Invasive Breast Tumors Research Articles

300P - Outcome of triple negative inflammatory breast cancers (TNIBC) treated with dose dense neoadjuvant epirubicin cyclophosphmide, prognostic impact of pre and post neoadjuvant chemotherapy (NAC) tumour infiltrating lymphocytes (TIL) and post NAC lymphovascular invasion

BackgroundInflammatory breast cancers (IBC) particularly triple negative (TN) subtype have poor prognosis. MethodsBetween January 2010 and December 2016, all patients with TNIBC seen at breast cancer disease center, St Louis hospital, Paris, France, were treated with neoadjuvant dose dense Cyclophophamide (1.2g/m2 d1) - Epirubicin (75mg/m2 d1) q2w (SIM regimen) followed with 12 injections of paclitaxel (80mg/m2) qw or 4 injections of docetaxel (100mg/m2) q3w. All patients have histologically proven TN tumors and no evidence of metastases. Mastectomy and axillary clearance was performed after chemotherapy. pCR was defined as no residual invasive tumor in breast and lymph nodes. TIL and lymphovascular invasion were evaluated pre and post NAC by 2 independent anatomopathologists dedicated to breast cancer. Delta TIL was defined as the difference between post chemotherapy and pre chemotherapy TIL. ResultsThirty TNIBC patients were treated, 28 underwent surgery and 2 progressed during chemotherapy. Median follow-up was 45 months (8 – 103). 9/30 patients (30%) achieved pCR. Median disease free survival was not reached. Median TIL infiltration at diagnosis was 11% (0-60) and dropped to 1% after chemotherapy (0 – 80). On univariate analysis, LVI after chemotherapy (HR=2.1 [95% CI, 1.1–3.6], p=0.02), TIL on mastectomy (HR=1.8 [95% CI, 1.1–3.1], p=0.03), delta TIL (HR=2.2 [95% CI, 1.4–3.5], p=0,001) were associated with DFS but no pCR (p=0,051). On multivariate analysis, only delta TIL remainedstatistically significant (HR=1.9 [95% CI, 1.1–3.4], p=0.03). ConclusionsWe showed in this retrospective series of 30 TNIBC that dose dense dose intense chemotherapy is efficient in this population. Delta TIL is a strong prognostic factor associated with DFS. We show that a positive Delta TILis, among others, a strong and independent predictor of DFS: in TNIBC contrary to the results obtained in TN non inflammatory breast cancers, an increase in TIL after chemotherapy is associated with a decrease in DFS.The exact impact of LVI must be further investigated. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

79P - Parkin, APEX1 and BCL2L1 tissue expression in southern Brazilian patients with different breast cancer molecular subtypes

BackgroundBreast cancer is the most commonly occurring cancer in women and is the leading cause of cancer death in women in Brazil. Despite being widely studied, it is a disease that is not yet fully understood in its complexity. On the other hand, changes in parkin (parkin RBR E3 ubiquitin protein ligase) expression patterns have been described in several diseases, including breast cancer. Nevertheless, the association of these changes with cancer prognostic and predictive factors remains unclear. Also, parkin regulates APEX1 (apurinic/apyrimidinic endodeoxyribonuclease 1), a protein crucial for repair of oxidized DNA damage, and BCL2L1 (BCL2 like 1), an apoptotic regulator. Both proteins were related to breast cancer. MethodsImmunohistochemical analysis of Parkin, APEX1 and BCL2L1expression were performed in different breast cancer ductal invasive samples from Southern Brazilian patients to characterize their patterns and explore its association with clinical features and disease outcome.Therefore, 112 samples were organized into 15 Tissue Micro Arrays. The samples were classified in four molecular subtypes based on clinicopathological criteria (46 Luminal B, 24 Luminal A, 24 Basal and 18 HER2). These samples were obtained from Hospital Nossa Senhora das Graças (Curitiba, PR, Brazil) patients who were followed from 5 to 18 years. ResultsParkin, APEX1 and BCL2L1 showed different expression patterns between the subtypes assessed. While in Luminal A and B APEX1 expression was increased, parkin expression was higher among Basal and HER2 subtypes. BCL2L1 expression was increased mainly in HER2 subtype. When regarding to estrogen (ER) and progesterone (PR) receptors, APEX1 was more expressed in ER/PR-positive samples, whereas Parkin and BCL2L1 in negative ones. No such difference was observed considering only HER2. BCL2L1 expression pattern was significantly associated with disease-free survival time independent of molecular subtypes, lymph node status and tumor size (p=0.020). The higher the expression levels of BCL2L1, the shorter the disease-free survival time. ConclusionsThe expression of BCL2L1 is direclty associated with relapse of ductal invasive breast tumors, independently of other clinical variables. Legal entity responsible for the studyPontifícia Universidade Católica do Paraná (PUCPR). FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Olfactory receptor gene abundance in invasive breast carcinoma

