Increased Responsiveness of Stored Platelets after Short-Term Refrigeration

Introduction

Refrigeration of platelets is considered to provide advantages in therapy of acute hemorrhage due to increased platelet responsiveness. The alleviation of inhibitory signaling caused by cold temperature (CT) has been identified as an important mechanism contributing to enhanced platelet reactivity, detectable in freshly prepared platelets within 1 h of cold storage. The aim of this study was to confirm the effects of short-term refrigeration in platelets from apheresis-derived platelet concentrates (APC).

Methods

APC were stored under standardized conditions for 1 day or for 2 days at room temperature and then refrigerated for 1 h, followed by sampling of platelets for analysis. Platelet reactivity was measured by aggregation studies using threshold concentrations of different agonists and by detection of fibrinogen binding using flow cytometry. The exploration of inhibitory signaling comprised the detection of VASP phosphorylation using flow cytometry or Western blot and the measurement of cyclic nucleotide levels.

Results

Aggregation responses induced with ADP, collagen, or thrombin receptor-activating peptide-6 (TRAP-6) were increased in APC after cold storage for 1 h, associated with elevated TRAP-6-induced fibrinogen binding. VASP phosphorylation levels were decreased after cold exposition, detectable in 1-day- and 2-day-stored APC with flow cytometry, and in 2-day-stored APC with Western blot technique. Induced cGMP levels were lower after storage at CT in APC on day 1 and on day 2, whereas cAMP levels were reduced on 2-day-stored APC.

Conclusion

Short-term refrigeration for 1 h is sufficient to induce an attenuation of inhibitory signaling, accompanied with increased aggregation responses in APC stored for up to 2 days. The "on demand" refrigeration of PC may be a reasonable approach for the preparation of platelets with enhanced responsiveness to treat patients with hemorrhage more effectively, which should be further addressed in consecutive studies.

The empty pelvis syndrome: a core data set from the PelvEx collaborative

BACKGROUND

Empty pelvis syndrome (EPS) is a significant source of morbidity following pelvic exenteration (PE), but is undefined. EPS outcome reporting and descriptors of radicality of PE are inconsistent; therefore, the best approaches for prevention are unknown. To facilitate future research into EPS, the aim of this study is to define a measurable core outcome set, core descriptor set and written definition for EPS. Consensus on strategies to mitigate EPS was also explored.

METHOD

Three-stage consensus methodology was used: longlisting with systematic review, healthcare professional event, patient engagement, and Delphi-piloting; shortlisting with two rounds of modified Delphi; and a confirmatory stage using a modified nominal group technique. This included a selection of measurement instruments, and iterative generation of a written EPS definition.

RESULTS

One hundred and three and 119 participants took part in the modified Delphi and consensus meetings, respectively. This encompassed international patient and healthcare professional representation with multidisciplinary input. Seventy statements were longlisted, seven core outcomes (bowel obstruction, enteroperineal fistula, chronic perineal sinus, infected pelvic collection, bowel obstruction, morbidity from reconstruction, re-intervention, and quality of life), and four core descriptors (magnitude of surgery, radiotherapy-induced damage, methods of reconstruction, and changes in volume of pelvic dead space) reached consensus-where applicable, measurement of these outcomes and descriptors was defined. A written definition for EPS was agreed.

CONCLUSIONS

EPS is an area of unmet research and clinical need. This study provides an agreed definition and core data set for EPS to facilitate further research.

Modeling Respiratory Syncytial Virus Adult Vaccination in the United States With a Dynamic Transmission Model

BACKGROUND

Respiratory syncytial virus (RSV) is shown to cause substantial morbidity, hospitalization, and mortality in infants and older adults. Population-level modeling of RSV allows to estimate the full burden of disease and the potential epidemiological impact of novel prophylactics.

METHODS

We modeled the RSV epidemiology in the United States across all ages using a deterministic compartmental transmission model. Population-level symptomatic RSV acute respiratory tract infection (ARI) cases were projected across different natural history scenarios with and without vaccination of adults aged ≥60 years. The impact of vaccine efficacy against ARIs, infectiousness and vaccine coverage on ARI incidence were assessed. The impact on medical attendance, hospitalization, complications, death, and other outcomes was also derived.

RESULTS

Without a vaccine, we project 17.5-22.6 million symptomatic RSV ARI cases annually in adults aged ≥18 years in the US, with 3.6-4.8 million/year occurring in adults aged ≥60 years. Modeling indicates that up to 2.0 million symptomatic RSV-ARI cases could be prevented annually in ≥60-year-olds with a hypothetical vaccine (70% vaccine efficacy against symptomatic ARI and 60% vaccine coverage) and that up to 0.69 million/year could be prevented in the nonvaccinated population, assuming 50% vaccine impact on infectiousness.

CONCLUSIONS

The model provides estimated burden of RSV in the US across all age groups, with substantial burden projected specifically in older adults. Vaccination of adults aged ≥60 years could significantly reduce the burden of disease in this population, with additional indirect effect in adults aged <60 years due to reduced transmissibility.

Diffusion and partitioning of different PFAS compounds through thermoplastic polyurethane and three different PVC-EIA liners

Perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorobutane sulfonic acid (PFBS), 6:2 fluorotelomer sulfonic acid (6:2 FTS), and GenX are tested for diffusion and sorption through thermoplastic polyurethane (TPU) and three ethylene interpolymer alloy (PVC-EIA) liners (EIA1, EIA2, and EIA3) with decreasing ketone ethylene ester (KEE) contents. The tests were conducted at room temperature (23 °C), 35 °C, and 50 °C. The tests show significant diffusion through the TPU as manifested by a decrease in the source concentration and an increase in the receptor concentrations of PFOA and PFOS over time, especially at higher temperatures. On the other hand, the PVC-EIA liners show excellent diffusive resistance to the PFAS compounds especially at 23 °C. At higher temperatures, the diffusion resistance of the PVC-EIA liner with the lowest KEE content, EIA3, was best at 50 °C followed by EIA1 (highest KEE content) and finally EIA2. Sorption tests showed no measurable partitioning of any of the compounds to the liners examined. Based on 535 days of diffusion testing, permeation coefficients are provided for all the compounds considered for the four liners at three temperatures. In addition, the P_g values for PFOA and PFOS are provided for a linear low density polyethylene (LLDPE) and a coextruded LLDPE - ethylene vinyl alcohol (EVOH) geomembrane based on 1246 to 1331 days of testing and are compared to those estimated for EIA1, EIA2, and EIA3.

Minimum standards of pelvic exenterative practice: PelvEx Collaborative guideline

This document outlines the important aspects of caring for patients who have been diagnosed with advanced pelvic cancer. It is primarily aimed at those who are establishing a service that adequately caters to this patient group. The relevant literature has been summarized and an attempt made to simplify the approach to management of these complex cases.

Platelet toll-like-receptor 2 and 4 mediate different immune-related responses to bacterial ligands

Background  Like immune cells, platelets express toll-like receptors (TLRs) on their surface membrane. TLR2 and TLR4 are able to recognize bacterial antigens and have the potential to influence hemostatic functions and classical intracellular signaling pathways. This study investigated the role of TLR2 and TLR4 for immune-related functions in human platelets.

