An Exploratory Study of Physical Therapists From High-Income Countries Practising Outside of Their Scope in Low and Middle-Income Countries

PURPOSE

To quantify how often physical therapists from high-income countries (HIC) travelling to low- and middle-income countries (LMIC) practise outside their scope of practice, in what circumstances, and their likelihood of doing the same in the future.

METHODS

An exploratory descriptive study using a survey.

RESULTS

One hundred and twenty-six licensed physical therapists from around the world participated. Physical therapists typically spent less than a month (73.8 per cent) in LMIC; 67.5 per cent believed that physical therapists practise outside of their scope, and 31.7 per cent reported doing so. Reasons were believing that something is better than nothing (47.5 per cent ), a mismatch between the physical therapist's and host's expectations (40.0 per cent ), and preserving their relationship with the host (25.0 per cent ). It was deemed appropriate by 64.5 per cent to practise outside of their scope in some situations and 53.8% considered repeating the activity in the future. Half of the respondent's first experience in LMIC occurred as a student or in their first decade of practice.

CONCLUSIONS

Working in LMIC requires a keen understanding of the risks and challenges associated with such experiences. To ensure best practice, a skill set that consists of critical self-reflection, systems thinking, and structural competency combined with clinical competency and accountability is imperative.

An unbiased, automated platform for scoring dopaminergic neurodegeneration in C. elegans

Caenorhabditis elegans (C. elegans) has served as a simple model organism to study dopaminergic neurodegeneration, as it enables quantitative analysis of cellular and sub-cellular morphologies in live animals. These isogenic nematodes have a rapid life cycle and transparent body, making high-throughput imaging and evaluation of fluorescently tagged neurons possible. However, the current state-of-the-art method for quantifying dopaminergic degeneration requires researchers to manually examine images and score dendrites into groups of varying levels of neurodegeneration severity, which is time consuming, subject to bias, and limited in data sensitivity. We aim to overcome the pitfalls of manual neuron scoring by developing an automated, unbiased image processing algorithm to quantify dopaminergic neurodegeneration in C. elegans. The algorithm can be used on images acquired with different microscopy setups and only requires two inputs: a maximum projection image of the four cephalic neurons in the C. elegans head and the pixel size of the user's camera. We validate the platform by detecting and quantifying neurodegeneration in nematodes exposed to rotenone, cold shock, and 6-hydroxydopamine using 63x epifluorescence, 63x confocal, and 40x epifluorescence microscopy, respectively. Analysis of tubby mutant worms with altered fat storage showed that, contrary to our hypothesis, increased adiposity did not sensitize to stressor-induced neurodegeneration. We further verify the accuracy of the algorithm by comparing code-generated, categorical degeneration results with manually scored dendrites of the same experiments. The platform, which detects 20 different metrics of neurodegeneration, can provide comparative insight into how each exposure affects dopaminergic neurodegeneration patterns.

An unbiased, automated platform for scoring dopaminergic neurodegeneration in C. elegans

Caenorhabditis elegans ( C. elegans ) has served as a simple model organism to study dopaminergic neurodegeneration, as it enables quantitative analysis of cellular and sub-cellular morphologies in live animals. These isogenic nematodes have a rapid life cycle and transparent body, making high-throughput imaging and evaluation of fluorescently tagged neurons possible. However, the current state-of-the-art method for quantifying dopaminergic degeneration requires researchers to manually examine images and score dendrites into groups of varying levels of neurodegeneration severity, which is time consuming, subject to bias, and limited in data sensitivity. We aim to overcome the pitfalls of manual neuron scoring by developing an automated, unbiased image processing algorithm to quantify dopaminergic neurodegeneration in C. elegans . The algorithm can be used on images acquired with different microscopy setups and only requires two inputs: a maximum projection image of the four cephalic neurons in the C. elegans head and the pixel size of the user’s camera. We validate the platform by detecting and quantifying neurodegeneration in nematodes exposed to rotenone, cold shock, and 6-hydroxydopamine using 63x epifluorescence, 63x confocal, and 40x epifluorescence microscopy, respectively. Analysis of tubby mutant worms with altered fat storage showed that, contrary to our hypothesis, increased adiposity did not sensitize to stressor-induced neurodegeneration. We further verify the accuracy of the algorithm by comparing code-generated, categorical degeneration results with manually scored dendrites of the same experiments. The platform, which detects 19 different metrics of neurodegeneration, can provide comparative insight into how each exposure affects dopaminergic neurodegeneration patterns.

