Human transcriptional signature of protection after Plasmodium falciparum immunization and infectious challenge via mosquito bites

The identification of immune correlates of protection against infectious pathogens will accelerate the design and optimization of recombinant and subunit vaccines. Systematic analyses such as immunoprofiling including serological, cellular, and molecular assessments supported by computational tools are key to not only identify correlates of protection but also biomarkers of disease susceptibility. The current study expands our previous cellular and serological profiling of vaccine-induced responses to a whole parasite malaria vaccine. The irradiated sporozoite model was chosen as it is considered the most effective vaccine against malaria. In contrast to whole blood transcriptomics analysis, we stimulated peripheral blood mononuclear cells (PBMC) with sporozoites and enriched for antigen-specific cells prior to conducting transcriptomics analysis. By focusing on transcriptional events triggered by antigen-specific stimulation, we were able to uncover quantitative and qualitative differences between protected and non-protected individuals to controlled human malaria infections and identified differentially expressed genes associated with sporozoite-specific responses. Further analyses including pathway and gene set enrichment analysis revealed that vaccination with irradiated sporozoites induced a transcriptomic profile associated with Th1-responses, Interferon-signaling, antigen-presentation, and inflammation. Analyzing longitudinal time points not only post-vaccination but also post-controlled human malaria infection further revealed that the transcriptomic profile of protected vs non-protected individuals was not static but continued to diverge over time. The results lay the foundation for comparing protective immune signatures induced by various vaccine platforms to uncover immune correlates of protection that are common across platforms.

Challenges in oncology career: are we closing the gender gap? Results of the new ESMO Women for Oncology Committee survey

BACKGROUND

Following a European Society for Medical Oncology Women for Oncology (ESMO W4O) survey in 2016 showing severe under-representation of female oncologists in leadership roles, ESMO launched a series of initiatives to address obstacles to gender equity. A follow-up survey in October 2021 investigated progress achieved.

MATERIALS AND METHODS

The W4O questionnaire 2021 expanded on the 2016 survey, with additional questions on the impact of ethnicity, sexual orientation and religion on career development. Results were analysed according to respondent gender and age.

RESULTS

The survey sample was larger than in 2016 (n = 1473 versus 482), especially among men. Significantly fewer respondents had managerial or leadership roles than in 2016 (31.8% versus 51.7%). Lack of leadership development for women and unconscious bias were considered more important in 2021 than in 2016. In 2021, more people reported harassment in the workplace than in 2016 (50.3% versus 41.0%). In 2021, ethnicity, sexual orientation and religion were considered to have little or no impact on professional career opportunities, salary setting or related potential pay gap. However, gender had a significant or major impact on career development (25.5% of respondents), especially in respondents ≤40 years of age and women. As in 2016, highest ranked initiatives to foster workplace equity were promotion of work-life balance, development and leadership training and flexible working. Significantly more 2021 respondents (mainly women) supported the need for culture and gender equity education at work than in 2016.

CONCLUSIONS

Gender remains a major barrier to career progression in oncology and, although some obstacles may have been reduced since 2016, we are a long way from closing the gender gap. Increased reporting of discrimination and inappropriate behaviour in the workplace is a major, priority concern. The W4O 2021 survey findings provide new evidence and highlight the areas for future ESMO interventions to support equity and diversity in oncology career development.

Profound abnormalities in thymic epithelial cells in Rag1 hypomorphic mice: implications for immune reconstitution after stem cell transplantation

Thymic epithelial cells (TEC) are a heterogeneous population of stromal cells which orchestrate T cell development and selection. Although recent reports highlighted TEC complexity, their developmental origin, hierarchy and differentiation still remain ill-defined. We compared TEC distribution and gene expression in wild-type (WT) mice and in mice carrying Rag1 hypomorphic mutations (Rag1mut) observed in patients with immunedeficiency and immune dysregulation. Single cell RNA-seq analysis of TECs isolated from Rag1mut mice revealed an excess of cortical TECs (cTECs). Medullary TECs (mTECs), albeit reduced in number, showed a similar distribution in previously described mature subsets. To address whether TEC abnormalities in Rag1mut mice might result from a developmental block, we compared them to TECs from neonate WT mice. Indeed, we observed a similar TEC distribution in adult Rag1mut mice and newborn WT mice, although we identified peculiar features in cTEC subsets of Rag1mut mice. Transplantation of WT hematopoietic stem cells (HSC) into Rag1mut mice was able not only to correct thymocyte development, but also to revert TEC phenotype to normalcy. However, in a competitive transplantation setting where 10% of WT and 90% mutant HSCs were used, only partial restoration of thymocyte subsets was observed, associated with incomplete rescue of TEC phenotype. In summary, we show that abnormalities of TEC composition in Rag1 mutant mice correlate with impaired development of thymocytes, highlighting the role of lymphostromal cross-talk in TEC maturation. Moreover, these data point to the need to achieve full donor chimerism after HSC transplantation in order to rescue the thymic compartment and prevent defects of immune tolerance.

This research was supported by the Intramural Research Program of the NIAID, NIH

540 Baseline mTOR transcriptional signatures in CD8 T cells are associated with immune-related adverse events but not anti-tumor responses in patients receiving immune checkpoint inhibitors

Background

Immune checkpoint inhibitors (ICIs) have changed the cancer treatment landscape, but immune-related adverse events (irAEs) can affect a wide range of tissues in patients receiving ICIs. Severe irAEs can be life-threatening or fatal and prohibit patients from receiving further ICI treatment. While the clinical features of irAEs are well documented, the pathological mechanisms and predictive biomarkers are largely unknown. In addition, there is a critical need to preserve ICI-induced anti-tumor immunity while controlling for irAEs, which requires deciphering molecular and cellular signatures associated specifically with irAEs beyond those more generally linked to anti-tumor immunity.

Methods

To unbiasedly identify immune cells and states associated with irAEs, we applied CITE-seq to measure transcripts and surface proteins (83 protein markers) from PBMCs collected from patients with thymic epithelial tumors before and after treatment with an anti-PD-L1 antibody (avelumab, NCT01772004, NCT03076554).

