Clinical and pathological factors associated with survival in patients with pancreatic cancer who receive adjuvant therapy after neoadjuvant therapy: A retrospective multi-institutional analysis

BACKGROUND

Neoadjuvant therapy is being increasingly used for patients with pancreatic cancer. The role of adjuvant therapy in these patients is unclear. The purpose of this study was to identify clinical and pathologic characteristics that are associated with longer overall survival in patients with pancreatic cancer who receive adjuvant therapy after neoadjuvant therapy.

METHODS

This study was conducted using multi-institutional data. All patients underwent surgery after at least 1 cycle of neoadjuvant therapy for pancreatic cancer. Patients who died within 3 months after surgery and were known to have distant metastasis or macroscopic residual disease were excluded. Mann-Whitney U test, χ2 analysis, Kaplan-Meier plot, and univariate and multivariate Cox regression analysis were performed as statistical analyses.

RESULTS

In the present study, 529 patients with resected pancreatic cancer after neoadjuvant therapy were reviewed. For neoadjuvant therapy, 177 (33.5%) patients received neoadjuvant chemotherapy, and 352 (66.5%) patients received neoadjuvant chemoradiotherapy. The median duration of neoadjuvant therapy was 7.0 months (interquartile range, 5.0-8.7). Patients were followed for a median of 23.0 months after surgery. Adjuvant therapy was administered to 297 (56.1%) patients and was not associated with longer overall survival for the entire cohort (24 vs 22 months, P = .31). Interaction analysis showed that adjuvant therapy was associated with longer overall survival in patients who received less than 4 months neoadjuvant therapy (hazard ratio 0.40; 95% confidence interval 0.17-0.95; P = .03) or who had microscopic margin positive surgical resections (hazard ratio 0.56; 95% confidence interval 0.33-0.93; P = .03).

CONCLUSION

In this retrospective study, there was a survival benefit associated with adjuvant therapy for patients who received less than 4 months of neoadjuvant therapy or had microscopic positive margins.

Generation of liver metastases in a mouse model using ultrasound-guided intravenous injection

Here, we present a protocol to generate a murine model of liver metastasis by directly injecting tumor cells into the portal vein under ultrasound guidance. We describe steps for animal and cell preparation and two techniques for injecting tumor cells. One technique is freehand, while the other technique is device-assisted using a 3D-printed prototype device. Finally, we describe tumor surveillance with bioluminescent imaging.

Abstract PR010: Multiplex imaging reveals features of organotropism in pancreatic ductal adenocarcinoma

PDAC patients have a dismal prognosis with an 11% 5-year survival rate, driven in part by the fact that 90% of patients are diagnosed with metastatic disease. In a cohort of 300 PDAC patients, we observed that patients who had lung-only metastasis had longer overall survival than the majority of patients with metastasis to the liver. We used gene expression data to develop a signature based on gene expression in primary tumors of liver versus lung organotropism, which we called pORG. Our pORG signature predicts long term survival in PDAC patients and reveals unique features of the primary tumor, including increased interferon and immune activity in lung tropic tumors and increased proliferation and replication stress in liver-tropic tumors. To validate our findings, we generated cyclic immunofluorescence multiplex imaging data for a subset of 34 patients. Single cell image analysis revealed B and T cell infiltration and spatial clustering in low pORG/ lung tropic tumors, and markers of replication stress in high pORG patients. Our work suggests unique targetable tumor and microenvironment features linked to organotropism in PDAC.

Citation Format: Jennifer Eng, Jason Link, Carl Pelz, Rosalie Sears. Multiplex imaging reveals features of organotropism in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr PR010.

Characterization data of reference materials used for phase II of the priority program DFG SPP 2005 "Opus Fluidum Futurum - Rheology of reactive, multiscale, multiphase construction materials"

A thorough characterization of base materials is the prerequisite for further research. In this paper, the characterization data of the reference materials (CEM I 42.5 R, limestone powder, calcined clay and a mixture of these three components) used in the second funding phase of the priority program 2005 of the German Research Foundation (DFG SPP 2005) are presented under the aspects of chemical and mineralogical composition as well as physical and chemical properties. The data were collected based on tests performed by up to eleven research groups involved in this cooperative program.

High-content single-cell combinatorial indexing

Single-cell combinatorial indexing (sci) with transposase-based library construction increases the throughput of single-cell genomics assays but produces sparse coverage in terms of usable reads per cell. We develop symmetrical strand sci ('s3'), a uracil-based adapter switching approach that improves the rate of conversion of source DNA into viable sequencing library fragments following tagmentation. We apply this chemistry to assay chromatin accessibility (s3-assay for transposase-accessible chromatin, s3-ATAC) in human cortical and mouse whole-brain tissues, with mouse datasets demonstrating a six- to 13-fold improvement in usable reads per cell compared with other available methods. Application of s3 to single-cell whole-genome sequencing (s3-WGS) and to whole-genome plus chromatin conformation (s3-GCC) yields 148- and 14.8-fold improvements, respectively, in usable reads per cell compared with sci-DNA-sequencing and sci-HiC. We show that s3-WGS and s3-GCC resolve subclonal genomic alterations in patient-derived pancreatic cancer cell lines. We expect that the s3 platform will be compatible with other transposase-based techniques, including sci-MET or CUT&Tag.

