Triple-Negative Breast Cancer in Ghanaian Women: The Korle Bu Teaching Hospital Experience

Breast cancers that have negative or extremely low expression of estrogen receptor and progesterone receptor and non-amplification of human epidermal growth factor receptor-2 (HER2)/neu are termed triple-negative breast cancer (TNBC). The majority of TNBC tumors belong to the biologically aggressive basal subtype, and they cannot be managed with targeted endocrine or anti-HER2/neu agents. In western, high resource environments, risk factors for TNBC include younger age at diagnosis and hereditary susceptibility. Women of African ancestry in the United States and in continental Africa have higher frequencies of TNBC, prompting speculation that this risk may have an inherited basis and may at least partially explain breast cancer survival disparities related to racial/ethnic identity. Efforts to document and confirm the breast cancer burden of continental Africa have been hampered by the limited availability of registry and immunohistochemistry resources. Our goal was to evaluate the breast cancers diagnosed in one of the largest health care facilities in western Africa, and to compare the frequencies as well as risk factors for TNBC versus non-TNBC in this large referral tertiary hospital. The Korle Bu Teaching Hospital is affiliated with the University of Ghana and is located in Accra, the capital of Ghana. We conducted an institutional, Department of Pathology-based review of the breast cancer cases seen at this facility for the 2010 calendar year, and for which histopathologic specimens were available. The overall study population of 223 breast cancer cases had a median age of 52.4 years, and most had palpable tumors larger than 5 cm in diameter. More than half were TNBC (130; 58.3%). We observed similar age-specific frequencies, distribution of stage at diagnosis and tumor grade among cases of TNBC compared to cases of non-TNBC. Ghanaian breast cancer patients tend to have an advanced stage distribution and relatively younger age at diagnosis compared to Caucasian Americans and African Americans. The triple-negative molecular marker pattern was the most common subtype of breast cancer seen among this sample of Ghanaian women, regardless of age, tumor grade, or stage of diagnosis. Research into the molecular pathogenesis of TNBC may help elucidate the reasons for its increased prevalence among women with African ancestry.

Nanoroughened adhesion-based capture of circulating tumor cells with heterogeneous expression and metastatic characteristics

BACKGROUND

Circulating tumor cells (CTCs) have shown prognostic relevance in many cancer types. However, the majority of current CTC capture methods rely on positive selection techniques that require a priori knowledge about the surface protein expression of disseminated CTCs, which are known to be a dynamic population.

METHODS

We developed a microfluidic CTC capture chip that incorporated a nanoroughened glass substrate for capturing CTCs from blood samples. Our CTC capture chip utilized the differential adhesion preference of cancer cells to nanoroughened etched glass surfaces as compared to normal blood cells and thus did not depend on the physical size or surface protein expression of CTCs.

RESULTS

The microfluidic CTC capture chip was able to achieve a superior capture yield for both epithelial cell adhesion molecule positive (EpCAM+) and EpCAM- cancer cells in blood samples. Additionally, the microfluidic CTC chip captured CTCs undergoing transforming growth factor beta-induced epithelial-to-mesenchymal transition (TGF-β-induced EMT) with dynamically down-regulated EpCAM expression. In a mouse model of human breast cancer using EpCAM positive and negative cell lines, the number of CTCs captured correlated positively with the size of the primary tumor and was independent of their EpCAM expression. Furthermore, in a syngeneic mouse model of lung cancer using cell lines with differential metastasis capability, CTCs were captured from all mice with detectable primary tumors independent of the cell lines' metastatic ability.

CONCLUSIONS

The microfluidic CTC capture chip using a novel nanoroughened glass substrate is broadly applicable to capturing heterogeneous CTC populations of clinical interest independent of their surface marker expression and metastatic propensity. We were able to capture CTCs from a non-metastatic lung cancer model, demonstrating the potential of the chip to collect the entirety of CTC populations including subgroups of distinct biological and phenotypical properties. Further exploration of the biological potential of metastatic and presumably non-metastatic CTCs captured using the microfluidic chip will yield insights into their relevant differences and their effects on tumor progression and cancer outcomes.

Comparative Analysis of Breast Cancer Phenotypes in African American, White American, and West Versus East African patients: Correlation Between African Ancestry and Triple-Negative Breast Cancer

INTRODUCTION

Triple-negative breast cancer (TNBC) is more common among African American (AA) and western sub-Saharan African breast cancer (BC) patients compared with White/Caucasian Americans (WA) and Europeans. Little is known about TNBC in east Africa.

METHODS

Invasive BC diagnosed 1998-2014 were evaluated: WA and AA patients from the Henry Ford Health System in Detroit, Michigan; Ghanaian/west Africans from the Komfo Anokye Teaching Hospital in Kumasi, Ghana; and Ethiopian/east Africans from the St. Paul's Hospital Millennium Medical College in Addis Ababa, Ethiopia. Histopathology and immunohistochemistry for estrogen receptor (ER), progesterone receptor (PR), and HER2/neu expression was performed in Michigan on formalin-fixed, paraffin-embedded samples from all cases.