Results

Samples from 9 patients were analyzed. No patient had a history of pre-existing paraneoplastic autoimmune disease. Anti-tumor activity was observed in all cases, and 5 patients had clinical and/or biochemical evidence of immune-related muscle inflammation (myositis with or without myocarditis). Multilevel models applied within highly resolved cell clusters revealed transcriptional states associated with ICI response and more uniquely with irAEs. A total of 190,000 cells were included in the analysis after quality control. Most notably, CD45RA+ effector memory CD8 T cells with an mTOR transcriptional signature were highly enriched at baseline and post treatment in patients with irAEs.

Conclusions

Our findings suggest the potential therapeutic avenues by using mTOR inhibitors to dampen autoimmune responses while potentially sparing anti-tumor activity, to prevent treatment discontinuation and improve clinical outcomes for cancer patients treated with ICIs.

Acknowledgements

This research was supported in part by the Intramural Research Program of the NCI (the Center for Cancer Research), NIAID and NIAMS, and through a Cooperative Research and Development Agreement between the National Cancer Institute and EMD Serono.

Trial Registration

NCT01772004, NCT03076554

Ethics Approval

This study is approved by NCI institutional review board.

Abstract PO-234: Relationship between increased concentrations of circulating chemokines and population differences in tumor biology

Genetic ancestry is a significant determinant of multiple aspects of tumor biology, immunity, and inflammatory responses. In lung cancer, in addition to increased incidence in African American (AA) men compared with other racial and ethnic groups in the US, differences in tumor biology between AAs and European Americans (EAs) have been identified. Natural selection is a strong driver of gene selection leading to population differences that can be linked to geographic and genetic ancestry. A classic example involves the Duffy antigen receptor for chemokines, also known as DARC. Individuals with African ancestry are more likely to lack DARC expression on their red blood cells (also known as Duffy null), as this confers resistance to malaria. Loss of erythrocyte expression of DARC is associated with increased circulating chemokine levels in the CXCR and CCR families as DARC serves as a dummy chemokine reservoir. Additionally, Duffy null individuals have lower circulating neutrophils, known as benign ethnic neutropenia. However, loss of DARC expression is exclusive to erythrocytes in Duffy null individuals. As venous endothelial cells and tumor cells also express DARC, we questioned whether the increased circulating bioavailability of DARC ligands in AAs led to increased DARC- dependent signaling in the tumor microenvironment (TME) of AA lung cancer patients. DARC expression on tumor cells is associated with increased aggressiveness and invasion, and endothelial cells have been shown to transcytose DARC ligands into the luminal space. As DARC ligands are associated with angiogenesis and granulocyte recruitment, we hypothesized that tumors of AAs would present with increased blood vessel invasion and granulocyte recruitment to the TME. Using the Somalogic multiplex proteomic assay, we observed significantly elevated levels of the ELR+ CXCR chemokines, with the exception of IL-8 (CXCL8), in serum samples from AA healthy control and stage 1 lung adenocarcinoma patients compared with EAs (samples from the NCI-UMD Case-Control Study), We did not find any evidence of increased angiogenesis as measured by CD31 immunohistochemical staining in AA patients (n= 39) compared with EA patients (n= 107). Immune cell composition did not differ between AAs and EAs as measured by CIBERSORT analysis in both healthy controls and patients between AAs and EAs. Therefore, while AAs have significantly higher levels of circulating DARC ligands compared with EAs, they do not appear to contribute to increased DARC-dependent signaling in normal and tumor lung tissue microenvironment in AAs.

Citation Format: Sheryse Taylor, Julian Candia, Adriana Zingone, John Tsang, Brid Ryan. Relationship between increased concentrations of circulating chemokines and population differences in tumor biology [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-234.

Prominent antibody mediated auto-immune response in idiopathic CD4 lymphopenic patients

Patients with Idiopathic CD4 Lymphocytopenia (ICL) have low circulating CD4 T cell numbers, accompanied sometimes by low numbers of CD8, B and/or NK cells, making them susceptible to opportunistic infections. The etiology is unknown and there is no familiar linkage. In spite of their immune deficiency 32% of ICL patients have clinically defined auto-immune disease. To analyze the presence of auto-antibodies in these patients we hybridized sera from 34 patients and 15 healthy control (HC) to a 9,000 proteins human array. When identifying positive targets as the ones with Z score ≥4 we found that all 34 ICL patients, unrelated to their autoimmune disease manifestations, had IgG antibodies against tens of proteins while the HC had none. There was considerable variability in both numbers and identities of targets. We next evaluated whether some of these antigens might be displayed on the T cell membrane. Using a flow-based assay we tested sera from 72 ICL patients and found that 50% of them had either IgG, mostly but not exclusively IgG1 and/or IgG4 isotypes, or IgM antibodies against T cell membrane proteins. Functionally, 50% of the plasma with IgG1 or IgG3 antibodies induced antibody dependent cell mediated cytotoxicity against healthy T-lymphocytes. In addition, sera from 20% of the patients with anti-lymphocyte antibodies induced complement deposition on healthy CD3 T cells and some of them induced complement dependent cytotoxicity. Furthermore, we observed complement deposition (C1q, C4c and C3b) on CD4 T cells in 14% of the 72 ICL patients when analyzed directly ex vivo. Our data support a high prevalence and pathogenicity of autoantibodies in ICL, which offers a potential therapeutic target.

Single cell RNAseq analysis reveals profound abnormalities in the distribution and diversity of thymic epithelial cells in Rag1 mutant mice

The thymus contains a heterogeneous population of stromal cells which orchestrate T cell development and selection. Recent works highlighted the complexity of thymic stromal cells, and medullary thymic epithelial cells (mTECs) in particular. However, the developmental origin, hierarchy, and function of these subpopulations remain ill-defined. Moreover, the characterization of cortical TECs (cTECs) has been largely restricted to the adult thymus. Here, we compared TEC distribution and gene expression in wild-type (WT) and in mice carrying Rag1 hypomorphic mutations observed in patients with immune deficiency and immune dysregulation.

