Refitting of the UKPDS 68 risk equations to contemporary routine clinical practice data in the UK

OBJECTIVE

Economic evaluations of new diabetes therapies rely heavily upon the UK Prospective Diabetes Study (UKPDS) equations for prediction of cardiovascular events; however, concerns persist regarding their relevance to current clinical practice and appropriate use in populations other than newly diagnosed patients. This study refits the UKPDS 68 event equations, using contemporary data describing low- and intermediate-risk patients.

RESEARCH DESIGN AND METHODS

Anonymized patient data describing demographics, risk factors and incidence of cardiovascular and microvascular events were extracted from The Health Improvement Network (THIN) database over the 10-year period from 1 January 2000 to 31 December 2009. Following multiple imputation of missing values, accelerated failure-time Weibull regression equations were refitted to produce new coefficients for each risk group. Discriminatory performance was assessed and compared with both UKPDS 68 and UKPDS 82 risk equations, and the implication of coefficient choice within an economic evaluation was assessed using the Cardiff type 2 diabetes model.

RESULTS

When applied to patient-level data, the three sets of coefficients (UKPDS, THIN low-risk and intermediate-risk) lead to fairly consistent predictions of the 5-year risk of events. Exceptions include lower predicted rates of myocardial infarction and higher rates of ischaemic heart disease, congestive heart failure and end-stage renal disease with both sets of revised THIN coefficients compared with UKPDS. Over a modelled lifetime, the coefficients derived from the low-risk data predict fewer total cardiovascular events compared with UKPDS, while those from the intermediate-risk data predict a greater number. The areas under the receiver-operating characteristic curves demonstrated a marginal improvement in the discriminatory performance of the refitted equations. The incremental cost-effectiveness ratio associated with dapagliflozin versus sulphonylurea in addition to metformin changed from £7,708 to £7,519 and £6,906 per QALY gained, using the THIN intermediate- and low-risk coefficients, respectively.

CONCLUSION

The results suggest that while the UKPDS equations perform best in newly diagnosed patients, they may overpredict the lifetime risk in this group and underpredict it in patients with more advanced diabetes. Implementation of the revised coefficients will result in different absolute numbers of predicted diabetes-related events; however, they are not expected to significantly affect the conclusions of economic modelling.

Brain computer interfaces for neurorehabilitation – its current status as a rehabilitation strategy post-stroke

The idea of using brain computer interfaces (BCI) for rehabilitation emerged relatively recently. Basically, BCI for neurorehabilitation involves the recording and decoding of local brain signals generated by the patient, as he/her tries to perform a particular task (even if imperfect), or during a mental imagery task. The main objective is to promote the recruitment of selected brain areas involved and to facilitate neural plasticity. The recorded signal can be used in several ways: (i) to objectify and strengthen motor imagery-based training, by providing the patient feedback on the imagined motor task, for example, in a virtual environment; (ii) to generate a desired motor task via functional electrical stimulation or rehabilitative robotic orthoses attached to the patient's limb – encouraging and optimizing task execution as well as "closing" the disrupted sensorimotor loop by giving the patient the appropriate sensory feedback; (iii) to understand cerebral reorganizations after lesion, in order to influence or even quantify plasticity-induced changes in brain networks. For example, applying cerebral stimulation to re-equilibrate inter-hemispheric imbalance as shown by functional recording of brain activity during movement may help recovery. Its potential usefulness for a patient population has been demonstrated on various levels and its diverseness in interface applications makes it adaptable to a large population. The position and status of these very new rehabilitation systems should now be considered with respect to our current and more or less validated traditional methods, as well as in the light of the wide range of possible brain damage. The heterogeneity in post-damage expression inevitably complicates the decoding of brain signals and thus their use in pathological conditions, asking for controlled clinical trials.

Confronting Auditory Hallucinations Using Virtual Reality: The Avatar Therapy

The AVATAR therapy is a computer-based intervention which aims to reduce the frequency and severity of voices. The approach is based on computer technology which enables each patient to create an avatar of the entity (human or non-human) that they believe is talking to them. The therapist promotes a dialogue between the patient and the avatar in which the avatar progressively comes under the patient's control. Using real-time voice conversion delivery software, the therapist can modify the relationship between the patient and his/her voice. The innovation of this new intervention is discussed in the present paper as well as the advantages of using a computer based system. The subjective view of the technology from a participant's point of view is also presented.

Polycyclic aromatic hydrocarbon metabolites in Arctic cod (Boreogadus saida) from the Beaufort Sea and associative fish health effects

In 2012, Arctic cod (Boreogadus saida) were collected from offshore regions of the Beaufort Sea to determine the concentrations of CYP1A1 phase I metabolites of polycyclic aromatic hydrocarbons (OH-PAHs) in liver and to correlate measured concentrations with (i) morphometric measurements that are known to be indicative of fish health and, (ii) biochemical end points of health including vitamin A/E and metabolites and hepatic deiodinase activity (DI). Four ring OH-PAHs were detected in 90% of our samples with a mean liver concentration of 1829.2 ± 159.2 ng/g (ww). Total (∑) concentrations of 5/6-membered ring OH-PAHs in liver were smaller [mean of 931.6 ± 104.3 ng/g, (ww)] and detected less frequently (75%) than the 4-ring OH-PAHs. Fish length and liver weight were both negatively correlated to ∑ concentrations of 4-ringed OH-PAHs (p < 0.001). Liver somatic index was also negatively correlated to ∑4-OH-PAHs (p < 0.05) but not for ∑5/6-OH-PAHs (p > 0.1). There was a significant positive relationship between DI and 4-ring OH-PAHs (p < 0.05) in liver, suggesting an induction of this enzyme. No such correlation was observed for the 5/6-ring OH-PAHs. Retinyl palmitate (RP) was the only vitamin that could be measured in liver ranging from 0.230 to 26.3 ug/g (ww). No associations between RP and levels of the 4- or 5/6-ringed OH-PAHs were observed. Continued baseline studies are clearly warranted to further understand effects of OH-PAHs on fish health before planned exploration activities begin in this region.