The CellRaft AIRⓇ system: A novel system enabling organoid imaging, identification, and isolation

Three-dimensional (3D) culture systems have been developed that can re-capitulate organ level responses, simulate compound diffusion through complex structures, and assess cellular heterogeneity of tissues, making them attractive models for advanced in vitro research and discovery. Organoids are a unique subtype of 3D cell culture that are grown from stem cells, are self-organizing, and closely replicate in vivo pathophysiology. Organoids have been used to understand tissue development, model diseases, test drug sensitivity and toxicity, and advance regenerative medicine. However, traditional organoid culture methods are inadequate because they are low throughput and ill-suited for single organoid imaging, phenotypic assessment, and isolation from heterogenous organoid populations. To address these bottlenecks, we have adapted our tissue culture consumable and instrumentation to enable automated imaging, identification, and isolation of individual organoids. Organoids grown on the 3D CytoSortⓇ Array can be reliably tracked, imaged, and phenotypically analyzed using brightfield and fluorescent microscopy as they grow over time, then released and transferred fully intact for use in downstream applications. Using mouse hepatic and pancreatic organoids, we have demonstrated the use of this technology for single-organoid imaging, clonal organoid generation, parent organoid subcloning, and single-organoid RNA extraction for downstream gene expression or transcriptomic analysis. The results validate the ability of the CellRaft AIRⓇ System to facilitate efficient, user-friendly, and automated workflows broadly applicable to organoid research by overcoming several pain points: 1) single organoid time-course imaging and phenotypic assessment, 2) establishment of single cell-derived organoids, and 3) isolation and retrieval of single organoids for downstream applications.

Prognostic role of serum thymidine kinase 1 kinetics during neoadjuvant chemotherapy for early breast cancer

Background

Emerging data support the use of thymidine kinase 1 (TK1) activity as a prognostic marker and for monitoring of response in breast cancer (BC). The long-term prognostic value of TK1 kinetics during neoadjuvant chemotherapy is unclear, which this study aimed to elucidate.

Methods

Material from patients enrolled to the single-arm prospective PROMIX trial of neoadjuvant epirubicin, docetaxel and bevacizumab for early BC was used. Ki67 in baseline biopsies was assessed both centrally and by automated digital imaging analysis. TK1 activity was measured from blood samples obtained at baseline and following two cycles of chemotherapy. The associations of TK1 and its kinetics as well as Ki67 with event-free survival and overall survival (OS) were evaluated using multivariable Cox regression models.

Results

Central Ki67 counting had excellent correlation with the results of digital image analysis (r = 0.814), but not with the diagnostic samples (r = 0.234), while it was independently prognostic for worse OS [adjusted hazard ratio (HR_adj) = 2.72, 95% confidence interval (CI) 1.19-6.21, P = 0.02]. Greater increase in TK1 activity after two cycles of chemotherapy resulted in improved event-free survival (HR_adj = 0.50, 95% CI 0.26-0.97, P = 0.04) and OS (HR_adj = 0.46, 95% CI 0.95, P = 0.04). There was significant interaction between the prognostic value of TK1 kinetics and Ki67 (p_interaction 0.04).

Conclusion

Serial measurement of serum TK1 activity during neoadjuvant chemotherapy provides long-term prognostic information in BC patients. The ease of obtaining serial samples for TK1 assessment motivates further evaluation in larger studies.

•

This is a correlative analysis of a prospective phase II study on neoadjuvant chemotherapy for breast cancer.

•

Serial measurement of serum TK1 activity during treatment provides independent long-term prognostic information.

•

We demonstrate the validity and clinical utility of both central and automated image analysis-based Ki67 assessment.

•

Finally, we explore the biologic correlations between TK1 and Ki67.

Artificial intelligence as the next step towards precision pathology

Pathology is the cornerstone of cancer care. The need for accuracy in histopathologic diagnosis of cancer is increasing as personalized cancer therapy requires accurate biomarker assessment. The appearance of digital image analysis holds promise to improve both the volume and precision of histomorphological evaluation. Recently, machine learning, and particularly deep learning, has enabled rapid advances in computational pathology. The integration of machine learning into routine care will be a milestone for the healthcare sector in the next decade, and histopathology is right at the centre of this revolution. Examples of potential high-value machine learning applications include both model-based assessment of routine diagnostic features in pathology, and the ability to extract and identify novel features that provide insights into a disease. Recent groundbreaking results have demonstrated that applications of machine learning methods in pathology significantly improves metastases detection in lymph nodes, Ki67 scoring in breast cancer, Gleason grading in prostate cancer and tumour-infiltrating lymphocyte (TIL) scoring in melanoma. Furthermore, deep learning models have also been demonstrated to be able to predict status of some molecular markers in lung, prostate, gastric and colorectal cancer based on standard HE slides. Moreover, prognostic (survival outcomes) deep neural network models based on digitized HE slides have been demonstrated in several diseases, including lung cancer, melanoma and glioma. In this review, we aim to present and summarize the latest developments in digital image analysis and in the application of artificial intelligence in diagnostic pathology.