Single cell RNA-seq analysis of TECs isolated from adult Rag1 mutant mice revealed an excess of cTECs, which segregated in different clusters. The mTEC compartment, albeit reduced, showed a similar distribution of previously described subsets (mTEC I–IV), suggesting perturbation of mTEC development rather than mTEC differentiation into functional subsets. To address whether such abnormalities of cTEC and mTEC abundance and subset distribution in Rag1 mutant mice may reflect defects in TEC development, we extended scRNA-seq analysis to TECs from WT mice of neonatal age. A similar pattern was observed in TECs of adult Rag1 mutant mice and WT mice of neonatal age, indicating altered TEC development when Rag1 activity is perturbed. This defect correlates with a decreased number of double-positive thymocytes, suggesting that impaired lymphostromal cross-talk in the thymus of Rag1 mutant mice (and patients with similar defects) is associated with abnormalities of TEC composition which may contribute to altered immune tolerance that is often observed in these conditions.

Quantitative Expression of GATA3 Specifies Lineage Fates and Functions of Innate Lymphoid Cells

Innate lymphoid cells (ILCs) are the innate counterparts of the CD4 T helper cells of the adaptive system. While the CD4 T cell development and differentiation have been well studied, the development of ILC subsets is far from clear. Lymphoid tissue inducer (LTi) population is the founding member of ILCs, however, recent study has shown that these cells are not derived from a PLZF-expressing ILC common progenitor that generates other ILCs. The transcription factor(s) determining the fate of non-LTi progenitor versus LTi progenitor are unknown. Here we report that GATA3 is absolutely required for the generation of PLZF-expressing non-LTi progenitors, which express high level of GATA3, but not for the generation of RORgammat-expressing LTi progenitors consistent with low levels of GATA3 expression in these progenitors. Nevertheless, low level of GATA3 expression by LTi progenitors is critical for the generation of functional LTi cells. Thus, quantitative expression of GATA3 functionally determines the fates and functions of distinct ILC progenitors.

P2822Seasonal variation in in-hospital cardiac arrest and associated mortality

Background

Previous reports have documented seasonal variation in out-of-hospital cardiac arrest (OHCA), with peak incidence in winter months, regardless of geographical region. However, seasonal variation in in-hospital cardiac arrest (IHCA) has not been well studied.

Purpose

To assess seasonal variation in incidence of in-hospital cardiac arrest, as well as gender and mortality differences.

Methods

We queried the 2014 National Inpatient Service (NIS) database for the total numbers of inpatient hospitalizations and in-hospital cardiac arrests for each month, as identified by ICD-9 codes (99.60 and 99.63). The trend for each month was plotted to assess seasonal variations in hospitalizations, IHCA, and mortality.

Seasonal Variations in IHCA

Results

The mean age of the study population was 57.3±0.2 years and 58.9% were female. Out of 29,717,872 total inpatient hospitalizations in 2014, the overall IHCA event for the year was 0.38%. Females were more likely to be hospitalized; however, males were more likely to have IHCA. These gender differences persisted throughout the year. Overall, more hospitalizations and IHCA were seen in the winter compared to the summer, and this trend was seen in both men and women. The highest incidence of in-hospital cardiac events occurred in January and the lowest incidence occurred in June. There was no seasonal variation in mortality in both male and female patients who suffered IHCA.

Conclusion(s)

In this observational study, seasonal variation is present in in-hospital cardiac arrest. Cardiac events are highest in the winter months as compared to the summer months; however, the mechanism of this variation is unknown and warrants further study.

Acknowledgement/Funding

None

A Modified Injector and Sample Acquisition Protocol Can Improve Data Quality and Reduce Inter-Instrument Variability of the Helios Mass Cytometer

Mass cytometry is a powerful tool for high-dimensional single cell characterization. Since the introduction of the first commercial CyTOF mass cytometer by DVS Sciences in 2009, mass cytometry technology has matured and become more widely utilized, with sequential platform upgrades designed to address specific limitations and to expand the capabilities of the platform. Fluidigm's third-generation Helios mass cytometer introduced a number of upgrades over the previous CyTOF2. One of these new features is a modified narrow bore sample injector that generates smaller ion clouds, which is expected to improve sensitivity and throughput. However, following rigorous testing, we find that the narrow-bore sample injector may have unintended negative consequences on data quality and result in lower median and higher coefficients of variation in many antibody-associated signal intensities. We describe an alternative Helios acquisition protocol using a wider bore injector, which largely mitigates these data quality issues. We directly compare these two protocols in a multisite study of 10 Helios instruments across 7 institutions and show that the modified protocol improves data quality and reduces interinstrument variability. These findings highlight and address an important source of technical variability in mass cytometry experiments that is of particular relevance in the setting of multicenter studies. © 2019 International Society for Advancement of Cytometry.

Efficacy and tolerability of trastuzumab emtansine in advanced human epidermal growth factor receptor 2-positive breast cancer

INTRODUCTION

The management of human epidermal growth factor receptor 2 (HER2)-positive breast cancer has changed dramatically with the introduction and widespread use of HER2-targeted therapies. There is, however, relatively limited real-world information about the effectiveness and safety of trastuzumab emtansine (T-DM1) in Hong Kong Chinese patients. We assessed the efficacy and toxicity profiles among local patients with HER2-positive advanced breast cancer who had received T-DM1 therapy in the second-line setting and beyond.

METHODS

This retrospective study involved five local centres that provide service for over 80% of the breast cancer population in Hong Kong. The study period was from December 2013 to December 2015. Patients were included if they had recurrent or metastatic histologically confirmed HER2+ breast cancer who had progressed after at least one line of anti-HER2 therapy including trastuzumab. Patients were excluded if they received T-DM1 as first-line treatment for recurrent or metastatic HER2+ breast cancer. Patient charts including biochemical and haematological profiles were reviewed for background information, T-DM1 response, and toxicity data. Adverse events were documented during chemotherapy and 28 days after the last dose of medication.

RESULTS

Among 37 patients being included in this study, 28 (75.7%) had two or more lines of anti-HER2 agents and 26 (70.3%) had received two or more lines of palliative chemotherapy. Response assessment revealed that three (8.1%) patients had a complete response, eight (21.6%) a partial response, 11 (29.7%) a stable disease, and 12 (32.4%) a progressive disease; three patients could not be assessed. The median duration of response was 17.3 (95% confidence interval, 8.4-24.8) months. The clinical benefit rate (complete response + partial response + stable disease, ≥12 weeks) was 37.8% (95% confidence interval, 22.2%-53.5%). The median progression-free survival was 6.0 (95% confidence interval, 3.3- 9.8) months and the median overall survival had not been reached by the data cut-off date. Grade 3 or 4 toxicities included thrombocytopaenia (13.5%), raised alanine transaminase (8.1%), anaemia (5.4%), and hypokalaemia (2.7%). No patient died as a result of toxicities.