Charge regulated solid-liquid interfaces interacting on the nanoscale: Benchmarking of a generalized speciation code (SINFONIA)

Surface chemistry of mineral phases in aqueous environments generates the electrostatic forces involved in particle-particle interactions. However, few models directly take into account the influence of surface speciation and changes in solution speciation when the diffuse layer potential profiles of approaching particles overlap and affect each other. These electrostatic interactions can be quantified, ideally, through charge regulation, considering solution and surface speciation changes upon particle approach by coupling state-of-the-art surface complexation models for the two particle surfaces with a Poisson-Boltzmann type distribution of electrostatic potential and ions in the inter-particle space. These models greatly improve the accuracy of inter-particle force calculations at small inter-particle separations compared to constant charge and constant potential approaches. This work aims at advancing charge regulation calculations by including full chemical speciation and advanced surface complexation models (Basic Stern-, three-, or four plane models and charge distribution concepts), for cases of similar and dissimilar surfaces involving the numerical solution of the Poisson-Boltzmann equation for arbitrary electrolytes. The concept was implemented as a Python-based code and in COMSOL. The flexibility and precision of both, concept and implementations are demonstrated in several benchmark calculations testing the new codes against published results or simulations using established speciation codes, including aqueous speciation, surface complexation and various interaction force examples. Due to the flexibility in terms of aqueous chemistry and surface complexation models for various geometries, a large variety of potential applications can be tackled with the developed codes including industrial, biological, and environmental systems, from colloidal suspensions to gas bubbles, emulsions, slurries like cement paste, as well as new possibilities to assess the chemistry in nano-confined systems.

Measurement of the Iron Spectrum in Cosmic Rays from 10 GeV/n to 2.0 TeV/n with the Calorimetric Electron Telescope on the International Space Station

The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray iron over a wide energy interval. In this Letter a measurement of the iron spectrum is presented in the range of kinetic energy per nucleon from 10  GeV/n to 2.0  TeV/n allowing the inclusion of iron in the list of elements studied with unprecedented precision by space-borne instruments. The measurement is based on observations carried out from January 2016 to May 2020. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The energy is measured by a homogeneous calorimeter with a total equivalent thickness of 1.2 proton interaction lengths preceded by a thin (3 radiation lengths) imaging section providing tracking and energy sampling. The analysis of the data and the detailed assessment of systematic uncertainties are described and results are compared with the findings of previous experiments. The observed differential spectrum is consistent within the errors with previous experiments. In the region from 50  GeV/n to 2  TeV/n our present data are compatible with a single power law with spectral index -2.60±0.03.

Leukocyte Heterogeneity in Pancreatic Ductal Adenocarcinoma: Phenotypic and Spatial Features Associated with Clinical Outcome

Immunotherapies targeting aspects of T cell functionality are efficacious in many solid tumors, but pancreatic ductal adenocarcinoma (PDAC) remains refractory to these treatments. Deeper understanding of the PDAC immune ecosystem is needed to identify additional therapeutic targets and predictive biomarkers for therapeutic response and resistance monitoring. To address these needs, we quantitatively evaluated leukocyte contexture in 135 human PDACs at single-cell resolution by profiling density and spatial distribution of myeloid and lymphoid cells within histopathologically defined regions of surgical resections from treatment-naive and presurgically (neoadjuvant)-treated patients and biopsy specimens from metastatic PDAC. Resultant data establish an immune atlas of PDAC heterogeneity, identify leukocyte features correlating with clinical outcomes, and, through an in silico study, provide guidance for use of PDAC tissue microarrays to optimally measure intratumoral immune heterogeneity. Atlas data have direct applicability as a reference for evaluating immune responses to investigational neoadjuvant PDAC therapeutics where pretherapy baseline specimens are not available. SIGNIFICANCE: We provide a phenotypic and spatial immune atlas of human PDAC identifying leukocyte composition at steady state and following standard neoadjuvant therapies. These data have broad utility as a resource that can inform on leukocyte responses to emerging therapies where baseline tissues were not acquired.This article is highlighted in the In This Issue feature, p. 1861.