RESULTS

A total of 234 Ghanaian (mean age 49 years), 94 Ethiopian (mean age 43 years), 272 AA (mean age 60 years), and 321 WA (mean age 62 years; p = 0.001) patients were compared. ER-negative and TNBC were more common among Ghanaian and AA compared with WA and Ethiopian cases (frequency ER-negativity 71.1 and 37.1 % vs. 19.8 and 28.6 % respectively, p < 0.0001; frequency TNBC 53.2 and 29.8 % vs. 15.5 and 15.0 %, respectively, p < 0.0001). Among patients younger than 50 years, prevalence of TNBC remained highest among Ghanaians (50.8 %) and AA (34.3 %) compared with WA and Ethiopians (approximately 16 % in each; p = 0.0002).

CONCLUSIONS

This study confirms an association between TNBC and West African ancestry; TNBC frequency among AA patients is intermediate between WA and Ghanaian/West Africans consistent with genetic admixture following the west Africa-based trans-Atlantic slave trade. TNBC frequency was low among Ethiopians/East Africans; this may reflect less shared ancestry between AA and Ethiopians.

Abstract 1040: Differential levels of glycogen in breast cancer cell lines: A potential new target

Cancer cells have been known to alter their metabolic processes in order to survive and proliferate. Normally in muscle and liver, excess glucose is stored within the cells as glycogen. Elevated levels of glycogen have also been found in various cancers, including breast cancers. Recent studies have implicated glycogen metabolism as important in promoting survival of cancer cells, suggesting targeting of glycogen metabolism as a possible treatment to inhibit cancer cell growth. In general, modulation of cancer metabolism is believed to be an attractive adjunct strategy to conventional or targeted therapies. Here we set out to investigate glycogen levels as well as levels of proteins involved in glycogen synthesis and degradation vary across different breast cancer cell lines.

A glucose metabolism qPCR array found differential levels of the alpha subunit of phosphorylase kinase 1, a key enzyme involved in glycogen degradation among three different breast cancer cell lines. Expression levels of glycogen synthesis and degradation enzymes were assessed using qPCR and immunoblot in various breast cancer cell lines. Glycogen levels in these breast cancer cell lines were quantified using an amyloglucosidase reaction coupled with other enzymatic reactions to produce a fluorescent product. It was found that MDA-MB-231, SUM149, and MCF7 cell lines had increased levels of glycogen, between 6.5 and 23.5 μg glycogen per mg protein, whereas SUM190 and normal-like breast epithelial cell line MCF10A had undetectable levels of glycogen. These findings demonstrate that glycogen metabolism can vary widely amongst cancer types, indicating that therapies targeted to disrupt glycogen degradation may produce differential results and that further study of the role of glycogen metabolism in cancer is warranted.

Citation Format: Joel A. Yates, Megan Altemus, Zhifen Wu, Michelle L. Wynn, Sofia D. Merajver. Differential levels of glycogen in breast cancer cell lines: A potential new target. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1040.

RhoC GTPase Is a Potent Regulator of Glutamine Metabolism and N-Acetylaspartate Production in Inflammatory Breast Cancer Cells

Inflammatory breast cancer (IBC) is an extremely lethal cancer that rapidly metastasizes. Although the molecular attributes of IBC have been described, little is known about the underlying metabolic features of the disease. Using a variety of metabolic assays, including (13)C tracer experiments, we found that SUM149 cells, the primary in vitro model of IBC, exhibit metabolic abnormalities that distinguish them from other breast cancer cells, including elevated levels of N-acetylaspartate, a metabolite primarily associated with neuronal disorders and gliomas. Here we provide the first evidence of N-acetylaspartate in breast cancer. We also report that the oncogene RhoC, a driver of metastatic potential, modulates glutamine and N-acetylaspartate metabolism in IBC cells in vitro, revealing a novel role for RhoC as a regulator of tumor cell metabolism that extends beyond its well known role in cytoskeletal rearrangement.

Chronic Mastitis in Egypt and Morocco: Differentiating between Idiopathic Granulomatous Mastitis and IgG4-Related Disease

Idiopathic granulomatous mastitis (IGM) is a benign, frequently severe chronic inflammatory lesion of the breast. Its etiology remains unknown and reported cases vary in their presentation and histologic findings with an optimal treatment algorithm yet to be described owing mainly to the disease's heterogeneity. IgG4‐related disease (IgG4‐RD) is a newly recognized systemic fibroinflammatory condition characterized by a dense lymphoplasmacytic infiltrate with many IgG4‐positive plasma cells, storiform fibrosis, and obliterative phlebitis. Immunosuppressive therapy is considered to be an effective first‐line therapy for IgG4‐RD. We sought to clarify and classify chronic mastitis according to the histologic findings of IgG4‐RD mastitis with respect to IGM and to develop a robust diagnostic framework to help select patients for optimal treatment strategies. Using the largest collection to date (43 cases from Egypt and Morocco), we show that despite sharing many features, IGM and IgG4‐RD mastitis are separate diseases. To diagnostically separate the diseases, we created a classification schema—termed the Michigan Classification—based upon our large series of cases, the consensus statement on IgG4‐RD, and the histologic description of IGM in the literature. Using our classification, we discerned 17 cases of IgG4‐RD and 8 cases of IGM among the 43 chronic mastitis cases, with 18 indeterminate cases. Thus, our Michigan Classification can form the basis of rational stratification of chronic mastitis patients between these two clinically and histopathologically heterogeneous diseases.