Expression of olfactory receptors (ORs) has been reported in many human tissues outside the nasal epithelium. ORs have been validated as biomarkers in prostate cancer. In breast cancer, however, the expression and role of OR genes remain understudied. We examined the significance of OR transcript abundance in a large invasive breast carcinoma population and identified two OR genes, OR2W3 and OR2B6 to be potentially correlated to breast cancer progression. 960 breast invasive tumors and 56 human breast cancer cell lines were assessed for OR gene expression and 21 OR genes were highly abundant among 198 cases. Our transcriptome analysis discovered three significantly abundant OR genes among three sub-populations of invasive breast carcinoma patients. OR2W3 was correlated with invasion genes and basal-like subtype whereas OR2B6 was correlated with proliferation genes and luminal A subtype. Analyzing the OR gene upregulation among breast cancer cell lines showed that OR2B6 and OR2W3 were abundant similar to invasive breast tumors. Our study suggests that specific OR genes may be correlated with breast cancer characteristics, making ORs potential new diagnostic, and/or treatment markers. This study suggests future directions for the exploration of a role for ORs in the mechanisms of breast cancer proliferation and progression.

CD133 in Breast Cancer Cells: More than a Stem Cell Marker.

Initially correlated with hematopoietic precursors, the surface expression of CD133 was also found in epithelial and nonepithelial cells from adult tissues in which it has been associated with a number of biological events. CD133 is expressed in solid tumors as well, including breast cancer, in which most of the studies have been focused on its use as a surface marker for the detection of cells with stem-like properties (i.e., cancer stem cells (CSCs)). Differently with other solid tumors, very limited and in part controversial are the information about the significance of CD133 in breast cancer, the most common malignancy among women in industrialized countries. In this review, we summarize the latest findings about the implication of CD133 in breast tumors, highlighting its role in tumor cells with a triple negative phenotype in which it directly regulates the expression of proteins involved in metastasis and drug resistance. We provide updates about the prognostic role of CD133, underlining its value as an indicator of increased malignancy of both noninvasive and invasive breast tumor cells. The molecular mechanisms at the basis of the regulation of CD133 levels in breast tumors have also been reviewed, highlighting experimental strategies capable to restrain its level that could be taken into account to reduce malignancy and/or to prevent the progression of breast tumors.

Perturbed myoepithelial cell differentiation in BRCA mutation carriers and in ductal carcinoma in situ

Myoepithelial cells play key roles in normal mammary gland development and in limiting pre-invasive to invasive breast tumor progression, yet their differentiation and perturbation in ductal carcinoma in situ (DCIS) are poorly understood. Here, we investigated myoepithelial cells in normal breast tissues of BRCA1 and BRCA2 germline mutation carriers and in non-carrier controls, and in sporadic DCIS. We found that in the normal breast of non-carriers, myoepithelial cells frequently co-express the p63 and TCF7 transcription factors and that p63 and TCF7 show overlapping chromatin peaks associated with differentiated myoepithelium-specific genes. In contrast, in normal breast tissues of BRCA1 mutation carriers the frequency of p63+TCF7+ myoepithelial cells is significantly decreased and p63 and TCF7 chromatin peaks do not overlap. These myoepithelial perturbations in normal breast tissues of BRCA1 germline mutation carriers may play a role in their higher risk of breast cancer. The fraction of p63+TCF7+ myoepithelial cells is also significantly decreased in DCIS, which may be associated with invasive progression.

Radiation-induced angiosarcoma of the breast: A review.