Acidic fibroblast growth factor underlies microenvironmental regulation of MYC in pancreatic cancer

Despite a critical role for MYC as an effector of oncogenic RAS, strategies to target MYC activity in RAS-driven cancers are lacking. In genetically engineered mouse models of lung and pancreatic cancer, oncogenic KRAS is insufficient to drive tumorigenesis, while addition of modest MYC overexpression drives robust tumor formation, suggesting that mechanisms beyond the RAS pathway play key roles in MYC regulation and RAS-driven tumorigenesis. Here we show that acidic fibroblast growth factor (FGF1) derived from cancer-associated fibroblasts (CAFs) cooperates with cancer cell–autonomous signals to increase MYC level, promoter occupancy, and activity. FGF1 is necessary and sufficient for paracrine regulation of MYC protein stability, signaling through AKT and GSK-3β to increase MYC half-life. Patient specimens reveal a strong correlation between stromal CAF content and MYC protein level in the neoplastic compartment, and identify CAFs as the specific source of FGF1 in the tumor microenvironment. Together, our findings demonstrate that MYC is coordinately regulated by cell-autonomous and microenvironmental signals, and establish CAF-derived FGF1 as a novel paracrine regulator of oncogenic transcription.

Direct Measurement of the Cosmic-Ray Carbon and Oxygen Spectra from 10 GeV/n to 2.2 TeV/n with the Calorimetric Electron Telescope on the International Space Station

In this paper, we present the measurement of the energy spectra of carbon and oxygen in cosmic rays based on observations with the Calorimetric Electron Telescope on the International Space Station from October 2015 to October 2019. Analysis, including the detailed assessment of systematic uncertainties, and results are reported. The energy spectra are measured in kinetic energy per nucleon from 10  GeV/n to 2.2  TeV/n with an all-calorimetric instrument with a total thickness corresponding to 1.3 nuclear interaction length. The observed carbon and oxygen fluxes show a spectral index change of ∼0.15 around 200  GeV/n established with a significance >3σ. They have the same energy dependence with a constant C/O flux ratio 0.911±0.006 above 25  GeV/n. The spectral hardening is consistent with that measured by AMS-02, but the absolute normalization of the flux is about 27% lower, though in agreement with observations from previous experiments including the PAMELA spectrometer and the calorimetric balloon-borne experiment CREAM.

Characterization data of reference cement CEM III/A 42.5N used for priority program DFG SPP 2005 "Opus Fluidum Futurum - Rheology of reactive, multiscale, multiphase construction materials"

Two types of cements were selected as the reference cement in the priority program 2005 of the German Research Foundation (DFG SPP 2005). A thorough characterization of CEM I 42.5 R has been made in a recent publication [1]. In this paper, the characterization data of the other reference cement CEM III/A 42.5 N are presented from the aspects of chemical and mineralogical compositions as well as physical and chemical properties. The characterization data of the slag, which is the second main constituent of this specific cement besides the clinker, are presented independently. For all data received, the mean values and the corresponding errors were calculated. The data shall be used for the ongoing research within the priority program. Also, researchers from outside this priority program can benefit from these data if the same materials are used.

Abstract I16: KRAS and environmental signals regulate MYC to drive lineage plasticity, pancreas cancer progression, and therapeutic resistance

Cellular plasticity in cancer is emerging as a biomarker of aggressive behavior and an important therapeutic resistance mechanism. The ability of cancer cells to switch lineage and differentiation states provides survival advantages in adverse tumor microenvironments and under therapeutic stress. Pancreatic ductal adenocarcinoma (PDAc) tumors display a dense immunosuppressive microenvironment and a high degree of cellular heterogeneity contributing to poor outcomes. Normally, pancreatic cellular plasticity allows for acinar-to-ductal metaplasia (ADM) in response to inflammation or injury as a reversible process and important mechanism for regeneration of functional tissue. However, mutant KRAS, which is a hallmark of over 90% of PDAc, drives ADM that progresses to ductal precursor lesions (PanINs) and PDAc. We have demonstrated that PDAc can further develop ductal to neuroendocrine lineage plasticity, and that this confers therapeutic resistance and is a biomarker of poor outcomes in patients. This discovery is consistent with other reports in prostate, lung, and breast cancer where neuroendocrine differentiation confers an aggressive, therapeutically resistant state. Mechanistically, we have demonstrated a role for the MYC oncoprotein in PDAc ductal – NE lineage plasticity. MYC is functionally activated by post-translational modifications to a conserved motif, Serine 62-Proline 63, in the MYC N-terminal transactivation domain. In PDAc, KRAS mutations and environmental signaling stimulate MYC Serine 62 phosphorylation and PIN1-mediated Proline 63 isomerization, which promote MYC DNA binding and regulation of pro-oncogenic target genes. We have also observed that cancer-associated fibroblasts (CAFs) can promote PDAc lineage plasticity and that the proline isomerase PIN1 involved in post-translational activation of MYC is also critical for fibroblast activation. Thus, PIN1 has a tumor cell intrinsic and stromal cell function, where loss of PIN1 in pancreatic stellate cells suppresses their activation to CAFs and their support of tumor growth. To understand crosstalk between the tumor microenvironment and cancer cell plasticity, and to develop effective therapeutic strategies that overcome this survival mechanism, we are using 3-D bioprinting to model tumor-stromal interactions and pursuing novel drugs that target post-translational regulation of MYC.

