Circulating tumor DNA (ctDNA) is gaining momentum as sensitive diagnostic tool for advanced disease characterization because of its ability both to capture the tumor’s heterogeneity and its dynamic ...adaptations. However, the consistency between all the available platforms is still debated.
The aim of the study was to explore the performance of the novel diagnostic NGS platform PredicinePLUS™ and to compare its results with the clinically available Guardant360™ platform for possible analytical inconsistencies. The study suggests that PredicinePLUS™ NGS platform can detect genomic alterations and measure allele frequency in samples of MBC patients and confirmed that different NGS platforms could be potentially compared provided that certain sample management and analytical requirements are met.
Iron disulfide is one of the most promising anode candidates for sodium ion batteries (SIBs). Nevertheless, sluggish kinetic behavior, huge volumetric variations, and poor interface compatibility ...cause the growth of sodium dendrites, which seriously limit further applications of SIBs. Herein, a core–shell flower-like FeS 2 /C@VS 2 heterojunction, with enriched edge sites, dangling bonds, and extraordinary interface compatibility, was fabricated for SIBs. The inner core–shell structure and doped carbon matrix create a stable nanostructure, and effectively reduce volume expansion during repeated Na + plating/stripping. Comprehensive experimental characteristics and theoretical calculations evidence that the adsorption energy increases and the barrier energy decreases for Na + diffusion of the hybrid composite, with excellent interface compatibility, indicating that the fast Na + diffusion process results from the superior kinetic behavior. The driving force of the magnetohydrodynamic (MHD) effect can redistribute the Na + flux well, thus inhibiting the growth of sodium dendrites and improving the structural and electrochemical stability. Moreover, the V sites of FeS 2 /C@VS 2 promote insertion of Na + ion, while the electron-rich Fe sites enhance the conversion reaction kinetics. The obtained FeS 2 /C@VS 2 exhibits excellent Na + storage properties, high reversible capacity (589 mA h g −1 at 0.05 A g −1 ), and excellent cycle stability (460 mA h g −1 after 500 cycles at 1 A g −1 ). This protocol for constructing a synergistic division-of-labor cooperative system, using the magnetoelectric strategy and interfacial interactions, provides a strategy for accelerating the insertion/conversion reaction involved in transition metal sulfides in SIBs.
Triple-negative breast cancer (TNBC) is one of the most aggressive and metastatic breast cancer subtypes lacking targeted therapy. Our recent work demonstrated that circulating tumor cell (CTC) ...clusters and polyclonal metastasis of TNBC are driven by aggregation of CD44
cancer stem cells (CSC) and associated with an unfavorable prognosis, such as low overall survival. However, there is no existing therapeutic that can specifically block CTC or CSC cluster formation.
Using patient-derived xenograft (PDX) models, we established an
tumor cell clustering assay for a pilot screening of blockade antibodies. After identifying EGFR as a target candidate, we modulated the gene expression and inhibited its kinase activity to determine its functional importance in tumor cell clustering and therapeutic inhibition of lung metastasis. We also examined the molecular regulation network of EGFR and a potential connection to CSC marker CD44 and microRNAs, which regulate CTC clustering.
We report here that EGFR inhibition successfully blocks circulating CSC (cCSC) clustering and lung metastasis of TNBC. EGFR enhances CD44-mediated tumor cell aggregation and CD44 stabilizes EGFR. Importantly, blocking EGFR by a novel anti-EGFR monoclonal antibody (clone LA1) effectively blocked cell aggregation
and reduced lung metastasis
. Furthermore, our data demonstrated that the tumor suppressor microRNA-30c serves as another negative regulator of cCSC clustering and lung metastasis by targeting CD44 as well as its downstream effector EGFR.
Our studies identify a novel anti-EGFR therapeutic strategy to inhibit cCSC aggregation and therefore abolish cCSC cluster-mediated metastasis of TNBC.