Angiosarcoma is a rare, aggressive malignant vascular neoplasm with poor prognosis that has a predilection for skin and superficial soft tissue. It can arise spontaneously or in association with factors like chronic lymphedema or radiation therapy. Radiotherapy used to treat invasive breast tumors is a known risk factor for the development of the so-called radiation-induced angiosarcoma (RIAS), a condition that has been described in the literature with increasing frequency. Radiation-induced angiosarcoma of the breast usually arises on the previously irradiated skin area several years after radiotherapy and presents as painless multifocal erythematous patches or plaques similar to a hematoma. Cutaneous biopsy is essential for the diagnosis. Histologically, RIAS is characterized by irregular anastomosing vessels lined by endothelial cells showing nuclear atypia. Treatment is mostly surgical, and mastectomy with negative margins is considered the standard procedure. However, recurrences are common, and an approach combining surgery, chemo- and radiotherapy may be more effective. The purpose of this study is to review the most recent medical literature on RIAS of the breast, with emphasis on its pathophysiology, clinical and histological features and current treatment options.

Surgical Management of Breast Cancer in Turkey: a 30-Year Single-Center Retrospective Study of 2531 Patients

Mastectomy and lumpectomy are well-established surgical methods for the surgical treatment of breast cancer. The comparison of these methods within the 30-year period in terms of clinicopathological characteristics, recurrence, and survival patterns is required in order to provide aid in clinical decision-making. A total of 2531 women who underwent mastectomy or lumpectomy between 1982 and 2012 for primary invasive breast tumors were compared. Starting from 2003, similar variables for patients with primary invasive breast tumors who underwent sentinel node biopsy (SNB) were presented. Mastectomy was performed in 1870 patients and lumpectomy in 661. The median follow-up was 38 months for all patients. The ratio of mastectomy was lower for the patients who underwent SNB. There was no significant difference in breast cancer-related survival or disease-free survival between lumpectomy and mastectomy even after adjusting for the clinicopathological variables. Lumpectomy and mastectomy demonstrate similar survival rates for patients with invasive breast carcinoma. Tumor grade, stage, hormone receptor status, lymphovascular invasion, and distant recurrence have an impact on breast cancer-related survival.

Cytokeratin-Supervised Deep Learning for Automatic Recognition of Epithelial Cells in Breast Cancers Stained for ER, PR, and Ki-67.

Immunohistochemistry (IHC) of ER, PR, and Ki-67 are routinely used assays in breast cancer diagnostics. Determination of the proportion of stained cells (labeling index) should be restricted on malignant epithelial cells, carefully avoiding tumor infiltrating stroma and inflammatory cells. Here, we developed a deep learning based digital mask for automated epithelial cell detection using fluoro-chromogenic cytokeratin-Ki-67 double staining and sequential hematoxylin-IHC staining as training material. A partially pre-trained deep convolutional neural network was fine-tuned using image batches from 152 patient samples of invasive breast tumors. Validity of the trained digital epithelial cell masks was studied with 366 images captured from 98 unseen samples, by comparing the epithelial cell masks to cytokeratin images and by visual evaluation of the brightfield images performed by two pathologists. A good discrimination of epithelial cells was achieved (AUC of mean ROC = 0.93; defined as the area under mean receiver operating characteristics), and well in concordance with pathologists' visual assessment (4.01/5 and 4.67/5). The effect of epithelial cell masking on the Ki-67 labeling index was substantial. 52 tumor images initially classified as low proliferation (Ki-67 < 14%) without epithelial cell masking were re-classified as high proliferation (Ki-67 ≥ 14%) after applying the deep learning based epithelial cell mask. The digital epithelial cell masks were found applicable also to IHC of ER and PR. We conclude that deep learning can be applied to detect carcinoma cells in breast cancer samples stained with conventional brightfield IHC.

Vitamin D receptor expression in invasive breast tumors and breast cancer survival

BackgroundVitamin D has been suggested to prevent and improve the prognosis of several cancers, including breast cancer. We have previously shown a U-shaped association between pre-diagnostic serum levels of vitamin D and risk of breast cancer-related death, with poor survival in patients with the lowest and the highest levels respectively, as compared to the intermediate group. Vitamin D exerts its functions through the vitamin D receptor (VDR), and the aim of the current study was to investigate if the expression of VDR in invasive breast tumors is associated with breast cancer prognosis.MethodsVDR expression was evaluated in a tissue microarray of 718 invasive breast tumors. Covariation between VDR expression and established prognostic factors for breast cancer was analyzed, as well as associations between VDR expression and breast cancer mortality.ResultsWe found that positive VDR expression in the nuclei and cytoplasm of breast cancer cells was associated with favorable tumor characteristics such as smaller size, lower grade, estrogen receptor positivity and progesterone receptor positivity, and lower expression of Ki67. In addition, both intranuclear and cytoplasmic VDR expression were associated with a low risk of breast cancer mortality, hazard ratios 0.56 (95% CI 0.34–0.91) and 0.59 (0.30–1.16) respectively.ConclusionsThis study found that high expression of VDR in invasive breast tumors is associated with favorable prognostic factors and a low risk of breast cancer death. Hence, a high VDR expression is a positive prognostic factor.