Overrepresentation of multiple birth pregnancies in young infants with four metabolic bone disorders: further evidence that fetal bone loading is a critical determinant of fetal and young infant bone strength

The frequency of multiple birth pregnancies, mostly twin pregnancies, was overrepresented in four different groups of young infants with fractures and bone abnormalities. This finding suggests that fetal bone loading through fetal movement is an important determinant of fetal bone formation and its resultant bone strength.

INTRODUCTION

It has been suggested that intrauterine confinement related to the multiple birth pregnancy (MBP) may lead to an increased risk for fragility fractures in young infants as a result of decreased fetal bone loading.

METHODS

To objectively test this idea, the frequency of MBPs was evaluated in five groups of young infants with bone disorders: (1) infants exposed to prolonged in utero exposure to magnesium, (2) infants with dietary copper deficiency, (3) infants with rickets from vitamin D deficiency, (4) infants with temporary brittle bone disease, and (5) infants with multiple unexplained fractures in which child abuse was the most likely diagnosis.

RESULTS

Compared to a control group and controlled for preterm birth, there was a statistically greater frequency of MBPs in each group.

CONCLUSIONS

The results of this study suggest the following: (a) The overrepresentation of MBPs (95 % twins) in these five groups indicates that fetal bone loading is a critical determinant of fetal bone strength; (b) fetal and young infant bone strength is a multifactorial characteristic; and (c) infants from MBPs are at increased risk for fragility fractures during the first 12 months of life, and thus may be mistakenly diagnosed as victims of child abuse.

Coarse particulate matter and airborne endotoxin within wood stove homes

Emissions from indoor biomass burning are a major public health concern in developing areas of the world. Less is known about indoor air quality, particularly airborne endotoxin, in homes burning biomass fuel in residential wood stoves in higher income countries. A filter-based sampler was used to evaluate wintertime indoor coarse particulate matter (PM₁₀₋₂.₅) and airborne endotoxin (EU/m³, EU/mg) concentrations in 50 homes using wood stoves as their primary source of heat in western Montana. We investigated number of residents, number of pets, dampness (humidity), and frequency of wood stove usage as potential predictors of indoor airborne endotoxin concentrations. Two 48-h sampling events per home revealed a mean winter PM₁₀₋₂.₅ concentration (± s.d.) of 12.9 (± 8.6) μg/m³, while PM₂.₅ concentrations averaged 32.3 (± 32.6) μg/m³. Endotoxin concentrations measured from PM₁₀₋₂.₅ filter samples were 9.2 (± 12.4) EU/m³ and 1010 (± 1524) EU/mg. PM₁₀₋₂.₅ and PM₂.₅ were significantly correlated in wood stove homes (r = 0.36, P < 0.05). The presence of pets in the homes was associated with PM₁₀₋₂.₅ but not with endotoxin concentrations. Importantly, none of the other measured home characteristics was a strong predictor of airborne endotoxin, including frequency of residential wood stove usage.

Improvements to Rapfish: a rapid evaluation technique for fisheries integrating ecological and human dimensions

This paper reports recent developments in Rapfish, a normative, scalable and flexible rapid appraisal technique that integrates both ecological and human dimensions to evaluate the status of fisheries in reference to a norm or goal. Appraisal status targets may be sustainability, compliance with a standard (such as the UN code of conduct for responsible fisheries) or the degree of progress in meeting some other goal or target. The method combines semi-quantitative (e.g. ecological) and qualitative (e.g. social) data via multiple evaluation fields, each of which is assessed through scores assigned to six to 12 attributes or indicators: the scoring method allows user flexibility to adopt a wide range of utility relationships. For assessing sustainability, six evaluation fields have been developed: ecological, technological, economic, social, ethical and institutional. Each field can be assessed directly with a set of scored attributes, or several of the fields can be dealt with in greater detail using nested subfields that themselves comprise multidimensional Rapfish assessments (e.g. the hierarchical institutional field encompasses both governance and management, including a detailed analysis of legality). The user has the choice of including all or only some of the available sustainability fields. For the attributes themselves, there will rarely be quantitative data, but scoring allows these items to be estimated. Indeed, within a normative framework, one important advantage with Rapfish is transparency of the rigour, quality and replicability of the scores. The Rapfish technique employs a constrained multidimensional ordination that is scaled to situate data points within evaluation space. Within each evaluation field, results may be presented as a two-dimensional plot or in a one-dimensional rank order. Uncertainty is expressed through the probability distribution of Monte-Carlo simulations that use the C.L. on each original observation. Overall results of the multidisciplinary analysis may be shown using kite diagrams that compare different locations, time periods (including future projections) and management scenarios, which make policy trade-offs explicit. These enhancements are now available in the R programming language and on an open website, where users can run Rapfish analyses by downloading the software or uploading their data to a user interface.

