Elucidating the genomic architecture of Asian EGFR-mutant lung adenocarcinoma through multi-region exome sequencing

EGFR-mutant lung adenocarcinomas (LUAD) display diverse clinical trajectories and are characterized by rapid but short-lived responses to EGFR tyrosine kinase inhibitors (TKIs). Through sequencing of 79 spatially distinct regions from 16 early stage tumors, we show that despite low mutation burdens, EGFR-mutant Asian LUADs unexpectedly exhibit a complex genomic landscape with frequent and early whole-genome doubling, aneuploidy, and high clonal diversity. Multiple truncal alterations, including TP53 mutations and loss of CDKN2A and RB1, converge on cell cycle dysregulation, with late sector-specific high-amplitude amplifications and deletions that potentially beget drug resistant clones. We highlight the association between genomic architecture and clinical phenotypes, such as co-occurring truncal drivers and primary TKI resistance. Through comparative analysis with published smoking-related LUAD, we postulate that the high intra-tumor heterogeneity observed in Asian EGFR-mutant LUAD may be contributed by an early dominant driver, genomic instability, and low background mutation rates.

EGFR mutant lung adenocarcinoma (LUAD) exhibit diverse clinical outcomes in response to targeted therapies. Here the authors show that these LUADs involve a complex genomic landscape with high intratumor heterogeneity, providing insights into the evolutionary trajectory of oncogene-driven LUAD and potential mediators of EGFR TKI resistance.

J/ψ Elliptic Flow in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

We report a precise measurement of the J/ψ elliptic flow in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The J/ψ mesons are reconstructed at midrapidity (|y|<0.9) in the dielectron decay channel and at forward rapidity (2.5<y<4.0) in the dimuon channel, both down to zero transverse momentum. At forward rapidity, the elliptic flow v_{2} of the J/ψ is studied as a function of the transverse momentum and centrality. A positive v_{2} is observed in the transverse momentum range 2<p_{T}<8  GeV/c in the three centrality classes studied and confirms with higher statistics our earlier results at sqrt[s_{NN}]=2.76  TeV in semicentral collisions. At midrapidity, the J/ψ  v_{2} is investigated as a function of the transverse momentum in semicentral collisions and found to be in agreement with the measurements at forward rapidity. These results are compared to transport model calculations. The comparison supports the idea that at low p_{T} the elliptic flow of the J/ψ originates from the thermalization of charm quarks in the deconfined medium but suggests that additional mechanisms might be missing in the models.

A Study of Orotracheal Intubation in Emergency Departments of Five District Hospitals in Hong Kong

Objective

To study the success rates and complications of orotracheal intubation in emergency departments of five district hospitals in Hong Kong in order to identify ways for improvement.

Method

This was a prospective observational study. The emergency department doctors performing the intubation were asked to complete an intubation study form immediately after the procedure over a period of four months. Data collected included vital signs, experiences of intubators, method of intubation and complications.

Results

A total of 347 cases were collected and 93% of them were non-trauma cases. Fifty-two percent (52%) of the cases were in cardiac arrest before intubation. Rapid sequence intubation (RSI) was applied in 36% of the cases. Junior doctors first intubated about 72% of the patients. Successful intubation was achieved in 1 and 2 attempts in 70% and 89% of the cases respectively. In 10 cases (3%), secondary methods such as laryngeal mask airway, Combitube, Trachlight or cricothyroidotomy were needed. The overall complication rate was 7.8% and the complication rate in the RSI group was 15.3%. The complication rate was even higher (20%) if intubation without medication was used in non-cardiac arrest patients. Significant drop in blood pressure was the most common complication and it could be attributed to the use of midazolam as induction medication. The success rate was found to correlate with the experience of the first intubator (p<0.05) and the laryngeal view (p<0.001). The complication rate increased with repeated attempts (p<0.001) and was higher among junior doctors (p<0.05). Early use of elastic gum bougie was associated with lower complication and higher success rates.