CONCLUSIONS

In patients with HER2-positive advanced breast cancer who have been heavily pretreated with anti-HER2 agents and cytotoxic chemotherapy, T-DM1 is well tolerated and provided a meaningful progression-free survival of 6 months and an overall survival that has not been reached. Further studies to identify appropriate patient subgroups are warranted.

The multifactorial aetiology of fracture nonunion and the importance of searching for latent infection

Objectives

A successful outcome following treatment of nonunion requires the correct identification of all of the underlying cause(s) and addressing them appropriately. The aim of this study was to assess the distribution and frequency of causative factors in a consecutive cohort of nonunion patients in order to optimise the management strategy for individual patients presenting with nonunion.

Methods

Causes of the nonunion were divided into four categories: mechanical; infection; dead bone with a gap; and host. Prospective and retrospective data of 100 consecutive patients who had undergone surgery for long bone fracture nonunion were analysed.

Results

A total of 31% of patients had a single attributable cause, 55% had two causes, 14% had three causes and 1% had all four. Of those (31%) with only a single attributable cause, half were due to a mechanical factor and a quarter had dead bone with a gap. Mechanical causation was found in 59% of all patients, dead bone and a gap was present in 47%, host factors in 43% and infection was a causative factor in 38% of patients.

In all, three of 58 patients (5%) thought to be aseptic and two of nine (22%) suspected of possible infection were found to be infected. A total of 100% of previously treated patients no longer considered to have ongoing infection, had multiple positive microbiology results.

Conclusion

Two thirds of patients had multiple contributing factors for their nonunion and 5% had entirely unexpected infection. This study highlights the importance of identifying all of the aetiological factors and routinely testing tissue for infection in treating nonunion. It raises key points regarding the inadequacy of a purely radiographic nonunion classification system and the variety of different definitions for atrophic nonunion in the current mainstream classifications used for nonunion.

Cite this article: L. Mills, J. Tsang, G. Hopper, G. Keenan, A. H. R. W. Simpson. The multifactorial aetiology of fracture nonunion and the importance of searching for latent infection. Bone Joint Res 2016;5:512–519. DOI: 10.1302/2046-3758.510.BJR-2016-0138.

Comparing the meanings of living with advanced breast cancer between women resilient to distress and women with persistent distress: a qualitative study

BACKGROUND

Most women with advanced breast cancer (ABC) show little distress, but about one in ten show persistent distress over time. It remains unclear if meanings ascribed by patients to ABC differentiate these distress trajectories.

STUDY AIMS

This qualitative study (a) compared illness meanings of ABC between women with persistent psychological distress and those with low/transient distress, and (b) examined how illness meanings might influence coping strategies.

METHODS

The sample was drawn from a prior quantitative study exploring psychological distress trajectories following ABC diagnosis. Overall, 42 Cantonese- or Mandarin-speaking Chinese women diagnosed with locally advanced or metastatic ABC were recruited based on their distress trajectory status (low-stable, transient, or persistent distress). Interviews were recorded, transcribed, and analyzed following grounded theory approach using simultaneous analysis.

RESULTS

Women with persistent distress viewed their diagnosis as another blow in life, the illness was global, permeating every aspect of their life. Maladaptive rumination and thought suppression were common responses to illness demands. These women had poor social support. A sense of demoralization stood out in their narratives. In contrast, women with transient/low-stable distress encapsulated the illness, with minimum impacts of their life. They did not evidence dysfunctional repetitive thoughts. Living in a supportive environment, they were able to accept and/or live in the present-moment.

CONCLUSIONS

Rumination, thought suppression, social constraints, and pre-existing exposure to life stress may be potential risks for chronic distress in response to advanced breast cancer. Persistent and transient distress responses to cancer may have different underpinnings. Copyright © 2016 John Wiley & Sons, Ltd.

Abstract P4-12-28: HER2-related biomarkers in HER2+ breast cancer patients in Asia Pacific

Recent findings suggest that HER2-related molecular markers such as PTEN deletion or downregulation, PIK3CA mutation, truncated HER2 receptor (p95HER2), and tumor HER2 mRNA levels, have the potential to predict anti-HER2 treatment response. We evaluated the distribution of these biomarkers at the time of primary diagnosis and their relationship to responsiveness to lapatinib treatment in the metastatic setting in HER2+ breast cancer patients.

We conducted an observational study of female HER2+ breast cancer patients who were initiated on lapatinib treatment following recurrence or metastases in five Asia Pacific countries. Patients were enrolled between August 2010 and December 2012. Eligible patients had a tumor biopsy specimen available from their primary breast cancer diagnosis or before they started on any anti-HER2 treatment, had not been exposed to more than two lines of anti-HER2 treatment in the metastatic setting or other experimental anti-HER2 treatment, and had no other primary tumor. Biomarkers levels at primary diagnosis were measured; PTEN levels were assessed by immunohistochemistry and PIK3CA mutations were detected by a mass spectroscopy-based approach. The primary endpoint was progression-free survival (PFS) from the initiation of first lapatinib-based regimen given in metastatic setting to disease progression from that regimen or death from any cause. PFS analysis was conducted with a data cut-off date of 31 December 2012.

A total of 162 patients were included in this study and 96% have confirmed HER2+ breast cancer primary tumor. The mean age was 52±10 years and 97% had metastases at study entry, with bone being the most common site of metastasis (48%). About a quarter had PTEN protein loss (24%), 30% had PIK3CA mutation, and 7% had both at primary diagnosis. No significant association was observed between both biomarkers or between each biomarker and estrogen receptor status or HER2 status.

Table 1. Relationship between PTEN and PIK3CA PIK3CA mutation, n (%)PIK3CA wild-type, n (%)p-valuePTEN status  0.674Loss11 (29)27 (71) Normal33 (33)68 (67) 

Patients with altered PTEN expression, or PIK3CA mutation showed comparable PFS with lapatinib-based treatment as those with normal PTEN or PIK3CA expression at analysis cut-off date (median PFS 7.5 and 8.5 months respectively vs. 8.9 and 9.0 months respectively; p = 0.502 and p = 0.268 respectively). There remained no significant difference in PFS after having adjusted for significant confounders (HR 1.2 and 1.1 respectively; 95% CI 0.7–1.9 and 0.7–1.8 respectively; p = 0.481 and p = 0.730 respectively). The distribution of p95HER2 expression and tumor HER mRNA levels and their association with PFS will be included at the time of presentation.