Materials and Methods  Washed platelets and neutrophils were prepared from fresh human peripheral blood. Basal-, Pam3CSK4- (as TLR2 agonist) and Lipopolysaccharides (LPS; as TLR4 agonist) -induced CD62P expression, fibrinogen binding and TLR2 or TLR4 expression, intracellular reactive oxygen species (ROS) production in H ₂ DCFDA-loaded platelets and uptake of fluorescence-labeled TLR ligands, and fluorophore-conjugated fibrinogen were evaluated by flow cytometry. Analysis of platelet–neutrophil complexes was performed after coincubation of washed platelets and neutrophils in the presence and absence of TLR2 or TLR4 agonists on poly-L-lysine coated surfaces, followed by immunostaining and immunofluorescence imaging.

Results  Pam3CSK4 rapidly and transiently increased TLR2 and TLR4 expression. Over the course of 30 minutes after activation with Pam3CSK4 and LPS, the expression of both receptors decreased. Pam3CSK4-stimulated intracellular ROS production and the uptake of TLR ligands or fibrinogen much stronger than LPS. Besides, TLR4 activation led to a significant increase of platelet–neutrophil contacts.

Conclusion  Stimulation leads to rapid mobilization of TLR2 or TLR4 to the platelet surface, presumably followed by receptor internalization along with bound TLR ligands. After activation, platelet TLR2 and TLR4 mediate different immune-related reactions. In particular, TLR2 induces intracellular responses in platelets, whereas TLR4 initiates interactions with other immune cells such as neutrophils.

[Cardiogenic shock following yew needle poisoning : Digoxin immune fab, va-ECMO and albumin dialysis for the treatment of a suicidal yew leaf poisoning]

We present the case of a 46-year-old male who developed refractory bradycardia with cardiogenic shock after attempting suicide by ingestion of yew leaves. Due to delayed availability of the Digoxin immune fab, a va-ECMO was established to maintain sufficient circulation. Administration of the digoxin fab resulted in recovery of spontaneous circulation. Continuous venovenous hemodiafiltration with hemoadsorption and albumin dialysis were initiated with the intention to remove immune fab-toxin complexes and as organ support in acute kidney and liver failure. Within 5 days the patient was successfully weaned from ECMO, liver support and renal replacement and discharged without physical sequelae.

Influence of long-term proteasome inhibition on platelet responsiveness mediated by bortezomib

INTRODUCTION

Although platelets contain a full proteasome system, its role in platelet function is not completely understood yet. Since the proteasome system may be involved in time-delayed processes, platelet responsiveness was investigated after long-term, bortezomib-mediated proteasome inhibition.

MATERIALS AND METHODS

Citrate-anticoagulated whole blood was stored with 5 nM and 1 μM bortezomib for 24 h. Consecutively, aggregation was measured by light transmission in platelet-rich-plasma (PRP). Flow cytometry was performed to determine phosphorylation levels of the vasodilator-stimulated phosphoprotein (VASP), fibrinogen binding, PAC1-antibody binding and purinergic receptor expression in PRP, P2Y12 activity or glycoprotein (GP) Ib and IIb expression in whole blood. P2Y1 and P2X1 activities were assessed by calcium flux-induced fluorescence in washed platelets. Using PRP, adherent platelets on fibrinogen-, collagen- and ristocetin-coated surfaces were visualized and quantified by immunostaining.

RESULTS

Under bortezomib, VASP phosphorylation was less inducible and nitric oxide-induced inhibition of fibrinogen binding was slightly reduced. Proteasome inhibition did not tamper adenosine diphosphate-mediated aggregation or purinergic receptor expression and activity. Induced expression of activated fibrinogen receptors and fibrinogen binding were not significantly influenced by incubation with bortezomib for 24 h. Aggregation values with threshold agonist concentrations were increased under bortezomib. Despite unchanged GPIb expression, bortezomib-treated platelets showed enhanced adhesion on coated surfaces.

CONCLUSIONS

In platelets incubated for 24 h, bortezomib mediates a slight attenuation of inhibitory signaling, associated with facilitated platelet aggregation using threshold agonist concentrations and enhanced adhesion on agonist-coated surfaces.

PFOA and PFOS diffusion through LLDPE and LLDPE coextruded with EVOH at 22 °C, 35 °C, and 50 °C

Diffusion of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) through 0.1 mm and 0.75 mm LLDPE and 0.1 mm and 0.75 mm LLDPE coextruded with ethyl vinyl alcohol (denoted as CoEx) at room temperature (23 °C), 35 °C, and 50 °C is examined. These tests had negligible source depletion throughout the monitoring period, indicating limited contaminant partitioning and diffusion through the LLDPE. At 483 days, 23 °C receptor PFOA and PFOS concentrations, c_r, were <8 μg/L (c_r/c_o < 3.2 × 10^-4) for all tests, and at 399 days elevated temperature receptor concentrations were < 0.4 μg/L (c_r/c_o < 1.6 × 10^-5) at 35 °C and <0.5 μg/L (c_r/c_o < 2.0 × 10^-5) at 50 °C for both PFOA and PFOS. LLDPE partitioning coefficient, S_gf was 0.9-1.4 (PFOA) and 2.8-5.3 (PFOS) based on sorption tests at 23 °C. Based on the best estimates of permeation coefficient, P_gCoEx, for CoEx was consistently lower than P_gLLDPE. For PFOA, CoEx had P_gCoEx < 0.26 × 10^-16 m²/s at 23 °C, <11 × 10^-16 m²/s (35 °C), and < 10 × 10^-16 m²/s (50 °C) while LLDPE had P_gLLDPE < 3.1 × 10^-16 m²/s (23 °C), <13 × 10^-16 m²/s (35 °C), and <19 × 10^-16 m²/s (50 °C). For PFOS, CoEx and LLDPE had P_gCoEx < 0.55 × 10^-16 m²/s and P_gLLDPE < 3.2 × 10^-16 m²/s (23 °C), P_gCoEx < 8.3 × 10^-16 m²/s and P_gLLDPE < 40 × 10^-16 m²/s (35 °C), and P_gCoEx < 8.2 × 10^-16 m²/s and P_gLLDPE < 52 × 10^-16 m²/s (50 °C). These values are preliminary and may change (e.g., decrease) as more data comes available over time. The P_g values deduced for PFOA and PFOS are remarkably lower than those reported for other contaminants of concern, excepting BPA, which exhibits similar behaviour.

Simultaneous pelvic exenteration and liver resection for primary rectal cancer with synchronous liver metastases: results from the PelvEx Collaborative

AIM

At presentation, 15-20% of patients with rectal cancer already have synchronous liver metastases. The aim of this study was to determine the surgical and survival outcomes in patients with advanced rectal cancer who underwent combined pelvic exenteration and liver (oligometastatic) resection.

METHOD

Data from 20 international institutions that performed simultaneous pelvic exenteration and liver resection between 2007 and 2017 were accumulated. Primarily, we examined perioperative outcomes, morbidity and mortality. We also assessed the impact that margin status had on survival.