Conclusion

Orotracheal intubation in the emergency department was associated with high complication rate. Many complications came from junior intubators. Hypotension was the most common complication. Potentially avoidable complications may be a result of failure to use RSI in non-cardiac arrest patients and failure to use bougie in cases of poor laryngeal view.

How Evidence-Based is our Practice in a Hong Kong Emergency Department?

Objective

To evaluate how evidence-based our daily practice was.

Design

Retrospective study.

Setting

Emergency department of a public district hospital.

Patients and Methods

Between 1st August 2000 to 7th August 2000, 91 patients' records were chosen at random. A chief diagnosis was assigned for each patient. Corresponding treatments were reviewed by searching relevant randomised controlled trials (RCTs), systematic reviews and meta-analyses. Each patient had only one chief diagnosis but could have multiple interventions for that diagnosis.

Results

Out of 91 records, 14 were discarded. All of them had not been given any intervention and 11 required admission. For the remaining 77 records, there were 38 subjects in medical, paediatric, or gynaecological specialties and 39 in surgical or orthopaedic specialties. Intervention(s) given for each subject were then searched electronically through our hospital Knowledge Gateway and the results were expressed as either EBM-positive or EBM-negative. “EBM-positive” interventions denoted a support by RCTs. “EBM-negative” interventions denoted an absence of any supportive RCTs. Each patient might have EBM-positive and/or EBM-negative interventions together if that patient received more than one treatment. There were 52 patients (52/77 = 68%) who had one of their interventions being RCT-supported. The majority were patients with (1) antipyretic use of paracetamol in upper respiratory tract infection, or (2) control of pain by nonsteroidal anti-inflammatory drug, dologesic and paracetamol. There were 25 patients (25/77 = 32%) who did not receive any RCT-supported interventions. Concurrently 53 patients out of 77 (69%) received EBM-negative interventions. The majority were patients with (1) the use of antibiotics, antitussives and antihistamines in upper respiratory tract infection, (2) antispasmodics in gastroenteritis or patients with nonspecific abdominal pain, and (3) the use of analgesic balm in minor orthopaedic complaints.

Conclusion

Sixty-eight percent of patients had EBM-positive interventions. Thirty-two percent of patients did not receive any EBM-positive intervention. It was quite encouraging as compared to studies in other specialties with similar design. Concurrently 69% of patients had also been given EBM-negative interventions. There were areas for improvement if we were to implement EBM practice in the emergency department.

Targeted BMI1 inhibition impairs tumor growth in lung adenocarcinomas with low CEBPα expression

Lung cancer is the most common cause of cancer deaths. The expression of the transcription factor C/EBPα (CCAAT/enhancer binding protein α) is frequently lost in non-small cell lung cancer, but the mechanisms by which C/EBPα suppresses tumor formation are not fully understood. In addition, no pharmacological therapy is available to specifically target C/EBPα expression. We discovered a subset of pulmonary adenocarcinoma patients in whom negative/low C/EBPα expression and positive expression of the oncogenic protein BMI1 (B lymphoma Mo-MLV insertion region 1 homolog) have prognostic value. We also generated a lung-specific mouse model of C/EBPα deletion that develops lung adenocarcinomas, which are prevented by Bmi1 haploinsufficiency. BMI1 activity is required for both tumor initiation and maintenance in the C/EBPα-null background, and pharmacological inhibition of BMI1 exhibits antitumor effects in both murine and human adenocarcinoma lines. Overall, we show that C/EBPα is a tumor suppressor in lung cancer and that BMI1 is required for the oncogenic process downstream of C/EBPα loss. Therefore, anti-BMI1 pharmacological inhibition may offer a therapeutic benefit for lung cancer patients with low expression of C/EBPα and high BMI1.