Abstract only
TPS275
Background: Androgen deprivation therapy (ADT) is the backbone of therapy for metastatic hormone sensitive prostate cancer (mHSPC). Despite a high response rate, the majority of ...patients progress to metastatic castration-resistant prostate cancer (mCRPC). Both disease settings are heterogeneous with variable responses to treatment. While prostate specific antigen is an important biomarker for prognosis and disease monitoring, it has limitations. Biomarkers predictive of disease response and progression are critically needed. Circulating tumor cells (CTCs) are shed from tumors and are found in blood during advanced stages of disease. Serial characterization of CTCs serves as a real-time ‘liquid biopsy’ for molecular profiling of PC. Recent reports suggest that phenotypic & genomic heterogeneity in CTCs and cell-free DNA (cfDNA) is associated with response to AR-targeted therapy highlighting the importance of CTC as a predictive biomarker. In addition, there is a high concordance between mutations in CTCs’ DNA and CRPC tissue through whole cell exome sequencing. We showed that atypical chemokine receptor CXCR7 is up-regulated following AR-targeted therapies, activating MAPK/ERK signaling and resulting in treatment resistance (Li et al., Cancer Res. 2019). To examine the potential of CXCR7/MAPK/ERK signaling in predicting treatment response, we propose to evaluate MAPK/ERK gene signature, pERK and AR level in CRPC or mHSPC patients receiving systemic therapy. Methods: Men with new CRPC or mHSPC are eligible prior to initiating new therapy for the respective disease setting of ADT + AR targeted therapy or chemotherapy. For CRPC arm, we will collect samples at baseline, 3, 6 months & at time of progression. For mHSPC arm, samples are collected at baseline, after 7 months & at progression. We will enroll 120 patients. Collected samples are subjected to identification, isolation, and enumeration of CTCs. Our primary molecular testing will include AR and pERK staining. CfDNA exome and methylome analysis will be performed to evaluate genomic heterogeneity and epigenomic alterations. We will explore pairwise association among biomarkers of interest, stratified by subgroups, using measures of association.
Abstract
Introduction: Notwithstanding the increasing efficacy of systemic therapy, metastatic breast cancer (MBC) is still an incurable disease. The prolonged exposure to endocrine therapy will ...result in acquired resistance with consequent disease progression. Understanding the underlying mechanisms of resistance is therefore crucial for early resistance detection and for treatment choice optimization. The aim of this study was a comprehensive characterization through circulating tumor DNA analysis (ctDNA) for hypothesis generation on endocrine resistance. Methods: This retrospective study analyzed a pilot cohort of 35 metastatic breast cancer (MBC) patients (pts) treated and evaluated for ctDNA at Northwestern University (Chicago, IL). ctDNA was analyzed using the PredicinePLUS™ NGS 180-gene panel (Predicine Inc, CA). Endocrine resistance was defined as a relapse during the first 2 years of adjuvant endocrine therapy or progressive disease within endocrine therapy (ET) for MBC. Associations between clinico-pathological characteristics and gene variants were tested though Fisher’s exact test. Results: The study included 27 hormone receptor positive MBC (HR+) pts, 5 HER2 positive and 1 Triple Negative MBC (TNBC) patient. Among HR+ pts, 24 received ET in previous lines, including 21 cases treated with an aromatase inhibitor (AI)-based backbone, while 14 received an ET association with CDK4/6 inhibitors. Fifteen were classified as endocrine resistant according to clinical criteria. In the subgroup of pts previously treated with AI, the main detectable gene variants wereTP53 (48%), PIK3CA (26%), GNAS (30%), ESR1 (25%), CDH1 (22%), BRCA2(22%), ARID1A (41%) and AR (52%). Notably, TP53 and ESR1 aberrations were mainly polygenic (ESR1:c.1138G>C, c.1261A>C, c.1551G>A c.1607T>C, c.1609T>A, c.1610A>C, c.1610A>G, c.1613A>G, c.172G>A; TP53:c.1024C>T, c.473G>A, c.524G>A, c.536A>G, c.559G>A, c.586C>T, c.587G>C, c.638G>A, c.659A>G, c.713G>A, c.772del), while the main genes showing copy number variations were in BRCA2 (Loss), JAK2 (Loss), PPP2R2A (Loss), RB1 (Loss), SERPINB3 and SERPINB4 (Gain). Moreover, among the totally detected 448 gene variants, only ESR1 mutations were associated with previous AI prescription (P=0.030). Conclusion:The present study offers an insight on the mutational landscape of MBC patients treated with endocrine therapy alone or associated with CDK4/6 inhibitors. ESR1 mutations were confirmed as the predominant resistance factor and were mainly polygenic. New promising targets such as SERPINB3, SERPINB4, ARID1A and AR add new intriguing clues on the potential role of Epithelial to Mesenchymal transition in endocrine resistance and warrant further investigation on a larger, prospective, cohort.