A CMOS Camera-Based Pulse Oximetry Imaging System

In this paper a CMOS camera-based system for non-contact pulse oximetry imaging in transmission mode is described. Attention is drawn to the current uses of conventional pulse oximetry and the potential application of pulse oximetry imaging to developing objective wound assessment systems.

PD08-02: Targeting BCL-2 Expressing Breast Tumors with BH3-Mimetics – A New Class of Drugs in Breast Cancer?

Background: Impairment of apoptosis is a hallmark of cancer and can result in resistance to chemotherapy. Tumor resistance to apoptosis is frequently acquired through deregulated expression of BCL-2 family members or inactivation of the p53 tumor suppressor pathway. Over-expression of the pro-survival protein BCL-2 is common in breast cancer (where it is readily detected by immunostaining), and has been shown to be an important prognostic marker. A potential role for BCL-2 as a therapeutic target in breast cancer, however, has not been explored. Recently, small molecules termed ‘BH3-mimetics’ have been developed that mimic the action of pro-apoptotic BH3-only proteins. These bind and neutralize pro-survival proteins including BCL-2. Here we have derived a panel of primary breast tumor xenografts (that include basal-like breast tumors) to study the efficacy of the BH3-mimetic ABT-737 combined with docetaxel in targeting BCL-2-positive breast cancer.

Methods and Results: We first studied the expression of BCL-2, pro-survival family members BCL-XL and MCL-1, and the pro-apoptotic protein BIM in tissue microarrays of 197 primary breast tumors, which were subtyped on the basis of ER, PR, HER2, CK5/6 and EGFR expression. BCL-2 was overexpressed in luminal (83.3%), HER2−positive (50.0%), basal-like (18.5%) and ‘marker-null’ (41.4%) breast cancers. BCL-2-positive tumors generally co-expressed BCL-XL (96.2%), MCL-1 (94.7%) and BIM (93.5%). To determine whether the BH3-mimetic ABT-737 (which neutralizes BCL-2, BCL-XL and BCL-W) was effective in targeting BCL-2-expressing breast tumors, we generated a panel of 28 primary breast tumor xenografts in immunocompromised NOG mice. Five xenograft lines (838T, 24T, 315T, 13T and 806T) were selected for further analysis. Four were basal-like, and one (315T) was a luminal B tumor, as determined by gene profiling. Mice bearing tumor xenografts were treated with ABT-737 (50 mg/kg i.p. d1-10), docetaxel (10 mg/kg i.p. d1) or a combination in q21d cycles. Tumor response and overall survival were significantly improved by combination therapy, but only for tumors that expressed elevated levels of BCL-2. Treatment with ABT-737 alone was ineffective, suggesting that ABT-737 sensitized tumors to docetaxel. Combination therapy was accompanied by a marked increase in apoptosis and dissociation of BIM from BCL-2, indicating that a perturbation of BIM complexes may contribute to the activation of the apoptotic cascade. Notably, ABT-737 appeared effective in targeting BCL-2-expressing basal-like tumor xenografts (838T and 24T) harboring p53 mutations.

Discussion: Primary breast tumor xenograft models that recapitulate the phenotype of the primary tumor have been developed as useful ‘proof-of-principle', pre-clinical models. Here we provide the first in vivo evidence that BH3-mimetics can be used to sensitize primary BCL-2-expressing breast tumors to taxane chemotherapy. Our results suggest that elevated BCL-2 expression constitutes a predictive response marker in breast cancer. These findings provide a rationale for the development of clinical protocols using the oral analogue ABT-263 (navitoclax) as an adjunct to taxane chemotherapy in BCL-2-expressing basal-like and luminal breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD08-02.

Value of drug-eluting stents after failed percutaneous transluminal angioplasty in the infrapopliteal vessels for the treatment of critical limb ischemia: favorable mid-term patency and limb salvage results

AIM

The endovascular treatment of infrapopliteal arterial disease in the setting of critical limb ischemia (CLI) is increasing in use. In patients in whom percutaneous transluminal angioplasty (PTA) resulted in suboptimal angiographic results, flow limiting dissection or re-coil is thought to limit clinical success. This single-center experience examines the angiographic and clinical results when Drug-Eluting Stents (DES) were placed in a large cohort of patients with CLI after immediate infrapopliteal PTA failure.

METHODS

A retrospective review of a prospectively collected single-center endovascular database was performed. Sixty-seven Rutherford grade 4, 5, and 6 patients were treated between October 2005 and February 2010 with PTA because lack of an acceptable autologous vein for bypass-grafting or severe medical comorbidities precluded them from surgical bypass. The study cohort had suboptimal angiographic results immediately after PTA that was subsequently treated with DES. Patients were then placed on clopidogrel and aspirin indefinitely. Angiographic, clinical, and the results of noninvasive vascular examinations were collected.