Abstract P2-03-07: Digital image analysis of Ki67 in hot spots is superior to alternative proliferation associated markers in breast cancer

INTRODUCTION

Proliferative activity is one of the most important prognostic parameters in cancer. During the pathological examination of breast tumors, it is routinely evaluated by a count of the number of mitoses. Adding immunohistochemical stains of the nuclear protein Ki67 provides extra prognostic and predictive information. However, the currently used methods for both of these evaluations battle imperfections, primarily in reproducibility. In this study, we make an equally broad and detailed evaluation of mitoses, Ki67 and the more recently described Phosphohistone H3 (PHH3) in primary breast cancer using digital image analysis (DIA). Furthermore, we aim to investigate the prognostic and predictive value of proliferation-associated biomarkers in breast cancer stromal cells in relation to patient outcome.

MATERIALS AND METHODS

Two cohorts of primary breast cancer specimens (total n=297) with clinicopathological data including >10 years survival data, were sectioned and stained for Ki67, PHH3 and pancytokeratin (CKMNF116) and all glass slides were digitally scanned at x20. The DIA software used was the Visiopharm Integrator System (VIS) by Visiopharm A/S, Hoersholm, Denmark. VIS operates by a 'digital fusion' method that automatically excludes non-epithelial tissue restricting the analysis of the biomarkers (Ki67 and PHH3) to CKMNF116 positive cells. Both manual and DIA scores were compared for sensitivity and specificity for the gene expression based Luminal B versus A subtype, for high versus low transcriptomic grade as well as for their prognostic value in terms of Cox regression hazard ratios and breast cancer specific and overall survival. Further, we investigated whether the expression of Ki67 in the tumors' hot spots, invasive edges or as an average across all regions should be assessed for maximum power in relation to these outcomes. In addition, by inverting the DIA algorithm run by the VIS on the same cohorts, the expression of Ki67 and PHH3 was evaluated in the tumor stromal compartment.

RESULTS

Regardless of tumor region, DIA of Ki67 outperformed the other markers in sensitivity and specificity for gene expression subtypes and transcriptomic grade. In contrast to mitotic counts, tumors with high expression of Ki67 as defined by DIA, had significantly increased hazard ratio for all-cause mortality within 10 years from diagnosis. DIA of Ki67 was superior to manual Ki67 and PHH3 evaluations as well as to mitotic counts in terms of separation of patients with poor versus relatively good survival. Finally, we replaced the manual mitotic counts with DIA of Ki67 in hot spots as the marker for proliferation when determining histological grade. This increased the differences in estimated mean overall survival between the highest and lowest grades and added significantly more prognostic information to the classic Nottingham histological grade.

CONCLUSIONS

We conclude that digital image analysis of Ki67 in hot spots should be suggested as the marker of choice for proliferative activity in breast cancer.

Citation Format: Robertson S, Stålhammar G, Wedlund L, Gholizadeh S, Lippert M, Rantaleinen M, Bergh J, Hartman J. Digital image analysis of Ki67 in hot spots is superior to alternative proliferation associated markers in breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-03-07.

Sparse-view neutron-photon computed tomography: Object reconstruction and material discrimination

Taking into account the advantages of both neutron- and photon-based systems, we propose combined neutron-photon computed tomography (CT) under a sparse-view setting and demonstrate its performance for 3D object visualization and material discrimination. We use a high-performance regularization method for CT reconstruction by combining regularization based on total variation (TV) and curvelet transform in cone beam geometry. It is coupled with proposed 2D material signatures which is pairs of photon to neutron transmission ratios and neutron transmission values per object space voxels. Classification of materials is performed by association of a voxel signature with library signatures; and per object - by majority of voxels in the object. Representation of object-material pairs, for the model in our experiment, a complex scene with group of high-Z and low-Z materials, attains the reconstruction accuracy of 92.1% and the overall high-Z discrimination accuracy of object representation is 85%, and by about 7.5% higher discrimination accuracy than that with 1D signatures which are ratios of photon to neutron transmissions. With a relative noise level of 10%, the method yields the reconstruction accuracies of 87.2%. The analyses are performed in cone beam configuration, with Monte Carlo modeling of neutron-photon transport for the model of object geometry and material contents.

Abstract P6-01-04: Evolutionary analyses of matched primary and metastatic breast cancer reveal both linear and parallel progression with lack of axillary lymph node involvement

This abstract was withdrawn by the authors.