Citation Format: Ellen Langer, Yulong Su, Meghan Joly, Brittany Allen-Petersen, Amy Farrell, Patrick Worth, Dan Liefwalker, Jason Link, Brett Sheppard, Rosalie Sears. KRAS and environmental signals regulate MYC to drive lineage plasticity, pancreas cancer progression, and therapeutic resistance [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr I16.

Characterization data of reference cement CEM I 42.5 R used for priority program DFG SPP 2005 "Opus Fluidum Futurum - Rheology of reactive, multiscale, multiphase construction materials"

A thorough characterization of starting materials is the precondition for further research, especially for cement, which contains various phases and presents quite a complex material for fundamental scientific investigation. In the paper at hand, the characterization data of the reference cement CEM I 42.5 R used within the priority program 2005 of the German Research Foundation (DFG SPP 2005) are presented from the aspects of chemical and mineralogical compositions as well as physical and chemical properties. The data were collected based on tests conducted by nine research groups involved in this cooperative program. For all data received, the mean values and the corresponding errors were calculated. The results shall be used for the ongoing research within the priority program.

Innate αβ T Cells Mediate Antitumor Immunity by Orchestrating Immunogenic Macrophage Programming

Unconventional T-lymphocyte populations are emerging as important regulators of tumor immunity. Despite this, the role of TCRαβ⁺CD4^-CD8^-NK1.1^- innate αβ T cells (iαβT) in pancreatic ductal adenocarcinoma (PDA) has not been explored. We found that iαβTs represent ∼10% of T lymphocytes infiltrating PDA in mice and humans. Intratumoral iαβTs express a distinct T-cell receptor repertoire and profoundly immunogenic phenotype compared with their peripheral counterparts and conventional lymphocytes. iαβTs comprised ∼75% of the total intratumoral IL17⁺ cells. Moreover, iαβT-cell adoptive transfer is protective in both murine models of PDA and human organotypic systems. We show that iαβT cells induce a CCR5-dependent immunogenic macrophage reprogramming, thereby enabling marked CD4⁺ and CD8⁺ T-cell expansion/activation and tumor protection. Collectively, iαβTs govern fundamental intratumoral cross-talk between innate and adaptive immune populations and are attractive therapeutic targets. SIGNIFICANCE: We found that iαβTs are a profoundly activated T-cell subset in PDA that slow tumor growth in murine and human models of disease. iαβTs induce a CCR5-dependent immunogenic tumor-associated macrophage program, T-cell activation and expansion, and should be considered as novel targets for immunotherapy.See related commentary by Banerjee et al., p. 1164.This article is highlighted in the In This Issue feature, p. 1143.

Abstract 799: Aberrant mitochondrial protein involvement through early PDAC initiation and progression using multiplexed DNA-PAINT and correlative histology

Prior to pancreatic ductal adenocarcinoma (PDAC), pancreatic acini cells change their morphology through pancreatic intraepithelial neoplasia (PanIN) stages, becoming increasingly dysplastic as stroma and tissue hypoxia increase. This increasing hypoxia forms a cancer promoting microenvironment, wherein we propose metabolic changes trigger aberrant mitochondrial networks form healthy tissue. We developed tissue superresolution imaging to directly quantify structural mitochondrial response through patient histology, whereby DNA-PAINT can provide super-resolution detail decoupled from photo bleaching to visualize mitochondria through tissue layers. Expanding from preliminary data, target mitochondrial dynamics proteins’ organization will also be correlated to PanIN stages.

Introduction: Early oncogene involvement in PDAC progression links to metabolic and mitochondrial regulatory changes. Typically nutrient deprivation and hypoxia trigger cell death from increased reactive oxygen species production and organelle damage which trigger apoptosis, yet these prolonged effects can be cancer promoting when less severe. Mitochondrial dynamics and proteins related to mitochondrial fission and fusion can reduce apoptotic signaling, enhance aerobic glycolysis, and increase ROS to allow cancer progression.

Materials and Methods: Adapting from previous proof of concept, mitochondria (TOM20) within formalin-fixed paraffin embedded (FFPE) tissue sections were imaged with stochastic optical reconstruction microscopy (STORM). In brief: cadaver healthy pancreas FFPE tissue samples underwent deparafinization, antigen retrieval, indirect immuno-labeling with AlexaFluor647, TIRF illumination with a 60x objective was used for data collection, whereby data processing was conducted using the open-source FIJI and custom MATLAB software.

Results and Discussion: Preliminary data shows proof of principle that both STORM and DNA-PAINT can be correlated to histological staining of human pancreas.

Conclusions: Superresolution imaging reveals ultrastructural details of mitochondria in FFPE patient samples not resolved via conventional fluorescence imaging. Through quantitative feature analysis, we would be able to correlate aberrant mitochondria structure and abundance to PDAC progression.

Acknowledgements: Funding provided by the Cancer Early Detection Advanced Research (CEDAR) Center of OHSU Knight Cancer Institute.