Our preliminary findings suggest that PTEN alteration, or PIK3CA mutation may not be predictive of clinical response to lapatinib treatment in HER2+ breast cancer patients. The final PFS results with additional markers will provide more clues regarding their relationship to treatment response.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-28.

Systematic detection of polygenic cis-regulatory evolution

The idea that most morphological adaptations can be attributed to changes in the cis-regulation of gene expression levels has been gaining increasing acceptance, despite the fact that only a handful of such cases have so far been demonstrated. Moreover, because each of these cases involves only one gene, we lack any understanding of how natural selection may act on cis-regulation across entire pathways or networks. Here we apply a genome-wide test for selection on cis-regulation to two subspecies of the mouse Mus musculus. We find evidence for lineage-specific selection at over 100 genes involved in diverse processes such as growth, locomotion, and memory. These gene sets implicate candidate genes that are supported by both quantitative trait loci and a validated causality-testing framework, and they predict a number of phenotypic differences, which we confirm in all four cases tested. Our results suggest that gene expression adaptation is widespread and that these adaptations can be highly polygenic, involving cis-regulatory changes at numerous functionally related genes. These coordinated adaptations may contribute to divergence in a wide range of morphological, physiological, and behavioral phenotypes.

The hidden blood loss after hip fracture

INTRODUCTION

Despite advances in surgical and anaesthetic techniques the mortality after hip fracture has not significantly changed in the last 40 years. Pre-operative anaemia is a risk factor for peri-operative death. We speculate that a significant proportion of the blood loss related to hip fractures has occurred prior to surgery. Identifying patients at risk of pre-operative anaemia can facilitate appropriate medical optimisation. This study is unique in its attempt to quantify the blood loss associated with the initial hip injury.

METHODS

In a retrospective study all patients with both a diagnosis of hip fracture and an operative delay of >48 h were assessed. The information collected included: fracture classification, serial haemoglobins and patient co-morbidities. The exclusion criteria included a pre-injury diagnosis of anaemia, anti-coagulation and gastrointestinal bleeds.

RESULTS

Between 2007/2008 sixty-eight intracapsular and fifty extracapsular hip fracture patients had serial haemoglobins and operative delays of >48 h (mean 75 h, range 48-270 h). The mean lowest recorded haemoglobin prior to surgery for both extracapsular and intracapsular fractures were 95.0 g/L (+/-SEM 2.2) and 108.5 g/L (+/-SEM 2.2) respectively. This difference was statistically significant (Student's t-test p<0.05). The mean haemoglobin drop in the extracapsular and intracapsular fracture groups was 20.2 g/L (range 0-49 g/L) and 14.9 g/L (range 0-59 g/L) respectively.

CONCLUSIONS

Hip fracture patients have a large drop in haemoglobin that is associated with the initial trauma rather than the operation. This highlights the need for anaesthetic and orthopaedic staff to be vigilant to the risk of pre-operative anaemia in this cohort of frail patients even when the initial haemoglobin is apparently normal.

Generation of multi-functional antigen-specific human T-cells by lentiviral TCR gene transfer

T-cell receptor (TCR) gene transfer is an attractive strategy to generate antigen-specific T-cells for adoptive immunotherapy of cancer and chronic viral infection. However, current TCR gene transfer protocols trigger T-cell differentiation into terminally differentiated effector cells, which likely have reduced ability to mediate disease protection in vivo. We have developed a lentiviral gene transfer strategy to generate TCR-transduced human T-cells without promoting T-cell differentiation. We found that a combination of interleukin-15 (IL15) and IL21 facilitated lentiviral TCR gene transfer into non-proliferating T-cells. The transduced T-cells showed redirection of antigen specificity and produced IL2, IFNgamma and TNFalpha in a peptide-dependent manner. A significantly higher proportion of the IL15/IL21-stimulated T-cells were multi-functional and able to simultaneously produce all three cytokines (P<0.01), compared with TCR-transduced T-cells generated by conventional anti-CD3 plus IL2 stimulation, which primarily secreted only one cytokine. Similarly, IL15/IL21 maintained high levels of CD62L and CD28 expression in transduced T-cells, whereas anti-CD3 plus IL2 accelerated the loss of CD62L/CD28 expression. The data demonstrate that the combination of lentiviral TCR gene transfer together with IL15/IL21 stimulation can efficiently redirect the antigen specificity of resting primary human T-cells and generate multi-functional T-cells.

Obesity and genetics regulate microRNAs in islets, liver, and adipose of diabetic mice

Type 2 diabetes results from severe insulin resistance coupled with a failure of b cells to compensate by secreting sufficient insulin. Multiple genetic loci are involved in the development of diabetes, although the effect of each gene on diabetes susceptibility is thought to be small. MicroRNAs (miRNAs) are noncoding 19-22-nucleotide RNA molecules that potentially regulate the expression of thousands of genes. To understand the relationship between miRNA regulation and obesity-induced diabetes, we quantitatively profiled approximately 220 miRNAs in pancreatic islets, adipose tissue, and liver from diabetes-resistant (B6) and diabetes-susceptible (BTBR) mice. More than half of the miRNAs profiled were expressed in all three tissues, with many miRNAs in each tissue showing significant changes in response to genetic obesity. Furthermore, several miRNAs in each tissue were differentially responsive to obesity in B6 versus BTBR mice, suggesting that they may be involved in the pathogenesis of diabetes. In liver there were approximately 40 miRNAs that were downregulated in response to obesity in B6 but not BTBR mice, indicating that genetic differences between the mouse strains play a critical role in miRNA regulation. In order to elucidate the genetic architecture of hepatic miRNA expression, we measured the expression of miRNAs in genetically obese F2 mice. Approximately 10% of the miRNAs measured showed significant linkage (miR-eQTLs), identifying loci that control miRNA abundance. Understanding the influence that obesity and genetics exert on the regulation of miRNA expression will reveal the role miRNAs play in the context of obesity-induced type 2 diabetes.