Effects of postpartum mobile phone-based education on maternal and infant health in Ecuador

OBJECTIVE

To evaluate the effects of a mobile phone-based intervention on postnatal maternal health behavior and maternal and infant health in a middle-income country.

METHODS

A prospective evaluation enrolled consecutive postpartum women at two public hospitals in Quito, Ecuador, between June and August 2012. Inclusion criteria were live birth, no neonatal intensive care admission, and Spanish speaking. Intervention and control groups were assigned via random number generation. The intervention included a telephone-delivered educational session and phone/text access to a nurse for 30days after delivery. Maternal and infant health indicators were recorded at delivery and 3months after delivery via chart review and written/telephone-administered survey.

RESULTS

Overall, 102 women were assigned to the intervention group and 76 to the control group. At 3months, intervention participants were more likely to attend the infant's postnatal check-up (P=0.022) and to breastfeed exclusively (P=0.005), and less likely to feed formula (P=0.016). They used more effective forms of contraception (more implants P=0.023; fewer condoms P=0.036) and reported fewer infant illnesses (P=0.010). There were no differences in maternal acute illness or check-up attendance.

CONCLUSION

Mobile phone-based postnatal patient education is a promising strategy for improving breastfeeding, contraceptive use, and infant health in low-resource settings; different strategies are needed to influence postpartum maternal health behavior.

Clinical predictors of long-term survival in HER2-positive metastatic breast cancer

Prior to availability of anti-HER2 therapies, HER2-positive metastatic breast cancer (MBC) was associated with a poor prognosis. Prospective randomized trials have demonstrated survival benefit from anti-HER2 treatments. Anecdotal observations have suggested that a small but meaningful fraction of patients with HER2-positive MBC may be "exceptional responders" with long survival. We hypothesized that demographic and/or clinicopathologic characteristics can be identified to distinguish short-term from long-term survivors. A retrospective, single-institution review of 168 patients with HER2-positive MBC who received treatment with anti-HER2 therapy in the metastatic setting was performed. Cox proportional hazards analysis was used to assess factors associated with long-term survival. Median overall survival from the time of breast cancer recurrence was 3.9 years (95 % CI 3.4-5.2). From the time of diagnosis of MBC, 56 (33 %) survived for 5 or more years and 12 (7 %) survived more than 10 years. Of the 66 patients diagnosed with central nervous system metastases, 9 (14 %) survived more than 5 years following that diagnosis. Younger age at diagnosis, lower stage, hormone receptor positive status, and only having one organ involved at diagnosis were associated with longer survival. Four patients discontinued anti-HER2 therapy and are without evidence of progression of disease after a median 7.4 years (0.2-12.0) since stopping therapy. In a cohort of patients with HER2-positive MBC treated primarily with trastuzumab and lapatinib, 7 % of patients were "exceptional responders." Combining these clinical factors with molecular determinants of prolonged survival may provide insights for individualizing treatment selection.

Abstract 3852: Prevalent loss of BRCA1 and BRCA2 expression in African TNBC suggests their prominent role in sporadic carcinogenesis

BRCAness is a property shared by breast tumors with sporadic BRCA1 mutations or arising in patients with germline BRCA1 mutations, or tumors which down-regulate BRCA1 expression by other mechanisms. Women with African ancestry have been shown to have breast tumors that have characteristics similar to BRCA mutated tumors, but there is scant data on the signaling and regulation of the BRCA1 and BRCA 2 pathways in theses tumors.

We have hypothesized that defective expression of key players in the BRCA1 and BRCA2 pathways may contribute to the BRCAness observed in sporadic breast cancers in women with African ancestry.

Method:

1. Genomic and transcriptomic studies using Next Generation Sequencing technologies of normal DNA extracted from saliva and tumor DNA and RNA, extracted from frozen tumors were performed on four triple negative breast cancer (TNBC) specimens from Ghanaian women. Whole exome sequencing and RNA-sequencing (RNA-seq) were completed on all patients.

2. Immunohistochemistry staining for BRCA1, BRCA2 and PALB2 protein was completed for 49 Ghanaian TNBC tumor samples. IHC staining was also performed on some of the tumors that were sequenced. IHC staining was performed on PDX tumors derived from Ghanaian TNBC.

3. Generation of patient derived xenografts (PDX) models of TNBC from Ghanaian breast cancer patients for sequencing, q and standard PCR, and Western blot to determine the signaling of BRCA1 and BRCA2 pathway in Ghanaian TNBCs.

Results:

We discovered novel BRCA2 nonsense variant that will likely result in truncation or no expression. This tumor did not show BRCA2 expression on IHC. All the patients who had previously reported BRCA1 and BCRA2 variants had no expression of the proteins on IHC. Of the 49 Ghanaian TNBC tumors that were stained for BRCA1 and BRCA2, half did not express either BRCA1 or BRCA2, 10% had no expression of BRCA1 alone and none had loss of BRCA2 expression alone.