RESULTS

Of 128 patients, 72 (56.2%) were men with a median age of 60 years [interquartile range (IQR) 15 years]. The median size of the liver oligometastatic deposits was 2 cm (IQR 1.8 cm). The median duration of surgery was 406 min (IQR 240 min), with a median blood loss of 1090 ml (IQR 2010 ml). A negative resection margin (R0 resection) was achieved in 73.5% of pelvic exenterations and 66.4% of liver resections. The 30-day mortality rate was 1.6%, and 32% of patients had a major postoperative complication. The 5-year overall survival for patients in whom an R0 resection of both primary and metastatic disease was achieved was 54.6% compared with 20% for those with an R1/R2 resection (P = 0.006).

CONCLUSION

Simultaneous pelvic exenteration and liver resection is feasible, with acceptable morbidity and mortality. Simultaneous resection should only be performed where an R0 resection of both pelvic and hepatic disease is anticipated.

The Impact of Cold Storage on Adenosine Diphosphate-Mediated Platelet Responsiveness

Introduction  Cold storage of platelets is considered to contribute to lower risk of bacterial growth and to more efficient hemostatic capacity. For the optimization of storage strategies, it is required to further elucidate the influence of refrigeration on platelet integrity. This study focused on adenosine diphosphate (ADP)-related platelet responsiveness.

Materials and Methods  Platelets were prepared from apheresis-derived platelet concentrates or from peripheral whole blood, stored either at room temperature or at 4°C. ADP-induced aggregation was tested with light transmission. Activation markers, purinergic receptor expression, and P2Y12 receptor function were determined by flow cytometry. P2Y1 and P2X1 function was assessed by fluorescence assays, cyclic nucleotide concentrations by immunoassays, and vasodilator-stimulated phosphoprotein (VASP)-phosphorylation levels by Western blot analysis.

Results  In contrast to room temperature, ADP-induced aggregation was maintained under cold storage for 6 days, associated with elevated activation markers like fibrinogen binding or CD62P expression. Purinergic receptor expression was not essentially different, whereas P2Y1 function deteriorated rapidly at cold storage, but not P2Y12 activity. Inhibitory pathways of cold-stored platelets were characterized by reduced responses to nitric oxide and prostaglandin E1. Refrigeration of citrated whole blood also led to the attenuation of induced inhibition of platelet aggregation, detectable within 24 hours.

Conclusion  ADP responsiveness is preserved under cold storage for 6 days due to stable P2Y12 activity and concomitant disintegration of inhibitory pathways enabling a higher reactivity of stored platelets. The ideal storage time at cold temperature for the highest hemostatic effect of platelets should be evaluated in further studies.

Low expression of ANT1 confers oncogenic properties to rhabdomyosarcoma tumor cells by modulating metabolism and death pathways

Rhabdomyosarcoma (RMS) is the most frequent form of pediatric soft-tissue sarcoma. It is divided into two main subtypes: ERMS (embryonal) and ARMS (alveolar). Current treatments are based on chemotherapy, surgery, and radiotherapy. The 5-year survival rate has plateaued at 70% since 2000, despite several clinical trials. RMS cells are thought to derive from the muscle lineage. During development, myogenesis includes the expansion of muscle precursors, the elimination of those in excess by cell death and the differentiation of the remaining ones into myofibers. The notion that these processes may be hijacked by tumor cells to sustain their oncogenic transformation has emerged, with RMS being considered as the dark side of myogenesis. Thus, dissecting myogenic developmental programs could improve our understanding of RMS molecular etiology. We focused herein on ANT1, which is involved in myogenesis and is responsible for genetic disorders associated with muscle degeneration. ANT1 is a mitochondrial protein, which has a dual functionality, as it is involved both in metabolism via the regulation of ATP/ADP release from mitochondria and in regulated cell death as part of the mitochondrial permeability transition pore. Bioinformatics analyses of transcriptomic datasets revealed that ANT1 is expressed at low levels in RMS. Using the CRISPR-Cas9 technology, we showed that reduced ANT1 expression confers selective advantages to RMS cells in terms of proliferation and resistance to stress-induced death. These effects arise notably from an abnormal metabolic switch induced by ANT1 downregulation. Restoration of ANT1 expression using a Tet-On system is sufficient to prime tumor cells to death and to increase their sensitivity to chemotherapy. Based on our results, modulation of ANT1 expression and/or activity appears as an appealing therapeutic approach in RMS management.

A randomised phase II study investigating durvalumab in addition to an anthracycline taxane-based neoadjuvant therapy in early triple-negative breast cancer: clinical results and biomarker analysis of GeparNuevo study

BACKGROUND

Combining immune-checkpoint inhibitors with chemotherapy yielded an increased response rates in patients with metastatic triple-negative breast cancer (TNBC). Therefore, we evaluated the addition of durvalumab to standard neoadjuvant chemotherapy (NACT) in primary TNBC.

PATIENTS AND METHODS

GeparNuevo is a randomised phase II double-blind placebo-controlled study randomising patients with TNBC to durvalumab or placebo given every 4 weeks in addition to nab-paclitaxel followed by standard EC. In the window-phase durvalumab/placebo alone was given 2 weeks before start of nab-paclitaxel. Randomisation was stratified by stromal tumour-infiltrating lymphocyte (sTILs). Patients with primary cT1b-cT4a-d disease, centrally confirmed TNBC and sTILs were included. Primary objective was pathological complete response (pCR) (ypT0 ypN0).

RESULTS

A total of 174 patients were randomised, 117 participated in the window-phase. Median age was 49.5 years (range 23-76); 47 patients (27%) were younger than 40 years; 113 (65%) had stage ≥IIA disease, 25 (14%) high sTILs, 138 of 158 (87%) were PD-L1-positive. pCR rate with durvalumab was 53.4% (95% CI 42.5% to 61.4%) versus placebo 44.2% (95% CI 33.5% to 55.3%; unadjusted continuity corrected χ2P = 0.287), corresponding to OR = 1.45 (95% CI 0.80-2.63, unadjusted Wald P = 0.224). Durvalumab effect was seen only in the window cohort (pCR 61.0% versus 41.4%, OR = 2.22, 95% CI 1.06-4.64, P = 0.035; interaction P = 0.048). In both arms, significantly increased pCR (P < 0.01) were observed with higher sTILs. There was a trend for increased pCR rates in PD-L1-positive tumours, which was significant for PD-L1-tumour cell in durvalumab (P = 0.045) and for PD-L1-immune cell in placebo arm (P = 0.040). The most common immune-related adverse events were thyroid dysfunction any grade in 47%.

CONCLUSIONS

Our results suggest that the addition of durvalumab to anthracycline-/taxane-based NACT increases pCR rate particularly in patients treated with durvalumab alone before start of chemotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov number: NCT02685059.

Sample preparation for Raman microspectroscopy

Raman spectroscopy and its variants allow for the investigation of a wide range of biological and biomedical samples, i. e. tissue sections, single cells and small molecules. The obtained information is on a molecular level. By making use of databases and chemometrical approaches, the chemical composition of complex samples can also be defined. The measurement procedure is straight forward, however most often sample preparation protocols must be implemented. While pure samples, such as high purity powders or highly concentrated chemicals in aqueous solutions, can be directly measured without any prior sample purification step, samples of biological origin, such as tissue sections, pathogens in suspension or biofluids, food and beverages often require pre-processing steps prior to Raman measurements. In this book chapter, different strategies for handling and processing various sample matrices for a subsequent Raman microspectroscopic analysis were introduced illustrating the high potential of this promising technique for life science and medical applications. The presented methods range from standalone techniques, such as filtration, centrifugation or immunocapture to innovative platform approaches which will be exemplary addressed. Therefore, the reader will be introduced to methods that will simplify the complexity of the matrix in which the targeted molecular species are present allowing direct Raman measurements with bench top or portable setups.