Obesity and genetics regulate microRNAs in islets, liver, and adipose of diabetic mice

Type 2 diabetes results from severe insulin resistance coupled with a failure of b cells to compensate by secreting sufficient insulin. Multiple genetic loci are involved in the development of diabetes, although the effect of each gene on diabetes susceptibility is thought to be small. MicroRNAs (miRNAs) are noncoding 19-22-nucleotide RNA molecules that potentially regulate the expression of thousands of genes. To understand the relationship between miRNA regulation and obesity-induced diabetes, we quantitatively profiled approximately 220 miRNAs in pancreatic islets, adipose tissue, and liver from diabetes-resistant (B6) and diabetes-susceptible (BTBR) mice. More than half of the miRNAs profiled were expressed in all three tissues, with many miRNAs in each tissue showing significant changes in response to genetic obesity. Furthermore, several miRNAs in each tissue were differentially responsive to obesity in B6 versus BTBR mice, suggesting that they may be involved in the pathogenesis of diabetes. In liver there were approximately 40 miRNAs that were downregulated in response to obesity in B6 but not BTBR mice, indicating that genetic differences between the mouse strains play a critical role in miRNA regulation. In order to elucidate the genetic architecture of hepatic miRNA expression, we measured the expression of miRNAs in genetically obese F2 mice. Approximately 10% of the miRNAs measured showed significant linkage (miR-eQTLs), identifying loci that control miRNA abundance. Understanding the influence that obesity and genetics exert on the regulation of miRNA expression will reveal the role miRNAs play in the context of obesity-induced type 2 diabetes.

Triple Negative Breast Cancer Patients with Brain Metastasis Are Associated with More Concurrent Lung Metastases

Background: Breast cancer is a heterogeneous disease with different molecular subtypes. It is known that triple negative breast cancer and the HER-2 positive breast cancer subtypes are associated with more brain metastases. We further explored different subtypes of breast cancer patients with brain metastasis and analyzed their clinical behaviour with particular reference to the Hong Kong Chinese population. Methodology: We reviewed all breast cancer patients with brain metastasis presented to the Department of Clinical Oncology in the Queen Mary Hospital, the University of Hong Kong which is a teaching hospital during January 2004 to June 2008. Sociodemographic factors, date of primary breast cancer diagnosis and the tumour features, clinical behaviour at presentation, treatment received such as surgery, chemotherapy, hormonal therapy and targeted therapy, time of local recurrence, metastasis including brain metastasis, the recursive partitioning analysis (RPA) classes and treatment for the brain metastasis were all recorded. We classified the patients into 3 main subtypes, hormone positive, triple-negative (TNC) and HER-2 positive subtypes and further studied the clinical features and brain metastasis behaviour. Statistical analysis using SPSS 16.0 version was applied. Results: Altogether, there were 60 breast cancer patients with brain metastasis occurred during January 2004 to June 2008 requiring further management in our Department. Hormone positive patients constituted 46.6% while TNC accounted for 15.5% and HER-2 positive patients accounted for 37.9% of the cohort. The majority presented with symptoms at the time of the brain metastasis (93.1%) with headache being the most common symptom (43.1%), and 54 patients received whole brain radiotherapy (WBRT) and 8 patients received surgical resection of the brain metastasis. There were no significant statistical significance between the breast cancer subtypes and the metastatic behaviour except that the TNC patients were associated with concurrent lung metastasis when they first presented with brain metastasis (p = 0.03) when compared to the hormone positive and HER-2 positive patients. The ANOVA analysis showed there was a statistically significant difference between the RPA Classes of the patients and their time of survival after the brain metastasis (p = 0.002). Further ANOVA Post Hoc showed the RPA Class 3 patients were associated with shorter time of survival after brain metastasis when compared to the Class 1 patients (2.4 months vs 11.8 months, p = 0.001). However, patients with brain metastasis and different breast cancer subtypes did not have statistically significant different time of survival after their brain metastases. Conclusion: Hong Kong Chinese triple negative breast cancer patients with brain metastasis were associated with more concurrent lung metastasis. The RPA Classification still serves as a prognostic indicator with reference to the survival after brain metastasis in the breast cancer patients when compared to the breast cancer subtypes. Further large-scale multi-centre epidemiology study is warranted to confirm the above findings.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3072.

Primary Follicular Lymphoma of the Small Intestine

While nodal follicular lymphoma is prevalent in western countries, primary extranodal presentation is rare. We present the clinico-pathological and radiologic features of a patient with primary follicular lymphoma of the small intestine presenting with intestinal obstruction. This is followed by the discussion on the frequency and staging systems for primary gastrointestinal lymphomas, and the relevance of monoclonal anti-CD20 antibody therapy.

Triple-negative breast cancer in Hong Kong Chinese patients

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Background: There is increasing data showing that breast cancer is a heterogeneous disease which should be assessed separately in different populations, as it differs substantially between Chinese and Caucasian women. Triple-negative breast tumours which are negative for ER, PR and HER-2 neu receptors are associated with younger age at presentation, tumour of higher grade with larger size and a poorer prognosis. There is recent suggestion that the prognostic outlook of Chinese triple-negative breast cancers might be somewhat different from those in the Western population, but few studies have attempted to understand the role of ethnic factor in the triple-negative entity. Methods: We conducted a preliminary retrospective comparison of 170 Hong Kong Chinese primary breast cancer patients seen as new cases during January 2004 and December 2004 in a teaching hospital. Clinico-pathological features of triple-negative tumours were compared to their non-triple-negative counterpart. Results: Triple negative breast cancer accounted for 12.4% of all breast cancer patients seen in the year of 2004 (n = 21). It is associated with more cancers with grade 3 tumour (68.4% vs 36.8%; p = 0.02) but there was no statistically difference between the age of presentation, tumour size, extensive intraductal component, lymph node status and rate of local relapse or metastasis after adjuvant therapy. Subset analysis further revealed that when triple negative breast cancer patients (n = 21) were compared to the HER-2 positive patients (n = 40) in the studied population, HER-2 positive patients were still associated with higher proportion of node positive disease (57.5% vs 30.0%; p = 0.04). Disease free survival and overall survival were not studied due to limited follow-up time. Conclusions: Our preliminary findings suggested that Hong Kong Chinese triple-negative breast cancers are associated with a more favourable outlook and might behave differently when compared to their Western counterpart. Further large-scale study of the ethnic factor with long-term follow-up is warranted.