Abstract P2-03-03: Molecular differences between screen-detected and interval breast cancers are largely explained by PAM50 subtypes

Purpose:Interval breast cancer is of clinical interest as it exhibits an aggressive phenotype and evades detection by screening mammography. A comprehensive picture of somatic changes that drive tumors to become symptomatic in the screening interval can improve understanding of the biology underlying these aggressive tumors.

Experimental design:Initiated in April 2013, Clinical Sequencing of Cancer in Sweden (Clinseq) is a scientific and clinical platform for the genomic profiling of cancer. The breast cancer pilot study consisted of women diagnosed with breast cancer between 2001-2012 in the Stockholm/Gotland regions. A subset of 318 breast tumors were sequenced, of which 113 were screen-detected and were 60 interval cancers.We applied targeted deep-sequencing of cancer-related genes, low-pass whole-genome sequencing and RNA-sequencing technology to characterize somatic differences in the genomic and transcriptomic architecture by interval cancer status. Mammographic density and PAM50 molecular subtypes were considered.

Results:In the crude analyses, TP53, PPP1R3A, and KMT2B were significantly more frequently mutated in interval cancers than in screen-detected cancers. Acquired somatic copy number aberrations with a frequency difference of at least 15% between the two groups included gains in 17q23-q25.3 and losses in 16q24.2. Gene expression analysis identified 447 significantly differentially expressed genes, of which 120 were replicated in an independent microarray dataset. After adjusting for PAM50, most differences were no longer significant.

Conclusions: Molecular differences by interval cancer status were observed, but they were largely explained by PAM50 subtypes. This work offer new insights into the biological differences between the two tumor groups.

Translational relevance: Although screen-detected cancers are biologically distinct from interval cancers in terms of somatic mutations, copy number aberrations and gene expression, most of the differences are no longer significant after adjusting for breast cancer intrinsic subtypes (PAM50). We also show that the molecular differences appear to form a spectrum from less aggressive (screen-detected) to more aggressive (interval) manifestations of the disease, which can be characterized by PAM50 subtypes, namely, luminal A, luminal B, HER2-enriched and basal-like, in that order. This work clarifies the picture on what type of breast cancer we are likely to identify through population-based screening, and what type of cancer we are likely to miss. Current knowledge of PAM50 subtype-specific risk factors need to be expanded as our findings might influence how we screen women with a higher risk of basal-like breast cancer for example, beyond known risk groups BRCA1 mutation carriers and women of African-American descent.

Citation Format: Czene K, Ivansson E, Klevebring D, Tobin NP, Lindström LS, Holm J, Prochazka G, Hilliges C, Palmgren J, Törnberg S, Humphreys K, Hartman J, Frisell J, Rantalainen M, Lindberg J, Hall P, Bergh J, Grönberg H, Li J. Molecular differences between screen-detected and interval breast cancers are largely explained by PAM50 subtypes [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-03-03.

3D imaging using combined neutron-photon fan-beam tomography: A Monte Carlo study

The application of combined neutron-photon tomography for 3D imaging is examined using MCNP5 simulations for objects of simple shapes and different materials. Two-dimensional transmission projections were simulated for fan-beam scans using 2.5MeV deuterium-deuterium and 14MeV deuterium-tritium neutron sources, and high-energy X-ray sources, such as 1MeV, 6MeV and 9MeV. Photons enable assessment of electron density and related mass density, neutrons aid in estimating the product of density and material-specific microscopic cross section- the ratio between the two provides the composition, while CT allows shape evaluation. Using a developed imaging technique, objects and their material compositions have been visualized.

Abstract P6-07-09: Somatic mutations in A kinase anchoring proteins (AKAPs) in metastatic tumors - A potential characteristic of breast cancer metastasis

Introduction

Genomic heterogeneity in primary solid tumors has been extensively studied using deep sequencing technologies during the last decade. The heterogeneity of cancer tumors is today a well-established concept partly reflected in the low number of genes being recurrently mutated in over 10% of the tumors. However, most available data relates to the primary breast cancer tumors and little has been described about the mutational profiles of the metastatic lesions and their relation to its original malignant cell population. Prospective and retrospective studies have demonstrated that altered receptor status in the metastatic lesion occurs at high rates during cancer progression and is additionally affected by adjuvant therapy with major implications for management of the metastatic disease. Here, we report the exome sequences of paired primary and metastatic lesions from ten breast cancer patients.

Results

We found a marked heterogeneity of somatic mutations as well as chromosomal aberrations in the metastatic lesions. A number of mutated genes were enriched in the metastases including, significantly, members of the A-kinase anchoring protein family (AKAPs), p < 0.02; Fisher's exact test.