Citation Format: Lorenzo Gerratana, Qiang Zhang, Andrew A Davis, Ami N Shah, Jianjun Yu, Shidong Jia, Youbin Zhang, Firas Wehbe, Amir Behdad, Leonidas C Platanias, William J Gradishar, Massimo Cristofanilli. Characterization of metastatic breast cancer through a novel next generation sequencing platform for hypothesis generation on endocrine resistance abstract. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-11-09.
Abstract
Introduction: Advanced breast cancer can be more aggressive and portend a worse prognosis in the younger population (age < 50). While several studies have outlined clinico-pathologic ...features and molecular features of primary disease in young women with breast cancer, data in the metastatic setting remain scarce. Thus, the goal of this study was to explore the underlying clinic-pathologic and molecular profile of young women with metastatic breast cancer.
Methods: We conducted a retrospective analysis of 138 females with metastatic breast cancer treated at Northwestern Medicine who provided consent for serial evaluation of circulating biomarkers. Patient were divided into two cohorts based on age at the time of metastasis, namely premenopausal (defined as age < 50) and postmenopausal (age ≥ 50). CellSearch™ immunomagnetic kit (Menarini Silicon Biosystems) was utilized to enumerate circulating tumor cells (CTCs), and the CellSearch™ CXC Kit (in 7.5 cc whole blood) characterized CTC HER2 expression. Circulating tumor DNA (ctDNA) was sequenced using the Guardant360 next-generation sequencing (NGS) assay (Guardant Health). When available, tissue samples from the primary and metastatic site(s) were sequenced using FoundationOne and/or Tempus xT NGS assays. Associations were drawn using Pearson’s χ2 test, independent samples T-tests, and multivariate logistic regression.
Results: Of the 138 women, 54 (39%) were premenopausal with median age of 42 (range: 28-49), and 84 (61%) were postmenopausal with median age of 57 (range: 50-81). For the premenopausal cohort, 96% had invasive ductal carcinoma, 2% invasive lobular carcinoma and 2% mixed/unknown, compared to postmenopausal with 74%, 19% and 7% respectively, p=0.003. No statistically significant association was observed based on disease subtype (HR+/HER2-, HR+/HER2+, HR-/HER2+, TNBC), correspondingly stratified as 46%, 17%, 9%, 28% (premenopausal) and 57%, 10%, 13% 20% (postmenopausal). In total, 39% of the premenopausal and 40% of the postmenopausal patients had inflammatory breast cancer (IBC). Among patients initially diagnosed with non-metastatic disease, time (years) to metastasis was 2.76 (95% CI 2.11 to 3.41) for the premenopausal and 6.08 (95% CI 4.89 to 7.27) for the postmenopausal cohort, p=0.0001. Statistically significant associations were found when comparing the NGS datasets, derived from serial collection of ctDNA +/- tissue samples. Specifically, the premenopausal group had a higher incidence of GATA3 (11 vs 6 cases; p=0.017) alterations, but a lower incidence of NF1 (1 vs 18; p<0.001) and RB1 (1 vs 9; p=0.049) alterations. Most common gene alterations included TP53 (67%), PIK3CA (45%), ERBB2 (26%), GATA3 (26%), MYC (24%), FGFR1 (19%) and ESR1 (17%) for the younger cohort, versus TP53(67%), PIK3CA (39%), ESR1 (27%), NF1 (27%), MYC (23%), ERBB2 (23%) and FGFR1 (20%) for the postmenopausal cohort. There were no statistically significant differences between the cohorts in terms of total number of ctDNA alterations at baseline draw (medianIQR: 31-7 premenopausal group; 52-7 postmenopausal group), presence of ≥5 CTCs (54%; 46% of total cases, respectively), occurrence of CTC clusters (26%; 24%), or HER2+ CTC expression (44%; 45%).