Studies are ongoing on the PDX models to identify the expression of members of the BRCA1 and BRCA2 pathways in TNBC of women with African ancestry.

Conclusion:

A large proportion of TNBCs from African women have loss of expression of BRCA1 and BRCA2. Identifying the signaling alterations in the BRCA1 and BRCA2 pathways may help to identify novel drug targets for TNBC or may help predict response to PARP inhibitors or related drugs.

IHC is an important and relatively inexpensive method for determining patients with BRCA pathway alteration who my benefit from DNA repair targeted therapy. This will be very beneficial for women in Africa who do not have access to BCRA germline testing.

Citation Format: Evelyn M. Jiagge, Shukmei Wong, Gabriel Lupu, Mu Qiao, Michele Dziubinski, Lisa A. Newman, John Carpten, Max Wicha, Sofia D. Merajver. Prevalent loss of BRCA1 and BRCA2 expression in African TNBC suggests their prominent role in sporadic carcinogenesis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3852. doi:10.1158/1538-7445.AM2015-3852

Abstract 5536: KB-164, a novel and highly potent Src family kinase inhibitor, reduces cancer cell invasion and abrogates downstream oncogenic pathways in triple negative breast cancer

Src is a non-receptor tyrosine kinase, which acts as an integrator of diverse signaling pathways used by cancer cells for cell proliferation, migration and metastasis. Recent interest in developing target specific therapy for improved benefits with manageable toxic effects has sharply increased the interest in testing new Src family kinase inhibitors for their potential anticancer therapeutic properties.

In this study, we sought to investigate the chemical characteristics and the biological effects of the novel Src family kinase inhibitor KB-164, in Src expressing triple negative breast cancer cells. We show that KB-164 acts as a potent Src kinase inhibitor (IC50 1.3 nmol/L) in MDA-MB 231 cells, 100-fold more potent than the most widely used Src family kinase inhibitor dasatinib. At concentrations of 50nmol/L, KB-164 led to complete inhibition of Src activation for 48 hours. Analysis of downstream effectors of Src revealed that treatment with KB-164 inhibits the phosphorylation of several oncogenic pathways i.e. EGFR, ERK1/2, P38MAPK and AKT. A dramatic decrease in cancer cell motility and invasion was observed on treatment with KB-164 in both SUM 149 and MDA-MB 231 triple negative breast cancer cell lines. We also show that triple negative breast cancer cells derived from the patients are equally sensitive to growth inhibition by KB-164 within an IC50 of 1.8-nmol range. No cytotoxicity was observed both in vitro (18 micro mol/L in normal human mammary epithelial cells) and in vivo (70mg/kg in mice). Our findings indicate that KB-164 inhibits signaling pathways involved in controlling tumor cell proliferation and survival, suggesting that KB-164 might prove to be a promising therapeutic agent for breast cancer.

Citation Format: Rabia A. Gilani, Kristoffer R. Brandvold, Li Wei Bao, Sameer Phadke, Michael E. Steffey, Matthew B. Soellner, Sofia D. Merajver. KB-164, a novel and highly potent Src family kinase inhibitor, reduces cancer cell invasion and abrogates downstream oncogenic pathways in triple negative breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5536. doi:10.1158/1538-7445.AM2015-5536

Abstract 4834: Single cell multiplex gene expression analysis to unravel heterogeneity of PDX samples established from tumors of breast cancer patients with different ethnicity

Intra-tumor heterogeneity represents one of the main challenges in cancer therapeutics. This heterogeneity is generated at the genetic level primarily by genomic alterations and clonal selection and at the epigenetic level by tumor cell differentiation. In addition, inter-tumor heterogeneities may also be related to differences in tumor biology in different ethnic populations. To explore the cell heterogeneity in breast cancer, we studied patient derived xenograft (PDX) models generated from African (Ghana), African-American, and Caucasian breast cancer patients. Gene expression of a selected panel of cancer associated genes was determined in single cells using C1 and BioMark HD platforms. Analyzed multiplex RT-qPCR data revealed significant heterogeneity in mRNA expression within and between studied PDX samples at single cell resolution. We observed a significantly different mRNA expression profile within each ethnic group of breast cancer PDX samples. In addition, distinct gene expression signatures were observed between the PDX samples of different ethnic origin. ALDH1a1, ALDH1a3, CD44, CD24, and CD133 were among the CSC markers that were differentially expressed in different PDX single cell samples. Vimentin, EpCAM, HER2, CDH1, CDH2, TGFb1, cytokeratins, GATA3 and MKI67 genes related to the epithelial to mesenchymal (EMT) and mesenchymal to epithelial (MET) phenotypes also demonstrated significantly variable expression in the studied PDX samples. YAP1, TM4SF1, TSPAN6, AMOTL2, STAP2 and ANXA3 genes were differentially expressed in the PDX samples. These candidate biomarkers represent a collection of genes that may warrant further investigation for their potential involvement in cancer initiation, promotion and progression to metastasis, and drug resistance. These data emphasize the importance of studying tumors at single cell resolution to unravel gene expression variation. Upon validation in clinical tumor specimens, this approach could help to identify cellular subpopulations within tumors and possibly identify novel targets for cancer therapy.