RESULTS

In total, 123 stents (94 sirolimus, 27 everolimus, 2 paclitaxel) were placed in 67 patients to treat a total of 84 angiographic lesions. Simultaneous femoral-popliteal intervention was performed in 66% of the patients while 45% of the treated lesions were total occlusions. Lesion length ranged from 17 mm-142 mm (mean 50 mm). Initial technical success was 100%, with all 84 lesions being treated successfully with less than 10% stenosis after stent implantation. Mean follow-up was 20 months (1-42 months) with 6, 12, and 24-month primary patency rates of 90%, 86%, and 72% respectively. Freedom from major amputation was 91.1% (61/67) with all six amputations occurring in the Rutherford grade 6 group (6/11). Overall mortality rate was 19% (13/67) with one death occurring within 30 days.

CONCLUSION

The use of drug-eluting stents following suboptimal PTA for the treatment of infrapopliteal arterial disease in this cohort of patients with CLI produced high primary patency and limb salvage rates supporting the efficacy of this treatment strategy.

The Role of Threat Appraisals and Safety-Seeking Behaviours in Determining Need for Care in Psychosis

Introduction

Van Os et al. (2009) have proposed a Proneness-Persistence-lmpairment model to explain the psychosis continuum, and cognitive models of psychosis have suggested that appraisals of anomalous experiences may be key in determining ‘need for care’.

Objectives

The present study investigated the interaction between appraisals and safety behaviours in the maintenance of impairing psychotic symptoms.

Aims

It was predicted that individuals with psychotic symptoms without a need for care would display fewer threat appraisals and safety behaviours than their clinical counterparts, and that these variables would predict distress.

Methods

The study recruited people with persistent psychotic experiences but who had no-need-for-care (Persistence group; n = 39) and individuals diagnosed with a psychotic disorder who were receiving current treatment (Impairment group; n = 28). The participants were assessed on semi-structured interviews of appraisals and safety behaviours in relation to their psychotic experiences and on anxiety and depression questionnaires.

Results

Both groups had similar levels of psychotic symptoms in the last month, including first rank symptoms. However there was a large significant difference between Impairment and Persistence groups in threat appraisals and safety behaviours, with the Persistence group reporting higher levels of both. A mediation analysis found that threat appraisals mediated the relationship between safety behaviours and anomaly-related distress, suggesting that threat appraisals may maintain anomaly-related distress, a defining feature of Impairment status.

Conclusions

These data provide support for the cognitive model of psychosis, with threat appraisals potentially playing a major role in the transition from non-clinical anomalous experiences to clinical psychotic status.

Preparation of Energetic Metastable Nano-Composite Materials by Arrested Reactive Milling

Highly metastable, nano-scale energetic materials were prepared by Arrested Reactive Milling (ARM). When reactive milling is carried out with materials systems suitable for Self-Propagating High Temperature Synthesis (SHS), reaction between the components occurs spontaneously and violently after a certain period of milling. In this research, metastable nanocom-posites with high energy density, were prepared by arresting the milling process prior to the spontaneous reaction. Products thus obtained are powders with particle sizes in the 10–50 μm range. Individual particles are intimate mixtures of reactive components, comparable to Metast-able Intermolecular Composites (MIC), with near theoretical maximum density. The time of arrest determines the degree of grain refinement and therefore the sensitivity to mechanical, electrical, or thermal initiation. Particle sizes of the product powders can be adjusted by appropriate choice of milling parameters. This paper describes the application of ARM to the material systems Al-Fe2O3 and Al-MoO3. After empirical determination of optimum milling parameters, the reactive composites are structurally characterized by electron microscopy and x-ray diffraction. First results of combustion tests are presented.

Abstract P5-06-03: Truncated ERBB2 Receptors: Diagnostic and Therapeutic Targets

Background:

Patients with ERBB2+ breast cancer have aggressive disease and poor prognoses. It is now apparent that many ERBB2+ tumors also express truncated ERBB2 receptors (t-ERBB2s), namely p110 and p95. Increased expression of t-ERBB2s by breast tumors correlates with increased nodal involvement, distant metastasis, and poor clinical outcome in patients. Because t-ERBB2s lack the epitope bound by trastuzumab, expression of high levels of these isoforms may designate patients who would be better treated with alternative anti-ERBB2 therapy such as lapatinib; unfortunately, there is currently no clinical method to distinguish full-length p185- versus t-ERBB2 in patient tumor samples. Materials and Methods:

Recombinant forms of p185-, p110- and p95-ERBB2 were constructed using standard cloning techniques and expressed in human mammary epithelial cells (HMLE) via retroviral vector. The expression and subcellular localization of constructs were confirmed by western blot analysis and confocal microscopy. The ability of p185- and t-ERBB2 constructs to transform HMLE cells was evaluated using soft agar assays, and the effects on migration and invasion of these cells were investigated by transwell assays. Finally, the in vivo tumor formation by p185- vs. t-ERBB2 expressing cells was evaluated in immunodeficient mice. Additionally, a novel proximity-based antibody-capture method method to discern full-length versus t-ERBB2 in patient tumor samples was assessed (COPIA). Block tumors and fine-needle aspirates from patient tumor samples were used for quantifying total and phosphorylated ERBB2 receptors.

