areas solely in terms of the proportion of the population at a specified socioeconomic level or identified as belonging to a particular racial/ethnic group. Random effects frailty models were conducted for all patients and then stratified by race/ethnicity controlling for sociodemographics, tumor characteristics, and NCCN-guideline appropriate treatment.

Results:The study population included 6,145 breast cancer patients. 52.6% were Hispanic, 26.3% were NHW, and 17.2% were NHB. After controlling for multiple covariates, those living in extreme economically disadvantaged neighborhoods had a statistically significant increased mortality compared to those living in more economically advantaged neighborhoods (HR: 1.58 95%CI: 1.29, 1.92, p&lt;0.001), Table 1. Patients living in an economically disadvantaged NHB neighborhood also had a statistically significant increased mortality compared to those living in more economically advantaged NHW neighborhoods (HR: 2.0 95% CI: 1.54, 2.60, p&lt;0.001). In race-stratified analyses, an NHW person living in a predominantly economically disadvantaged NHB neighborhood had increased mortality compared to a NHW person living in an economically advantaged NHW neighborhood (HR: 2.02 95%CI: 1.19-3.41, p&lt; 0.0071) controlling for tumor subtype and NCCN-guideline appropriate treatment.

Conclusion:This is the first study to evaluate breast cancer survival by ICE, which identifies inequitable associations by conveying extreme concentrations of both economic deprivation/privilege and racial/ethnic segregation. Our study suggests that breast cancer survival disparities is partly influenced by extreme racial/ethnic and economic segregation. Even when accounting for sociodemographics, tumor characteristics, and NCCN-guideline appropriate treatment, survival disparities remained, suggesting potential social and environmental factors impacting survival. To address these disparities, effective interventions are needed that account for the social and environmental contexts in which cancer patients live and are treated.

Table 1: Breast Cancer Hazard Ratio by Economic, Racial/Ethnic, and Racialized Economic Residential Segregation Residential SegregationType of Segregation (ICE)QuartileModel 1Model 2Model3HR (95% CI)HR (95% CI)HR (95% CI)Economic SegregationQ11.83 (1.1, 3.03)*1.64 (0.89, 3.02)1.58 (1.29, 1.92)*Economic SegregationQ22.36 (1.48, 3.76)*2.45 (1.38, 4.34)*1.44 (1.16, 1.79)*Economic SegregationQ31.16 (0.72, 1.8)1.08 (0.61, 1.9)1.16 (0.94, 1.44)Economic SegregationQ4111NHB SegregationQ11.6 (0.9, 2.84)1.42 (0.72, 2.82)1.41 (0.96, 2.07)NHB SegregationQ20.92 (0.52, 1.6)0.91 (0.47, 1.77)1 (0.68, 1.48)NHB SegregationQ30.61 (0.29, 1.26)0.85 (0.37, 1.94)0.82 (0.52, 1.31)NHB SegregationQ4111Hispanic SegregationQ11.38 (0.83, 2.28)1.13 (0.61, 2.08)1.36 (1.12, 1.66)*Hispanic SegregationQ279 (0.47, 1.32)0.74 (0.4, 1.38)0.86 (0.67, 1.08)Hispanic SegregationQ30.94 (0.59, 1.49)0.98 (0.57, 1.67)1.05 (0.86, 1.29)Hispanic SegregationQ4111NHB Economic SegregationQ12.68 (1.6, 4.47)*2.02 (1.09, 3.74)2 (1.54, 2.6)*NHB Economic SegregationQ21.85 (1.15, 2.97)*1.39 (0.79, 2.44)1.56 (1.22, 2.02)*NHB Economic SegregationQ31.2 (0.69, 2.07)1.09 (0.58, 2.06)1.19 (0.88, 1.6)NHB Economic SegregationQ4111Hispanic Economic SegregationQ11.91 (1.19, 3.07)*1.45 (0.83, 2.54)1.64 (1.24, 2.15)*Hispanic Economic SegregationQ21.45 (0.8, 2.62)1.06 (0.52, 2.17)1.44 (1.06, 1.96)*Hispanic Economic SegregationQ31.26 (1.73, 2.18)0.95 (0.49, 1.84)1.11 (0.8, 1.54)Hispanic Economic SegregationQ4111Model 1: Adjusted for ICE, race/ethnicity, age, insuranceModel 2: Adjusted for Model 1 covariates plus receptor status, clinical stageModel 3: Adjusted for Model 1 and 2 covariates plus stage appropriate treatmentQ1: Most disadvantaged neighborhoods; Q4: Reference: most advantaged neighborhoods.*p &lt; 0.05

Citation Format: Neha Goel, Kristin N Kelly, Sina Yadegarynia, Seraphina Choi, Susan B Kesmodel, Ashly Westrick. Where you live matters: Impact of economic, racial/ethnic, and racialized economic residential segregation on breast cancer survival [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SS1-01.