Citation Format: Ebrahim Azizi, Evelyn M. Jiagge, Shamileh Fouladdel, Shukmei Wong, Michele L. Dziubinski, Mary Sehl, Anahita Kyani, Jun Li, Hui Jiang, Tahra K. Luther, Shawn G. Clouthier, Sean P. McDermott, John Carpten, Lisa A. Newman, Sofia D. Merajver, Max S. Wicha. Single cell multiplex gene expression analysis to unravel heterogeneity of PDX samples established from tumors of breast cancer patients with different ethnicity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4834. doi:10.1158/1538-7445.AM2015-4834

Abstract 1203: Metastasis-associated oncogene RhoC as a regulator of glutamine metabolism in the inflammatory breast cancer cell line SUM149

Metabolic reprogramming is increasingly recognized as a fundamental hallmark of cancer. While the Warburg effect and normal proliferative metabolism are similar, they are not equivalent. We hypothesize that there are key drivers of malignant metabolism that can be modulated to impede cancer proliferation without substantial effects on normal tissue growth. Using 13C-labeled glucose and glutamine tracers in combination with mass spectrometry and measurements of extracellular glucose, lactate, and glutamine flux, we have characterized system level differences in a series of breast cancer cell lines as well as normal-like breast epithelial cells. We observed an increase in the reductive carboxylation of glutamine-derived citrate and alpha-ketoglutarate in the triple-negative inflammatory breast cancer cell line SUM149. We also observed that the SUM149 exhibit high levels of HIF-1α and low levels of oxygen consumption under normoxia, suggesting that the cell line is highly adapted to hypoxia. Surprisingly, the stable depletion of HIF-1α via shRNA had no significant effect on the metabolic profile of these cells. Previous work by our lab and others has demonstrated that the GTPase RhoC is a driver of the metastatic phenotype exhibited by inflammatory breast cancer. Activation of RhoC is known to induce cytoskeletal rearrangements and increase invasive potential. The Rho GTPase family of proteins has also recently been linked to metabolism, specifically regulation of glutaminase activity. Here we show that stable knockdown of RhoC in SUM149 cells results in a marked decrease in the rate of both glutamine uptake and intracellular reductive carboxylation. This work reinforces the role of RhoC as an important driver of inflammatory breast cancer metastatic potential. We conclude that RhoC remains an important clinical target with the potential to alter patient outcomes.

Citation Format: Joel A. Yates, Michelle L. Wynn, ZhiFen Wu, Charles R. Evans, Charles Burant, Santiago D. Schnell, Sofia D. Merajver. Metastasis-associated oncogene RhoC as a regulator of glutamine metabolism in the inflammatory breast cancer cell line SUM149. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1203. doi:10.1158/1538-7445.AM2015-1203

Breast Cancer Risk Reduction, Version 2.2015

Breast cancer is the most frequently diagnosed malignancy in women in the United States and is second only to lung cancer as a cause of cancer death. To assist women who are at increased risk of developing breast cancer and their physicians in the application of individualized strategies to reduce breast cancer risk, NCCN has developed these guidelines for breast cancer risk reduction.

"Smart" Nanoparticles Enhance the Cytoplasmic Delivery of Anti-RhoC Silencing RNA and Inhibit the Migration and Invasion of Aggressive Breast Cancer Cells

Rho-GTPases are small GTP-binding proteins that contribute to the epithelial-to-mesenchymal transition by regulating several cellular processes including organization of the actin cytoskeleton, cell motility, transcription, and cell proliferation. Overexpression of RhoC-GTPases (RhoC) in breast cancer has been implicated in poor disease prognosis due to increased cancer cells invasion, migration, and motility, which warranted its consideration as a therapeutic target for inhibiting breast cancer metastasis. Using silencing RNA (siRNA) molecules to knockdown RhoC expression is a promising approach to inhibit breast cancer metastases. However, transforming anti-RhoC siRNA molecules into a viable therapy remains a challenge due to the lack of a biocompatible carrier that can selectively deliver the RNA cargo into breast cancer cells. We report the use of a degradable, pH-sensitive, β-cyclodextrin (βCD)-based polymeric carrier that condenses anti-RhoC siRNA forming "smart" particles. These smart anti-RhoC particles were efficiently internalized, successfully escaped the endosome, and delivered the RNA cargo into the cytoplasm of SUM149 and MDA-MB-231 breast cancer cells. Our results show that anti-RhoC particles used at a low N/P ratio of 2.5/1 suppressed RhoC protein levels by 100% and 90% in SUM149 and MDA-MB-231 cells, respectively. Further, anti-RhoC particles inhibited the invasion, motility, and migration of SUM149 and MDA-MB-231 cells by 40-47%, 57-60%, and 61.5-73%, respectively. Smart particles encapsulating the scrambled siRNA sequence did not affect RhoC protein expression or the invasion, motility, and migration of SUM149 and MDA-MB-231 cells, which indicate the biocompatibility of the polymeric carrier and selectivity of the observed RhoC knockdown. These results collectively indicate the therapeutic potential of smart anti-RhoC particles in arresting the metastatic spread of breast cancer cells.