Abstract 3541: Characterization of olfactory receptor upregulation in invasive breast cancer

Abstract Despite some progress in early detection and new therapies, breast cancer remains the second most common cause of cancer-related deaths among women. Majority of deaths occur due to invasion and metastasis among triple-negative breast cancer (TNBC) patients. Gene profiling of mammary tumors has enabled identification of novel genes with potential roles in cancer invasion using next generation sequencing technologies. This study is the first to examine upregulation of olfactory receptors (ORs) among a large invasive breast carcinoma population and begins to establish a correlation of OR genes in breast cancer invasion. Invasive breast carcinoma cases from the TCGA database were used. Among data from 1100 unique patients, 960 cases of invasive breast carcinoma had RNAseq of their primary tumors in addition to exome sequencing data. The abundance of all 408 human coding OR genes among the 960 cases were analyzed using a three-factor stratification algorithm, and 30 OR genes were identified as highly abundant among 198 breast invasive carcinoma patients. Supervised clustering of the 198 patients based on the similarity of OR upregulation levels identified five subpopulations among the invasive carcinoma patients in which only one OR gene (OR2A7, OR2B6, OR2C1, OR2W3) was significantly upregulated. Abundance of OR2W3 was significantly elevated in two subpopulations with 30- and 19-fold increase compared to their level of abundance in normal mammary tissue. These two subpopulations were composed of 74% and 70% TNBC tumor subtypes and included all the stage iv cancer patients in the study. Transcript abundance of 21 genes included in the Oncotype DX gene expression diagnostic test was measured for each patient subpopulation. The subpopulation with abundance in OR2W3 was correlated with significant upregulation of invasion genes (CTSV, MMP-11) and the subpopulation with abundance of OR2B6 was correlated with significant upregulation of proliferation genes (MKI67, AURKA, BIRC67, CCNB1, MYBL2). Interestingly, only the cases with significant upregulation of OR2W3 were correlated with significantly reduced survival probability compared to invasive breast carcinoma patients not expressing OR2W3. Furthermore, analysis of OR transcript abundance levels among 56 human breast cancer cell lines showed that 3 ORs (OR2A7, OR2B6, OR2W3) were exclusively upregulated in one cell group with 2, 1.3 and 2.1-fold increase compared to their upregulation levels in a human mammary epithelial cell line (MCF10A). The cell group with significant upregulation of OR2W3 was composed of 83% TNBC cell lines. These results show a consistent elevated upregulation of the OR2W3 gene in all the invasive breast tumors and cell lines. Our ongoing discovery research suggests that OR2W3 may be an indicator of breast cancer invasion. It is also possible that OR2W3 has signaling or other mechanistic roles in breast cancer progression, metastasis and reduced survival. Citation Format: Shirin Masjedi, Laurence J. Zwiebel, Todd D. Giorgio. Characterization of olfactory receptor upregulation in invasive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3541.

Abstract 1073: Role of CD44 in the transition of ductal carcinoma in situ to invasive breast carcinoma