No significant financial relationships to disclose.

Current trend of breast cancer therapeutics from the U.S. clinical trial database

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Background: The standard of breast cancer care has been based on clinical trial results. With the International Committee of Medical Journal Editors (ICMJE) requiring all clinical trials registered in a public trial registry as a condition of publication, the US trials registry “ClinicalTrials.gov” has become a global registry of currently available clinical trials. We aim to explore the current clinical trials to study the trend of breast cancer therapeutics development based on analysis of a comprehensive breast cancer trial database. Methods: We performed a systematic review of all breast cancer therapeutic clinical trials. All data were captured from ClinicalTrials.gov for all “industry-sponsored” phase I-IV trials in October, 2007 including trials that were first registered between October 2005 and September 2007. Essential data was extracted by a tailor-made Statistical Analysis System Program developed by Professor JP Karlberg at the University of Hong Kong. The data included register identity, study phase, study compounds and recruitment status etc. Results: Altogether 443 clinical therapeutic interventional trials were identified and classified into 10 modes of action. The latest five mostly studied compounds accounted for 32.73% of all the therapeutic trials (n = 145). Lapatinib, a dual kinase inhibitor is studied most in 31 trials (9 monotherapy). Docetaxel, a mitotic inhibitor is studied in 27 trials (10 monotherapy) while letrozole, an aromatase inhibitor, currently used in adjuvant setting is tested in 18 out of a total 22 trials as monotherapy. Antimetabolites such as gemcitabine being involved in 24 trials (2 monotherapy) with capecitabine studied in 21 trials (11 monotherapy), were followed by bevacizumab, a VEGF monoclonal antibody which is currently studied in 20 trials, and tested as combinations in 75% of the related trials. Conclusions: According to the US trial registry, current most commonly tested compounds for breast cancer include lapatinib, followed by docetaxel, gemcitabine, letrozole, and capecitabine. There is increasing new therapeutics with combination strategy. This supports the trend of personalized medicine in the management of breast cancer which is a heterogeneous disease.

No significant financial relationships to disclose.

Influence of palliative surgical resection on overall survival in patients with advanced colorectal cancer: a retrospective single institutional study

BACKGROUND

The role of palliative surgical resection in patients presenting with locally advanced or metastatic colorectal cancer (CRC) is unclear. Resection is often limited to symptomatic management of bleeding, obstruction, perforation or for relief of pain, in patients with an adequate performance status and an expected life span of over several weeks. An exploratory analysis to evaluate the influence of a palliative surgical resection on survival outcome in patients with advanced CRC is reported.

METHOD

A retrospective review of medical records of all patients diagnosed with advanced CRC at our institution between the years 1998 and 2003 was undertaken. Tumour registry data were reviewed to identify age, gender, modalities of therapy [i.e. surgery (S), chemotherapy (C), radiation] and overall survival. IRB approval was obtained for this study.

RESULTS

One hundred and eighty-five patients were identified. Median age was 67 years (range 30-99). M:F ratio was 1:1. Sixty-two per cent of patients (115/185) underwent a palliative surgical intervention. Median survival of patients who underwent S and those that did not undergo S was 22 and 3 months respectively (P < 0.0001). Forty-eight per cent of patients (79/184) underwent systemic C. Median survival of patients who received C + S, and patients who received C alone was 30 and 15 months respectively (P < 0.0004). Fifty-one per cent of patients who underwent S, received C; 30% of patients who did not undergo S, received C. Chemotherapy data were available on 46 of 79 patients. Patients treated with S + C, and C without S, received a median of 9 and 6 months of therapy respectively. The median number of regimens used were similar in both.

CONCLUSION

These exploratory data suggest a positive influence of a palliative resection performed during the disease course of patients with advanced CRC. The increased frequency of utilization and the more prolonged duration of C in the surgically treated patients may in part contribute to this improved survival. This may also be reflective of performance status at the time of diagnosis. Future trials enrolling patients with advanced CRC should prospectively stratify for surgical intervention to further clarify the influence of this modality on the outcome of systemic therapy in this disease.

MicroRNA-mediated feedback and feedforward loops are recurrent network motifs in mammals

MicroRNAs (miRNAs) are regulatory molecules that participate in diverse biological processes in animals and plants. While thousands of mammalian genes are potentially targeted by miRNAs, the functions of miRNAs in the context of gene networks are not well understood. Specifically, it is unknown whether miRNA-containing networks have recurrent circuit motifs, as has been observed in regulatory networks of bacteria and yeast. Here we develop a computational method that utilizes gene expression data to show that two classes of circuits-corresponding to positive and negative transcriptional coregulation of a miRNA and its targets-are prevalent in the human and mouse genomes. Additionally, we find that neuronal-enriched miRNAs tend to be coexpressed with their target genes, suggesting that these miRNAs could be involved in neuronal homeostasis. Our results strongly suggest that coordinated transcriptional and miRNA-mediated regulation is a recurrent motif to enhance the robustness of gene regulation in mammalian genomes.

Costs and benefits of dose-dense chemotherapy scheduling in Hong Kong Chinese patients with primary breast cancer

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Background: Routine prophylactic administration of recombinant granulocyte colony-stimulating factor (G-CSF, filgrastim) has enabled more frequent scheduling of adjuvant cytotoxic drugs in primary breast cancer. Dose-dense chemotherapy of this kind has become popular in recent years, but few studies have compared the costs and benefits of this treatment approach. Methods: We conducted a retrospective comparison of 150 Hong Kong Chinese primary breast cancer patients treated with either conventional 3-weekly chemotherapy or G-CSF-supported 2-weekly (dose-dense) chemotherapy using similar cytotoxic regimens (four cycles of doxorubicin and cyclophosphamide, followed by four cycles of taxane) between April 2004 and May 2006 in two teaching hospitals. Assessments of treatment tolerance, toxicity, scheduling, and expense were applied to both patient cohorts. Results: Compared to conventionally treated patients (n = 117), dose-dense patients (n = 33) benefited from 52.3% fewer chemotherapy delays (21.2% vs. 44.4%; p = 0.02), 79.3% fewer hospital admissions for febrile neutropenia (3.0% vs. 14.5%; p = 0.07), and 54.8% enhancement of cytotoxic dose intensity (p < 0.001). Dose-dense patients also developed less nausea (p < 0.001) and stomatitis (p = 0.01) but more frequent bone pain (p < 0.001). After subtracting costs saved by fewer hospital admissions, dose-dense patients incurred higher total expenses approximating US$500 per cycle. Conclusion: Routine G-CSF administration to Hong Kong Chinese patients with primary breast cancer is associated with major improvements in cytotoxic drug delivery, which could plausibly translate into greater therapeutic efficacy in some patients. In addition, dose- dense treatment is shorter, safer, and more reliably scheduled, and is associated with unexpected improvements in nausea and stomatitis. The extent to which these gains justify the rise in net costs needs to be further defined in prospective randomized studies, both in different adjuvant patient subsets and in differently resourced socioeconomic contexts.