The enrichment of AKAP mutations in metastatic lesions was confirmed in an independent cohort containing 20 patients with paired primary and metastatic lesions, which showed the same mutational pattern. In total, 14 nonsynonymous mutations were found in ten of the fourteen AKAP family members. Out of the totally 30 patients examined, ten (30%) carried one or more mutations in AKAP genes either in primary tumor, metastasis, or both. In seven of these ten patients, the AKAP mutation was found uniquely in the metastatic lesion.

Several copy number variations (CNV), mostly deletions in regions containing AKAP genes were detected. For example, the down-regulation of AKAP12 is often associated with promoter hypermethylation or loss of its locus 6q24-25.2 and has been associated with tumor progression and metastasis. In our data deletion of the AKAP12 locus is present in six out of twenty patients.

Discussion

AKAPs are members of a protein family acting as anchors for Protein Kinase A (PKA) by specifically associate PKA regulatory subunits to cellular organelles and direct its active signal transduction spatially and temporally. Several of the AKAP members have been associated to cancer development and metastatic spread, mostly based on differential expression and effects on migration in in vitro assays but both polymorphisms and somatic mutations have been reported in human tumors.

Our findings indicate that in metastatic lesions, the primary tumor genome is extensively transformed, with enrichment of mutations in a distinct set of genes. Together, these findings suggest the involvement of AKAPs in the metastatic process and provide a potential avenue for targeted therapy directed at metastatic breast cancer. Molecular and genetic characterization of the metastatic lesions is not only important in the clinical setting but should also provide the means to reveal genetic patterns specific for the disseminated malignancy.

Citation Format: Kjällquist U, Erlandsson R, Alkodsi A, Tobin N, Karlsson E, Hatschek T, Hartman J, Linnarsson S, Bergh J. Somatic mutations in A kinase anchoring proteins (AKAPs) in metastatic tumors - A potential characteristic of breast cancer metastasis. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-07-09.

[A toddler with a red, swollen arm after vaccination]

An almost 4-year-old girl developed swelling, redness and pruritus of the vaccinated arm 2 days after immunisation with DPTP. The girl had no fever. The reaction spread around the upper arm and the elbow. We made the diagnosis of 'extensive limb swelling'. The symptoms disappeared spontaneously within 1 week.

Absence of skeletal anomalies in siblings with a maternally inherited 12q13.13-q13.2 microdeletion partially involving the HOXC gene cluster

Microdeletions (12q13.13-q13.2) involving the HOXC gene cluster are rare. Only three patients with this contiguous deletion have been reported, all resulting in phenotypic features that include skeletal anomalies, facial dysmorphism, and intellectual disability. The deletion of the HOXC gene cluster is thought to result in skeletal anomalies in these patients. We report on siblings with a 969 kb deletion in the 12q13.13-q13.2 region detected by array comparative genomic hybridization (aCGH). This deletion spans seven of nine HOXC cluster genes. FISH analysis confirmed the siblings and mother were carriers of the 12q13.13-q13.2 deletion. Although minor facial dysmorphic features were present in both siblings, no skeletal anomalies were present in the siblings or the mother. The proband had autistic-like features and mild developmental delay, while the sibling and mother are of normal intelligence. The absence of skeletal anomalies in our family suggests that deletion of the entire HOXC gene cluster may be required to result in an abnormal skeletal phenotype, or those skeletal anomalies in previously reported patients may be attributed to other genes within the deletion interval.

Abstract P4-07-12: miR-206 inhibits cell migration through direct targeting of the actin-binding protein coronin 1C in triple-negative breast cancer

Patients with triple-negative breast cancer (TNBC) have an overall poor prognosis, which is primarily due to a high metastatic capacity of these tumors. Novel therapeutic approaches to target the signaling pathways that promote metastasis are desirable, in order to improve the outcome of TNBC patients. A loss of function of a microRNA, miR-206, is related to increased metastasis potential in breast cancers but the mechanism remains to be elucidated. In this study, we show that miR-206 was decreased in TNBC clinical tumor samples and cell lines whereas one of its predicted targets, actin-binding protein CORO1C, was increased. Expression of miR-206 significantly reduced proliferation by inducing a G1-S cell cycle arrest and migration and also repressed CORO1C mRNA and protein levels. We demonstrate that miR-206 interacts with the 3’-untranslated region (3’-UTR) of CORO1C and regulates this gene post-transcriptionally. Further, silencing of CORO1C reduced tumor cell migration and affected the actin skeleton and cell morphology, similar to miR-206 expression, but did not reduce proliferation. Our findings suggest that miR-206 targets CORO1C in TNBC cells, thereby affecting the actin filaments which results in a repressed tumor cell migration. This pathway is a novel mechanism offering a mechanistic basis whereby the metastatic potential of TNBC tumors could be targeted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-07-12.