Conclusion: Our data reveal that premenopausal women diagnosed with metastatic breast cancer had a more rapid progression to metastasis and differ from their postmenopausal counterparts in both their pathologic profile (almost exclusively invasive ductal carcinoma) and molecular profile (notably, gene alteration frequencies of NF1, RB1 and GATA3), which could have significant implications in developing targeted treatment paradigms for younger women. Additionally, CTC prevalence in the metastatic setting differs from earlier stage breast cancer data showing a higher proportion of ≥5 CTCs in postmenopausal patients.
Citation Format: Kristen Carroll, Ami M Shah, Lorenzo Gerratana, Chenyu Lin, Andrew A Davis, Qiang Zhang, Youbin Zhang, Lisa Flaum, Amir Behdad, Leonidas C Platanias, William J Gradishar, Massimo Cristofanilli. Clinico-pathological and molecular features in young women with metastatic breast cancer abstract. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD8-03.
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3036
Background: The presence of HER2 expressing (HER2+) circulating tumor cells (CTCs) occurs often in metastatic breast cancer (MBC) patients (pts). We have previously showed that the ...ratio among CTCs expressing high level of HER2 and the total number of HER2+ CTCs (circulating HER2 ratio, cHer2 ratio) has a prognostic role in MBC patients. Here we further investigate the role of the cHER2 ratio in the process of metastatic spread. Methods: Under IRB-approved study we prospectively analyzed blood samples of patients with MBC enrolled before starting a new line of therapy. Samples were collected from pts treated at Northwestern University (Chicago, IL) between 2016 and 2020. CTCs were enumerated through CellSearch (Menarini Silicon Biosystems, Bologna, Italy) and characterized for HER2 expression using the CellSearch CXC Kit. HER2+ CTCs were divided in 3 different categories (1+,2+,3+) leaning on fluorescence intensity. Pts with <5 CTCs (stage IV
indolent
) were excluded from the analysis. The cHER2 ratio, defined as the sum of 2+ CTCs and 3+ CTCs divided by the total number of HER2+ CTCs, was used to split the remaining pts in 2 different cohorts: cHER2 ratio high (> 0.75) (cHER2
high
) and cHER2 ratio low (≤0.75) (cHER2
low
). The frequency of each metastatic site (i.e. liver, lung, central nervous system, bone, lymph nodes, skin/soft tissue, serosa) and the total number of different sites involved (1-7, ≤2 and >2 sites) were compared among the two sub-populations and analyzed through Fisher exact test. Results: Out of 98 pts enrolled, 77 were classified as cHER2
low
and 21 as cHER2
high
. We observed a higher frequency of oligometastatic pts (≤2 sites involved) in the cHER2
high
cohort (16, 76%), compared to only 29 (37%) in the cHER2
low
(p<0.005). Moreover, the cHER2 ratio was associated with a tropism toward specific sites of disease spread with higher incidence of liver, lung and lymph nodes metastases in the cHER2
low
cohort (p<0.05). No other statistical associations were observed in respect of specific organ tropism. The frequency of involvement for each metastatic site among the two cohorts are reported in the table. Conclusions: Measuring CTCs enumeration and HER2 expression we identified two cohorts, cHER2
high
and cHER2
low
, associated with distinct patterns of metastatic spread. The cHER2
low
pts were correlated to multiple sites of metastatic involvement, with particular tropism toward liver, lung and lymph nodes. These results confirm the prognostic role of the cHER2 ratio, suggesting a peculiar biological meaning of the HER2+ 1+ CTCs.Table: see text
Abstract
Introduction: CTCs play a critical role in BCa metastases. Molecular and genomic characterization of CTCs may help to predict BCa prognosis and identify which patients may derive treatment ...benefit, especially for those with metastatic or recurrent disease. However, CTCs are present at very low concentrations in the peripheral blood and their enrichment and expansion is technically challenging. Here we describe an ex vivo CTC culture workflow to expand CTCs for patients with Stage III/IV BCa.