Results and Discussion:

Recombinant p185- and t-ERBB2 constructs were stably expressed in HMLE cells, and were correctly targeted to the cell membrane, as shown by confocal immunofluorescence microscopy and immunoblot. Expression of p110 t-ERBB2 increased migration and invasion of HMLE cells compared to p185 ERBB2 (P&lt;0.0001), while p110, p95m and p185 ERBB2s were equally effective at enhancing anchorage-independent growth. In vivo, expression of p110 t-ERBB2 but not other isoforms led to increased tumor formation in mice compared to controls (P&lt;0.005). No apparent phenotypes were elicited by expression of intracellular t-ERBB2 isoforms. Using COPIA testing, t-ERBB2 isoforms were detected in strongly ERBB2- positive tumors (16 of 31 samples, 52%) and were phosphorylated in 10 of 31 (32%). As expected, t-ERBB2s were not detected in ERBB2-negative tumor samples.

Truncated ERBB2s, particularly p110, may be major pathogenic drivers in ERBB2+ cancers. These isoforms may accelerate disease progression by promoting invasion and metastasis, and likely mediate resistance to trastuzumab and other therapies. Thus, t-ERBB2s represent attractive novel targets for diagnosis and treatment of ERBB2+ breast cancers.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-06-03.

Abstract P5-05-02: Whole Genome In Vivo RNA Interference Screening Identifies the Leukemia Inhibitory Factor Receptor as a Novel Breast Tumor Suppressor

Background: Cancer is caused by mutations in oncogenes and tumor suppressor genes resulting in the deregulation of processes fundamental to the normal behavior of cells. The identification and characterization of oncogenes and tumor suppressors has led to new treatment strategies that have significantly improved cancer outcome. The advent of next generation sequencing has allowed the elucidation of the fine structure of cancer genomes, however, the identification of pathogenic changes is complicated by the inherent genomic instability of cancer cells. Therefore, functional approaches for the identification of novel genes involved in the initiation and development of tumors are critical. Methods: In order to identify functionally important tumor suppressor genes we have conducted the first human whole genome in vivo RNA interference (RNAi) screen. Partially transformed human mammary epithelial cells (HMLEs), which do not form tumors in immunodeficient mice, were infected with the Expression Arrest™ GIPZ lentiviral shRNA library consisting of 62,000 shRNAs targeting the whole human genome, and injected into the mammary fat pad of immunodeficient mice. shRNAs that silenced tumor suppressor genes fully transformed the mammary epithelial cells resulting in tumor formation. Candidate tumor suppressor genes were identified by PCR amplification and sequencing of tumor integrated shRNAs. For validation, candidate tumor suppressor genes were silenced in HMLEs and ectopically expressed in fully transformed breast cancer cells. The effect of modifying gene expression on the transformed phenotype was assessed using soft agar colony formation assays. Clinical significance was determined by comparing expression in normal and cancerous human breast tissue using Oncomine Research. Results and Discussion: Using our novel approach, we identify previously validated tumor suppressor genes including TP53 and MNT, as well as several novel candidate tumor suppressor genes including leukemia inhibitory factor receptor (LIFR). Silencing LIFR expression with multiple shRNA constructs fully transformed human mammary epithelial cells resulting in enhanced colony formation in soft agar (P&lt;0.05). Furthermore, overexpression of LIFR significantly inhibited colony formation in soft agar of fully transformed MDA231 and MCF7 breast cancer cells (P&lt;0.01). In addition, our analysis of clinical data revealed that LIFR expression is significantly decreased in a large percentage of human cancers including breast (P&lt;0.0001), lung (P&lt;0.0001), hepatocellular (P&lt;0.0001) and gastrointestinal tumors (P&lt;0.0001). These results validate LIFR as a previously unidentified highly significant tumor suppressor, and also demonstrate the power of whole genome in vivo RNAi screens as a method for identifying novel genes regulating tumorigenesis.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-05-02.

Abstract P4-01-05: Lapatinib Resistance Confers Cross-Resistance to Microtubule Inhibitors in ErbB2-Overexpressing Breast Cancer Cells

ErbB2 gene amplification occurs in approximately 20% of all breast cancers and is associated with an aggressive subtype with poor clinical prognosis. Acquired resistance to erbB2-targeted therapies is a common occurance even in patients who show an initial clinical response to trastuzumab or lapatinib-based regimens. Optimal treatment for relapsed disease following erbB2 targeted therapies has not been defined. Therefore, we sought to evaluate whether cytotoxic agents have cross-resistance to lapatinib in cell lines that have acquired resistance to lapatinib. Here we established a model of acquired lapatinib resistance derived from erbB2 overexpressing breast cancer cell lines, BT474 and SKBR3. Lapatinib resistant cell lines, BTLapR and SKLapR, were generated by growth in the continuous presence of 2.6 uM lapatinib (peak plasma concentration in human subjects) resulting in IC50 of 4.72 uM (BTLapR) and 0.083 uM (BT474) (P&lt;0.0001). IC50 of SKLapR and SKBR3 were 17.72 uM and 0.1637 uM (P&lt;0.0001), respectively. Next, resulting cells were treated with different classes of chemotherapeutics (2 taxanes, 2 vinca-alkaloids, 1 epothilone, 1 anthracycline, 1 antimetabolite, 2 platinums, and 1 alkylating agent) in order to address cross-resistance to lapatinib. BT474 and BTLapR as well as SKBR3 and SKLapR were exposed to each chemotherapeutic agent and cell viability was evaluated at 72h using a cell proliferation assay (AlamarBlue®). We found that BTLapR was significantly cross-resistant to 5 microtubule inhibitors (paclitaxel, docetaxel, vinorelbine, vinblastine, and ixabepilone), but SKLapR was not (shown in table below).