Abstract OT1-2-03: A prospective randomized phase II study to identify predictive biomarkers and mechanisms of resistance in patients with HER2-negative metastatic breast cancer treated with the combination of bevacizumab and paclitaxel

Background

Several phase III trials have evaluated the combination of bevacizumab and chemotherapy in patients with metastatic breast cancer (MBC). These individual studies as well as a meta-analysis indicate high response rates (RR) and increased progression-free survival (PFS), however no significant gain of overall survival (OS) by the addition of bevacizumab to chemotherapy. To date, there are no methods to reliably select patients with MBC that benefit from treatment with bevacizumab.

Trial design

This project is a prospective, randomized, 2-arm, open-label, single-center, phase II trial aiming to identify predictive markers and mechanisms of resistance to bevacizumab in MBC by longitudinal biopsies and functional imaging. The study will be initiated with a non-randomized, feasibility stage including ten patients who will be treated with bevacizumab and paclitaxel, in order to determine the safety of metastatic tumor biopsies during therapy with bevacizumab. In a second phase, 20 patients will be randomized (1:1) between two treatment arms: Paclitaxel 80 mg / m2 weekly with or without bevacizumab 15 mg / kg every 3 weeks.

Mandatory, repeated peripheral blood sampling and fine needle aspiration biopsies (FNAB) will be collected at baseline, at day 4 after the first cycle and at progression. At baseline, a core biopsy will be obtained as well. Patients will also undergo two 18F]-fluoro-L-thymidine (FLT) Positron Emission Tomography (PET)/CT scans (18F-FLT PET/CT), at baseline and at day 4 after the first cycle.

Eligibility criteria

Eligible are patients aged 18-70 years, with newly diagnosed HER2-negative MBC (stage IV or recurrent) that are candidates for chemotherapy (ECOG 0-2), with measurable disease and at least one lesion that is accessible for biopsy. Adequate bone marrow, hepatic and renal function are required, as well as absence of thromboembolic disease, bleeding diathesis or second concurrent malignancy. No previous systemic treatment for MBC is allowed.

Specific aims

1. To assess early therapeutic response to bevacizumab in MBC by whole-exome sequencing and gene expression of serial metastatic biopsies and functional imaging.

2. To identify potential biomarkers present in plasma that can be used for patient selection or for monitoring therapy with bevacizumab in MBC.

3. To explore mutations and gene expression alterations as mechanisms of resistance to bevacizumab in MBC.

Statistical methods

The main objective of the study is exploratory. For most of the planned analyses, each patient will serve as her own control and baseline values of potential biomarkers will be compared in pairs with intra-patient, longitudinal samples, which significantly increases the statistical power.

For the identification of biomarkers, the results of the molecular analyses will be correlated with clinical outcome measurements including RR, PFS, and OS.

Present accrual and target accrual.

The trial was opened for inclusion in May 2013 and one patient has been accrued by June 1st 2013. A total of 30 patients will be included during a period of 2 years.

Contact:

Principal Investigator: Theodoros.Foukakis@ki.se; Study Director: Jonas.Bergh@ki.se.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-2-03.

Comparison of anesthesia technique on outcomes of endovascular repair of abdominal aortic aneurysms: a five-year review of monitored anesthesia care with local anesthesia vs. general or regional anesthesia

AIM

This retrospective study compares outcomes according to anesthesia technique of a consecutive series of 48 endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) performed by one vascular surgeon at a single institution over a five-year period.

METHODS

Demographic, pre-procedure, procedure-related, recovery room, surgical unit, and hospital outcome variables were extracted and compared between patients receiving general or regional anesthesia and those receiving monitored anesthesia care (MAC) with local anesthesia.

RESULTS

Eighteen (37.5%) patients received general or regional anesthesia and 30 (62.5%) patients received MAC with local anesthesia. No statistically significant differences in demographics or pre-procedure variables were calculated between study groups. Conversion to open repair was not required, no intraoperative complications occurred, and conversion from MAC with local anesthesia to general anesthesia was not required. The only significant differences calculated were in length of anesthesia (P=0.001, power 0.962) and time to ambulation (P=0.004, power 0.871), with significantly lower median times in the MAC and local anesthesia groups. Other than one (2.1%) patient in the MAC with local anesthesia group whose death was related to history of severe coronary disease, no other acute medical complications occurred.