Methods: Duplicate whole blood samples (7.5ml/each) were collected in EDTA tubes from 16 patients with stage III/IV BCa patients before or after systemic therapy and stored at 15-30 °C until processing. CTC enumeration was performed on one of the samples from each patient using the CELLSEARCH® System to confirm the presence of >=5 CTCs per 7.5mL of blood. CTCs enrichment was performed on the second sample from each patient using the ParsortixTM System (ANGLE PLC), a microfluidic based technology that captures rare cells based on size and deformability. Using a proprietary Cell Separation Cassette with a critical gap size of 6.5μm, the Parsortix System captured viable CTCs from the blood inside the cassette. The CTCs were then harvested by inverting the flow direction and flushing the CTCs from the cassette into 210μL of PBS. The harvested CTCs were transferred and grown in ultralow attachment plates containing RPMI-1640 medium supplemented with EGF (20ng/ml), basic FGF (20ng/ml), B27 (10ml), and 1×Antibiotic-antimycotic. CTCs were cultured in a humid 37oC incubator with 5% CO2 and 4% O2. CTC counting was performed every week using a hemocytometer. DNA isolation of the CTC culture was performed on Day 21 using DNAzol.
Results: All 16 patients had >=5 CTCs as defined by the CELLSEARCH System (based on cellular morphology and the correct phenotype of CK+, EpCAM+, DAPI+ and CD45-) at the time of the blood collection. Using the Parsortix System, highly purified CTCs (ranging in number from 300 to 17,250 cells) were isolated from the blood samples for each of the 16 patients and placed into culture (day 0). During the first week, the CTCs could be expanded to 3.5 - 5.5 fold, and then to 9.5 - 22.5 fold during the second week, to maximum amount of 112,500 within 14 days. The isolated CTCs were maintained without altered morphology at the same concentrations until Day 21. An average of 186ng and 1200ng of DNA could be isolated and purified from ~10,000 and ~110,000 cultured CTCs, respectively.
Conclusions: We identified and optimized a workflow for the recovery and culturing of CTCs from Stage III/IV BCa patients, demonstrating that cell-size dependent isolation using the Parsortix System allows for effective ex vivo culture. With further optimization, this strategy may be utilized for organoids development for drug testing and molecular analysis, representing an important tool for personalized precision therapy.
Citation Format: Qiang Zhang, Youbin Zhang, Lisa Ellen Flaum, Brian Helfand, Lorenzo Gerratana, William Gradishar, Leonidas Platanias, Massimo Cristofanilli, Massimo Cristofanilli. A novel ex vivo culture workflow to enrich and expand circulating tumor cells (CTCs) from patients with stage III/IV breast cancer (BCa) abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-370.