Abstract Ductal carcinoma in situ (DCIS) transition to invasive tumor is an important issue for breast cancer. The human MCF10DCIS.com cell line (abbreviated as MCF10DCIS) is derived from the human MCF10A breast epithelial cell line. The MCF10DCIS xenografts are similar to human high grade comedo DCIS. In the xenograft assay, MCF10DCIS cells form DCIS-like lesion, remain as DCIS-like lesion in the first few weeks, and then progress into invasive carcinoma. Thus, it is an excellent model to study human breast cancer transition from DCIS to invasive carcinoma. To the best of our knowledge, it is also the only cell model for DCIS transition to invasive carcinoma. We investigated the role of CD44 in breast cancer transition from DCIS to invasive carcinoma by knockdown the expression of CD44 in the MCF10DCIS xenograft model. Our results show that knockdown of CD44 expression in the MCF10DCIS cells enhances DCIS transition to invasive carcinoma. Accordingly, a previous study has shown that CD44 expression is lower in invasive human breast tumors compared with DCIS, especially in luminal A subtype. We have also observed that CD44 expression is lower in the invasive carcinomas compared with DCIS. Furthermore, we provide evidence that CD44 plays a role in maintaining the integrity of the myoepithelial layer. Our study uncovered an unexpected role of CD44 in the prevention of DCIS transition to invasive carcinoma. Our findings have important implications for breast cancer. Note: This abstract was not presented at the meeting. Citation Format: Fang Liu, Jun Zhou, Tanima Kundu-Roy, Joseph Wahler, Jae Young So, Yong Lin, You-Rong Lou, Nicola J. Barnard, Isao Matsuura, Nanjoo Suh. Role of CD44 in the transition of ductal carcinoma in situ to invasive breast carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1073.

Abstract 2015: Downregulation of MZB1 by aminoguanidine, APOE mimetic and nitroxyl compounds associated with reduction in invasive breast tumor volume and metastasis

Abstract Triple negative breast cancer (TNBC) is notoriously known for poor prognosis due to a lack of actionable molecular target(s). Remarkably, the majority of TNBC patients suffer the cancer relapse even they receive treatment given for early stage breast cancers. Up-to-date, lots of therapeutic agents have been developed and actionable molecular targets have been proposed. Nevertheless, the survival rate for metastatic invasive breast cancer is low because of poor prognosis. In this study, we determined whether different classes of chemo-agents (or compounds) interact with different cellular and molecular pathways they might share some common pathway(s) if their therapeutic outcome is similar. We first tested the effect of aminoguanidine (AG), APOE mimetics (COG), and nitroxyl (HNO) compounds on carcinogenesis and metastasis using an orthotopic breast cancer model. In vivo imaging analysis indicated that these compounds significantly reduced the tumor loading in the xenografts (MDA-MB-231-GFP). Moreover, compounds AG and COG are able to reduce brain metastasis significantly. RNA-Seq analysis identified only one gene which is commonly altered in all treatment groups. This gene encodes marginal zone B and B1 cell specific protein (MZB1). MZB1 was downregulated after treatment and its expression was inversely correlated with the efficacy of brain metastasis. In addition, pathway comparison analysis of RNA-Seq data revealed there are three top canonical pathways including (1) Role of NFAT in Regulation of the Immune Response, (2) PKC theta Signaling in T Lymphocytes, and (3) iCOS-iCOSL Signaling in T Helper Cells, downregulated in all treatment groups. In conclusion, our findings demonstrated three different classes of compounds can reduce not only tumor loading but metastasis. MZB1, identified from our transcriptome analysis, may serve as an actionable molecular target for TNBC. All-in-all, it provides new insights into the development of new therapeutic targets and biomarkers for TNBC. Citation Format: Yuk Sing Robert Cheng, Debashree Basudhar, Rdinour Lisa, Veena Somasundaram, David Wink. Downregulation of MZB1 by aminoguanidine, APOE mimetic and nitroxyl compounds associated with reduction in invasive breast tumor volume and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2015.

Multi-omic Dissection of Oncogenically Active Epiproteomes Identifies Drivers of Proliferative and Invasive Breast Tumors.

SummaryProliferative and invasive breast tumors evolve heterogeneously in individual patients, posing significant challenges in identifying new druggable targets for precision, effective therapy. Here we present a functional multi-omics method, interaction-Correlated Multi-omic Aberration Patterning (iC-MAP), which dissects intra-tumor heterogeneity and identifies in situ the oncogenic consequences of multi-omics aberrations that drive proliferative and invasive tumors. First, we perform chromatin activity-based chemoproteomics (ChaC) experiments on breast cancer (BC) patient tissues to identify genetic/transcriptomic alterations that manifest as oncogenically active proteins. ChaC employs a biotinylated small molecule probe that specifically binds to the oncogenically active histone methyltransferase G9a, enabling sorting/enrichment of a G9a-interacting protein complex that represents the predominant BC subtype in a tissue. Second, using patient transcriptomic/genomic data, we retrospectively identified some G9a interactor-encoding genes that showed individualized iC-MAP. Our iC-MAP findings represent both new diagnostic/prognostic markers to identify patient subsets with incurable metastatic disease and targets to create individualized therapeutic strategies.