Citation Format: Matthew J. Rames, Fehmi Civitci, Ting Zheng, Josiah Wagner, Jason Link, Xiaolin Nan. Aberrant mitochondrial protein involvement through early PDAC initiation and progression using multiplexed DNA-PAINT and correlative histology [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 799.

Short-term prediction of secondary progression in a sliding window: A test of a predicting algorithm in a validation cohort

Introduction

The Multiple Sclerosis Prediction Score (MSPS, www.msprediction.com) estimates, for any month during the course of relapsing–remitting multiple sclerosis (MS), the individual risk of transition to secondary progression (SP) during the following year.

Objective

Internal verification of the MSPS algorithm in a derivation cohort, the Gothenburg Incidence Cohort (GIC, n =  144) and external verification in the Uppsala MS cohort (UMS, n = 145).

Methods

Starting from their second relapse, patients were included and followed for 25 years. A matrix of MSPS values was created. From this matrix, a goodness-of-fit test and suitable diagnostic plots were derived to compare MSPS-calculated and observed outcomes (i.e. transition to SP).

Results

The median time to SP was slightly longer in the UMS than in the GIC, 15 vs. 11.5 years (p = 0.19). The MSPS was calibrated with multiplicative factors: 0.599 for the UMS and 0.829 for the GIC; the calibrated MSPS provided a good fit between expected and observed outcomes (chi-square p = 0.61 for the UMS), which indicated the model was not rejected.

Conclusion

The results suggest that the MSPS has clinically relevant generalizability in new cohorts, provided that the MSPS was calibrated to the actual overall SP incidence in the cohort.

A Stromal Lysolipid-Autotaxin Signaling Axis Promotes Pancreatic Tumor Progression

Pancreatic ductal adenocarcinoma (PDAC) develops a pronounced stromal response reflecting an aberrant wound-healing process. This stromal reaction features transdifferentiation of tissue-resident pancreatic stellate cells (PSC) into activated cancer-associated fibroblasts, a process induced by PDAC cells but of unclear significance for PDAC progression. Here, we show that PSCs undergo a dramatic lipid metabolic shift during differentiation in the context of pancreatic tumorigenesis, including remodeling of the intracellular lipidome and secretion of abundant lipids in the activated, fibroblastic state. Specifically, stroma-derived lysophosphatidylcholines support PDAC cell synthesis of phosphatidylcholines, key components of cell membranes, and also facilitate production of the potent wound-healing mediator lysophosphatidic acid (LPA) by the extracellular enzyme autotaxin, which is overexpressed in PDAC. The autotaxin-LPA axis promotes PDAC cell proliferation, migration, and AKT activation, and genetic or pharmacologic autotaxin inhibition suppresses PDAC growth in vivo. Our work demonstrates how PDAC cells exploit the local production of wound-healing mediators to stimulate their own growth and migration. SIGNIFICANCE: Our work highlights an unanticipated role for PSCs in producing the oncogenic LPA signaling lipid and demonstrates how PDAC tumor cells co-opt the release of wound-healing mediators by neighboring PSCs to promote their own proliferation and migration.See related commentary by Biffi and Tuveson, p. 578.This article is highlighted in the In This Issue feature, p. 565.

Deep learning based Nucleus Classification in pancreas histological images

Tumor specimens contain a variety of healthy cells as well as cancerous cells, and this heterogeneity underlies resistance to various cancer therapies. But this problem has not been thoroughly investigated until recently. Meanwhile, technological breakthroughs in imaging have led to an explosion of molecular and cellular profiling data from large numbers of samples, and modern machine learning approaches including deep learning have been shown to produce encouraging results by finding hidden structures and make accurate predictions. In this paper, we propose a Deep learning based Nucleus Classification (DeepNC) approach using paired histopathology and immunofluorescence images (for label), and demonstrate its classification prediction power. This method can solve current issue on discrepancy between genomic- or transcriptomic-based and pathology-based tumor purity estimates by improving histological evaluation. We also explain challenges in training a deep learning model for huge dataset.

A Data Collection Form for Intensive Care Units

The rationale for development of a data collection form for intensive care units is discussed. The form developed in our ICU to facilitate entry of data into video terminals -which document the course of each ICU patient is described. Substantial time saving and reduction in error incidence are obtained, especially so with respect to the coding of diagnoses. The diagnoses and operations are recorded as free text within the constraint of a computer format. For all other data, coding is included as part of the data sheet.