IC 50 of Significant Drugs on Lapatinib Resistant BT474 cells

Previous studies have shown that resistance to lapatinib can switch cell survival signaling from the erbB2 to ER pathway, and that ER signaling can stimulate beta III tubulin expression. We therefore hypothesize the differential responses to microtubule inhibitors in BTLapR and SKLapR might be explained by the fact that BT474 has both estrogen (ER) and progesterone receptor (PR), but SKBR3 express neither. Moreover, beta-III tubulin is known to be a key resistance mechanism of microtubule inhibition. Western blot analysis of baseline protein expression in both acquired lapatinib-resistant and parental cells indicates that ER signaling is involved in stimulating beta III tubulin and is linked to the development of resistance to microtubule inhibitors. These findings point to a potential mechanism to address cross resistance between lapatinib and microtubule-interacting agents, which could have potential clinical implications when considering salvage therapies following lapatinib treatment.

Current status and future potential of somatic mutation testing from circulating free DNA in patients with solid tumours

Genetic alterations can determine the natural history of cancer and its treatment response. With further advances in DNA sequencing technology, multiple novel genetic alterations will be discovered which could be exploited as prognostic, predictive and pharmacodynamic biomarkers in the development and use of cancer therapeutics. As such, the importance in clinical practice of efficient and robust somatic mutation testing in solid tumours cannot be overemphasized in the current era of personalized medicine. However, significant challenges remain regarding the testing of genetic biomarkers in clinical practice. Reliance on archived formalin fixed, paraffin embedded tumour, obtained from diagnostic biopsies, for testing somatic genetic alterations could restrict the scientific community in asking relevant questions about a patient's cancer biology. Problems inherent with using formalin fixed, archival tissue are well recognized and difficult to resolve. It could be argued that to achieve rapid and efficient incorporation of genetic biomarkers into clinical practice, somatic mutation testing in cancer patients should be simpler, less invasive using a readily available clinical sample, whilst maintaining robustness and reproducibility. In this regard, use of circulating free DNA (cfDNA) from plasma or serum as an alternative and/or additional source of DNA to test cancer specific genetic alterations is an attractive proposition. In light of encouraging results from recent studies, this mini review will discuss the current role and future potential of somatic mutation testing from circulating or cell free DNA derived from the blood of patients with solid tumours.

Phase II study of cisplatin and imatinib in advanced salivary adenoid cystic carcinoma

Patients with adenoid cystic carcinoma of the salivary glands show over-expression of KIT in a high proportion of cases. Options for systemic treatment are limited in locally advanced and metastatic disease. We explored the efficacy of imatinib and cisplatin combined in this group of patients. A Gehan's two-stage, phase II trial was conducted on 28 patients. Those with progressive, locally advanced, and metastatic disease with an over-expression of KIT were treated with single agent imatinib 800 mg daily for two months, followed by a combination of imatinib 400mg daily and cisplatin 80 mg/m(2) at four-weekly intervals for six cycles. This was followed by maintenance single agent imatinib 400mg daily until the disease progressed. Response was monitored using fluorodeoxyglucose positron emission tomography (FDG-PET) and morphological imaging using computed tomography, magnetic resonance, and chest radiographs (CT/MRI/CXR). Morphological imaging showed partial response in three of 28 patients, and five patients showed a response on FDG-PET. In addition, 19 patients had useful stabilisation of disease. The median time to progression and overall survival was 15 months (range 1-43) and 35 months (range 1-75), respectively. The combination of imatinib and cisplatin was reasonably well tolerated. This combination may provide stabilisation in locally advanced and metastatic adenoid cystic carcinoma of the salivary glands.

Issues on fit-for-purpose validation of a panel of ELISAs for application as biomarkers in clinical trials of anti-Angiogenic drugs

Background:

Successful introduction of new anticancer agents into the clinic is often hampered by a lack of qualified biomarkers. Studies have been conducted of 17 ELISAs representing a potential panel of pharmacodynamic/predictive biomarkers for drugs targeted to tumour vasculature.

Methods:

The fit-for-purpose approach to method validation was used. Stability studies were performed using recombinant proteins in surrogate matrices, endogenous analytes in healthy volunteer and cancer patient plasma. The impact of platelet depletion was investigated.

Results:

Method validation focused on measuring precision and showed that 15 of the 17 assays were within acceptable limits. Stability at −80°C was shown for 3 months with all recombinant proteins in surrogate matrices, whereas under the same conditions instability was observed with KGF in platelet-rich and platelet-depleted plasma, and with PDGF-BB in platelet-depleted plasma from cancer patients. For measurement of extracellular circulating analytes, platelet depletion should be conducted before freezing of plasma to prevent release of PDGF-BB, FGFb and VEGF-A. A protocol was developed to remove >90% platelets from plasma requiring centrifugation at 2000 g for 25 min.

Conclusions:

These studies highlight the need for assay validation and crucial assessment of sample handling issues before commencement of biomarker analysis in clinical trials.