Bioinformatics Analysis of Stromal Molecular Signatures Associated with Breast and Prostate Cancer.

This study aimed to identify stromal molecular signatures associated with breast and prostate cancer. The microarray data GSE26910 was downloaded from Gene Expression Omnibus database, including six invasive breast tumor stroma, six matched normal controls, six invasive prostate tumor stroma, and six matched controls. The differentially expressed genes (DEGs) in invasive breast and prostate tumors stroma were, respectively, identified. Then common stromal genes (B_P.DEGs) were further screened. Protein-protein interaction (PPI) network was constructed and Gene Ontology analysis was performed. Besides, gene-chemical interactions were mapped in Comparative Toxicogenomics Database to screen the chemicals related to feature genes. The results showed that, in total, 16 B_P.DEGs were identified. Thereinto, only seven B_P.DEGs were mapped into PPI, and only four functional modules (adenylate cyclase activating polypeptide 1 (pituitary) receptor type I (ADCYAP1R1) module, aspartoacylase (ASPA) module, glutathione S-transferase mu 5 (GSTM5) module, and periplakin (PPL) module) were involved in important biological processes associated with cancer progression. In addition, the chemicals, such as dihydrotestosterone, apocarotenal, testosterone, and progesterone, were screened for the roles of feature genes in the progression of breast and prostate cancer. In conclusion, ADCYAP1R1, GSTM5, and PPL were stromal molecular signatures and might play a key role in the progression of breast and prostate cancer.

A combinatorial biomarker predicts pathologic complete response to neoadjuvant lapatinib and trastuzumab without chemotherapy in patients with HER2+ breast cancer.

HER2-positive (+) breast cancers, defined by HER2 overexpression and/or amplification, are often addicted to HER2 to maintain their malignant phenotype. Yet, some HER2+ tumors do not benefit from anti-HER2 therapy. We hypothesize that HER2 amplification levels and PI3K pathway activation are key determinants of response to HER2-targeted treatments without chemotherapy. Baseline HER2+ tumors from patients treated with neoadjuvant lapatinib plus trastuzumab [with endocrine therapy for estrogen receptor (ER)+ tumors] in TBCRC006 (NCT00548184) were evaluated in a central laboratory for HER2 amplification by fluorescence in situ hybridization (FISH) (n = 56). HER2 copy number (CN) and FISH ratios, and PI3K pathway status, defined by PIK3CA mutations or PTEN levels by immunohistochemistry were available for 41 tumors. Results were correlated with pathologic complete response (pCR; no residual invasive tumor in breast). Thirteen of the 56 patients (23%) achieved pCR. None of the 11 patients with HER2 ratio <4 and/or CN <10 achieved pCR, whereas 13/45 patients (29%) with HER2 ratio ≥4 and/or CN ≥10 attained pCR (P = 0.0513). Of the 18 patients with tumors expressing high PTEN or wild-type (WT) PIK3CA (intact PI3K pathway), 7 (39%) achieved pCR, compared with 1/23 (4%) with PI3K pathway alterations (P = 0.0133). Seven of the 16 patients (44%) with HER2 ratio ≥4 and intact PI3K pathway achieved pCR, whereas only 1/25 (4%) patients not meeting these criteria achieved pCR (P = 0.0031). Our findings suggest that there is a clinical subtype in breast cancer with high HER2 amplification and intact PI3K pathway that is especially sensitive to HER2-targeted therapies without chemotherapy. A combination of HER2 FISH ratio and PI3K pathway status warrants validation to identify patients who may be treated with HER2-targeted therapy without chemotherapy.