The role of proteasome activity for activating and inhibitory signalling in human platelets

Platelets express key proteins of the proteasome system, but its functional role in the regulation of platelet integrity, however, is not fully understood yet. Therefore, this study evaluated activating and inhibitory platelet signalling pathways using the potent and selective proteasome inhibitor bortezomib. In washed platelets, the effect of bortezomib on viability and on aggregation was assessed. In addition, fibrinogen binding and CD62P expression were determined. The influence on activating and inhibitory signalling was detected by phosphorylation levels of essential messenger molecules. Platelet viability was maintained after incubation with 0.01 μM to 1 μM bortezomib, but tampered with 100 μM bortezomib. Agonist-induced aggregation was only reduced under 100 μM bortezomib and with weak induction by 10 μM adenosine diphosphate. Similarly, phosphorylated kinase levels of the activating signalling pathways were not affected by 0.01 μM to 1 μM bortezomib. In contrast, proteasome inhibition resulted in the reduction of inhibitor-induced vasodilator-stimulated phosphoprotein phosphorylation, accompanied with the partial decrease of induced inhibition of fibrinogen binding and CD62P expression. In conclusion, platelet activation and aggregation are not dependent on proteasome activity. Instead, inhibitory signalling is partially attenuated under proteasome inhibition. Supramaximal inhibitory concentrations of bortezomib (above 1 μM) lead to heterogeneous effects on activating or inhibitory systems, probably caused by decreasing platelet viability.

The Role of Human Platelet Preparation for Toll-Like Receptors 2 and 4 Related Platelet Responsiveness

Background  Like immune cells, platelets express the repertoire of toll-like receptors (TLR), among them TLR2 and TLR4, which are important for the recognition of bacterial patterns. Receptor-mediated functional effects in platelets have been investigated, but reliable conclusions are tampered due to heterogeneous study designs with variable platelet preparation methods. This study compares TLR2- and TLR4-dependent platelet responsiveness in platelet-rich plasma (PRP) and in washed platelets (WPs).

Material and Methods  Fresh peripheral blood samples from healthy donors served for the preparation of PRP and WP. Basal and agonist-stimulated TLR2 and TLR4 expression levels were evaluated by flow cytometry. Light transmission aggregometry was used to investigate functional effects of TLR2 and TLR4 stimulation with Pam3CSK4 or LPS (lipopolysaccharides from Escherichia coli ) as ligands. The capacity of chemokine release was determined by immunoassays.

Results  Pam3CSK4 and LPS (in combination with thrombin) were able to induce aggregation in WP, but not in PRP, with threshold concentrations of 15 µg/mL. Basal expression levels of TLR2 and TLR4 were higher in WP than in PRP, increasing several-fold rapidly and persistently upon platelet activation with potent agonists. Pam3CSK4 (15 µg/mL) or LPS led to the submaximal release of RANTES, PF4, PDGF, NAP-2, and sCD40L from WP. In PRP, secretory effects are less pronounced for RANTES, PDGF, or PF4, and not detectable for NAP-2 or sCD40L.

Conclusion  The effects mediated by TLR2 and TLR4 stimulation are dependent on platelet preparation, an important issue for experimental designs and for manufacturing of platelet concentrates in transfusion medicine.

Abstract P3-10-01: Single-cell profiling identifies hypoxic carcinoma cells as source of an immunosuppressive VEGFA metagene

Background:

We have previously shown that expression of the IL8/VEGFA-metagene eliminates the good prognostic effect of TILs in TNBC (PMID 21978456, 28750120). We also showed that the VEGFA metagene predicted response to neoadjuvant bevacizumab in the GeparQuinto trial (Karn 2017 SABCS #851166). The main cellular sources of the transcripts that comprise the VEGFA metagene are unknown since mRNA profiling of bulk biopsies contains signals from different cell types.

Methods:

Individual genes that comprise the VEGFA metagene were measured in bulk tissue- and single cell-RNA-Seq from breast cancer subtypes and normal cells on different platforms (Affymetrix n=4915, Agilent n=597, Illumina n=2433, RNA-Seq n=1215, Exome Capture RNA-Seq n=226, HTG-Seq n=243, sc-RNA-Seq n=24710). For blinded, orthogonal validation we performed immunohistochemistry. Effect of neoadjuvant chemotherapy with or without bevacizumab was studied by RNA-Seq and IHC on samples from GeparQuinto trial. SWOG S0800 (GSE114403), PROMIX (GSE87455), and GeparSixto trials were used for validation. TCGA was mined for mutations and somatic CNA. RNA-Seq from GeparNuevo was used for correlation with checkpoint inhibitor treatment.

Results:

We identified a stable core of six genes (VEGFA, ANGPTL4, ADM, NDRG1, DDIT4, CSTB) in different cohorts. Strong expression of this signature was mainly restricted to TNBC subtype and associated with poor prognosis within this subgroup. Single cell RNA-Seq of breast epithelial cells from 4 reduction mammoplasties and 4 TNBC revealed that these genes are coexpressed in individual epithelial cells and not associated with endothelial cells. In line with their presumed functions in cellular stress and hypoxia, immunohistochemistry revealed strong para-necrotic expression in TNBC. Moreover, high gene expression in TNBC was associated with mutations in DNA damage control pathways, somatic copy number alterations, and lower TILs. While chemotherapy led to downregulation, bevacizumab increased expression. In multivariate analysis, high pretreatment values predict pCR to both bevacizumab and chemotherapy (OR 2.40, P=0.006), which may be explained by sensitivity of tumors which are already under cellular stress. On the other hand, expression of the VEGFA metagene seems to create an immunosuppressive environment that counteracts the positive prognostic effect of TILs. In pre-treatment biopsies from the GeparNuevo checkpoint inhibitor trial we found a negative correlation of VEGFA metagene expression with the amount of the recently identified tissue-resident memory T cell subset (CD8TRM, PMID 29942092; P=0.002), while the subsequent increase of CD8TRM during treatment was larger in tumors with high VEGFA (P=0.019).

Conclusions:

Perinecrotic carcinoma cells under stress from hypoxia and or chromosomal instability are the source of the VEGFA metagene signature. Its predictive value in TNBC suggests estimating and reporting the amount of necrosis in the pathology report may be helpful in predicting response to preoperative chemotherapy, and could be used as stratification factor in clinical trials. The signature indicates an immunosuppressive environment and should be further studied in the context of immune therapies in combinations with anti-angiogenic treatment.

Citation Format: Karn T, Denkert C, Sinn BV, Weber K, Nekljudova V, Rody A, Meissner T, Hatzis C, El-Balat A, Becker S, Solbach C, Untch M, Schneeweiss A, von Minckwitz G, Loibl S, Pusztai L, Holtrich U. Single-cell profiling identifies hypoxic carcinoma cells as source of an immunosuppressive VEGFA metagene [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-10-01.