Abstract PO-005: Where you live matters: Impact of economic, racial/ethnic, and racialized economic residential segregation on breast cancer survival

Background Racial and economic residential segregation remains a problem within the United States (US). Although advances in screening, detection, diagnosis, and treatment have reduced overall breast cancer mortality, well-documented socioeconomic and racial/ethnic survival disparities persist. The objective of this study was to analyze the effect of economic and racial/ethnic residential segregation, as measured by the Index of Concentration at the Extremes (ICE), on breast cancer survival. Methods Patients treated at our medical campus, comprised of a safety-net hospital and an academic cancer center, with stage I-IV breast cancer from 2005-2017 were identified from our tumor registry. Census tracts were used as neighborhood proxies. Using 5-year estimates from the American Community Survey, 5 ICE variables were computed: economic (high vs. low), race/ethnicity (non- Hispanic White (NHW) vs. non-Hispanic Black (NHB) and NHW vs. Hispanic) and racialized economic (low-income NHB vs high-income NHW and low-income Hispanics vs. high-income NHW) segregation. ICE uniquely captures spatial economic and racial/ethnic segregation by mapping social inequality not otherwise captured by evaluating a population of a specific socioeconomic level or belonging to a particular racial/ethnic group. Random effects frailty models were conducted for all patients and then stratified by race/ethnicity controlling for demographics, tumor characteristics, and NCCN-guideline appropriate treatment subtype. Results The study population included 6,145 breast cancer patients. 52.6% were Hispanic, 26.3% were NHW, and 17.2% were NHB. After controlling for multiple covariates, those living in extreme economically disadvantaged neighborhoods had an increased hazard ratio (HR) of death compared to those living in more economically advantaged neighborhoods (HR: 1.58 95% CI: 1.29-1.92, p&lt;0.001). Patients living in an economically disadvantaged NHB neighborhood also had an increased HR compared to those living in more economically advantaged NHW neighborhoods (HR: 2.0 95% CI:1.54-2.60, p&lt;0.001). In race-stratified analyses, a NHW living in an economically disadvantaged NHB neighborhood had an increased HR compared to a NHW living in an economically advantaged NHW neighborhood (HR: 2.02 95% CI:1.19-3.41, p&lt; 0.0071), even when controlling for demographics, tumor subtype, and appropriate treatment. Conclusion This study is the first to evaluate breast cancer survival by ICE, which brings social inequality to the forefront. Our study suggests that survival disparities persist at the extremes of economic deprivation/privilege and racial/ethnic residential segregation, even when accounting for demographics, tumor characteristics, and appropriate treatment, suggesting social/environmental factors are also impacting survival. To address these disparities, effective interventions are needed that account for the social and environmental contexts in which cancer patients live and are treated.

Citation Format: Neha Goel, Sina Yadegarynia, Kristin N. Kelly, Susan B. Kesmodel, Erin N. Kobetz, Ashly Westrick. Where you live matters: Impact of economic, racial/ethnic, and racialized economic residential segregation on breast cancer survival [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-005.

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.

Abstract IA21: Combination treatments that include PI3K-inhibitors for the treatment of triple-negative breast cancer

Alterations in the PI3K pathway are highly prevalent in triple-negative breast and high grade ovarian cancer, including BRCA1- and BRCA2-related disease. On the cellular level, loss of BRCA1 increases genomic instability and reliance on single strand break repair, hence creating an opportunity to treat BRCA-related TNBC or OC with PARP-inhibitors. In addition, loss of BRCA1 and/or p53 lead to relaxation of negative feed-back loops in mitogenic signaling, resulting in highly proliferative malignancies. For these reasons PARP-inhibitor Olaparib and PI3K-inhibitor NVP-BKM120 were tested in combination and found to be synergistic in mouse models of BRCA1-related BC. Surprisingly, PI3K-inhibition enhanced a DNA damage phenotype, caused by a profound decrease in DNA synthesis that could be observed after treatment with NVP-BKM120 in vivo and in vitro. The decrease in DNA synthesis was due to reduced Nucleoside synthesis resulting from a block in glycolysis that led to a drop in flux through the non-oxidative pentose phosphate pathway. In a preclinical mouse model (K14-Cre BRCA1f/fp53f/f), the combination of NVP-BKM120 and Olaparib could induce complete remissions, while PI3K-inhibitor alone marginally slowed disease progression and PARP-inhibitor alone stabilized the disease. This concept was translated into a clinical trial: BKM120/Olaparib for Triple Negative Breast Cancer or High Grade Serous Ovarian Cancer (NCT01623349; PI: Ursula Matulonis). Dose escalation for this study and accrual to an extension cohort at the MTD (NVP-BKM120 50 mg once a day in combination with Olaparib 300 mg twice a day) have been completed and a second dose escalation arm with NVP-BYL719 and Olaparib is ongoing.