Preoperative conventional axillary ultrasound (AUS) and sonoelastography (SE) for predicting axillary lymph node metastasis in breast cancer patients.

e12074 Background: Patients with operable breast cancer (BC) and clinically negative lymph nodes (CNLN) usually undergo sentinel lymph node biopsy (SNLB) or axillary lymph nodes dissection (ALND). AUS followed by fine-needle aspiration (FNA) or core-needle biopsy (CNB) could decrease number of unnecessary SNLBs and allow to assign patient to ALND directly. On the other hand, new AUS techniques such as SWE could enhance AUS specificity and allow to avoid SNLB in some patients. Aim: To assess sensitivity, specificity and negative predictive value of the AUS+SWE followed by FNA or CNB in patients with operable BC. Methods: Since Sep 2012 to Jan 2018 150 pts with operable BC and were enrolled. We include 30 pts in training cohort with clinically positive lymph nodes to verify AUS+SWE sensitivity and specificity. In validation cohort only those pts who were candidates for SNLB and who presented with tumor staging up to T3, and clinically negative axillae were included (n=120). All patients underwent preoperative AUS in B-mode, SWE, followed by FNA or CNB in case of suspicious nodes were detected. All pts underwent axilla surgery (SNLB = 46, ALND =74) and final pathology outcomes were available for all pts. Results: In training cohort of 30 patients with clinically positive lymph nodes the overall AUS+SWE sensitivity was set at 89.2%. The positive predictive value was calculated to be 96.1%. In the assessment of invasive breast tumors stages T1- T3 with clinically negative lymph nodes the sensitivity was 74.2%, specificity 95.5% positive predictive value was 85.2% and negative predictive value 91.4% If FNA or CNB follow the AUS+SWE in patients with CNLN the sensitivity was 86.7%, specificity 85.7% positive predictive value was 92.8% and negative predictive value was 75% (FNA or CNB was performed in 40 patients of 120 in validation set). Area under the ROC-curve was calculated as 0.860 [95% CI 0.766 to 0.954] for the US+SWE and 0.705 [95% CI 0.581 to 0.828] for the US+SWE followed by FNA or CNB. Conclusions: Axillary US+SWE should be included in the preoperative staging of all patients with invasive breast cancer. The addition US+SWE (not obviously followed by FNA or CNB) could lead to avoiding of unnecessary SNLB or ALND in patients with clinically and pathologically negative lymph nodes with negative predictive value of 91.4%. On the other hand in patients with US+SWE positive lymph nodes SNLB could also be skipped and the time interval to definitive therapy became shorter. Clinical trial information: BCA_US_SWE_001.

Plasminogen Activator Inhibitor 1 (PAI1) Promotes Actin Cytoskeleton Reorganization and Glycolytic Metabolism in Triple-Negative Breast Cancer.

Migration and invasion of cancer cells constitute fundamental processes in tumor progression and metastasis. Migratory cancer cells commonly upregulate expression of plasminogen activator inhibitor 1 (PAI1), and PAI1 correlates with poor prognosis in breast cancer. However, mechanisms by which PAI1 promotes migration of cancer cells remain incompletely defined. Here we show that increased PAI1 drives rearrangement of the actin cytoskeleton, mitochondrial fragmentation, and glycolytic metabolism in triple-negative breast cancer (TNBC) cells. In two-dimensional environments, both stable expression of PAI1 and treatment with recombinant PAI1 increased migration, which could be blocked with the specific inhibitor tiplaxtinin. PAI1 also promoted invasion into the extracellular matrix from coculture spheroids with human mammary fibroblasts in fibrin gels. Elevated cellular PAI1 enhanced cytoskeletal features associated with migration, actin-rich migratory structures, and reduced actin stress fibers. In orthotopic tumor xenografts, we discovered that TNBC cells with elevated PAI1 show collagen fibers aligned perpendicular to the tumor margin, an established marker of invasive breast tumors. Further studies revealed that PAI1 activates ERK signaling, a central regulator of motility, and promotes mitochondrial fragmentation. Consistent with known effects of mitochondrial fragmentation on metabolism, fluorescence lifetime imaging microscopy of endogenous NADH showed that PAI1 promotes glycolysis in cell-based assays, orthotopic tumor xenografts, and lung metastases. Together, these data demonstrate for the first time that PAI1 regulates cancer cell metabolism and suggest targeting metabolism to block motility and tumor progression. IMPLICATIONS: We identified a novel mechanism through which cancer cells alter their metabolism to promote tumor progression.

A Clinical Approach to Diffusion-Weighted Magnetic Resonance Imaging in Evaluating Chest Wall Invasion of Breast Tumors.