MYC regulates ductal-neuroendocrine lineage plasticity in pancreatic ductal adenocarcinoma associated with poor outcome and chemoresistance

Intratumoral phenotypic heterogeneity has been described in many tumor types, where it can contribute to drug resistance and disease recurrence. We analyzed ductal and neuroendocrine markers in pancreatic ductal adenocarcinoma, revealing heterogeneous expression of the neuroendocrine marker Synaptophysin within ductal lesions. Higher percentages of Cytokeratin-Synaptophysin dual positive tumor cells correlate with shortened disease-free survival. We observe similar lineage marker heterogeneity in mouse models of pancreatic ductal adenocarcinoma, where lineage tracing indicates that Cytokeratin-Synaptophysin dual positive cells arise from the exocrine compartment. Mechanistically, MYC binding is enriched at neuroendocrine genes in mouse tumor cells and loss of MYC reduces ductal-neuroendocrine lineage heterogeneity, while deregulated MYC expression in KRAS mutant mice increases this phenotype. Neuroendocrine marker expression is associated with chemoresistance and reducing MYC levels decreases gemcitabine-induced neuroendocrine marker expression and increases chemosensitivity. Altogether, we demonstrate that MYC facilitates ductal-neuroendocrine lineage plasticity in pancreatic ductal adenocarcinoma, contributing to poor survival and chemoresistance.

Quantitative analysis of histological tissue image based on cytological profiles and spatial statistics

The cellular heterogeneity and complex tissue architecture of most tumor samples is a major obstacle in image analysis on standard hematoxylin and eosin-stained (H&E) tissue sections. A mixture of cancer and normal cells complicates the interpretation of their cytological profiles. Furthermore, spatial arrangement and architectural organization of cells are generally not reflected in cellular characteristics analysis. To address these challenges, first we describe an automatic nuclei segmentation of H&E tissue sections. In the task of deconvoluting cellular heterogeneity, we adopt Landmark based Spectral Clustering (LSC) to group individual nuclei in such a way that nuclei in the same group are more similar. We next devise spatial statistics for analyzing spatial arrangement and organization, which are not detectable by individual cellular characteristics. Our quantitative, spatial statistics analysis could benefit H&E section analysis by refining and complementing cellular characteristics analysis.

Selective intraarterial fibrinolysis of acute central retinal artery occlusion

Purpose: To evaluate the outcome of our patients with central retinal artery occlusion after local fibrinolysis and to compare these data with results reported in the literature.

Material and Methods: Over a period of 7 years, 22 patients (11 male, 11 female, mean age 64.6 ± 12.1 years) were treated with super-selective local fibrinolysis. In 1 case, treatment was carried out via the maxillary-ophthalmic anastomoses due to preexisting occlusion of the ipsilateral internal carotid artery. The latency period from the onset of symptoms to the beginning of therapy was 7.6 ± 1.8 h. Urokinase was used in 7 cases (300,000–1.1 million units) and recombinant tissue plasminogen activator (20–40 mg) was applied in 15 patients. Visual acuity and fundus were examined before and after treatment.

Results: One patient (1/22 = 4.6%) recovered completely and regained a visual acuity of 20/20. Six patients (6/22 = 27.3%) showed a marked improvement with a range of visual outcome from 20/800 to 20/320. In 2 cases (2/22 = 9.1%) only a slight improvement was observed, with a visual outcome allowing detection of hand movements. In 13 cases (13/22 = 59.1%) no change in visual acuity as a result of treatment was observed. In 2/22 cases (9.2%) reversible neurological side-effects occurred, in 1 case suffered a stroke, and in another case intracerebral bleeding was observed.

Conclusion: In our study, the recovery of visual acuity and the complication rate were not as positive as reported in the literature.

Abstract P3-07-26: Biomarker comparison between androgen receptor – Positive-triple-negative breast cancer (AR+ TNBC) and quadruple-negative breast cancer (QNBC)

Background: Quadruple-negative breast cancer (QNBC) is a subgroup of triple-negative breast cancer (TNBC) that lacks androgen receptor (AR) expression. While TNBC patients with AR expression have shown a promising response to AR-targeted therapies, QNBC patients' treatment options remain limited, with no targeted therapy We investigated the biomarker profiles of large cohorts of AR+TNBC and QNBC to identify their molecular differences.

Method: TNBC tumors (defined as negative by IHC for ER, PR, Her2 and ISH for Her2) referred to Caris Life Sciences (Phoenix, AZ) between 2009 and 2015 were evaluated by board-certified pathologists with a combination of immunohistochemistry (AR, cKIT, cMET, EGFR, ER, ERCC1, Her2, MGMT, PD-1, PD-L1, PGP, PR, PTEN, RRM1, SPARC, TLE3, TOPO2A, TOPO1, TS and TUBB3), fluorescent/chromogenic in-situ hybridization (cMET, EGFR, Her2, TOP2A), and sequencing (Next-generation and Sanger). Tumors evaluated included a mix of primary tumors and metastases. QNBC tumors were defined as TNBC tumors that showed negative AR expression (<10% of cells staining).