Abstract
Introduction: Prognosis of metastatic breast cancer (MBC) is initially predicted by the cancer’s characteristics based on AJCC TNM system, including the size of the cancer tumor, invasion ...into nearby tissue, lymph nodes and other parts of the body beyond the breast. Although additional information including hormone-receptor status, HER2 status, and possibly Oncotype DX score contributed to improve prognostic evaluation, predicting clinical outcomes and treatment benefit for MBC is still a challenge in clinic because of the clinical and biologically heterogeneous condition. We recently reported that CTCs enumeration can classify MBC in two distinct prognostic groups independently of clinical and molecular characteristics (Crit Rev Oncol Hematol. 2019). Moreover, our group reported that CTCs is associated with HER2 expression in MBC which may indicate more aggressive tumor (2019 AACR #1919). Here we compared CTCs enumeration of Stage III and Stage IV, which would be helpful to evaluate the MBC metastasis capability and treatment in clinic. Methods: The study included 38 specimens prospectively collected under IRB-approved protocol from 38 patients with Stage III MBC, and 254 specimens from 254 patients with stage IV MBC who received standard systemic treatments based on disease subtypes at NMH (2016-2020). Duplicate whole blood samples (7.5ml/each) were collected in EDTA tubes from these patients who were longitudinally characterized for CTCs before therapy (baseline). CTCs enrichment and enumeration were performed in FDA approved semi-automated fluorescence CELLTRACKS ANALYZERII® System (Menarini) by using CELLSEARCH® CXC Kit contains antibodies targeting the Epithelial Cell Adhesion Molecule (EpCAM) antigen for capturing CTCs, anti-CK-PE which is specific for the intracellular protein cytokeratin in epithelial cells, DAPI for staining the cell nucleus, anti-CD45-APC is specific for leukocytes (2019 ASCO #1036). The CTCs were classified based on morphology and correct phenotype as CK+, DAPI+ and CD45-. Kruskal-Wallis test was used for statistics. Results: Patients were classified as Luminal, HER2 positive and TNBC disease subtypes in 46.6%, 46.7% and 6.7% respectively in Stage III patients, and 54%, 18% and 28% respectively in Stage IV patients. The patients at age above 50 were 26.% in Stage III group and 68% in Stage IV group respectively. IBC patients represented 61.5% and 33.5% of Stage III and Stage IV patients respectively. Metastasis in liver, lung and bone were diagnosed in 40.7%, 40.2% and 62.8% in Stage IV patients. CTC negative (<5 CTCs) and positive (≥5CTCs) patients were identified in 32/38 (84.22%, group 1) and 6/38 (15.78%, group 2) respectively in Stage III patients, and 149/254 (59%, Stage IV indolent ) and 105/254 (41%, Stage IV aggressive ) respectively in Stage IV patients. Patients in Group 1 have a significantly less recurrence probability than patients in Group 2 (p=0.015). Correspondingly, patients with Stage IV indolent also had significantly longer survival than patients with Stage aggressive disease (p=0.0021). When comparing the all population, Group 1 patients still have the highest survival probability (p=0.00057) within 47 months follow-up survey. More interesting, there was no any CTC-clusters found in all Stage III patients when there were 28 out of 254 stage IV patients (11.02%) were detected with CTC-clusters, who had the worst prognosis in compared to either Stage IV patients without CTC-clusters or Stage III patients (p=0.00035). Conclusions: In this study, we showed that enumeration of baseline CTC and CTC-clusters correlated with worse prognosis even the patients were pathologically diagnosed for the same stage, which provided an additional measure to predict disease recurrence after systemic therapies especially for Stage III MBC patients.
Citation Format: Qiang Zhang, Zheng Cai, Lorenzo Gerratana, Paolo D'Amico, Andrew A. Davis, Saya Liz Jacob, Elena Vagia, Ami N Shah, Lisa Flaum, Youbin Zhang, Wenan Qiang, Firas Wehbe, Amir Behdad, William Gradishar, Leonidas C Platanias, Massimo Cristofanilli. Prognostic value of baseline circulating tumor cells (CTCs) enumerations is for stage III and stage IV breast cancer abstract. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS2-20.
