bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P4-14-04: Total skin-sparing mastectomy in BRCA mutation carriers
Authors: Warren Peled A , Hwang ES , Ewing CA , Alvarado M , Esserman LJ
Published: August 2014

BACKGROUND: Total skin-sparing mastectomy (TSSM) with preservation of the nipple-areolar complex skin has become increasingly accepted as an oncologically safe procedure for both prophylactic and therapeutic indications. The goal of this study was to evaluate the oncologic outcomes after TSSM in BRCA mutation carriers.

METHODS: We identified 53 BRCA-positive patients who underwent bilateral TSSM for prophylactic (27 patients) or therapeutic (26 patients) indications from 2001 to 2011. Cases were age-matched (for prophylactic cases) or age- and stage-matched (for therapeutic cases) with non-BRCA-positive patients who underwent bilateral TSSM during this time period. Outcomes included tumor involvement of the resected nipple tissue, the development of new breast cancers in patients who underwent bilateral risk-reducing TSSM, and the development of any local-regional recurrence in patients who underwent therapeutic TSSM.

RESULTS: Outcomes from 212 TSSM procedures in 53 cases and 53 controls were analyzed. In patients undergoing TSSM for prophylactic indications, in situ cancer was found in 1 (1.9%) of the nipple specimens in the BRCA-positive patients vs. 2 specimens (3.7%) in the non-BRCA-positive cohort (p = 1). At a mean follow-up of 56 months, no new cancers developed in the BRCA-positive or the non-BRCA-positive cohorts. In patients undergoing TSSM for therapeutic indications, in situ or invasive cancer was found in 0 of the nipple specimens in the BRCA-positive patients vs. 2 specimens (3.9%) in the non-BRCA-positive cohort (p = 0.49). At a mean follow-up of 33 months, there were no local-regional recurrences in the BRCA-positive cohort.

CONCLUSIONS: TSSM is an oncologically safe procedure in BRCA-positive patients, as is evidenced by the low rates of tumor involvement of the nipple tissue and local-regional recurrence after therapeutic mastectomy. In BRCA-positive patients undergoing TSSM as a risk-reducing strategy, five-year follow-up demonstrates no increased risk for the development of new breast cancers; longer-term follow-up is anticipated to further confirm its safety.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-14-04.
Abstract P4-14-11: Risk reducing mastectomy for women with high personal breast cancer risk
Authors: Onyekwelu O , Shetty G , Baildam A
Published: August 2014

Introduction: For high-risk familial history of breast cancer, risk reducing mastectomy (RRM) is now regarded as one of the management options. The aim of this study is to analyse the outcome of women undergoing RRM from 1994 to 2010 during which surgical techniques evolved and were refined.

Methods: A cohort of women undergoing RRM was followed from this single centre. Surgical and further details about demographics, comorbidities, and follow-up were retrieved form medical records. Analysis was carried out using the IBM®-SPSS®-Statistics-19system.

Results: Of 154 women 139 had bilateral RRM and 15 had unilateral surgery after earlier contralateral breast cancer. Median age at operation was 39.4 years (22–63years). 54 (45.5%) women were BRCA1/2 gene mutation carriers. Most women had nipple sacrificing (86) skin-sparing mastectomy with immediate reconstruction. 132 (85.7%) had submuscular expander/implant reconstruction, whilst 9 had either LD flap reconstruction or TRAM flap reconstruction.

31 (20.1%) women had some complication including haematoma requiring evacuation, minor skin/nipple necrosis, but implant loss was rare (2). 52 (33.8%) women had revisional surgeries in 5 years post RRM of whom 29 had one unanticipated secondary operation. Complications were more common in the early years of the cohort.

On histology, 3 women were identified with lobular carcinoma in-situ and one was associated with 1mm of microinvasion. 4 had ductal carcinoma in-situ and 2 of them were BRCA carriers. Two (1.2%) primary breast cancers were subsequently identified during a mean follow-up period of 9.82 years (2–18 years) but this was substantially less than prediction modelling. Both were BRCA gene mutation carriers - one had nipple sparing RRM and the other did not.

Conclusions: In asymptomatic high-risk women, RRM is safe and efficacious in reducing medium term future breast cancer incidence. Surgery carries the risk of complications and cosmetic revisions can be anticipated.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-14-11.
Abstract P4-16-05: Benefit from Postoperative Radiotherapy for N1 Breast Cancer
Authors: Tsai Y-CS , Cheng H-CS , Yu B-L , Horng C-F , Chen C-M , Jian J-MJ , Chu N-M , Tsou M-H , Liu M-C , Huang AT
Published: August 2014

Purpose: To evaluate the outcomes for patients with Stage II breast cancer and one to three positive lymph nodes after mastectomy who were treated with observation or adjuvant radiotherapy to the chest wall (CW) and regional lymphatics; and to identify a group of patients who benefit from postmastectomy radiotherapy (PMRT).

Methods and Materials: The subjects were 716 patients diagnosed between 1990 and 2007 with Stage II breast cancer (one to three positive lymph nodes) treated with mastectomy at the Koo Foundation Sun Yat-Sen Cancer Center. 283 patients had undergone PMRT to the CW and regional lymphatics according to in-house treatment guideline or physician decision. Since 2003, we recommend PMRT for patients who had 2 or more risk factors; age less than 40 y/o, T2 disease, GrII/GrIII, prominent lymphovascular invasion (LVI), presence of extracapsular spreading (ECS), and negative Estrogen Receptor (ER(−)). Survival was analyzed by the Kaplan—Meier method. The survival free of isolated locoregional disease(LRR), metastasis free survival(MFS), disease free survival(DFS), and overall survival(OS) were analyzed according to the delivery of radiotherapy or not.