Single-cell Migration Chip for Chemotaxis-based Microfluidic Selection of Heterogeneous Cell Populations

Tumor cell migration toward and intravasation into capillaries is an early and key event in cancer metastasis, yet not all cancer cells are imbued with the same capability to do so. This heterogeneity within a tumor is a fundamental property of cancer. Tools to help us understand what molecular characteristics allow a certain subpopulation of cells to spread from the primary tumor are thus critical for overcoming metastasis. Conventional in vitro migration platforms treat populations in aggregate, which leads to a masking of intrinsic differences among cells. Some migration assays reported recently have single-cell resolution, but these platforms do not provide for selective retrieval of the distinct migrating and non-migrating cell populations for further analysis. Thus, to study the intrinsic differences in cells responsible for chemotactic heterogeneity, we developed a single-cell migration platform so that individual cells' migration behavior can be studied and the heterogeneous population sorted based upon chemotactic phenotype. Furthermore, after migration, the highly chemotactic and non-chemotactic cells were retrieved and proved viable for later molecular analysis of their differences. Moreover, we modified the migration channel to resemble lymphatic capillaries to better understand how certain cancer cells are able to move through geometrically confining spaces.

Abstract P6-08-50: Clinical predictors of long-term survival in Her2-positive (HER2+) metastatic breast cancer (MBC)

Introduction: Clinical observation suggests that a subset of patients with HER2+ MBC survive for prolonged periods when treated with Her2-targeting regimens. We hypothesized that we could identify clinical and pathological factors associated with prolonged survival.

Methods: An IRB approved, retrospective, single institution review of patients diagnosed with HER2+ MBC was performed. Patients treated with pertuzumab or ado-trastuzumab emtansine were not included because recent FDA approval did not permit long-term follow-up. Clinical and pathologic characteristics were abstracted from the medical record. Kaplan Meier curves were constructed to evaluate time to progression after first metastasis, and overall survival from time of first metastasis. Cox proportional hazards analysis was used to assess for factors associated with long-term survival. A p value of &lt;0.05 is statistically significant.

Results: Review identified 181 patients with HER2+ MBC. Median age was 47 (range 35-80). More than half (N=107) had hormone receptor positive disease; 21% had received adjuvant trastuzumab; and 25% had stage IV disease at diagnosis. Median overall survival from the time of MBC diagnosis was 4.2 yrs (range 0.1-15.5). Since the diagnosis of MBC, 70 (38%) survived for 5 or more yrs and 15 (8%) survived more than 10 yrs. One third (N=59) of patients had brain metastases. These patients had a median survival of 1.5 yrs (range 0-12.5 yrs) with 14% (N=8) living for more than 5 yrs following diagnosis of brain metastasis. Factors associated with decreased survival are listed in Table 1.

Factors Associated with Decreased Survival in Her2+ MBCFactorHazard Ratio (95% C.I.)P ValueAge (continuous)1.03 (1.01-1.04)0.0004Time to recurrence (continuous)0.99 (0.94-1.04)0.74Hormone receptor positive0.70 (0.49-0.99)0.042Brain metastasis1.09 (0.77-1.56)0.63Adjuvant anti-Her2 therapy0.98 (0.61-1.58)0.94Multiple (vs single) sites of disease at initial diagnosis of MBC1.66 (1.17-2.35)0.005

Conclusions: In the treatment era of trastuzumab and lapatinib, 8% of patients within this cohort with HER2+ MBC lived more than 10 yrs. Analysis of current standard clinical and pathologic characteristics are not predictive of survival duration. Identifying factors associated with prolonged survival may provide insights for individualizing treatment selection.

Citation Format: Pooja Murthy, Kelley M Kidwell, Dafydd G Thomas, Jennifer J Griggs, Sofia D Merajver, Anne F Schott, Jeffrey B Smerage, Catherine H Van Poznak, Max Wicha, Daniel F Hayes, N Lynn Henry. Clinical predictors of long-term survival in Her2-positive (HER2+) metastatic breast cancer (MBC) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-08-50.

The changing pattern of ano-rectal cancer, squamous cell carcinoma of the eye, and Hodgkin's lymphoma as non-AIDS-defining cancers, by HIV status, in Tanzania over 11 years (2002-2012): a retrospective case-report study

BACKGROUND

In Tanzania, 5.1% of adults aged 15-49 are infected with HIV. While rates of HIV-related malignancies have declined globally with antiretroviral therapy (ART), including Tanzania, rates of non-AIDS-defining cancers (NADCs) are believed to have increased. Therefore, we determined trends of three NADCs in Tanzania: ano-rectal cancer, squamous cell carcinoma of the eye, and Hodgkin's lymphoma.