Results: Among 2,071 TNBC tumors identified, 1,952 tumors had AR IHC performed, out of which 1,612 (83%) were QNBC and 340 (17%) were AR+ TNBC tumors. Tumor expression of PD-L1 (Ab: SP142, Spring Bioscience/130021, R&D Systems, cutoff used: 2+, 5%) was significantly higher in QNBC compared to AR+TNBC tumors (18% vs. 8%, p=0.01), while PD-1 (Ab: NAT105, Ventana) expression on tumor-infiltrating lymphocytes was comparable between the two cohorts (60% vs. 62%). QNBC tumors were significantly more likely to express proteins of cKIT (26% vs. 15%, p=0.01), EGFR (69% vs. 56%, p=0.03), TS (49% vs. 33%, p<0.0001) and TOPO2A (85% vs. 65%, p<0.0001) compared to AR+TNBC. TLE3 expression was significantly higher in AR+TNBC cohorts (48% vs. 32%, p<0.0001). Sequencing reveals that QNBC tumors carried significantly higher mutation rate of TP53 (71% vs. 55%, p<0.0001) while AR+TNBC tumors showed significantly higher mutation rates of PIK3CA (42% vs. 12%, p<0.0001), AKT1 (13% vs. 1%, p<0.0001) as well as ERBB2 (5% vs. 1%, p=0.0003).

Conclusion:

Biomarker comparisons between two molecular subgroups of the TNBC tumors confirm the molecular heterogeneity of this aggressive type of breast cancer. Our biomarker results suggests that for AR+TNBC tumors, future clinical trial design can consider fluoropyrimidines, taxanes, and agents targeting PI3K/AKT/mTOR pathway as well as pan-HER inhibitors, and those agents may be combined with anti-androgen therapies. On the other hand, clinical trials for immune checkpoint inhibitors, TOP2A inhibitors, as well as agents that target cKIT and EGFR should be considered for QNBC tumors. Our findings highlight the molecular differences that should be considered in the design of future clinical trial strategies, warranting further investigation for improving targeted therapy and outcomes in TNBC.

Citation Format: Xiu J, Obeid E, Gatalica Z, Reddy S, Goldstein LJ, Link J, Waisman J. Biomarker comparison between androgen receptor – Positive-triple-negative breast cancer (AR+ TNBC) and quadruple-negative breast cancer (QNBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-26.

Abstract P3-07-27: Distinct biomarker features in triple-negative breast cancer metastases to the brain, liver and bone

Background: Triple-negative breast cancer (TNBC) is characterized by its aggressive nature and accounts for a disproportionate number of metastatic disease cases and breast cancer-related deaths. Despite recent improvements, TNBC patients who develop metastatic diseases have limited treatment options. We investigated biomarkers from brain, liver and bone metastases collected from TNBC patients to identify therapeutic options and to examine molecular differences between the metastatic sites.

Method: Triple-negative breast cancer tumors referred to Caris Life Sciences (Phoenix, AZ) between 2009 and 2015 were tested with a combination of immunohistochemistry, fluorescent/chromogenic in-situ hybridization and sequencing (Next-generation and Sanger).

Result: 1570 TNBC tumors were analyzed, including 1297 tumors taken from breast, 54 from brain, 172 from liver and 47 from bone. Select biomarker frequencies of protein overexpression (IHC), gene amplification (ISH) and mutations (SEQ) are summarized in Table 1. Brain metastases showed the highest protein expression of TOPO2A and PDL1; liver metastases showed the highest expression of AR and SPARC, as well as the highest mutation rate of PIK3CA. Bone metastases showed the lowest expression of TS, RRM1 and ERCC1. BRCA1 and BRCA2 mutation rates ranged from 0-11% in various specimen sites.

Table 1Biomarker and MethodBreast Metastases (%)Brain Metastases (%)Liver Metastases (%)Bone Metastases (%)p value[pound]TOP2A IHC76100[sect]7339<0.0001PDL1 IHC1540[sect]8170.03AR IHC151036[sect]260.0005SPARC IHC173040[sect]150.0027PIK3CA SEQ165.329[sect]250.036TS IHC[dagger]49542415[sect]<0.0001RRM1 IHC[dagger]39433216[sect]0.006ERCC1 IHC[dagger]35554816[sect]0.002BRCA1 SEQ708n/ansBRCA2 SEQ11114n/ans[sect]:the group with the highest frequency of actionable results; [pound]:p values are calculated from comparing the group with the highest frequency with the lowest frequency using two tailed Fisher-Exact test, further detailed statistical analysis will be presented;[dagger]:low levels predict response to associated drugs; Ns: non-significant, i.e., p >0.05; n/a: data not available due to low N

Conclusion: Distinct biomarker features identified in different metastatic sites in TNBC present the rationale to investigate differential treatment strategies. Based on biomarker results, etoposide, immune-modulatory agents may seem promising for brain metastases; anti-androgen therapies and nab-paclitaxel may be promising in treating liver metastases; while fluoropyrimidines, gemcitabine and platinum may be considered for TNBC patients with bone metastases.

Citation Format: Xiu J, Gatalica Z, Reddy S, Waisman J, Link J. Distinct biomarker features in triple-negative breast cancer metastases to the brain, liver and bone. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-27.