Results: The median follow-up was 80 months. LRR, MFS, DFS and OS were significantly improved by PMRT. The 5- and 10-year LRR rate without PMRT was 89.9% and 81.6%, respectively and, with PMRT was 97.7% and 97.0% respectively (p <0.0001). The 5- and 10-year MFS rate without PMRT was 84.4% and 76.5%, respectively, and, with PMRT, was 90.8% and 87.2% respectively (p = 0.0153). The 5- and 10-year DFS rate without PMRT was 80.8% and 69.8%, respectively, and, with PMRT, was 89.6% and 86.1% respectively (p = 0.001). The 5- and 10-year OS rate without PMRT was 89.1% and 77.3%, respectively, and, with PMRT, was 94.6% and 86.2% respectively (p = 0.0039). 239 patients had less than 2 risk factors, their LRR, MFS and DFS did not benefit from PMRT.

Conclusion: Our data suggest that adjuvant PMRT improve LRR, MFS, DFS and OS for stage II breast cancer with one to three positive lymph nodes who had 2 or more risk factors (Age less than 40 y/o, T2, GrII/GrIII, LVI, ECS, ER(−)).

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-16-05.
Abstract P4-16-07: Selective use of post-mastectomy radiation therapy in the neoadjuvant setting
Authors: Warren Peled A , Wang F , Stover AC , Rugo HS , Melisko ME , Park JW , Alvarado M , Ewing CA , Esserman LJ , Fowble B , Hwang ES
Published: August 2014

Background: Neoadjuvant chemotherapy, once reserved for locally advanced breast cancer, has become more common in Stage II disease. While one of its proven benefits is an increase in the frequency of breast conserving surgery, many women will undergo mastectomy despite an excellent clinical response. Indications for post-mastectomy radiation (PMRT) following neoadjuvant therapy are not well defined. Some studies have suggested that certain subgroups of women (young age, triple negative disease) with negative nodes or 1–3 positive nodes after chemotherapy have a significant risk of local-regional failure without PMRT. We conducted a single-institution retrospective study of women undergoing neoadjuvant chemotherapy and mastectomy without PMRT to assess clinical outcomes among this cohort.

Methods: 101 women with initial stage I-III disease (20% stage I, 72% stage II, 8% stage III) received neoadjuvant chemotherapy (doxorubicin-based +/− taxane) followed by mastectomy without PMRT between 2005 and 2011. Mean age was 49 years (range 22–81 years). 16% were BRCA+. 66 patients (65%) had clinically negative axillary nodes at presentation, 34% had N1 disease and 1% had N2 disease. Subtype by IHC was 61% luminal A, 11% luminal B (ER+, Her2+), 20% triple negative and 8% ER−, Her2+. At the time of surgery, 81% were node negative and 19% had 1–3 positive nodes. Pathologic complete response (pCR) (breast + axilla) occurred in 28%. Median follow-up was 34 months (range 5.5–84.5 months).

Results: There were 2 (2%) local-regional failures (1 axillary recurrence at 52 months after mastectomy and 1 chest wall recurrence at 10 months). Both of these recurrences were in patients with negative nodes and luminal A tumors; patients had 2.2 and 2.5 cm of residual invasive cancer, respectively, and negative margins at mastectomy. There were no local-regional failures in women with triple negative cancers, those with 1–3 positive nodes, or patients younger than 40. Additionally, there were no failures in women with a pCR, including those with initial stage IIIA-B disease.

Conclusions: Among carefully selected patients fulfilling low risk criteria for local-regional recurrence, PMRT following neoadjuvant chemotherapy may be omitted without compromising local-regional control.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-16-07.
Abstract P4-17-08: Tissue Expander/Implant Breast Reconstruction with and without Postmastectomy Radiation: Predictive Factors for Complications
Authors: Nguyen SKA , Oxley P , Rastegar R , Joffres M , Kwan W
Published: August 2014

Purpose: 1) Review our complication rates with implant/expander reconstruction for breast cancer 2) Determine factors for complications, especially with postmastectomy radiation (PMRT)

Materials and Methods: Data were collected through chart review of all patients (2004–2008) from an academic hospital undergoing implant/expander reconstruction. SAS was used for two or multi-variable analyses (logistic regression) to determine predictive factors for complications. Among PMRT patients, we evaluated complications rates by risk factors.

Results: 237 patients underwent implant/expander reconstruction. Median time from implant placement until last follow-up was 173 days. 21.5% developed major complications (needing operative time or infection needing intravenous treatment). Diabetes was the most consistent factor associated with major complications (46.7 vs 20.1%, p = 0.02 and p = 0.009 in multivariable analysis). Radiation was linked to capsular contractures (18.6 vs 10.1%, p = 0.02). Chemotherapy (25.0 vs 19.0%, p = 0.26) or radiation (26.3 vs 19.1%, p = 0.21) did not predict major complications. Among patients receiving PMRT (80 patients), 26.2% had major complications, 34 had immediate PMRT on the expander and 44 had PMRT to the chest wall, followed by delayed reconstruction with expander/implant placement. In these, delayed reconstruction increased dehiscence (0 vs 18.2%, p = 0.009) compared to immediate reconstruction, with a trend for higher incidence of major complications in the delayed reconstruction group (14.7 vs 34.1%, p = 0.05). 40 Gy/16 versus 50–50.4 Gy/25-28 (28 vs 24%, p = 0.78) was not associated with major complications. Diabetes and smoking were associated with several complications.