Tumor-derived circulating endothelial cell clusters in colorectal cancer

Clusters of tumor cells are often observed in the blood of cancer patients. These structures have been described as malignant entities for more than 50 years, although their comprehensive characterization is lacking. Contrary to current consensus, we demonstrate that a discrete population of circulating cell clusters isolated from the blood of colorectal cancer patients are not cancerous but consist of tumor-derived endothelial cells. These clusters express both epithelial and mesenchymal markers, consistent with previous reports on circulating tumor cell (CTC) phenotyping. However, unlike CTCs, they do not mirror the genetic variations of matched tumors. Transcriptomic analysis of single clusters revealed that these structures exhibit an endothelial phenotype and can be traced back to the tumor endothelium. Further results show that tumor-derived endothelial clusters do not form by coagulation or by outgrowth of single circulating endothelial cells, supporting a direct release of clusters from the tumor vasculature. The isolation and enumeration of these benign clusters distinguished healthy volunteers from treatment-naïve as well as pathological early-stage (≤IIA) colorectal cancer patients with high accuracy, suggesting that tumor-derived circulating endothelial cell clusters could be used as a means of noninvasive screening for colorectal cancer. In contrast to CTCs, tumor-derived endothelial cell clusters may also provide important information about the underlying tumor vasculature at the time of diagnosis, during treatment, and throughout the course of the disease.

Pluripotent stem cells secrete Activin A to improve their epiblast competency after injection into recipient embryos

It is not fully clear why there is a higher contribution of pluripotent stem cells (PSCs) to the chimera produced by injection of PSCs into 4-cell or 8-cell stage embryos compared with blastocyst injection. Here, we show that not only embryonic stem cells (ESCs) but also induced pluripotent stem cells (iPSCs) can generate F0 nearly 100% donor cell-derived mice by 4-cell stage embryo injection, and the approach has a “dose effect”. Through an analysis of the PSC-secreted proteins, Activin A was found to impede epiblast (EPI) lineage development while promoting trophectoderm (TE) differentiation, resulting in replacement of the EPI lineage of host embryos with PSCs. Interestingly, the injection of ESCs into blastocysts cultured with Activin A (cultured from 4-cell stage to early blastocyst at E3.5) could increase the contribution of ESCs to the chimera. The results indicated that PSCs secrete protein Activin A to improve their EPI competency after injection into recipient embryos through influencing the development of mouse early embryos. This result is useful for optimizing the chimera production system and for a deep understanding of PSCs effects on early embryo development.

Induced-Decay of Glycine Decarboxylase Transcripts as an Anticancer Therapeutic Strategy for Non-Small-Cell Lung Carcinoma

Self-renewing tumor-initiating cells (TICs) are thought to be responsible for tumor recurrence and chemo-resistance. Glycine decarboxylase, encoded by the GLDC gene, is reported to be overexpressed in TIC-enriched primary non-small-cell lung carcinoma (NSCLC). GLDC is a component of the mitochondrial glycine cleavage system, and its high expression is required for growth and tumorigenic capacity. Currently, there are no therapeutic agents against GLDC. As a therapeutic strategy, we have designed and tested splicing-modulating steric hindrance antisense oligonucleotides (shAONs) that efficiently induce exon skipping (half maximal inhibitory concentration [IC₅₀] at 3.5–7 nM), disrupt the open reading frame (ORF) of GLDC transcript (predisposing it for nonsense-mediated decay), halt cell proliferation, and prevent colony formation in both A549 cells and TIC-enriched NSCLC tumor sphere cells (TS32). One candidate shAON causes 60% inhibition of tumor growth in mice transplanted with TS32. Thus, our shAONs candidates can effectively inhibit the expression of NSCLC-associated metabolic enzyme GLDC and may have promising therapeutic implications.