Considerations for the use of plasma cytokeratin 18 as a biomarker in pancreatic cancer

BACKGROUND

Enzyme-linked immunoassays of full-length (M65) and/or caspase-cleaved (M30) cytokeratin 18 (CK18) released from epithelial cells undergoing necrosis and/or apoptosis, respectively, may have prognostic or predictive biomarker utility in a range of solid tumour types. Characterisation of baseline levels of circulating full length and cleaved CK18 specifically in patients with pancreatic cancer.

METHODS

Plasma samples from 103 patients with pancreatic cancer stored at -80 degrees C were assayed for M65 and M30 levels. The median (inter-quartile range (IQR)) duration of plasma storage was 34 (23-57) months. Patients with metastatic disease (n=19) were found to have greater median (IQR) M65 levels (1145 (739-1698) U l(-1)) compared with the locally advanced (n=20; 748 (406-1150) U l(-1)) and resected (n=64; 612 (331-987) U l(-1)) patients (P=0.002). Elevated M65 levels were associated with poorer overall survival on univariate (P<0.001) but not multivariate (P=0.202) analysis. M65 concentrations also exhibited significant associations with concurrent serum-bilirubin levels (P<0.001) and the duration of plasma storage (P<0.001).

CONCLUSIONS

Baseline plasma CK18 levels in pancreatic cancer are affected by the presence of obstructive jaundice and prolonged plasma storage. Clinical biomarker studies utilising serial CK18 levels are warranted in pancreatic cancer, provided consideration is given to these potentially confounding factors.

A comparison of the 3D kinematic measurements obtained by single-plane 2D-3D image registration and RSA

3D computed tomography (CT) to single-plane 2D fluoroscopy registration is an emerging technology for many clinical applications such as kinematic analysis of human joints and image-guided surgery. However, previous registration approaches have suffered from the inaccuracy of determining precise motion parameters for out-of-plane movements. In this paper we compare kinematic measurements obtained by a new 2D-3D registration algorithm with measurements provided by the gold standard Roentgen Stereo Analysis (RSA). In particular, we are interested in the out-of-plane translation and rotations which are difficult to measure precisely using a single plane approach. Our experimental results show that the standard deviation of the error for out-of-plane translation is 0.42 mm which compares favourably to RSA. It is also evident that our approach produces very similar flexion/extension, abduction/adduction and external knee rotation angles when compared to RSA.

Truncated p95erbB2 Isoforms Are Capable of Transforming Human Mammary Epithelial Cells

Background:Objective clinical response to trastuzumab monotherapy in erbB2-amplified first line metastatic breast cancer is 34% (Vogel, et al., JCO 20: 719-26, 2002). Amongst patients who respond, most develop resistance (defined by disease progression on trastuzumab). One proposed mechanism of trastuzumab resistance is proteolytic cleavage of erbB2 receptor from its full-length (p185) form into truncated, constitutively active p95. Increased expression of p95erbB2 correlates with increased nodal involvement and poor clinical outcome. Because p95erbB2 lacks the trastuzumab binding epitope, expression may designate patients who would be suitable for treatment with erbB2 kinase inhibitors.Materials and Methods:Recombinant p185erbB2 and p95erbB2 constructs were stably expressed in several cell types via retroviral vector. Additionally, an intracellular form of p95erbB2 that arises via alternative translation and an intracellular p95erbB2 construct containing two copies of a nuclear localization sequence were also expressed. Expression and proper subcellular localization of constructs were confirmed by cell fractionation, western blot analysis and confocal microscopy. Transformation of human mammary epithelial (HMEC) and NIH3T3 cells by p185erbB2 and p95erbB2 isoforms was evaluated by anchorage independent growth using a quantitative fluorescent soft agar assay, and effects on migration and invasion of these cells were investigated by wound-healing and transwell assays. Cells transfected with oncogenic Ras or empty vector were used as positive and negative controls in these experiments.Results and Discussion:Recombinant p185erbB2 and p95erbB2 constructs were stably expressed in HMEC and NIH3T3 cells, and were correctly directed to the cell membrane; nuclear targeted intracellular p95erbB2 was correctly localized to the cell nucleus. Both p185 erbB2 and membrane-bound truncated p95erbB2 were sufficient to transform HMEC cells as compared to empty vector control transfected cells [mean fluorescence intensity empty vector control 2480 ± 464 (1 standard deviation); mean fluorescence intensity p185erbB2 9208 ± 2528, p= 0.0106; mean fluorescence intensity p95erbB2 6615 ± 1588, p= 0.0124)] as was the positive control oncogenic Ras (mean fluorescence intensity 4350 ± 433, p=0.0069). Interestingly, nuclear-targeted p95erbB2 was also sufficient to transform HMEC cells (mean fluorescence intensity 6492 ± 818, p=0.0018). These data support the hypothesis that truncated p95erbB2 species may be major pathogenic drivers in erbB2-amplified cancers. P95erbB2 therefore represents an attractive target for diagnosis and treatment of erbB2+ breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3136.

A small molecule inhibitor of XIAP induces apoptosis and synergises with vinorelbine and cisplatin in NSCLC

Background:

Evasion of apoptosis contributes to the pathogenesis of solid tumours including non-small cell lung cancer (NSCLC). Malignant cells resist apoptosis through over-expression of inhibitor of apoptosis proteins (IAPs), such as X-linked IAP (XIAP).