Conclusions: Diabetes is associated with a higher rate of major complications after expander/implant reconstruction while radiation increases capsular contractures. If PMRT is indicated, putting in an expander before radiation results in less morbidity than delayed reconstruction. Also, 40 Gy/16 versus 50–50.4 Gy/25-28 do not differ much in terms of complication rates.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-17-08.
Abstract P5-01-15: Anti-ER monoclonal antibody SP1 seems more sensitive in the identification of ER alpha positive breast cancer cases than anti-ER monoclonal antibody 1D5
Authors: Madeira KP , Daltoé RD , Sirtoli GM , Rezende LCD , Carvalho AA , Silva IV , Rangel LBA
Published: August 2014

Background: Accurate pathological analysis of biopsies is crucial for conclusive and precise disease diagnosis, prognosis and therapeutic guidelines. Evaluation of estrogen receptor (ER) expression in breast cancer (BC) is imperative in determining the disease prognosis, and patients' eligibility for hormonotherapy. Herein, ER alpha status was evaluated in 61 BC cases using two different anti-ER alpha monoclonal antibodies, SP1 (rabbit) and 1D5 (mouse).

Methods: Primary BC cases registered in two reference hospitals, with correspondent written informed consent, were used to generate in house tissue microarray platforms. ER alpha expression was accessed by immunohistochemistry using the monoclonal antibodies anti-ER alpha, SP1 and 1D5. Staining scoring followed the Allred method (PS, proportion score or percentage of stained cells; IS, intensity score). Concordance and correlation parameters were calculated using Kappa factor; Pearson, Spearman's, or intraclass correlation coefficient (CF). Staining patterns were compared by paired T-Test and Wilcoxon test.

Findings: SP1 and 1D5 provided equivalent results (Concordance rate, 96.7%; Kappa factor, 0.921), whereas SP1 was more prone for positive results than 1D5 (2 samples diverged). Total concordance of PS was obtained (Pearson and intraclass CF, 0.7351 and 0.6193, respectively); however, concordance between the antibodies seems more accurate in higher PS values. Excellent SI correlation between antibodies was observed throughout the population (Spearman's CF, ρ=0.9150). Following the Allred score, 17 out of 42 positive BC samples diverged; always pointing 1D5 to weaker staining than SP1. When calculating Spearman's CF of Total Score (TS) within the population, excellent correlation between both the antibodies (ρ=0.9238) was noted; nonetheless, results were less concordant result among the BC positive cases (ρ=0.7743). Indeed, 20 samples were differentially classified using the antibodies (only 3 had higher TS with 1D5). Considering the mean TS of all samples, or of invasive ductal carcinoma, SP1 provided higher scores than 1D5 (p < 0.05).

Interpretation: Despite the equivalence between the anti-ER alpha monoclonal antibodies, SP1 and 1D5, the former has proven superior to the latter with respect to the IS and TS. Therefore, we suggest the clinical use of SP1 while diagnosing BC, due to its higher accuracy in examining ER status; thus, enabling more accurate therapeutic decisions to treat the disease.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-01-15.
Abstract P5-03-03: Antitumor Activity and Cancer Stem Cells Effect of Cetuximab in Combination with Ixabepilone in Triple Negative Breast Cancers (TNBC)
Authors: Tanei T , Rodriguez AA , Dobrolecki L , Choi DS , Landis M , Chang JC
Published: August 2014

Purpose: The ErbB family, including EGFR, has been demonstrated to play key roles in metastasis, tumorigenesis, cell proliferation, and drug resistance. Recently, these characteristics have been linked to a small subpopulation of cells classified as cancer stem cells (CSCs) which are believed to be responsible for tumor initiation and maintenance. Ixabepilone is the microtubule-stabilizing agent has been expected to be more sensitive than the conventional taxanes. The aim of this study was to investigate whether the EGFR monoclonocal antibody cetuximab, in combination with ixabepilone is a more effective treatment, and kill cancer stem cells more effectively as compared to chemotherapy alone in TNBC.

Experimental Design and Results: Breast CSC populations were evaluated with FACS analysis (CD44+ and CD24−/low, or Aldefluor+) and mammosphere formation efficiency (MSFE). In vitro, we demonstrated that in triple negative cell lines (MDA-MB-231 and SUM159), cancer stem cell populations were decreased after treatment of cetuximab, or cetuximab plus ixabepilone. In vivo, cetuximab in combination with ixabepilone treatment caused significant tumor regression (cetuximab vs. cetuximab+ ixabepilone; tumor volume fold change P <0.05 (MDA-MB-231), P <0.0001 (SUM159) in triple negative breast cancer xenografts. Thus, cetuximab decreased CSC population in xenograft tumors. Decrease in autophagy (LC3b, p62 and autophagosomes) were seen in cetuximab-treated tumors.