A phase 1, randomized, dose-ranging study of GS-5816, a once-daily NS5A inhibitor, in patients with genotype 1-4 hepatitis C virus

GS-5816 is an inhibitor of the hepatitis C virus (HCV) NS5A protein that has demonstrated pan-genotypic activity and a high barrier to resistance in HCV replicon assays. The aim of this study was to evaluate the safety, antiviral activity and pharmacokinetics of once-daily doses of GS-5816 in patients with genotype 1-4 HCV infection. Patients with genotype 1-4 HCV infection were randomized to 3 days of GS-5816 at doses ranging from 5 to 150 mg or placebo. Adverse events were recorded, and plasma samples obtained for analysis of pharmacokinetics, HCV RNA and NS5A sequencing studies. GS-5816 5-150 mg for 3 days was well tolerated and resulted in rapid declines in HCV RNA that were sustained over the dosing period. In patients treated with the 150 mg dose of GS-5816, the mean maximal HCV RNA declines were 4.0, 4.0, 4.4, 3.3 and 3.5 log10 IU/mL in patients with genotype 1a, 1b, 2, 3 and 4 HCV infection, respectively. Pretreatment NS5A resistance-associated polymorphisms were detected in 31% (22/70) of patients. Genotype 1 and 3 HCV-infected patients without pretreatment NS5A resistance-associated polymorphisms had greater declines in HCV RNA than patients with resistance-associated polymorphisms. Plasma pharmacokinetics were supportive of once-daily dosing. GS-5816 demonstrated pangenotypic antiviral activity in patients with genotype 1-4 HCV infection. It will be further evaluated in combination with other pangenotypic direct-acting antivirals to achieve the goal of developing a well-tolerated, highly effective treatment for all HCV genotypes.

Consequences of early chilling stress in two Triticum species: plastic responses and adaptive significance

Phenotypic plasticity of two primitive wheat species (Triticum monococcum L. and Triticum dicoccum S.) was studied in response to early chilling stress. Selection pressure differentials, gradients and plasticity costs on plant morphogenesis, growth and reserve carbohydrate consumption were estimated. Regression analysis was applied to investigate differential developmental changes and patterns between treatments. Four-day-old seedlings of T. monococcum and T. dicoccum, differing in plant stature and reserve carbohydrates, were given an early chilling temperature (4 °C for 42 day) and compared with control plants grown at 23 °C. Early chilling stress resulted in a significant increase in leaf mass ratio (LMR) and relative growth rate (RGR), a reduction in flag leaf size, total biomass, specific leaf area (SLA) and reserve carbohydrate storage at flowering, together with advanced onset of flowering. Selection pressure within the early chilling environment favoured early flowering, smaller SLA, higher LMR and lower reserve carbohydrates, suggesting the observed responses were adaptive. Furthermore, a regression of daily cumulative plant biomass derived from a crop growth simulation model (CERES-Wheat) on crop vegetation period revealed a divergent developmental pattern in early-chilled plants. Using selection pressure gradient analysis, we found similar responses among these traits, except for SLA and sucrose, indicating that these two traits have indirect effects on fitness. Thus, the total effects of SLA and reserve sucrose on relative fitness seem to be buffered via the rapid growth rate in chilled plants. While lower SLA may reduce early chilling stress effects at an individual leaf level, a higher LMR and use of reserve carbohydrates indicated that compensatory growth of chilled plants during the recovery period relied on the concerted action of altered resource allocation and reserve carbohydrate consumption. However, a significant cost of plasticity was evident only for flowering time, LMR and fructan levels in the early chilling environment. Our results demonstrate that morphological and intrinsic developmental (ontogenetic) patterns in two Triticum species respond to early chilling stress.

An open-label expanded access study of lapatinib and capecitabine in patients with HER2-overexpressing locally advanced or metastatic breast cancer

BACKGROUND

The Lapatinib Expanded Access Program (LEAP) was designed to provide access to lapatinib plus capecitabine for HER2-positive metastatic breast cancer patients who previously received an anthracycline, a taxane, and a trastuzumab and had no other treatment options.

PATIENTS AND METHODS

LEAP opened globally and enrollment continued until lapatinib received regulatory approval in each participating country. Patients were assessed for progression-free survival (PFS) and overall survival (OS) and monitored for serious adverse events (SAEs).

RESULTS

As of 30 September 2008, 4283 patients from 45 countries enrolled in LEAP. The median treatment duration was 24.7 weeks. The most common drug-related SAEs were diarrhea (9.7%), vomiting (4.3%), and nausea (2.4%) and were mainly grade 3 or higher. The incidences of special interest SAEs were decreased left ventricle ejection fraction (0.5%), interstitial lung disease/pneumonitis (0.2%), and serious hepatobiliary events (0.4%). This safety profile is consistent with the overall lapatinib program. The median PFS and OS were 21.1 [95% confidence interval (CI) = 20.1-22.3] and 39.6 (95% CI = 37.7-40.7) weeks, respectively (n = 4006). Subgroup analysis showed longer PFS and OS in patients who had not received prior capecitabine.

CONCLUSIONS

These results demonstrate the safety and efficacy of lapatinib in a broader patient population compared with a clinical trial.