Abstract P2-08-10: Similarities between low hormone receptor positive and hormone receptor negative breast cancer: An analysis of 4366 patients from multicenter clinical trials

Background:

Currently, patients with breast cancer (BC) with hormone receptor (HR) immunohistochemical expression between 1-9% are eligible to receive endocrine therapy. However, recent data suggest that these tumors express a basal-like molecular phenotype associated with triple negative BC (TNBC) rather than luminal phenotype associated with HR positive BC. Here, we aimed to determine the differences between strong HR positive, low HR positive and negative HR BC, in regard to responsiveness to neoadjuvant chemotherapy (NACT) and disease free survival (DFS) in large cohorts from GBG clinical trials.

Methods:

In this retrospective analysis of data from women with BC treated in the neoadjuvant GeparQuinto (n=2572), GeparSixto (n=588) and GeparSepto (n=1206) clinical trials, we compared patients with three HR phenotypes: low positive (ER and/or PR= 1-9%), strong positive (ER or PR= 10-100%), and negative (ER and PR= &lt;1%), regarding pathological complete response (pCR, ypT0 ypN0) and DFS. A logistic regression model for endpoint pCR was performed on pooled data from all trials. Cox regression was used to model DFS for patients participating in GeparQuinto and GeparSixto trial, including 71 with low HR positive phenotype. The models were adjusted by age, tumor and nodal status, grading, Her2 status, histological type, stromal and tumor infiltrating lymphocytes and clinical trial. The survival model was additionally adjusted by pCR after NACT.

Results:

Patients median age was 49 years, the majority had clinical tumor stage 2 (54.1%), negative nodal status (54.7%), and Her2 negative tumors (72.4%). 85.1% of women had BC classified as no special histological type. The pCR rate across the studies was 26.2%. 145 (3.4%) patients had low HR positive, 2417 (57.3%) strong HR positive and 1658 (39.3%) HR negative tumors. After NACT, 16.3% of patients with strong HR positive BC achieved a pCR, while among those with HR negative and low HR positive tumors, pCR rates were 40.2% and 37.9%, respectively (p&lt;0.001). In the adjusted logistic regression model, there was no statistically significant difference between low HR positive and HR negative tumors (OR: 1.34, 95%-CI: (0.84-2.13), p=0.222). But strong HR positive tumors had a significantly lower chance of achieving a pCR compared to low HR positives (OR 0.48, 95%-CI: 0.30-0.76, p=0.002). Patients with strong HR positive BC had a better DFS than patients with low HR positive tumors (hazard ratio 0.35, 95%-CI: 0.18-0.70, p=0.003). DFS was not significantly different between patients with HR negative and low HR positive tumors (hazard ratio 0.74, 95%-CI: 0.38-1.43, p=0.370).

Conclusions:

Similarly to patients with negative HR tumors, patients with low HR positive tumors have a better responsiveness to NACT and worse survival rates, compared to patients with strongly HR positive BC. We suggest that studies on treatment options for basal-like/TNBC, should also consider including patients with low HR positive tumors.

Citation Format: Villegas SL, Lederer B, Untch M, Holms F, Ulmer H-U, Diebold K, Fasching PA, Weber K, Schmitt WD, Tesch H, Rezai M, Marmé F, Sinn B, Hackmann J, Schneeweiss A, Tannapfel A, Nekljudova V, Denkert C, Loibl S. Similarities between low hormone receptor positive and hormone receptor negative breast cancer: An analysis of 4366 patients from multicenter clinical trials [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-10.

The role of agonist-induced activation and inhibition for the regulation of purinergic receptor expression in human platelets

INTRODUCTION

Adenosine diphosphate (ADP) as physiological activator of human platelets mediates its effects via three purinergic receptors: P2Y1, P2Y12 and P2X1. The inhibition of P2Y12 is used pharmacologically to suppress aggregation underlining the physiological significance of this receptor. Since the regulation of purinergic receptor expression has not thoroughly been investigated yet, this study analyzed the content of purinergic receptors on the platelet surface membrane upon activation and inhibition.

MATERIALS AND METHODS

The surface expression of purinergic receptors was measured by flow cytometry using two different polyclonal antibodies as basal values and after incubation with thrombin receptor activating peptide (TRAP-6) or with inhibitors DEA/NO, MAHMA/NO or Prostaglandin E1 (PGE1). Western blot analysis was used to confirm inhibitory effects.

RESULTS

Both investigated antibodies revealed a significant increase of purinergic receptor expression upon TRAP-6 stimulation. The NO donors, DEA/NO and MAHMA/NO, did not influence basal or TRAP-6 stimulated values. PGE1 did not affect basal receptor expression, but diminished TRAP-6 stimulated purinergic receptor expression in a dose-dependent manner.

CONCLUSIONS

In summary, TRAP-6 induced platelet activation leads to an elevation of purinergic receptor expression. In contrast to other surface ligands, this effect is not suppressed by cGMP-mediated inhibition, but almost completely abrogated by enhanced cAMP-mediated signaling as induced by PGE1.

Recent progress in surface-enhanced Raman spectroscopy for biological and biomedical applications: from cells to clinics

The application of surface-enhanced Raman spectroscopy (SERS) in biological and biomedical detection schemes is feasible due to its excellent molecular specificity and high sensitivity as well as the capability of SERS to be performed in complex biological compositions. SERS-based investigation of cells, which are the basic structure and functional unit of organisms, represents the starting point of this review. It is demonstrated that SERS provides a deep understanding of living cells as well as their microenvironment which is needed to assess the development of diseases. The clinical relevance of SERS is proved by its application for the detection of cancer cells and tumour margins under in vivo conditions and examples for theranostic approaches are discussed. This review article provides a comprehensive overview of the recent progress within the last 3 years.

Abstract P2-09-02: Blinded molecular subtyping analysis from RNA-Seq of FFPE samples in the GeparQuinto trial reveals predictive value of VEGFA metagene for bevacizumab treatment

Background:

RNA-Seq from total RNA in FFPE tissue can be more challenging due to limited capture of partially degraded RNA. Exome-capture based RNA-Seq may circumvent such problems and allow reproducible complete molecular characterization of low-quality RNA from small clinical samples.

Methods:

HER2 negative patients within the GeparQuinto trial were treated with neoadjuvant anthracycline-taxane-based chemotherapy +/- bevacizumab. Patients with bevacizumab therapy had a significantly higher pCR rate, especially within the triple negative subgroup. We performed exome-capture RNA-Seq on 5µm FFPE sections from pre-therapeutic cores of 400 HER2 negative samples from this trial. In a prospectively planned, blinded study we correlated molecular subtypes and metagenes for proliferation, stroma, MHC2, and VEGFA with clinical and histopathological data. Molecular subtypes were defined using the AIMS methods. Metagenes were calculated as mean values corresponding to previously described gene clusters after platform transfer (Rody et al. 2011 PMID 21978456, Hu et al. 2009 PMID 19291283) and then z-transformed.