Citation Format: Gerburg M. Wulf, Ashish Juvekar, Costas M. Lyssiotis, Hai Hu, Kim Baek, Sina Yadegarynia, Ralph Scully, Eric Winer, John Asara, Lewis C. Cantley, Ursula Matulonis. Combination treatments that include PI3K-inhibitors for the treatment of triple-negative breast cancer. [abstract]. In: Proceedings of the AACR Special Conference: Targeting the PI3K-mTOR Network in Cancer; Sep 14-17, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(7 Suppl):Abstract nr IA21.

Abstract CT338: Combination of a PI3K- and a PARP-inhibitor to treat high-grade serous ovarian or triple-negative breast cancer

Clinical trials have shown promising responses of BRCA-linked breast and ovarian cancers to PARP inhibitor therapy, but remissions are often short-lived and incomplete. The PI3K pathway is frequently activated in these malignancies. Recently, we reported in vivo synergy of a PI3K- and a PARP-inhibitor in a mouse model of BRCA1-related breast cancer. While the PARP-inhibitor olaparib alone attenuated tumor growth modestly, a dramatic reduction in tumor growth was observed when olaparib was combined with the PI3K-inhibitor BKM120. In BRCA1-mutant HCC1937 BC cells, PI3K- (but not akt-) inhibition increased indicators of DNA damage, such as poly-ADP-ribosylation and γH2AX, suggesting a critical role of PI3K activity for the maintenance of genomic stability. Here, we report on the molecular mechanism underlying this synergy, on treatment outcomes in an improved mouse model system and the development of an early-phase clinical study. Pre-clinical modeling was done in BRCA1-mutant HCC1937 cells and in a mouse model based on the syngenic transplantation of tumors derived on the K14-Cre BRCA1f/fp53f/f background. Metabolic profiling in vitro and in vivo showed that PI3K-inhibition decreased flux through glycolysis and specifically through the non-oxidative pentose-phosphate pathway, the main source of ribose-5-phosphate required for the de novo synthesis of nucleotides in HCC1937 cells. Within 3 hours and preceding cell cycle changes, BKM120 caused a decrease in nucleotide pools that was further exacerbated by the addition of olaparib. Nucleotide shortage led to to replication stress with the appearance of γH2AX and increased poly-ADP-ribosylation. Tumors with complete loss of BRCA1 and p53 proved particularly vulnerable to this treatment strategy. We were able to induce complete and durable remissions of murine tumors arising on the K14-Cre BRCA1f/fp53f/f background with a 28-day course of BKM120 and Olaparib. These preclinical data have served as the rationale for a phase I, multi-center study (NCT01623349) combining the oral PARP inhibitor olaparib with the oral PI3-kinase inhibitor BKM120 in patients with recurrent HGSC or recurrent TNBC. The study is being conducted through the Stand Up to Cancer (SU2C)'s Targeting PI3-kinase in Women's Cancers Dream Team. It has a 3 + 3 design, escalating if 0/3 or 1/6 participants have a DLT during the first cycle of therapy. The study objectives are to determine the recommended phase II dose (RP2D) of daily continuous oral olaparib (using the tablet formulation) and BKM120, assess toxicities, safety, and preliminary activity of this combination, and determine pharmacokinetic profiles of both agents as well as translational endpoints. The study serves as an example for the development of a clinical trials concept for TNBC and HGSC based on a close collaboration of basic and clinical scientists through the SU2C mechanism.

Citation Format: Gerburg M. Wulf, Ashish Juvekar, Costas A. Lyssiotis, Hai Hu, Sina Yadegarynia, Hui Liu, Baek Kim, Eric Winter, Ralph Scully, John Asara, Lewis C. Cantley, Ursula Matulonis. Combination of a PI3K- and a PARP-inhibitor to treat high-grade serous ovarian or triple-negative breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT338. doi:10.1158/1538-7445.AM2014-CT338

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.

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.

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.

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.

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.

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.