Conclusions: These studies demonstrate that cetuximab in combination with ixabepilone is more effective than chemotherapy alone in TNBC by affecting CSCs, as well as bulk tumor. These data support a neoadjuvant phase II study comparing ixabepilone vs. ixabepilone +cetuximab in TNBC patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-03-03.
Abstract P5-04-05: E-Cadherin is Required for In Vivo Growth of Inflammatory Breast Cancer: Importance of Mesenchymal-Epithelial Transition (MET) and Role of HIF1α
Authors: Chu K , Boley KM , Cristofanilli M , Robertson FM
Published: August 2014

Background: Inflammatory breast cancer (IBC) is the most aggressive and deadly form of breast cancer and is phenotypically distinct from other forms of locally advanced breast cancer. The 5-year survival for IBC patients (40%) has not improved even with the implementation of multi-disciplinary care and targeted therapies (e.g. anti-HER2 or anti-estrogen therapies). Lymph node involvement is common at first diagnosis and the accelerated metastasis program that characterizes IBC account for a disproportionate number of the 40,000 women who will die from breast cancer. The most common molecular marker for IBC is the cell adhesion surface glycoprotein, E-Cadherin. Classically, E-Cadherin is thought to be a tumor suppressor and its loss is associated with the epithelial-mesenchymal transition (EMT) and acquisition of an invasive phenotype. The importance of EMT in metastasis is well accepted in numerous tumor models although the presence of EMT in patient samples is rarely demonstrated. Given the propensity of IBC to metastasize, one would expect a strong EMT signature in IBC cell lines, however the persistent robust expression of E-Cadherin in IBC patient tumors and in IBC cell lines, with a lack of expression of ZEB1, a transcriptional repressor of E-cadherin and diminished expression of genes within the transforming growth factor beta signaling pathway, suggests otherwise.

Methods: To further define the role of E-Cadherin in IBC, we used the SUM149 IBC cell line to manipulate E-Cadherin via shRNA knockdown and by overexpression of ZEB1 a known transcriptional repressor of E-cadherin.

Results: While the lack of E-Cadherin or ZEB1 overexpression in SUM149 cells led to an EMT phenotype in vitro, E-Cadherin was required for in vivo growth of SUM149 tumor cells. Gene profiling identified novel E-Cadherin signaling pathways including an hypoxia gene signature through HIF1a as well as cytokine responsive pathways. The requirement of HIF-1a for in vivo growth of SUM149 cells was confirmed by shRNA knockdown of HIF-1a.

Conclusions: The absolute requirement for E-Cadherin and maintenance of the mesenchymal-epithelial transition in IBC tumor growth is demonstrated. Furthermore, a novel functional link between E-Cadherin and HIF-1a and in their critical role in survival of IBC tumors is identified for the first time and warrants further investigation.

Supported in part by The Susan G Komen Organization Promise Grant KG081287 (FMR and MC)

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-04-05.
Abstract P5-04-07: Epithelial-mesenchymal transition phenotype in breast cancers is associated with clinicopathologic factors indicating aggressive biologic behavior and poor clinical outcome
Authors: Bae YK , Kim A , Choi JE , Kang SH , Lee SJ
Published: August 2014

Epithelial-mesenchymal transition (EMT) is defined by the loss of epithelial characteristics and the acquisition of a mesenchymal phenotype. EMT in epithelial tumors is a reversible process and expected to be involved in invasion, metastasis and chemoresistance of cancer cells. EMT-inducing factors down-regulate E-cadherin and up-regulate extracellular matrix proteins such as fibronectin. Cancer tissue may display a wide spectrum of expression phenotypes of EMT-related proteins. However, little is known about the clinical significance of the different EMT phenotypes in breast cancers. We investigated expression pattern of EMT-related proteins, E-cadherin and fibronectin in 1,498 invasive breast carcinomas by using immunohistochemistry on tissue microarrays. EMT phenotypes were divided into complete type (E-cadherin-negative and fibronectin-positive); incomplete type, including hybrid (E-cadherin-positive and fibronectin-positive) and null (E-cadherin-negative and fibronectin-negative) types; and a wild type (E-cadherin-positive and fibronectin-negative). We correlated EMT phenotype with clinicopathologic characteristics and patients survival. Loss of E-cadherin was observed in 140 (9.3%) cases and fibronectin was expressed in cancer cells of 320 (21.4%) cases. Twenty three (1.5%) cases were categorized as complete type, 414 (27.6%) as incomplete type (hybrid type, 297; null type, 117), and 1,061 (70.8%) as wild type. Complete EMT phenotype was significantly associated with advanced pT stage, lymph node metastasis, high histological grade, and triple negativity (p < 0.001). Overall survival and disease-free survival rates were significantly worse in the complete type, better in the incomplete type and best in the wild type (p = 0.002 and p < 0.001, respectively). In multivariate Cox proportional hazard model analysis, the complete EMT phenotype was not an independent prognostic factor for both overall and disease-free survival. In conclusion, breast cancer patients with EMT phenotype showed less favorable outcomes than those with wild type as it was strongly associated with clinicopathologic factors indicating aggressive biologic behavior.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-04-07.
Abstract P5-06-01: Active pak6 induces aneuploidy in breast cancer cells.
Authors: Paul BA , Lu ML
Published: August 2014

The natural history of breast cancer remains largely undefined. More than 50% of clinical specimens exhibit aneuploidy. Among these aneuploid cancers, nearly half have chromosome copy numbers approaching tetraploid. The high incidence of aneuploidy in advanced breast cancer is thought to be a byproduct of chromosome mis-segregation resulting from mutations in tumor suppressor genes regulating cell cycle checkpoints and corresponding to disease progression. However, recent large-scale sequencing projects have revealed that most tumors contain approximately 14–20 different mutant genes, suggesting heterogeneity exists throughout the genomes of cancer cells. This notion revives the concept that aneuploidy resulting from chromosome mis-segregation or other similar mechanisms may play an active role leading to transformation and disease progression.