Methods:

A phenylurea-based small molecule inhibitor of XIAP, XIAP antagonist compound (XAC) 1396-11, was investigated preclincally to determine its ability to sensitise to clinically relevant cytotoxics, potentially allowing dose reduction while maintaining therapeutic efficacy.

Results:

XIAP protein expression was detected in six NSCLC cell lines examined. The cytotoxicity of XAC 1396-11 against cultured NSCLC cell lines in vitro was concentration- and time-dependent in both short-term and clonogenic assays. XAC 1396-11-induced apoptosis was confirmed by PARP cleavage and characteristic nuclear morphology. XAC 1396-11 synergised with vinorelbine±cisplatin in H460 and A549 NSCLC cells. The mechanism of synergy was enhanced apoptosis, shown by increased cleavage of caspase-3 and PARP and by the reversal of synergy by a pan-caspase inhibitor. Synergy between XAC 1396-11 and vinorelbine was augmented by optimising drug scheduling with superior effects when XAC 1396-11 was administered before vinorelbine.

Conclusion:

These preclinical data suggest that XIAP inhibition in combination with vinorelbine holds potential as a therapeutic strategy in NSCLC.

Results of a residential indoor PM2.5 sampling program before and after a woodstove changeout

During 2005-2007, a woodstove changeout program was conducted in a Rocky Mountain valley community in an effort to reduce ambient levels of PM(2.5). In addition to changes in ambient PM(2.5), an opportunity was provided to evaluate the changes in indoor air quality when old stoves were replaced with US Environmental Protection Agency (EPA)-certified woodstoves. PM(2.5) samples were measured in 16 homes prior to and following the changeout. For each sampling event, PM(2.5) mass was continuously measured throughout the 24-h sampling periods, and organic/elemental carbon (OC/EC) and associated chemical markers of woodsmoke were measured from quartz filters. Results showed that average PM(2.5) concentrations and maximum PM(2.5) concentrations were reduced by 71% and 76%, respectively (as measured by TSI DustTraks). Levoglucosan was reduced by 45% following the introduction of the new woodstove. However, the concentrations of resin acids, natural chemicals found in the bark of wood, were increased following the introduction of the new woodstove. There were no discernible trends in methoxphenol levels, likely due to the semi-volatile nature of the species that were measured. Although there is some uncertainty in this study regarding the amount of ambient PM infiltration to the indoor environment, these findings demonstrated a large impact on indoor air quality following this intervention.

PRACTICAL IMPLICATIONS

Emissions from residential woodstoves are an important air quality issue (both indoors and ambient) in many regions throughout the US and the world. More specifically, woodstoves have been identified as a major source of PM(2.5) in valley locations throughout the Northern Rocky Mountains, where biomass combustion is the predominant source of home heating. In this study, we present results that demonstrate the dramatic reduction in PM(2.5) concentrations (as measured by TSI, Inc. DustTrak PM(2.5) air samplers) inside homes following the replacement of old, polluting woodstove with new EPA-certified woodstoves.

Optimisation of circulating biomarkers of cell death for routine clinical use

BACKGROUND

M30 and M65 enzyme-linked immunosorbent assays detect circulating cytokeratin 18 fragments released during caspase-dependent or total cell death, respectively, and have potential as biomarkers in epithelial cancers. While these assays have been validated, their robustness for routine clinical use is unknown.

PATIENTS AND METHODS

M30 and M65 were measured in matched serum and plasma samples from 31 lung cancer patients and 18 controls.

RESULTS

Time allowable between sample acquisition and processing is critical for assays in clinical use. A 4-h delay in processing at room temperature increased M30 (P < 0.0001), an effect minimised by incubation on ice. M30 and M65 in serum were resistant to processing variations including delays. Serum and plasma measurements correlated well although M30 but not M65 was lower in serum (P < 0.0005). Less variation between duplicate assays was observed in serum. Prolonged storage (-80 degrees C) led to increased M30 (12%, 6 months; 34%, 1 year). Sample dilution in the supplied assay diluent proved non-linear, whereas dilution in donor serum or porcine plasma restored linearity up to a ratio of 1 : 6.

CONCLUSION

We present recommendations that improve the reliability of these assays for clinical use and recommend serum as the preferred matrix with data more resistant to variations in collection.

Molecular characterization of the Fusarium graminearum species complex in Japan

Members of the Fusarium graminearum species complex are important cereal pathogens worldwide and belong to one of at least nine phylogenetically distinct species. We examined 298 strains of the F. graminearum species complex collected from wheat or barley in Japan to determine the species and trichothecene chemotype. Phylogenetic analyses and species-diagnostic polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLPs) revealed the presence and differential distribution of F. graminearum sensu stricto (s. str.) and F. asiaticum in Japan. F. graminearum s. str. is predominant in the north, especially in the Hokkaido area, while F. asiaticum is predominant in southern regions. In the Tohoku area, these species co-occurred. Trichothecene chemotyping of all strains by multiplex PCR revealed significantly different chemotype compositions of these species. All 50 strains of F. graminearum s. str. were of a 15- or 3-acetyl deoxynivalenol type, while 173 (70%) out of 246 strains of F. asiaticum were of a nivalenol type. The possibility of gene flow between the two species was investigated by use of 15 PCR-RFLP markers developed in this study. However, no obvious hybrids were detected from 98 strains examined, including strains collected from regions where both species co-occur.