Abstract P1-07-14: Rates of immune infiltration in patients with triple-negative breast cancers by molecular subtype and in patients with inflammatory and non-inflammatory breast cancers

Background

In patients with triple-negative breast cancer (TNBC), tumor-infiltrating lymphocytes (TILs) have been reported to be associated with improved survival. Lehmann et al. identified 6 molecular subtypes of TNBC [basal-like (BL) 1, BL2, mesenchymal (M), mesenchymal stem like (MSL), immunomodulatory (IM), and luminal androgen receptor (LAR)], and we previously reported that TNBC subtype is a predictor of pathologic complete response (pCR). Recently, the IM gene expression signature has been shown to be indicative of the presence of TILs and has been incorporated into TNBC subtyping as a modifier of the other groups rather than a separate subtype. However, the association between TNBC subtype and the presence of TILs is not known. We hypothesized that the BL2 and LAR subtypes, which have low pCR rates, have low rates of immune infiltration. Inflammatory breast cancer (IBC) is an aggressive cancer that is frequently triple-negative. The association between IBC and the presence of TILs also is not known. In this study, we analyzed the association between TNBC molecular subtype and the IM signature and determined whether the IM signature differed between patients with IBC and non-IBC.

Methods

We retrospectively analyzed 88 patients with TNBC from the World IBC Consortium dataset for whom IBC status was known (IBC, n=39; non-IBC, n=49) and tumor gene expression data were available. TNBC specimens were classified using the TNBCtype algorithm (Insight Genetics, Inc., TN, USA), which uses a 101-gene signature. For each tumor, the TNBCtype algorithm reports the TNBC molecular subtype (BL1, BL2, M, MSL, or LAR) and the IM status, which is described as positive (IM+) or negative (IM-). Recently, Fisher's exact test was used to analyze differences in subtype distribution between the IM+ and IM- tumors.

Results

The subtype distribution differed significantly between the IM+ and IM- tumors

IM signature in TNBC subtypesSubtypeTotal (n=88)IM+ (n=32)IM- (n=56)BL13015 (50)15 (50)BL2202 (100)M808 (100)MSL3113 (42)18 (58)LAR121 (8)11 (92)Not determined53 (60)2 (40) (p=0.0087). The majority of IM+ cases occurred in the BL1 and MSL subtypes. No IM+ cases were observed in the BL2 or M subtypes, and only 1 was observed in the LAR subtype. IM+ cases occurred at roughly the same frequency in patients with IBC (33%) and non-IBC (37%, p=0.73).

Conclusions

TNBC molecular subtypes differ in their degree of immune infiltration, and most IM+ TNBCs are of the BL1 and MSL subtypes. Our finding that the proportion of IM+ cases was not different between IBC and non-IBC indicates that TILs are recruited to the tumor microenvironment similarly in IBC and non-IBC tumors. Further, Pietenpol et al recently showed that the MSL signature represents normal stromal cells rather than tumor cells by performing laser-capture microdissection of TNBC specimen. Validation studies are needed to corroborate and further expand upon our findings.

Citation Format: Harano K, Wang Y, Lim B, Seitz RS, Morris SW, Bailey DB, Hout DR, Skelton RL, Ring BZ, Masuda H, Rao AUK, Woodward WA, Reuben JM, Ueno NT. Rates of immune infiltration in patients with triple-negative breast cancers by molecular subtype and in patients with inflammatory and non-inflammatory breast cancers [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-07-14.

Abstract OT2-01-22: NCT02456857: A phase II trial of liposomal doxorubicin, bevacizumab and everolimus (DAE) in patients (pts) with localized triple-negative breast cancer (TNBC) with tumors predicted insensitive to standard neoadjuvant chemotherapy (NACT)