A novel p21-activated kinase 6 (PAK6) was recently identified to be an androgen receptor (AR) and estrogen receptor (ER) interacting protein. An estrogen-stimulated PAK6 activation was observed in BT474 breast cancer cells. This activation is mediated by estrogen-stimulated activation of PKA. At the cellular level, active PAK6 promotes transformation to metastatic phenotypes in MCF7 breast cancer cells as evidenced by increases in cell motility, matrigel invasion, and soft agar growth. Further characterization of MCF7 cells expressing a constitutively active PAK6 mutant revealed an accumulation of cells with higher ploidy as compared to that of parental cells. Using a proteomic approach to determine the PAK6 downstream target, we identified that Cdt1, a DNA pre-replicative complex subunit, is overexpressed in response to PAK6 activation. In eukaryotes, the expression and stability of Cdt1 are strictly regulated to ensure only one round of DNA replication in each cell cycle. Deregulated overexpression of Cdt1 has previously been demonstrated to induce aneuploidy and malignant transformation due to re-initiation of DNA replication within the same S-phase. The identification of Cdt1 overexpression in response to PAK6 activation provides a plausible mechanism for the observed accumulation of higher ploidy cells in MCF7 cells expressing active PAK6. Taken together these findings suggest a direct link between hormonal signals, DNA replication, and maintenance of genomic integrity.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-06-01.
Abstract P5-07-01: Defining the mechanism of breast cancer growth by chemokine receptor CXCR7 and Epidermal Growth Factor Receptor coupling interaction.
Authors: Salazar N , Muñoz D , Singh RK , Lokeshwar BL
Published: August 2014

Introduction: Breast cancer (BrCa) ranks second in both incidence and cancer deaths for women in the USA. Recent advances have revealed a significant contribution of chemokines and their receptors in tumor growth, survival after chemotherapy, and organ-specific metastasis. CXCR7 is the latest CXC-chemokine receptor implicated in BrCa growth. It is endogenously over expressed in BrCa, but its mechanism of tumor growth enhancement is still not clearly defined. CXCR7 heterodimerizes with CXCR4 and binds to SDF-1 (CXCL12) and CXCL11. No direct ligand mediated physiological action has been implicated for CXCR7 in BrCa other than facilitating CXCR4-mediated cell motility, however, studies in other cancers have implicated CXCR7 in cell proliferation, anti-apoptotic activity and cell-cell adhesion. The expression pattern of CXCR7 in BrCa tissues and its potential contribution in BrCa cell proliferation and survival were investigated in representative BrCa cell lines using knock down and knock-in experiments.

Results: CXCR7 was only expressed in ER-α positive BrCa cells (e.g., MCF-7) and was not found in BrCa cells with known metastatic potential (MDA-MB231 and SKBr3). Depletion of CXCR7 in MCF-7 BrCa cells by both siRNA and shRNA decreased cell proliferation and caused cell cycle arrest. Since CXCR7 is an atypical G-protein coupled receptor where ligand activation does not elicit conventional intracellular signaling, we hypothesized that CXCR7 regulates BrCa proliferation through interaction with EGFR or activating other potential targets of MAP-kinase activation. CXCR7 depletion reduced site-specific phosphorylation of EGFR at Tyrosine 1110 after EGF-stimulation. CXCR7 depletion also reduced phosphorylation of ERK-1/2, indicating a potentially direct interaction with mitogenic signaling in MCF-7 cells. We tested for direct interaction of CXCR7 with EGFR by co-immunoprecipitation and immunofluorescence studies. We found EGFR and CXCR7 co-immunoprecipitate and co-localize as demonstrated by confocal microscopy. Interestingly, our results also demonstrate CXCR7 and EGFR are co-localized before EGF stimulation. Further corroboration of CXCR7-EGFR interaction was established using the proximity ligation assay (PLA) technique that allowed us to visualize CXCR7-EGFR co-localization both in cell culture and in human normal and breast cancer tissue.

Conclusion: This data demonstrates an important role for CXCR7 in BrCa growth and explores the mechanism of action of direct coupling of EGFR with CXCR7.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-07-01.
Abstract P5-07-04: Aurora kinase regulates PKC-mediated MMP-9 expression and invasion in MCF-7 breast cancer cells
Authors: Kim JS , Noh EM , Lee YR , Hwang B-M , Jung SH , Youn HJ , Lee SJ
Published: August 2014

Aurora kinase is a novel family of serine/threonine kinases. Elevated expression of aurora kinase A and B is observed in many tumor cells, and dysregulation of aurora kinase has been linked to tumorigenesis. Therefore, a number of studies focused in their oncogene activities as anti-tumor targets. Matrix metalloproteinase-9 (MMP-9), which degrades the extracellular matrix (ECM) and it is important process for breast cancer cell invasion. MMP-9 can be stimulated by activation of various cellular signaling pathways including protein kinase C (PKC), and mitogen-activated protein kinase (MAPKs), activator protein-1 (AP-1) and nuclear factor-kappaB (NF-κB) signaling pathways. Here, we show that 12-O-tetradecanoylphorbol-13-acetate (TPA), a directly PKC activator stimulation resulted in an up-regulation and phosphorlyation of aurora kinases in MCF-7 breast cancer cells. Also, Results showed that inhibition of the aurora kinases suppressed TPA-induced MMP-9 secretion/expression and cell invasion through suppression of NF-κB, AP-1, and MAPKs in MCF-7 breast cancer cell. In conclusion, this study provides new insight into the novel role of aurora kinase for expression of MMP-9 by TPA and regulation of aurora kinase by TPA through MAPKs signaling pathway.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-07-04.
Abstract P5-10-04: Metformin mediated upregulation of microRNA-193 triggers apoptosis by decreasing fatty acid synthase
Authors: Cochrane DR , Wahdan-Alaswad RS , Edgerton SM , Terrell KL , Spoelstra NS , Thor AD , Anderson SM , Richer JK
Published: August 2014

Background: We have previously shown that the anti-diabetic drug metformin kills triple negative (TN) breast cancer cells lines via apoptosis, at lower IC50 than luminal and HER2 subtypes (presented at ENDO, manuscript in preparation). Metformin reportedly shows greater efficacy against stem cells than differentiated cells, reducing mammosphere formation in in non-adherent culture. Fatty acid synthase (FASN) is an enzyme critical for de novo fatty acid synthesis that is overexpressed in breast cancer.