No significant financial relationships to disclose.

XELOX causes less disabling peripheral neuropathy than FOLFOX 4 for Chinese colorectal cancer patients

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Background: Infusional 5-FU plus leucovorin and oxaliplatin (FOLFOX4) is an efficacious treatment for colorectal cancer patients in both the adjuvant and metastatic settings. However, around 10% of FOLFOX4 patients will develop with disabling grade 3–4 neuropathy. Recent phase II studies have demonstrated that oral capecitabine in combination with oxaliplatin (XELOX) is as least as effective as FOLFOX4 for colorectal cancer. In this study, we assessed the toxicities of XELOX in Chinese colorectal cancer patients. Methods: Patients who received XELOX at Queen Mary Hospital, Hong Kong between November 2004 and November, 2006 were analyzed. Toxicities were graded by the National Cancer Institute common toxicity system. Results: Thirty-five patients received XELOX on an outpatient basis during the study period: Twenty-four as adjuvant therapy and 11 as treatment for metastatic disease. The most common side effect was grade 1–2 peripheral neuropathy which occurred in 77% of patients. No grade 3–4 neuropathy was reported. Grade 1–2 diarrhea and palmar-plantar erythrodysesthesia (PPE) also occurred in 40 % and 37 % of patients, respectively. The commonest grade 3 toxicities was diarrhea which occurred in 17% of the patients followed by 9% of patients experienced grade 3 PPE. No grade 4 toxicities were reported in our patient’s cohort. Overall, only one (3%) patient had neutropenic sepsis and 36% of patients required 20% reduction in drug dosage. No treatment related death was reported. Conclusions: Our study suggests that XELOX is a well-tolerated and convenient treatment regime. Although mild neuropathy is common in patients receiving XELOX, it causes far less disabling neuropathy than FOLFOX4 in Chinese metastatic colorectal cancer patients.

No significant financial relationships to disclose.

Intercellular transfer of MHC and immunological molecules: molecular mechanisms and biological significance

The intercellular transfer of many molecules, including the major histocompatibility complexes (MHC), both class I and II, costimulatory and adhesion molecules, extracellular matrix organization molecules as well as chemokine, viral and complement receptors, has been observed between cells of the immune system. In this review, we aim to summarize the findings of a large body of work, highlight the molecules transferred and how this is achieved, as well as the cells capable of acquiring molecules from other cells. Although a physiological role for this phenomenon has yet to be established we suggest that the exchange of molecules between cells may influence the immune system with respect to immune amplification as well as regulation and tolerance. We will discuss why this may be the case and highlight the influence intercellular transfer of MHC molecules may have on allorecognition and graft rejection.

Adoptive cell therapy using in vitro generated human CD4+ CD25+ regulatory t cells with indirect allospecificity to promote donor-specific transplantation tolerance

The holy grail in clinical transplantation is the establishment of long-term donor-specific transplantation tolerance with the minimum use of immunosuppressive agents. CD4+ CD25+ regulatory T cells (Tregs) play a crucial role in the prevention of autoimmunity, and appear to mediate transplantation tolerance. Harnessing Tregs for potential adoptive cell therapy to promote donor-specific transplantation tolerance is promising. Here we show that human CD4+ CD25+ Tregs with indirect allospecificity for an HLA-A2 (103-120) peptide can be generated from purified peripheral blood CD4+ CD25+ by priming with HLA-DR0101+ A2- autologous dendritic cells (DCs) pulsed with the A2 peptide in vitro. The antigen specificity for the A2 peptide was demonstrated in functional assays and flow cytometric analysis using a fluorescent tetramer composed of HLA-DR0101 and the A2 peptide. The CD4+ CD25+ Tregs with indirect allospecificity for the A2 peptide showed potent suppression of an indirect alloresponse by effector CD4+ CD25- T-helper cells. Importantly, the selected CD4+ CD25+ Tregs can be expanded substantially to meet a therapeutic end after T-cell receptor (TCR) stimulation by CD3/CD28 antibody-coated beads in the presence of high doses of interleukin-2 (IL-2). The expanded CD4+ CD25+ Tregs highly expressed Foxp3, and retained their suppressive properties and maintained expression of lymphoid homing receptor CD62L. Taken together, these data pave the way for clinical studies using in vitro generated and expanded human CD4+ CD25+ Tregs with indirect allospecificity as therapeutic reagents to promote donor-specific transplantation tolerance.

Endothelial cell function on a poly(acrylamide-co-polyethylene acid) interpenetrating polymer network: cardiovascular applications

Hydrogel coatings have been widely researched as a nonfouling surface modification of materials for cardiovascular applications. In this study, we examined cell-surface interactions between a poly(acrylamide-copolyethylene glycol/acrylic acid) interpenetrating network (IPN) hydrogel and aortic endothelial cells (ECs). The IPN was covalently attached to polystyrene to form a nanometer scale thick hydrogel, and the IPN layer was activated by conjugation of the cell adhesion peptide Arg-Gly-Asp (RGD). On IPN surfaces lacking the RGD peptide, EC did not adhere and spread even after long-term incubation. The IPN was able to support greater EC adhesion and spreading with increasing RGD surface concentrations. Upon adequate adhesion and spreading, ECs migrated and proliferated at high rates regardless of the RGD surface concentration. These results suggest that this IPN can be used to promote endothelialization of vascular implants made of polymeric and metal materials for cardiovascular applications.