Abstract
Introduction: Circulating tumor cells (CTCs) are the roots of metastasis which is the main cause for death in metastatic breast cancer (MBC). CTCs enumeration is strongly prognostic in ...advanced disease and can stratify patients in two distinct disease, Stage IV aggressive and Stage IV indolent. In the former disease, the detection of CTC clusters and HER2-expression increase prognostic and predictive value. The metastatic cascade is a complex, regulated process involving immune cells and endothelial cells for progression and neoangiogenesis. Circulating endothelial cells (CECs) from the inner wall of blood vessels are shed into the blood stream during formation of blood vessels which is considered a sensitive marker of endothelial damage in pathological conditions such as cancer. CECs have been also studied as a biomarker for tumor progression and monitoring anti-angiogenic therapeutic effects in MBC. We evaluated the concomitant detection of CTCs and CECs in MBC patients, along with expression of HER2 in CTCs that may offer an interesting clue to elucidate the metastasis mechanisms. Methods: Whole blood samples (7.5ml/each) were collected from 14 stage IV MBC patients before systemic therapy. CTCs enumeration was performed in FDA approved CELLTRACKS System (Menarini) by using CTC Kit contains specific antibodies targeting the EpCAM for capturing CTCs, anti-CK-PE (for epithelial cells), DAPI (for nucleus), anti-CD45-APC (for leukocytes), and anti-HER-2/neu-FLU. The CTCs were classified as CK+, EpCAM+, DAPI+ and CD45-. Meanwhile, the same patients’ blood samples (4.0ml/each) were processed for CEC analyzed by using CEC kit which immunomagnetically captures CD146+ cells, and then stains the cells for CD105-PE (specific for protein endolgin), CD45-APC, nucleus-DAPI. The positive CECs were classified as CD 146+, CD105+, DAPI+ and CD45-. The associations between CTCs, HER2 expression and CECs were evaluated. Results: The average age of patients was 53.1. Subtypes of Luminal, HER2 positive and TNBC were 64.2% 7.2% and 28.6% respectively. Distant metastasis were found in 13 out of 14 patients, including bone (7), liver (5), Lymph nodes (5) and Pleura (2). CTCs were found positive (≥5, Stage IV aggressive) in 5 patients (range: 5-47, mean=24), and HER expression was identified in all 5 of these cases with a range of numbers between 1 and 7 (mean=4.2). The ratios of HER+ CTC/total ratios were 8.51%, 17.95%, 20%, 30.77%, and 33.33%. HER2 expression were defined officially in our lab according to the percentile of positive HER2 CTCs/Total CTCs and the expression intensity as - (<20%), + (20-39%), ++ (40-59%) and +++ (≥60%) respectively. There were 9 patients (%) were identified as CTCs negative (<5, Stage IV indolent) with the mean=1, and HER+ CTCs were found in only 2 patients with Stage IV indolent. Meanwhile, CECs were found in all 14 patients with a range of numbers between 4 to 115. There were an average of 33 CECs in Stage IV aggressive disease, compared to 53 CECs in Stage IV indolent. The average of CECs were 53.44, 12 and 37.25 in Luminal, HER2 positive and TNBC groups respectively. On the other hand, patients with HER2+ CTCs had an average of 50 CECs which is significantly higher than average of 41 CECs in patients without HER2+ CTCs. Moreover, there were average of 94.5, 56 and 40.22 CECs were found in groups when HER2 expression was ++/+++, above + and - respectively. The results demonstrated that although CTC enumeration have a reverse correlation with CECs numbers, HER2 expression in CTCs was significantly related with high CECs numbers. Conclusions: Our data provides the first evidence of potential association between CTCs and CECs in metastatic breast cancer. The association between HER2 expression and CECs offers a potential new insight to mechanism connections between CECs and disease metastasis in MBC.
Citation Format: Qiang Zhang, Paolo D'Amico, Jeannine Donahue, Lorenzo Gerratana, Andrew A. Davis, Saya Liz Jacob, Zheng Cai, Elena Vagia, Wenan Qiang, Ami N. Shah, Katy Kerby, Lisa Flaum, Youbin Zhang, Firas Wehbe, Amir Behdad, William Gradishar, Leonidas Platanias, Massimo Cristofanilli. The detection and enumeration of circulating tumor cells (CTCs) and circulating endothelial cells (CECs) in metastatic breast cancer abstract. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS2-06.
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