Hypothesis: We hypothesized that miRNAs might be involved in the ability of metformin to preferentially kill TN cell lines at a lower IC50 than luminal A lines.

Methods: TN and luminal A (LA) breast cancer cell lines (MDA-468, HCC70 and MCF7, T47D, respectively) were used to study the effects of 10mM metformin action in vitro, at physiological and hyperglycemic culture conditions. Affymetrix chips Human Gene 1.1 and the miRNA 2.0 were utilized to profile gene and miRNA expression at 6 and 24 hrs. Mimics and lentiviral expression vectors were utilized to manipulate miRNA expression and a luciferase reporter was used to confirm miR-193 direct targeting of the FASN 3′ UTR.

Results: miR-193 is significantly higher in untreated LA as compared to TN cells. MiR-193 increases 2–4 fold within 6 hrs of metformin treatment in both TN, but not LA cell lines. A predicted target of miR-193, fatty acid synthase (FASN), is decreased by 8 fold following 24 hrs 10mM metformin treatment of the TN breast cancer cells. miR-193 directly targets FASN via a binding site in the 3′ UTR, downregulating gene expression. Restoration of miR-193 to TN lines, causes a dramatic decrease in FASN protein in a dose dependent fashion.

Conclusions and future directions: Metformin stimulates an increase in mature miR-193, which mediates the dramatic downregulation of FASN. This occurs coincident with apoptotic cell death. It remains to be determined if FASN is the only relevant direct target of miR-193 in TN cell lines. The addition of exogenous non-targetable FASN, lacking its 3′ UTR, will demonstrate whether this pathway is a primary mechanism of metformin action in TN cells. Future studies will investigate the ability of metformin to inhibit FASN in non-adherent mammosphere (stem cell-like) subpopulations, the role of fatty acid metabolism in mammosphere maintenance and anoikis resistance.

Supported by Komen Breast Cancer Foundation Grants KG100575 (ADT, JKR, SME, NSS) and KG090415 (JKR, DRC)

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-10-04.
Abstract P5-10-14: MicroRNAs as biomarkers and therapeutic adjuvants for the prognosis and treatment of drug-resistant breast cancers
Authors: Chang Y-F , Panneerdoss S , Zoghi B , Pertsemlidis A , Rao M
Published: August 2014

Intrinsic and acquired resistance to antineoplastic agents continues to be a major clinical impediment to successful treatment of cancer in general, and breast cancer in particular. For example, about 40% of ER-positive breast tumors fail to respond to tamoxifen therapy, and of those that initially respond many will eventually develop resistance. Similarly, taxanes used as a first-line chemotherapy agent will have a response rate of 50%, which comes down to 20–30% in second- or third-line chemotherapy; nearly half of the treated subjects do not respond to it and suffer side effects. These facts underscore the importance of understanding the mechanism of resistance, which is crucial for better management of breast cancer. Unfortunately, in spite of extensive inquiry in this field, little is known about the key molecules/signaling pathways that regulate this phenomenon. Recently, we have discovered that small non-coding RNAs, i.e. microRNA (miRNAs), may play a critical role in mediating drug resistance in breast cancers. We have identified miRNAs that are differentially expressed between chemoresistant and sensitive breast cancer cells. Specifically, we have combined a high-throughput screening platform with a library of chemically synthesized inhibitors for all known human miRNAs and identified specific miRNA that selectively sensitize/de-sensitize drug-resistant breast cancer cells to either tamoxifen or trastuzumab (herceptin), drugs that are commonly used as a first line treatment for ER-positive and Her2-positive breast cancers, respectively. Interestingly, we identified 10 and 12 miRNA inhibitors that sensitized resistant cells to tamoxifen and trastuzumab, respectively. Interestingly, expression of cognate miRNA/s that sensitize resistant tumors to drug-induced cell death in our screen was found to be lower in relapsed (drug resistant) metastatic breast cancer patients compared to normal matched control. In addition to tumor tissues, the levels of sensitizer miRNA/s in the blood sera of relapsed metastatic breast cancer patients was found to be dramatically lower than that of normal healthy individual. These findings are significant as it suggests that miRNAs can be efficiently detected in blood serum and therefore, can be used as a potential biomarker for predicting treatment outcomes. In addition, miRNAs may provide novel therapeutic tools for the treatment of drug-resistant breast cancers.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-10-14.
Abstract P5-13-02: Decision making from multidisciplinary team meetings to bedside: factors predicting for physicians' and breast cancer patients' acceptance of clinical trials proposed by MTMs
Authors: Deneuve J , Mazouni C , Arnedos M , Prenois F , Saghatchian M , André F , Bourrgier C , Delaloge S
Published: August 2014

Background: In University hospitals or Comprehensive Cancer Centers (CCC), breast cancer (BC) patients have a theoretically large access to clinical trials as part of the management and treatment of their localized or advanced disease. Though, most patients are not proposed inclusion into suitable trials or studies or do not accept them. We aimed at determining the factors that influence physicians and patient's choice to respectively propose or enter clinical trials for which the patients were considered eligible by MTM.