METHODS

This study was conducted at the Ocean Road Cancer Institute (ORCI) in Dar es Salaam. All medical records of patients diagnosed with ano-rectal cancer, squamous cell carcinoma of the eye, and Hodgkin's lymphoma between 2002 and 2012 were reviewed regarding HIV status, cancer clinical characteristics and management. Analysis was conducted to determine trends and proportions in these three NADCs and patient characteristics.

RESULTS

We identified 980 NADCs. The relative proportion of these three NADCs at ORCI out of all cancers treated increased from 2.37% in 2002 to a peak of 4.34% in 2009. The prevalence of HIV in patients diagnosed with these NADCs also increased-from 6.67% in 2002 to 20.87% in 2010-and 85% of squamous cell carcinoma of the eye cancer patients with a reported HIV status were HIV-positive.

CONCLUSIONS

The frequency and proportions of these three NADCs in Tanzania have increased over the past 11 years, as has the prevalence of HIV positivity amongst these NADC patients. The current and possibly increasing burden of NADCs in Tanzania and other low- and middle-income countries with high HIV rates should be a focus for future cancer prevention and control and HIV therapy programs.

Inferring the Effects of Honokiol on the Notch Signaling Pathway in SW480 Colon Cancer Cells

In a tumor cell, the development of acquired therapeutic resistance and the ability to survive in extracellular environments that differ from the primary site are the result of molecular adaptations in potentially highly plastic molecular networks. The accurate prediction of intracellular networks in a tumor remains a difficult problem in cancer informatics. In order to make truly rational patient-driven therapeutic decisions, it will be critical to develop methodologies that can accurately infer the molecular circuitry in the cells of a specific tumor. Despite enormous heterogeneity, cellular networks elicit deterministic digital-like responses. We discuss the use and limitations of methodologies that model molecular networks in cancer cells as a digital circuit. We also develop a network model of Notch signaling in colon cancer using a novel reverse engineering logic-based method and published western blot data to elucidate the interactions likely present in the circuits of the SW480 colon cancer cell line. Within this framework, we make predictions related to the role that honokiol may be playing as an anti-cancer drug.

Abstract 4977: Chronic mastitis in North Africa: Geographic overlap and a potential precursor comorbidity of inflammatory breast cancer

North African countries, such as Egypt and Morocco, have a high prevalence of non-infectious, chronic mastitis (up to 10% of patients presenting with breast problems) compared to less than 1% worldwide. This same geographic region also suffers from an unusually high prevalence of inflammatory breast cancer (IBC) - 10-15% of breast cancer cases - versus just 1-2% of cases in the U.S. IBC is a serious public health issue as it is the most lethal form of breast cancer because of the propensity for rapid onset of disseminated metastases, which are present in one-third of cases at diagnosis. It is our hypothesis that this geographic overlap is not coincidental, but that the high level of background chronic breast inflammation changes the mammary microenvironment making it more auspicious for the development of IBC. Here we report our work aimed at determining molecular and histologic criteria to classify mastitis into pathogenic groups in order to rationally guide treatment for this serious inflammatory illness, as well as study its possible role in the development of IBC.

We identified 44 cases of chronic mastitis of unknown etiology. Cases were defined as any female patient with histopathological diagnosis of chronic mastitis seen at the 5 study hospitals in Egypt and Morocco from 2008-2011. Exclusion criterion was previous diagnosis of malignancy. Biopsy slides were analyzed by a pathologist and stained for IgG4 and IgG. Out of the 44 cases of chronic mastitis using consensus guidelines and our molecular IgG4 profiling, we identified 10 as idiopathic granulomatous mastitis (IGM) and 17 as breast manifestations of IgG4-related disease. IGM is a rare non-neoplastic, chronic, often severe inflammatory lesion of the breast that mimics carcinoma clinically and radiologically. Treatment strategies include watchful waiting, immunosuppressive therapy, wide local or other excisions, or combinations of the above. IgG4-related disease is a newly recognized fibro-inflammatory condition. It is characterized by the formation of tumefactive lesions, a dense lymphoplasmacytic infiltrate with many IgG4-positive plasma cells, storiform fibrosis, obliterative phlebitis and, frequently, elevated serum IgG4 concentrations. While no randomized clinical trials have been conducted, glucocorticoid treatment is the standard first line therapy and appears to be quite effective in the majority of patients.

This series is the largest reported and is the first step toward changing the chronic breast inflammatory landscape in North Africa by classifying the chronic mastitis into pathogenic groups that can guide personalized treatment protocols. Further studies are needed to discern whether effective and timely treatment of these chronic inflammatory conditions may lower the incidence of IBC.

Citation Format: Steven G. Allen, Hanna Oltean, Kathy Toy, Omar S. Omar, Tamer Youssef, Mehdi Karkouri, Azza Abdel-Aziz, Ahmad Hablas, Ali Tahri, Celina Kleer, Amr Soliman, Sofia D. Merajver. Chronic mastitis in North Africa: Geographic overlap and a potential precursor comorbidity of inflammatory 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 4977. doi:10.1158/1538-7445.AM2014-4977

Factors related to incomplete treatment of breast cancer in Kumasi, Ghana

PURPOSE

The burden of cancer in Africa is an enlarging public health challenge. Breast cancer in Ghana is the second most common cancer among Ghanaian women and the proportion of diagnosed patients who complete prescribed treatment is estimated to be very limited, thereby potentially adding to lower survival and poor quality of life after diagnosis. The objective of this study was to identify the patient and system factors related to incomplete treatment of breast cancer among patients.