Results:

296 samples with RNA-Seq data were classified as either of high (n=226) or of limited quality (n=70). For 22 samples RNA yield was insufficient and 82 did not pass initial QC. 121 (41%), 63 (21%), 34 (11.5%), 46 (15.5%), and 32 (11%) samples were defined as basal-like, HER2-enriched, luminal A, luminal B, and normal-like, respectively. Subtyping was robust with regard to gene filtering, normalization, and sample quality. ER and PR status from local IHC strongly correlated with gene expression (overall correctness 84% and 80% for ER, and 85% and 74% for PR, in samples with high and limited quality, respectively) and luminal subtypes (95% ER positive). Proliferation metagene correlated with histological grade (median -0.73, -0.39, and 0.53 in G1, G2, and G3, respectively; P&lt;0.001) and MHC2 metagene correlated strongly with TIL counts (Rho=0.53, P&lt;0.001). Among the high quality samples response rates (49.3% pCR overall) differed significantly by subtype, with higher pCR rates in basal-like (68.9%) and HER2-enriched (45.5%) than in luminal B (35.7%), luminal A (17.9%), and normal-like (20.0%). MHC2- (OR 1.60, 95%CI 1.21-2.12, P=0.001), proliferation- (OR 2.88, 95%CI 2.00-4.16, P&lt;0.001), and VEGFA-metagenes (OR 1.92, 95%CI 1.41-2.60, P&lt;0.001) were significant predictors for pCR. In a multivariate logistic regression (adjusted for bevacizumab treatment and hormone receptor status) both VEGFA metagene (OR 2.59, 95%CI 1.40-4.77, P=0.002) and the interaction between the VEGFA-metagene and bevacizumab treatment arm (P=0.023) significantly predicted pCR.

Conclusions:

Exome-capture RNA-Seq allows robust genomic characterization of clinical samples with limited FFPE material from core biopsies, and molecular subtypes and immune metagenes are predictive for pCR. The VEGFA metagene is a specific predictor for response to neoadjuvant bevacizumab treatment.

Citation Format: Karn T, Meissner T, Weber K, Sinn B, Denkert C, Budczies J, Nekljudova V, Fasching PA, Holtrich U, Schem C, Solbach C, Hartmann A, Röcken C, Untch M, Young BM, Willis S, Leyland-Jones B, von Minckwitz G, Loibl S. Blinded molecular subtyping analysis from RNA-Seq of FFPE samples in the GeparQuinto trial reveals predictive value of VEGFA metagene for bevacizumab treatment [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-02.

Abstract P1-07-01: HLA class I expression is associated with tumor-infiltrating lymphocytes and response and survival after neoadjuvant chemotherapy in hormone receptor-positive, HER2-negative breast cancer

Background: Interactions between cancer cells and the host immune system influence tumor biology, response to therapy and patient survival and their modulation offers promising new approaches for cancer therapy. The downregulation or loss of HLA class I expression in breast cancer cells might be an effective mechanism to evade the recognition by the immune system facilitating malignant behavior.

Aim: To evaluate the association of tumor-infiltrating lymphocytes (TILs) with HLA class I expression and its theranostic value for therapy response and survival after neoadjuvant chemotherapy.

Methods: HLA class I expression was evaluated by immunohistochemistry in a cohort of 732 pre-therapeutic core biopsies from breast cancer patients treated within the neoadjuvant GeparTrio trial. Patients received anthracycline- and taxane-based neoadjuvant therapy and adjuvant endocrine treatment if hormone receptor-positive (HR+). A publicly available microarray dataset of pre-therapeutic core biopsies from 508 breast cancer patients that received neoadjuvant chemotherapy and endocrine treatment if HR+ was used for validation of the results. The association of HLA class I expression with predefined genomic signatures for immune cell populations was evaluated in publicly available data from the cancer genome atlas.

Results: HLA class I expression was associated with TILs (p &lt; 0.001) and was predictive of better response to neoadjuvant chemotherapy in the subgroup of patients with HR+/HER2- breast cancer (14 % in tumors with high HLA vs. 7 % in tumors with low HLA, p = 0.029). Interestingly, high HLA was also predictive for shorter progression-free survival in univariate analysis (HR 1.590, 95 % CI 1.062—2.380; p = 0.024) and after adjustment to clinical and pathological parameters (HR 1.701, 95 % CI 1.105—2.618; p = 0.016). The results could be validated in the independent microarray-based dataset (HR 1.521, 95% CI 1.088 – 2.129; p = 0.0142). HLA class I was not associated with therapy response or survival in hormone receptor-negative breast cancer. HLA class I was associated with a predefined signature for T-cells and cytotoxic T- cells in the cancer genome atlas dataset (rho = 0.546).

Conclusion: HLA class I expression is associated with better response but shorter progression-free survival in HR+/HER2- breast cancer following neoadjuvant chemotherapy. The underlying mechanisms warrant further investigation.

Citation Format: Sinn BV, Weber K, Denkert C, Fasching PA, Schmitt WD, Thomas K, Ingold-Heppner B, van Mackelenbergh M, Symmans WF, Marmé F, Taube E, Müller V, Kunze CA, Schem C, Pfitzner BM, Stickeler E, von Minckwitz G, Loibl S. HLA class I expression is associated with tumor-infiltrating lymphocytes and response and survival after neoadjuvant chemotherapy in hormone receptor-positive, HER2-negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-01.

Cost-effectiveness of PET for the management of lung tumours: Comparison of economic data

Modelling is an accepted, valid and often necessary method for assessing economic effectiveness in terms of cost per life year gained. Comparing an alternative strategy (a) with a baseline strategy (bl), the incremental cost (C0STa-C0STb|) divided by the incremental life expectancy (LEG-LEbï) defines the incremental cost-effectiveness ratio (ICER). Taking watchful waiting as the low-cost baseline strategy for the management of solitary pulmonary nodules, the ICER of positron emission tomography (PET) [3218 euros (EUR) per life year saved (LYS)] was more favourable than that of exploratory surgery (4210 EUR/LYS) or that of transthoracic needle biopsy (6120 EUR/LYS). Changing the baseline strategy to exploratory surgery, the use of PET led to cost savings and additional life expectancy in case of an intermediate pretest probability of malignancy. For management of potentially operable non-small cell lung cancer the use of PET in patients with normalisized mediastinal lymph nodes on CT was most cost-effective (143 EUR/LYS), and the costs of PET were almost balanced by a better selection of patients for beneficial cancer resection. Using PET in patients with enlarged lymph nodes on CT, the ICER raised to 36,667 EUR/LYS. When PET or CT were positive for mediastinal lymph nodes, the exclusion from biopsy confirmation led to cost savings that did not justify the expected reduction in life expectancy. Economic data from the USA and Japan also demonstrated the cost-effectiveness of PET-based algorithms for the management of lung tumours.

The Rivalta’s test as a diagnostic variable in feline effusions – evaluation of optimum reaction and storage conditions

Objective: The Rivalta’s test is used to diagnose feline infectious peritonitis (FIP) in cats with effusion. Only little information on the influence of sample storage and reaction conditions on test results is available, and diagnostic sensitivity and specificity to diagnose FIP vary considerably between few available studies. This study determined the influence of storage of effusion, modifications on reaction conditions, and inter-observer variation. Material and methods: The Rivalta’s test was repeated up to 21 days after storage at room temperature, in the refrigerator, or freezer. The test was performed by two independent, blinded investigators. It was also performed using different volumes of acetic acid, different acids, and different kinds of water. Results: Even after storage for 21 days, test results were comparable. While inter-observer variation revealed substantial disagreement, different modifications in performance showed no major influence on test outcome. Conclusion: The Rivalta’s test seems to be a very robust test concerning storage conditions. Modifications in reaction condition also do not substantially influence outcome. However, the test is subjective and depends on the evaluating person.