Methods: Patients who were considered eligible for a clinical trial by a BC-specific multidisciplinary team meeting (MTM) assessing their cases were prospectively registered during a 6 months period. The complete files of these patients were prospectively registered following initial written proposal by the MTM. The 27 clinical trials proposed were classified in 5 categories: cognitive studies, imaging, radiation therapy, diagnostic/prognostic biology, or interventional therapeutic studies. Detailed analysis of factors predicting physician's proposal and patient's final inclusion was conducted. Candidate factors were age, socio-demographic characteristics, PS, type of clinician, time intervals, stage of disease, type of disease, type of study, single vs multiple study proposal.

Results: MTM proposed 547 inclusions into clinical trials for 397 patients between March 3rd and Sept 21st, 2011. 267 pts were considered eligible for 1 trial, 100 for 2, 25 for 3, 4 for 4 and 1 for 5 trials; 211 for cognitive studies, 13 for imaging, 71 for radiation therapy, 136 for diagnostic/prognostic biology, 116 for interventional therapeutic studies. Upon referral physician's visit, the trial was only proposed in 39.3% and pts were finally included in 29.1% of the cases. Reasons for non inclusion were patients' refusal in only 5–11%, but absence of proposal by physician in 45–81%, according to the types of studies. The only factor predicting both proposal by the referral physician's and final inclusion into trials was type of study (both p < 0.001). Diagnostic/prognostic biology trials were proposed in 71%, while interventional therapeutic and cognitive studies were only respectively proposed in 35 and 19% of the cases. The factors predicting non-inclusion upon physicians' proposal were professional status (p = 0.03) and type of study (p = 0.0007). The highest inclusion rates were among retired pts and those with executive work (84 and 76% respectively).

Conclusion: The main reason for non inclusion into clinical trials remains absence of physicians' proposal, while professional status and type of study influence both the physicians' and the patients' decision. Educative measures dedicated mostly to treating physicians might be proposed.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-13-02.
Abstract P5-14-06: Analysis of test-therapy concordance for biomarkers uPA and PAI-1 in primary breast cancer in clinical hospital routine: Results of a prospective multi-center study at Certified Breast Cancers in Germany
Authors: Jacobs VR , Augustin D , Wischnik A , Kiechle M , Hoess C , Steinkohl O , Rack B , Kapitza T , Krase P
Published: August 2014

Objective: Biomarkers uPA and PAI-1 are guideline recommended by ASCO, USA, and AGO, Germany, to be used in primary breast cancer to avoid unnecessary CTX in medium risk recurrence patients [G2, N−, HR+, Her2neu−, >35 years]. For quality assurance of uPA/PAI-1 testing an analysis of test-therapy concordance was performed.

Methods: Prospective, non-interventional, multi-center study over two years among six Certified Breast Centers in Germany to analyze application of uPA/PAI-1 and use of the result in consecutive decision making in Tumor Board decision and actual therapy in the clinical setting for AOK Bayern-insured patients. Concordance and discordance rates of uPA/PAI-1 testing in daily clinical setting were calculated and individual reasons for decision making analyzed.

Results: Among n=93 uPA/PAI-1 tests evaluated n=42/93 (45.2%) were uPA+PAI-1 negative and n=51/93 (54.8%) uPA and/or PAI-1 positive. In the group of uPA+PAI-1 negative test result in n=35/42 (83.3%) CTX was avoided and and in n=7/42 (16.7%) CTX performed. In the group of uPA and/or PAI-1 positive test result in n=26/51 (51.0%) CTX was performed and in n=25/51 (49.0%) not. Concordance of uPA/PAI-1 test result vs. consecutive therapy was (35+26)/93=65.6% and discordance of uPA/PAI-1 test-therapy (7+25)/93 = 34.4%. However, discordance of uPA/PAI-1 test result vs. Tumor Board recommendation was only n=21/93 (22.6%). As reasons for discordance a variety of influencing and/or interference factors were indentified, affecting use of test and test results or even changing therapy decision, e.g. individual therapy decision by physician, parallel use of competitive biomarkers, study participation, missing CTX therapy option in advance (like advanced age), wrong target group, timing of uPA/PAI-1 test too early, test result in contradiction of physicians' expectations (expected negative result) and rejection of CTX recommended by patients despite uPA/PAI-1 test-proven benefit.

Conclusions: Individual process optimization of uPA/PAI-1 test indication, performance and result assessment could improve quality of care, reduce costs and lead to an improved application of uPA/PAI-1 test results as well as more stringency and consistency of test-therapy decisions in daily clinical setting.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-14-06.
Abstract P5-18-05: Interim Results from a Phase 1b/2a Study of Trastuzumab Emtansine and Docetaxel, With and Without Pertuzumab, in Patients With HER2-Positive Locally Advanced or Metastatic Breast Cancer
Authors: Martin M , García-Sáenz JÁ , Dewar JA , Albanell J , Limentani SA , Strasak A , Patre M , Branle F , Fumoleau P
Published: August 2014

Introduction: Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate comprising trastuzumab, a stable linker, and DM1 (a microtubule inhibitor). In 2 randomized trials in patients (pts) with HER2-positive metastatic breast cancer (MBC), T-DM1 significantly prolonged progression-free survival (PFS) compared with standard therapy (Hurvitz, ESMO 2011; Blackwell, ASCO 2012). The combination of T-DM1 and docetaxel (D) or pertuzumab (P) has shown enhanced antitumor activity in preclinical models of HER2-positive BC (Lewis Phillips, AACR 2008; Fields, AACR 2010).