BACKGROUND: Approximately 50% of TNBC pts treated with standard taxane/anthracycline-based NACT will have chemo-insensitive disease (CID) manifested as extensive residual disease (RCB-II or III) at the time of surgery. 40-80% of these pts will develop recurrence within 3 years of initial diagnosis. Recent advances in molecular profiling have identified subsets of TNBC with distinct, targetable molecular features. We developed a clinical trial to identify and characterize CID (ARTEMIS: A Randomized, TNBC Enrolling trial to confirm Molecular profiling Improves Survival). In the ARTEMIS trial, treatment naïve pts with localized TNBC undergo a pretreatment biopsy and then immediately start their initial phase of anthracycline-based chemotherapy so that the results of the molecular characterization are used in combination with response assessment (clinical exam/diagnostic imaging) to identify CID and inform the second phase of NACT, thus using a 'second hit' strategy in the middle of NACT to overcome drug resistance. The mesenchymal subtypes of TNBC have a high incidence of PI3K pathway activation. Preclinical models demonstrated response to PI3K inhibitors in this subtype. Metaplastic breast cancers make up ∼30% of tumors characterized as 'claudin-low/mesenchymal' by gene signature and are also associated with a high rate of PI3K activating molecular aberrations. A combination regimen of liposomal doxorubicin, bevacizumab and the mTOR inhibitors temsirolimus or everolimus (DAT or DAE) demonstrated response (including durable complete responses) in metastatic metaplastic breast cancer.

PRIMARY OBJECTIVE: Determine the rate of pathologic complete response (pCR/RCB-0) or minimal residual disease (RCB-I) after 4 cycles of DAE for treatment of mesenchymal TNBC deemed to be CID through the ARTEMIS trial

TRIAL DESIGN AND STATISTICAL METHODS: Only pts deemed to have mesenchymal CID on the ARTEMIS trial can enter this non-randomized phase II study. Realizing that pts without response to their initial cycles of chemotherapy have very low chance (5%) of achieving pCR with additional cycles of chemotherapy, it would be clinically meaningful to see pCR in this pt population improved to 20%. Counting pCR (RCB-0) or RCB-I as response, a two-stage Gehan-type design will be employed with 14 pts in the first stage. If at least one pt responds, 23 more pts will be added for a total of 37 pts. This design has a 49% chance of terminating after the first stage if the true response rate is 0.05, 23% chance if the true rate is 0.10, 10% if the true rate is 0.15 and 4% if the true rate is 0.20. If accrual continues to the second stage and a total of 37 pts are enrolled, the 95% confidence interval for a 0.20 response rate will extend from 0.10 to 0.35.

BRIEF ELIGIBILITY CRITERIA: Inclusion: localized TNBC enrolled onto ARTEMIS trial, adequate organ, bone marrow and cardiac parameters Exclusion: metastatic disease, pregnant or lactating pts, medical illness that increases chance of moderate to severe toxicity

CORRELATIVE SCIENCE: Correlate vimentin expression by IHC, mesenchymal signatures and PI3K pathway aberrations with response.

Citation Format: Moulder S, Hess K, Rauch M, Astrada B, Litton J, Mittendorf E, Ueno N, Tripathy D, Lim B, Piwnica-Worms H, Thompson A, Symmans WF. NCT02456857: A phase II trial of liposomal doxorubicin, bevacizumab and everolimus (DAE) in patients (pts) with localized triple-negative breast cancer (TNBC) with tumors predicted insensitive to standard neoadjuvant chemotherapy (NACT) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-01-22.

Abstract OT3-02-05: NCI-2016-00367: A phase IIB study of neoadjuvant ZT regimen (enzalutamide therapy in combination with weekly paclitaxel) for androgen receptor (AR)-positive triple-negative breast cancer (TNBC)

BACKGROUND: Approximately 50% of TNBC expresses AR by immunohistochemical (IHC) staining. Luminal androgen receptor (LAR) subtype is heavily enriched in hormonally regulated genes, yet negative for ER by IHC. LAR is associated with low pCR rates and long survival. Preclinical data have shown that taxanes inhibit translocation of AR from the cytoplasm to the nucleus where AR is activated. Combining paclitaxel with enzalutamide may inhibit the AR pathway synergistically thereby increasing pCR rates. We hypothesized that patients with AR-positive TNBC who have chemo-insensitive disease (CID) after initial anthracycline-based chemotherapy treated with ZT would have higher RCB-0 and RCB-I rates than those who receive conventional taxane-based chemotherapy. Our team developed a clinical trial to identify patients with CID (ARTEMIS: A Randomized, TNBC Enrolling trial to confirm Molecular profiling Improves Survival). In the ARTEMIS trial, treatment-naïve patients with localized TNBC undergo a pretreatment biopsy and then begin anthracycline-based chemotherapy. Molecular testing results and radiographic response assessment are used to identify CID and will guide the second phase of neoadjuvant chemotherapy (NACT) to overcome CID.