METHODS

This study was conducted at the Komfo Anokye Teaching Hospital in Kumasi, Ghana. We interviewed 117 breast cancer patients and next of kin of breast cancer patients diagnosed from 2008 to 2010.

RESULTS

Islamic religion, seeking treatment with traditional healers, and lack of awareness about national health insurance coverage of breast cancer treatment were predictors of incomplete treatment.

CONCLUSIONS

The results of this study support that Ghanaian women with diagnosed breast cancer have multiple addressable and modifiable patient factors that may deter them from completing the prescribed treatment. The results highlight the need for developing and testing specific interventions about the importance of completing treatment with a special focus on addressing religious, cultural, and system navigation barriers in developing countries.

Abstract 1179: Macrophage conditioned media increases the expression of a metastasis-associated oncogene, RhoC, and the migration of inflammatory breast cancer cells

Inflammatory breast cancer (IBC) is the most lethal form of breast cancer because it progresses rapidly and often presents with distant metastases at diagnosis. RhoC GTPases, known to play an important role in the movement of cells, are overexpressed in IBC tumor cells. The mechanism that causes this increase in RhoC expression is unknown. Tumor associated macrophages (TAMs) have been found to facilitate the movement and invasion of breast cancer. Therefore, as a component of the immune system attracted to sites of inflammation, we hypothesized that TAMs play a role in increasing RhoC expression in IBC cells, which consequently leads to IBC's severe migratory and metastatic capabilities.

The expression of RhoC increased in two different IBC cell lines, SUM149 and SUM190, in the presence of conditioned media (CM) from macrophage-differentiated U937 cells. This increase was not observed in either the normal-like MCF-10A cell line or the non-IBC MDA-MB-231 breast cancer cell line. From this observation, a novel microfluidic device allowed the study of the migratory phenotype of individual cells of the two IBC cell lines in response to standard chemoattractants as well as the macrophage CM. As expected, the presence of a serum gradient promoted the chemotaxis of IBC cells versus serum-free control. A CM gradient also increased the migration of IBC cells to a moderate degree. However, in the overlapping presence of CM without a gradient and serum with a gradient, the cells exhibiting an extreme migratory phenotype migrated roughly twice the distance of the serum gradient control. We believe the CM acts to “prime” the IBC cells in order to manifest an ultra-response to the serum chemoattractant. In both IBC cell lines stably-transfected with shRNA targeted to RhoC, we observed decreased migration when exposed to the CM migration conditions. Therefore, RhoC expression is necessary for this increase in migration.

Studies involving RhoC inhibitors are ongoing, but could yield promising therapies for the prevention of metastasis of IBC. Future studies will aim to identify which cytokines in the CM and which specific pathways are responsible for the increased RhoC expression and migration of IBC cells. By understanding the specific mechanism of TAMs' effects on IBC cells we hope to learn better how to control the lethal metastatic nature of inflammatory breast cancer.

Citation Format: Chelsea L. Fournier, Steven G. Allen, Yu-Chih Chen, Euisik Yoon, Sofia D. Merajver. Macrophage conditioned media increases the expression of a metastasis-associated oncogene, RhoC, and the migration of inflammatory breast cancer cells. [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 1179. doi:10.1158/1538-7445.AM2014-1179

Inflammatory breast cancer in north Africa: comparison of clinical and molecular epidemiologic characteristics of patients from Egypt, Tunisia, and Morocco

Understanding molecular characteristics that distinguish inflammatory breast cancer (IBC) from non-IBC is crucial for elucidating breast cancer etiology and management. We included 3 sets of patients from Egypt (48 IBC and 64 non-IBC), Tunisia (24 IBC and 40 non-IBC), and Morocco (42 IBC and 41 non-IBC). Egyptian IBC patients had the highest combined erythema, edema, peau d'orange, and metastasis among the 3 IBC groups. Egyptian IBC tumors had the highest RhoC expression than Tunisians and Moroccan IBCs (87% vs. 50%, vs. 38.1, for the 3 countries, respectively). Tumor emboli were more frequent in Egyptian IBC than non-IBC (Mean ± SD: 14.1 ± 14.0 vs. 7.0 ± 12.9, respectively) (P < 0.001) and Tunisians (Mean ± SD: 3.4 ± 2.5 vs. 1.9 ± 2.0, respectively) (P < 0.01). There was no difference of emboli in Moroccan tumors (1.7 ± 1.2 vs. 1.8 ± 1.2 for IBC and non-IBC, respectively (P=0.66). This study illustrates that RhoC overexpression and tumor emboli are more frequent in IBC relative to non-IBC from Egypt and Tunisia. Tumors of Moroccans were significantly different from Egyptian and Tunisian tumors for RhoC expression and emboli. Future studies should focus on relating epidemiologic factors and clinical pictures to molecular features of IBC in these and other populations.