Methods: This phase 1b/2a dose-escalation study examines the safety, tolerability, efficacy, and pharmacokinetics (PK) of T-DM1 (starting dose 2.4 mg/kg every 3 weeks [q3w]) combined with D (starting dose 75 mg/m2 q3w) in pts with MBC, and T-DM1 with D±P (840 mg loading dose, then 420 mg q3w) in pts with newly diagnosed locally advanced BC (LABC; clinical stage IIa-IIIc). The maximum tolerated dose (MTD) for T-DM1+D is established in pts with MBC and used as the starting dose for feasibility of T-DM1+D±P (up to 6 cycles) in pts with LABC. Eligibility criteria include HER2-positive MBC (locally assessed) or LABC (centrally confirmed). This interim report includes data from pts who completed at least 1 treatment cycle in phase 1b.

Results: During MBC feasibility, 21 pts were enrolled; median age was 47.0 years (yr; range, 33–70); median number of prior lines of MBC therapy was 2 (range, 0–10). Four pts experienced 6 DLTs (Table 1). The MTD was T-DM1 3.6 mg/kg q3w + D 60 mg/m2 q3w. Common grade (G) 3/4 adverse events (AEs): neutropenia (81%), leukopenia (52%), and thrombocytopenia (29%). ORR was 76.2% (16/21); median PFS was 11.8 months (range, 1.6–26.9). In LABC feasibility, 18 pts were enrolled; median age was 49.5 yr (range, 34–74). Four pts experienced 4 DLTs (Table 2). The MTD for T-DM1+D was 3.6 mg/kg q3w + 75 mg/m2 q3w; MTD for T-DM1+D+P was 3.6 mg/kg q3w + 75 mg/m2 q3w + 840 mg (with G-CSF primary prophylaxis). Common G3/4 AEs: T-DM1+D, neutropenia (2/9; 22%), increased alanine aminotransferase (ALT; 2/9; 22%), thrombocytopenia (TCP; 1/9; 11%); T-DM1+D+P, neutropenia (5/9; 56%), TCP (2/9; 22%), increased ALT (2/9; 22%), and cytolytic hepatitis (1/9; 11%). With 9 pts enrolled in the T-DM1+D LABC cohorts and 8 pts currently evaluable, pCR rate (ypT0N0) is 87.5%.

Conclusions: Full-dose T-DM1 can be safely combined with D in pts with MBC, and with D±P in pts with LABC. G-CSF is needed with higher doses of D. Pathological assessment for all LABC patients and PK analyses will be available for the full presentation.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-18-05.
Abstract P5-18-11: Pharmacokinetics and exposure-efficacy relationship of trastuzumab emtansine in EMILIA, a phase 3 study of trastuzumab emtansine vs capecitabine and lapatinib in HER2-positive locally advanced or metastatic breast cancer
Authors: Wang B , Jin J , Wada R , Fang L , Saad O , Olsen S , Althaus B , Swain S , Untch M , Girish S
Published: August 2014

Background: Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate composed of trastuzumab (T), the cytotoxic agent DM1, and a stable thioether linker; it is being evaluated for the treatment (tx) of HER2-positive cancer. EMILIA is a randomized, multicenter, open-label phase 3 study assessing the efficacy and safety of T-DM1 vs capecitabine (X) and lapatinib (L) in pts with HER2-positive locally advanced or metastatic breast cancer (MBC) previously treated with T and a taxane. We report the pharmacokinetics (PK) of T-DM1 in EMILIA and compare these data with historical data of single-agent T-DM1. The effects of T-DM1 exposure on efficacy outcomes in EMILIA are also reported.

Methods: In EMILIA, pts were randomized 1:1 to receive T-DM1 3.6 mg/kg q3w (n = 495) or X + L (n = 496) in 21-day cycles. At least 1 PK sample was collected from 350 pts in the T-DM1 arm; 307 of these had adequate PK profiles for the estimation of ≥1 PK parameter in cycle 1. PK parameters were estimated by noncompartmental analysis for serum T-DM1, serum total T (conjugated and unconjugated T), and plasma DM1. A logistic regression model was used to evaluate the relationship between T-DM1 exposure (ie, T-DM1 AUC and DM1 Cmax) and objective response rates (ORR). Analyses of progression-free survival (PFS) and overall survival (OS), stratified by T-DM1 exposure, were conducted. Cox regression was used to evaluate the effect of T-DM1 exposure and other potential covariates on PFS and OS.

Results: The PK parameters for T-DM1, total T, and DM1 in EMILIA and other studies of single-agent T-DM1 are summarized in Table 1. The PK parameters appear similar regardless of prior tx for MBC. No significant differences in mean serum T-DM1 AUC (P = 0.091) or plasma DM1 Cmax (P = 0.812) were observed between responders and non-responders following T-DM1 tx. Furthermore, variability in T-DM1 AUC and DM1 Cmax does not appear to affect the probability of response to therapy (P = 0.23 for T-DM1 AUC and P = 0.74 for DM1 Cmax). Based on Cox proportional hazards analysis, no significant exposure-efficacy relationship was observed between T-DM1 AUC (P = 0.23 for PFS and p = 0.53 for OS) or DM1 Cmax (P = 0.96 for PFS and P = 0.34 for OS) and PFS or OS, respectively.

Conclusions: T-DM1 PK data in EMILIA pts were similar to those observed in previous phase 2 studies, which include pts who have and have not received prior therapy for MBC. Variation in T-DM1 exposure among pts who received T-DM1 3.6 mg/kg q3w had no significant impact on ORR, PFS, or OS. Detailed analyses will be presented.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-18-11.