CONCLUSION

The results of this study suggest that use of MAC with local anesthesia during EVAR of AAAs is comparable to general and regional anesthesia in terms of safety and efficacy. Furthermore, MAC with local anesthesia confers additional outcome benefits versus general and regional anesthesia, as it is less invasive, offers greater hemodynamic stability, and enables better communication with the patient.

Ultrasonographic and DSCT scan analysis of single lima versus arterial T grafts 12 years after surgery

AIM

The aim of this study was to investigate long-term graft outcome in patients with left internal mammary artery to left anterior descending coronary artery (LIMA-LAD) and T-grafts by ultrasonography and dual source computed tomography (DSCT) and to analyse if ultrasonography can determine graft patency.

METHODS

Thirty-two patients, 28 males, 50.8+/-8.8 years at operation, were studied. Fifteen patients with single LIMA-LAD and additional vein grafts (group I) and 17 patients with LIMA-free right internal mammary artery (FRIMA) T-grafts (group II) underwent DSCT, transthoracic ultrasonography of the LIMA and an electrocardiogram. Differences were tested with unpaired and paired t tests.

RESULTS

In group I, 4.1+/-1.1 and in group II, 4.5+/-1.1 anastomoses/patients were performed. DSCT showed three string sign LIMA (20%) grafts and six occluded venous anastomoses (13%) in group I and three (distal) string sign LIMA grafts (18%), seven occluded LIMA anastomoses (23%) and nine occluded FRIMA anastomoses (23%) in group II. Ultrasonographic variables in the proximal part of the LIMA graft did not differ between the groups. No effect was found for proximal string sign LIMA grafts in ultrasonographic graft performance.

CONCLUSION

Ultrasonography cannot distinguish between string sign and patent single LIMA or T-grafts nor demonstrate distal anastomosis patency in T-grafts 12 years after surgery.

FOXM1 is a transcriptional target of ERalpha and has a critical role in breast cancer endocrine sensitivity and resistance

In this study we investigated the regulation of FOXM1 expression by estrogen receptor α (ERα) and its role in hormonal therapy and endocrine resistance. FOXM1 protein and mRNA expression was regulated by ER-ligands, including estrogen, tamoxifen (OHT), and fulvestrant (ICI182780; ICI) in breast carcinoma cell lines. Depletion of ERα by RNA interference (RNAi) in MCF-7 cells down-regulated FOXM1 expression. Reporter gene assays demonstrated that ERα activates FOXM1 transcription through an estrogen-response element (ERE) located within the proximal promoter region. The direct binding of ERα to the FOXM1 promoter was confirmed in vitro by mobility shift and DNA pull-down assays and in vivo by chromatin immunoprecipitation (ChIP) analysis. Our data also revealed that upon OHT treatment ERα recruits histone deacetylases (HDACs) to the ERE site of the FOXM1 promoter, which is associated with a decrease in histone acetylation and transcription activity. Importantly, silencing of FOXM1 by RNAi abolished estrogen-induced MCF-7 cell proliferation and overcame acquired tamoxifen resistance. Conversely, ectopic expression of FOXM1 abrogated the cell cycle arrest mediated by the anti-estrogen OHT. OHT repressed FOXM1 expression in endocrine sensitive but not resistant breast carcinoma cell lines. Further, qRT-PCR analysis of breast cancer patient samples revealed there was a strong and significant positive correlation between ERα and FOXM1 mRNA expression. Collectively, these results demonstrate FOXM1 to be a key mediator of the mitogenic functions of ERα and estrogen in breast cancer cells, and also suggest that the deregulation of FOXM1 may contribute to anti-estrogen insensitivity.

Function of HES6 an Inhibitor of HES1, in the Breast Cancer Cell Lines T47D and MCF-7 Is to Up-Regulate E2F-1 and Increased Proliferation

Hormone resistance remains as a major obstacle in breast cancer treatment. The majority of breast tumors are dependent on estrogens to grow, therefore anti-estrogens such as Tamoxifen is an effective treatment option. We have found that a transcription factor Hes6, earlier described in the nervous tissue, is up-regulated in hormone-independent breast cancer cells compared to normal estrogen sensitive breast cancer cells. By using a lenti-virus system, we have over-expressed Hes6 in T47D cells which are estrogen sensitive. This resulted in increased proliferation. We also found that estrogen treatment of MCF-7 breast cancer cells induced expression of endogenous Hes6 in the G1-phase. We could not find any binding of estrogen receptor α to the HES6 gene but instead found a binding site up-steam of the promoter in the ASCL1 gene. ASCL1 is a known inducer of HES6 and we are showing that ASCL1 is up-regulated by 17β-estradiol in MCF-7 cells. To find the mechanism behind the tumorogenic effects of Hes6, we analysed important factors of the cell-cycle. We found that the G1-phase factor E2F-1 was up-regulated in response to increased Hes6 expression. Since HES6 have been shown to be an inhibitor of HES1, this is in agreement with a previous study where we found that HES1 inhibited proliferation by binding to the promoter of and down-regulating E2F-1 expression. E2F-1 is an important limiting factor in late G1-phase of the cell cycle and can drive cell proliferation.We believe that the HES1-HES6 interplay is important in antiestrogen-resistant breast cancer. Studies are now ongoing to investigate if Hes6 is up-regulated in estrogen-independent human breast cancer samples.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2153.