PRIMARY OBJECTIVE: To determine RCB-0 and RCB-I rates of patients with TNBC who have CID to initial anthracycline-based chemotherapy and who received ZT.

TRIAL DESIGN AND STATISTICAL METHODS: Patients with CID from the ARTEMIS trial can enroll in the 12-week ZT (paclitaxel, 80 mg/m2 intravenously per week; enzalutamide, 160 mg orally per day). We will define pCR (RCB-0) or RCB-I as a response, using a Simon optimal 2-stage design with alpha=beta=10% and then setting the threshold for an acceptable pCR or RCB-I rate at 20%. We will enroll 12 patients into the first stage. If no patients experience pCR or RCB-I, we will stop the study after the first stage. If at least 1 patient experiences pCR or RCB-I, we will enroll 25 more patients for a total of 37 patients. We would declare the treatment worthy of further study if at least 4 of the 37 patients experience pCR or RCB-I. This design has a 54% probability of early termination after the first stage if the true pCR or RCB-I probability is 5%. Because patients with CID have a very low chance (5%) of achieving pCR with additional chemotherapy, improving pCR rates to 20% in this patient population would be clinically meaningful.

BRIEF ELIGIBILITY CRITERIA: Inclusion criteria: Primary invasive TNBC patients who have CID under the ARTEMIS trial; AR+ ≥1% nuclear staining by IHC; and adequate physical, organ, bone marrow, and cardiac functions. Exclusion criteria: Pregnant or lactating patients, history of colitis or absorption abnormality, known or suspected brain metastasis or leptomeningeal disease, or history of seizure.

CORRELATIVE SCIENCE: Enumeration of circulating tumor cells (CTCs) and expression of CTC-related gene transcripts will be measured to correlate CTC characteristics and/or gene profiles related to the AR pathway and treatment response to ZT.

Citation Format: Fujii T, Lim B, Helgason T, Hess KR, Gilcrease MZ, Willey JS, Tripathy D, Litton JK, Moulder S, Krishnamurthy S, Yang W, Reuben JM, Symmans WF, Ueno NT. NCI-2016-00367: A phase IIB study of neoadjuvant ZT regimen (enzalutamide therapy in combination with weekly paclitaxel) for androgen receptor (AR)-positive triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT3-02-05.

Abstract OT2-01-20: Phase IIB study of neoadjuvant panitumumab combined with carboplatin and paclitaxel (PaCT) for anthracycline-resistant triple-negative breast cancer (TNBC)

BACKGROUND: Approximately 50% of patients with TNBC treatedwithstandardtaxane/anthracycline-based neoadjuvant chemotherapy (NACT)have chemo-insensitive disease (CID), i.e., residual disease burden (RCB)-II/III at the time of surgery, and 40-80% of patients develop recurrence within 3 years. Recent developments in molecular profiling have identified subsets of TNBC with distinct, targetable molecular features. We developed a clinical trial to identify and characterize CID (ARTEMIS: A Randomized, TNBC-Enrolling trial to confirm Molecular profiling Improves Survival). In ARTEMIS, patients with localized TNBC will undergo a pretreatment biopsy, then begin anthracycline-based NACT. During NACT, we use molecular profiling and response assessment to identify CID and allocate patients to alternative therapies to overcome CID. Epidermal growth factor receptor (EGFR) is overexpressed in 25-30% of TNBC. In preclinical studies, suppression of EGFR signaling has shown efficacy in controlling cancers through suppression of the stem cell population, enhanced apoptosis via MAPK/PI3K signaling, and modulation of epithelial-mesenchymal transition (EMT). Moreover, in a phase II trial of triple negative inflammatory breast cancer, neoadjuvant PaCT yielded significantly higher pathologic complete response (pCR) rates than historic control. Taken together, we hypothesize that using PaCT to suppress EGFR in TNBC will enhance the pCR rate.