Sensitivity and specificity of an in-clinic point-of-care PCR test for the diagnosis of canine leishmaniasis

Canine leishmaniasis is an important infectious disease worldwide. Although commonly used, antibody tests are often falsely negative, and in such cases direct detection of the pathogen, such as PCR, is necessary. However, PCR is only performed in specialized laboratories and not available in all localities. The aim of this study was to compare the sensitivity and specificity of an in-clinic point-of-care (ICPOC) PCR for the diagnosis of canine Leishmania spp. infection to those of a well characterized reference real-time PCR. In this study, 515 samples from 251 dogs (201 EDTA blood samples, 244 conjunctival swabs, 19 lymph node aspirates, and 51 bone marrow aspirates) were collected prospectively and analysed for the presence of Leishmania DNA using an ICPOC test. The results were compared to those of a reference real-time PCR for identification of Leishmania kinetoplast minicircle DNA. Sensitivity and specificity with 95% confidence interval (CI 95%) were determined. Specificity was 100% for all samples examined. Sensitivity was 57.1% (CI 95%, 34.0-78.2) in bone marrow aspirates, 58.8% (CI 95%, 32.9-81.6) in lymph node aspirates, 46.9% (CI 95%, 32.5-61.7) in conjunctival swabs, and 10.0% (CI 95%, 3.3-21.8) in blood. The ICPOC PCR was easy to perform and was reliable in the case of positive test results. A negative result, however, did not exclude infection and therefore requires further diagnostics.

Expression of Cyclin D1 protein in residual tumor after neoadjuvant chemotherapy for breast cancer

PURPOSE

Hormone receptor (HR)-positive breast cancer (BC) shows a poor response to neoadjuvant chemotherapy (NACT). New treatment targets like the Cyclin D1-CDK4/CDK6 complex are promising adjuvant/post-neoadjuvant therapeutic strategies. Evaluating Cyclin D1 overexpression in residual tumor could recognize those patients that benefit most from such post-neoadjuvant treatment. In this study, we determined Cyclin D1 expression in residual BC after NACT. Secondary aims were to correlate Cyclin D1 expression levels with clinicopathological parameters and to assess its prognostic value after NACT.

METHODS

We retrospectively assessed the nuclear expression of Cyclin D1 on tissue microarrays with residual tumor from 284 patients treated in the neoadjuvant GeparTrio (n = 186) and GeparQuattro (n = 98) trials. Evaluation was performed with a standardized immunoreactive score (IRS) after selecting a cut-off value.

RESULTS

A high expression level (IRS ≥ 6) of Cyclin D1 was found in 37.3% of the assessed specimens. An increased Cyclin D1 expression was observed in HR-positive tumors, compared to HR-negative tumors (p = 0.02). Low Cyclin D1 levels correlated with clinical tumor stage 1-3 (p = 0.03). Among patients with HR-positive/Her2-negative tumors and high Cyclin D1 expression, a better disease-free survival (DFS) was graphically suggested, but not significant (p = 0.21).

CONCLUSION

Our study demonstrates a measurable nuclear expression of Cyclin D1 in post-neoadjuvant residual tumor tissue of HR-positive BC. Cyclin D1 expression was not prognostic for DFS after NACT. Our results and defined cut-off suggest that the marker can be used to stratify tumors according to protein expression levels. Based on this, a prospective evaluation is currently performed in the ongoing Penelope-B trial.

The role of adenosine diphosphate mediated platelet responsiveness for the stability of platelet integrity in citrated whole blood under ex vivo conditions

Background

Platelets are important for effective hemostasis and considered to be involved in pathophysiological processes, e.g. in cardiovascular diseases. Platelets provided for research or for therapeutic use are frequently separated from citrated whole blood (WB) stored for different periods of time. Although functionally intact platelets are required, the stability of platelet integrity, e.g. adenosine diphosphate (ADP) mediated responsiveness, has never been thoroughly investigated in citrated WB under ex vivo conditions.

Objectives

Platelet integrity was evaluated at different time points in citrated WB units, collected from healthy donors and stored for 5 days at ambient temperature. The analysis included the measurement of activation markers, of induced light transmission aggregometry and of purinergic receptor expression or function. Inhibitory pathways were explored by determination of basal vasodilator-stimulated phosphoprotein (VASP)-phosphorylation, intracellular cyclic nucleotide levels and the content of phosphodiesterase 5A. Fresh peripheral blood (PB) samples served as controls.

Results

On day 5 of storage, thrombin receptor activating peptide-6 (TRAP-6) stimulated CD62P expression and fibrinogen binding were comparable to PB samples. ADP induced aggregation continuously decreased during storage. Purinergic receptor expression remained unchanged, whereas the P2Y1 activity progressively declined in contrast to preserved P2Y12 and P2X1 function. Inhibitory pathways were unaffected except for a slight elevation of VASP phosphorylation at Ser²³⁹ on day 5.

Conclusion

After 5 days of storage in citrated WB, platelet responsiveness to TRAP-6 is sufficiently maintained. However, ADP-mediated platelet integrity is more sensitive to deterioration, especially after storage for more than 2 days. Decreasing ADP-induced aggregation is particularly caused by the impairment of the purinergic receptor P2Y1 activity. These characteristics should be considered in the use of platelets from stored citrated WB for experimental or therapeutic issues.

Preliminary evaluation of cytosine-phosphate-guanine oligodeoxynucleotides bound to gelatine nanoparticles as immunotherapy for canine atopic dermatitis

Cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODN) are a promising new immunotherapeutic treatment option for canine atopic dermatitis (AD). The aim of this uncontrolled pilot study was to evaluate clinical and immunological effects of gelatine nanoparticle (GNP)-bound CpG ODN (CpG GNP) on atopic dogs. Eighteen dogs with AD were treated for 8 weeks (group 1, n=8) or 18 weeks (group 2, n=10). Before inclusion and after 2 weeks, 4 weeks, 6 weeks (group 1+2), 8 weeks, 12 weeks and 16 weeks (group 2) 75 µg CpG ODN/dog (bound to 1.5 mg GNP) were injected subcutaneously. Pruritus was evaluated daily by the owner. Lesions were evaluated and serum concentrations and mRNA expressions of interferon-γ, tumour necrosis factor-α, transforming growth factor-β, interleukin (IL) 10 and IL-4 (only mRNA expression) were determined at inclusion and after 8 weeks (group 1+2) and 18 weeks (group 2). Lesions and pruritus improved significantly from baseline to week 8. Mean improvements from baseline to week 18 were 23 per cent and 44 per cent for lesions and pruritus, respectively, an improvement of ≥50 per cent was seen in six out of nine and three out of six dogs, respectively. IL-4 mRNA expression decreased significantly. The results of this study show a clinical improvement of canine AD with CpG GNP comparable to allergen immunotherapy. Controlled studies are needed to confirm these findings.