Objective:The purpose of this study is to evaluate diffusion weighted magnetic rsonance imaging (MRI) acquisitions in delineating posterior extent of breast tumors and in predicting chest wall invasion prior to treatment. To our knowledge, there has not been any literature specifically evaluating the utility of diffusion-weighted acquisitions in chest wall invasion of breast tumors.Materials and Methods:A retrospective review of our breast imaging database for keywords “chest wall invasion” and “breast MRI” was performed over the last 14 years. Diffusion sequences, T1 sequences (pre and post contrast), and T2 sequences were evaluated. Apparent diffusion coefficient (ADC) values in tumor and chest wall were assessed. Imaging findings were correlated with surgical pathology.Results:23 patients met inclusion criteria. All 23 had loss of fat plane on T2 sequences. 22/23 had loss of fat plane on postcontrast T1 sequences. Pectoralis muscle enhancement was present in 19/23 (83%) tumors and chest wall enhancement was present 9/23 (39%) tumors. Qualitative restricted diffusion within the pectoralis muscle was present in 18/23 (71%) tumors and in the chest wall was present in 8/23 (35%) tumors. Mean ADC values were 1.15 s/mm2 in the tumor and 1.29 s/mm2 in the chest wall. Sensitivity, specificity, positive predictive value and negative predictive value were 100%, 36%, 63%, and 100% for chest wall enhancement respectively and 69%, 36%, 61%, and 80% for chest wall diffusion-weighted imaging restriction respectively.Conclusion:Diffusion weighted sequences can be helpful in characterizing chest wall invasion of breast tumors.

A Clinical Approach to Diffusion-Weighted Magnetic Resonance Imaging in Evaluating Chest Wall Invasion of Breast Tumors

Objective: The purpose of this study is to evaluate diffusion weighted magnetic rsonance imaging (MRI) acquisitions in delineating posterior extent of breast tumors and in predicting chest wall invasion prior to treatment. To our knowledge, there has not been any literature specifically evaluating the utility of diffusion-weighted acquisitions in chest wall invasion of breast tumors. Materials and Methods: A retrospective review of our breast imaging database for keywords “chest wall invasion” and “breast MRI” was performed over the last 14 years. Diffusion sequences, T1 sequences (pre and post contrast), and T2 sequences were evaluated. Apparent diffusion coefficient (ADC) values in tumor and chest wall were assessed. Imaging findings were correlated with surgical pathology. Results: 23 patients met inclusion criteria. All 23 had loss of fat plane on T2 sequences. 22/23 had loss of fat plane on postcontrast T1 sequences. Pectoralis muscle enhancement was present in 19/23 (83%) tumors and chest wall enhancement was present 9/23 (39%) tumors. Qualitative restricted diffusion within the pectoralis muscle was present in 18/23 (71%) tumors and in the chest wall was present in 8/23 (35%) tumors. Mean ADC values were 1.15 s/mm2 in the tumor and 1.29 s/mm2 in the chest wall. Sensitivity, specificity, positive predictive value and negative predictive value were 100%, 36%, 63%, and 100% for chest wall enhancement respectively and 69%, 36%, 61%, and 80% for chest wall diffusion-weighted imaging restriction respectively. Conclusion: Diffusion weighted sequences can be helpful in characterizing chest wall invasion of breast tumors.

NDRG4 promoter hypermethylation is a mechanistic biomarker associated with metastatic progression in breast cancer patients

The risk of developing metastatic disease in breast cancer patients is traditionally predictable based on the number of positive axillary lymph nodes, complemented with additional clinicopathological factors. However, since lymph node-negative patients have a 20–30% probability of developing metastatic disease, lymph node information alone is insufficient to accurately assess individual risk. Molecular approaches, such as multigene expression panels, analyze a set of cancer-related genes that more accurately predict the early risk of metastasis and the treatment response. Here, we present N-Myc downstream-regulated gene 4 (NDRG4) epigenetic silencing as a mechanistic biomarker of metastasis in ductal invasive breast tumors. While aberrant NDRG4 DNA hypermethylation is significantly associated with the development of metastatic disease, downregulation of NDRG4 transcription and protein expression is functionally associated with enhanced lymph node adhesion and cell mobility. Here, we show that epigenetic silencing of NDRG4 modulates integrin signaling by assembling β1-integrins into large punctate clusters at the leading edge of tumor cells to promote an “adhesive switch,” decreasing cell adhesion to fibronectin and increasing cell adhesion and migration towards vitronectin, an important component of human lymph nodes. Taken together, our functional and clinical observations suggest that NDRG4 is a potential mechanistic biomarker in breast cancer that is functionally associated with metastatic disease.