OBJECTIVES: Primary objective: determine pCR and RCB-0/I rates in TNBC patients with CID given PaCT. Secondary objective: determine the benefit of using baseline genomic signatures to develop an alternative second phase of NACT.

TRIAL DESIGN AND STATISTICAL METHODS: Patients with &gt;10% volume reduction for non-CID or &lt;80% for CID will enroll in a biomarker-guided, experimental, nonrandomized phase II study and be given PaCT (panitumumab 2.5 mg/kg, carboplatin AUC 5, paclitaxel 80 mg/m2). Because pCR rates in pts with CID with additional cycles of taxane-based therapy are low (∼5%), a 20% response rate (RCB-0 or RCB-I) will be considered clinically meaningful. A two-stage Gehan-type design will be employed. If at least 1 of 14 patients responds, 23 more patients will be added, for a total of 37 patients. This design has a 49% chance of terminating after the first stage if the true response rate is 0.05, 23% if the rate is 0.10, 10% if the rate is 0.15, and 4% if the rate is 0.20. If accrual continues to the second stage and 37 patients are enrolled, the 95% confidence interval for a 0.20 response rate will be 0.10 to 0.35.

BRIEF ELIGIBILITY CRITERIA: Inclusion: localized TNBC; enrolled in ARTEMIS trial; adequate organ, bone marrow, and cardiac parameters; Exclusion: pregnant or lactating, known or suspected metastasis.

CORRELATIVE SCIENCE: Circulating tumor cells (CTCs) and cell free (cf) DNA in baseline and subsequent blood samples, EGFR expression (immunohistochemistry), stem cell/EMT/apoptosis marker changes in tissue and CTCs, PD-L1 glycosylation for EGFR sensitivity.

Citation Format: Lim B, Helgason T, Hess KR, Piwnica-Worms H, Yang W, Adrada BE, Rauch GM, Gilcrease M, Symmans FW, Huo L, Mittendorf EA, Thompson A, Stacy M-TL, Debu T, Ueno NT. Phase IIB study of neoadjuvant panitumumab combined with carboplatin and paclitaxel (PaCT) for anthracycline-resistant triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-01-20.

A Transcriptomic and Epigenomic Comparison of Fetal and Adult Human Cardiac Fibroblasts Reveals Novel Key Transcription Factors in Adult Cardiac Fibroblasts

•

The interplay between cardiomyocytes and cardiac fibroblasts is increasingly being recognized as important in cardiac disease.

•

Fetal and adult cardiac fibroblasts influence their neighboring cardiomyocytes in different ways. A genome-wide comparison of the 2 reveals that they share >80% of gene transcripts.

•

Motif analysis of empirical regulatory elements located next to differentially expressed genes led to identification of key differential regulators of fibroblast identity.

•

STAT1 and PLAGL1 were identified and validated as key transcription factors to maintain the adult cardiac fibroblast phenotype. Loss of either factor led to a significant change in phenotype, including smaller cell size, apoptosis, reduced turnover, and down-regulated collagen gene expression.

Cardiovascular disease remains the number one global cause of death and presents as multiple phenotypes in which the interplay between cardiomyocytes and cardiac fibroblasts (CFs) has become increasingly highlighted. Fetal and adult CFs influence neighboring cardiomyocytes in different ways. Thus far, a detailed comparison between the two is lacking. Using a genome-wide approach, we identified and validated 2 crucial players for maintaining the adult primary human CF phenotype. Knockdown of these factors induced significant phenotypical changes, including senescence and reduced collagen gene expression. These may now represent novel therapeutic targets against deleterious functions of CFs in adult cardiovascular disease.