Abstract P1-09-11: Outcome after neoadjuvant chemotherapy in progesterone receptor negative breast cancer patients – A pooled analysis of individual patient data from ten prospectively randomized controlled neoadjuvant trials

Background

The estrogen receptor (ER) as a nuclear transcription factor alters the transcription of estrogen sensitive genes to which the progesterone receptor gene belongs. The ER has also been described to exert non genomic effects by interacting with several cell signalling pathways that do not initially involve increases in gene transcription. These different patterns of action of the ER lead to the assumption that in tumors that utilize the non-genomic ER activity in order to stimulate tumorigenesis and proliferation progesterone receptor (PgR) expression would be decreased or absent. Therefore lack of PgR expression could be a surrogate marker of altered growth factor signalling. The aim of this study was to investigate if PgR expression may act as a predictive factor for response to neoadjuvant chemotherapy and long-term outcome in breast cancer patients.

Methods

5613 patients with primary breast cancer, follow-up, positive ER expression; HER2+ and HER2- from overall 10 (n=9785) German neoadjuvant trials receiving an anthracycline and taxane based chemotherapy were included. The pathologic complete response (pCR)(ypT0, ypN0), long term survival data (disease free survival (DFS), distant disease free survival (DDFS), overall survival (OS) and local recurrence free survival (LRFS)) and early relapse, defined as DFS &lt;37 months, were compared according to their PgR expression, overall and in subgroups defined by HER2.

Results

Tumors lacking PgR expression (1172 patients) were more often of grade 3 (38.4% v 26.3%; p&lt;0.001), tended to have an advanced clinical nodal involvement (6.8% v 4.7%; p=0.004) and were more likely to demonstrate HER2 positivity (36.2% v 22.3%; p&lt;0.001).

pCR rates were significantly higher in PgR negative patients in the entire cohort (13.8% v 7.5%; p&lt;0.001) as well as in the HER2 negative subgroup (11.2% v 5.8%; p&lt;0.001) whereas there was no significant difference in the HER2 positive (22.1% v 18%; p=0.117). After adjusting for known predictive factors in the multivariable logistic regression analysis PgR negativity was an independent predictive factor for pCR overall (OR 1.76; p&lt;0.001) and in the HER2 negative patients (OR 1.99; p&lt;0.001).

PgR negativity was also significantly associated with an early relapse overall (32.8% v 25.7%; p&lt;0.001) and in the subgroups defined by HER2 (HER2- 32.2% v 24.9%; p&lt;0.001 and HER2+ 39.9%v 30.5%; p=0.002).

Patients with PgR negative disease had a significantly worse DFS, OS, DDFS and LRFS (p&lt;0.001, respectively). Multivariable Cox regression analysis revealed that PgR was an independent prognostic factor. This was also observed in the HER2+ and- subgroups. Interestingly, in the PgR negative tumors HER2 status did not influence long-term outcome.

Conclusion

This analysis demonstrates that ER positive and PgR negative tumors represent a specific subset in primary breast cancer patients associated with higher response but also worse long term outcome after neoadjuvant chemotherapy. Interestingly, PgR negativity served as an independent predictive factor for achieving a pCR after neoadjuvant chemotherapy and therefore its status should be considered when deciding on systemic treatment.

Citation Format: van Mackelenberg M, Denkert C, Nekljudova V, Karn T, Schem C, Marme F, Stickeler E, Jackisch C, Hanusch C, Huober J, Fasching P, Blohmer J-U, Kümmel S, Müller V, Schneeweiss A, Untch M, von Minckwitz G, Weber K, Loibl S. Outcome after neoadjuvant chemotherapy in progesterone receptor negative breast cancer patients – A pooled analysis of individual patient data from ten prospectively randomized controlled neoadjuvant trials [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 P1-09-11.

Abstract P2-03-09: Comparison of the mutational landscape of breast cancer during pregnancy and non-pregnant controls

Background:Currently, breast cancer during pregnancy (BCP) is not believed to be biologically different from breast cancer unrelated to pregnancy based on limited datasets mainly obtained by immunohistochemistry. However, some groups report that BCP patients have an inferior survival compared to young non-pregnant breast cancer patients. The largest analysis based on the BCP registry by the German Breast Group (GBG) revealed however, no difference between pregnant and non-pregnant breast cancer patients, indicating that treatment rather than biology might be the reason for the inferior survival reported by others.

Methods: The BCP study (GBG 29/BIG 03-02) is a multicentre observational study for breast cancer during pregnancy. In tumour tissue collected within this study from pregnant M0 patients we investigated the following genes: AKT1, ATM, BRAF, CBFB, CCND1, CDH1, CDKN2A, CTCF, EGFR, ERBB2, ESR1, FGFR2, GATA3, KRAS, MAP2K4, MAP3K1, MDM2, MED12, MYC, PIK3CA, PIK3R1, PTEN, RB1, RUNX1, and TP53 by massive parallel sequencing (MPS). This included patients with all molecular subtypes: HR+/-, HER2+/-. Sequencing was done on an IonTorrent Proton using a custom designed Breast Cancer Panel (BCPv2). This panel comprises 236 amplicons split into two primer pools and covers hotspot regions of 138 exons of the 25 genes.

To test the hypothesis that breast cancer diagnosed during pregnancy is biologically not different from breast cancer diagnosed in young non-pregnant women, we compared the molecular profiles obtained, with genetic data from M0 patients not known to be pregnant from TCGA with age &lt;= 45. TCGA data were pre-processed to be compatible to the targeted MPS datasets from pregnant patient.

Results: Material from 141 patients from the BCP study was available from which ultimately 109 fully evaluable MPS datasets could be obtained. In the TCGA data set 114 breast cancer patients &lt;= 45 years could be identified. Pregnant patients with breast cancer were significantly younger, had more often HR- tumours (59.6% vs 30.1%) but had less frequently grade 3 tumours (30.6% vs 48.2%). All other clinical variables showed no significant differences between pregnant and non-pregnant patients. In the BCP data, overall 106 mutations could be found. The most frequent mutations were detected in TP53 (62%) and in PIK3CA (11.1%). In non-pregnant patients the mutation rates were different with 32.5% in TP53 and 21.1% in PIK3CA.

Exact matching by variables age, HR, HER2 and grade yielded 40 patients from both datasets. In these subcohorts, still divergent mutational rates for TP53 and PIK3CA between pregnant and non-pregnant women were noted, however, the differences failed to reach statistical significance.

Conclusions: Overall the mutational landscapes do not seem to be overtly different between pregnant patients and no-pregnant controls, although slight imbalances in mutational rates occurred, which might be partly explained by a selection bias and a small sample size after matching. Further comparisons using other datasets, looking into survival and regarding copy number variation are currently conducted.

This research is been funded by the German Cancer Consortium-DKTK and the BANSS Foundation.

Citation Format: Loibl S, Pfarr N, Weber K, Neunhöffer T, Villegas S, Stenzinger A, Furlanetto J, Aktas B, Budczies J, Marmé F, Kahmann L, Denkert C, Weichert W. Comparison of the mutational landscape of breast cancer during pregnancy and non-pregnant controls [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 P2-03-09.