The effects of lowering uric acid levels using allopurinol on markers of metabolic syndrome in end-stage renal disease patients: a pilot study

OBJECTIVE

Allopurinol was administered to end-stage renal disease (ESRD) patients with elevated uric acid levels presenting with symptoms of gout and also had risk factors of metabolic syndrome. The primary aim of this pilot study was to examine the effects of lowering uric acid levels using allopurinol on lipoprotein markers of metabolic syndrome in patients.

METHODS

The study was conducted using a prospective open-label protocol. End-stage renal disease patients (n=12) (mean age: 45.8+/- 13.6 years) undergoing chronic hemodialysis were recruited through their treating physician to participate in this study. All patients had ESRD and were prescribed allopurinol (300 mg/bid) for gout over a 3-month period. Pre-allopurinol and post-allopurinol data was obtained on low-density lipoprotein (LDL) cholesterol, LDL particle number, LDL particle size, high-density lipoprotein (HDL) cholesterol, large HDL particle number, total cholesterol, triglycerides, large very-low density lipoprotein (VLDL) particle number, and uric acid. Changes in lipid values were measured using a one-sample exact Wilcoxon rank sum test.

RESULTS

Significant changes occurred in the primary outcome measures of serum uric acid levels (-3.53 mg/dL, p=0.01), LDL cholesterol (-14.00 mg/dL, p=0.04), and triglycerides (32.67 mg/dL, p=0.01). Trends were observed in lipid markers that warrant further investigation.

CONCLUSION

Novel findings of our study suggest that lowering uric acid in ESRD patients may help to reduce the risk of cardiovascular disease in this population. It should be noted than an increase in triglycerides may mitigate the reduction in risk.

Post-treatment hemodynamics of a basilar aneurysm and bifurcation

To investigate whether or not a successful aneurysm treatment procedure can subject a parent artery to harmful hemodynamic stresses, computational fluid dynamics simulations are performed on a patient-specific basilar aneurysm and bifurcation before and after a virtual endovascular treatment. Prior to treatment, the aneurysm at systole is filled with a periodic train of vortex tubes, which form at the aneurysm neck and advect upwards into the dome. Following the treatment procedure however, the motion of the vortex train is inhibited by the aneurysm filling material, which confines the vortex tubes to the region beneath the aneurysm neck. Analysis of the post-treatment flow field indicates that the impingement of the basilar artery flow upon the treated aneurysm neck and the close proximity of a vortex tube to the parent artery wall increase the maximum wall shear stresses to values approximately equal to 50 Pa at systole. Calculation of the time-averaged wall shear stresses indicates that there is a 1.4 x 10(-7) m(2) area on the parent artery exposed to wall shear stresses greater than 37.9 Pa, a value shown by Fry [Circ. Res. 22(2):165-197, 1968] to cause severe damage to the endothelial cells that line the artery wall. The results of this study demonstrate that it is possible for a treatment procedure, which successfully isolates the aneurysm from the circulation and leaves no aneurysm neck remnant, to elevate the hemodynamic stresses to levels that are injurious to the artery wall.

Embolectomy in a rabbit acute arterial occlusion model using a novel electromechanical extraction device

A prototype endovascular electromechanical clot-extraction device was fabricated using a combination of shape memory polymer and shape memory nickel-titanium alloy (nitinol). Five embolic vascular occlusions were created in 4 rabbits by injecting thermally coagulated blood through a 4F catheter in the common carotid artery. Angiography immediately after clot injection showed complete or partial occlusion of the common carotid artery. Posttreatment angiography showed complete (2/5), partial (2/5), or no (1/5) restoration of blood flow.

Estrogen receptor β represses breast tumor growth and angiogenesis in vivo

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Background: Estrogens are well known stimulators of breast cancer cell growth in vitro as well as in vivo. Two different estrogen receptors exist, namely estrogen receptor (ER) α and β. ERα mediates the proliferative effect of estrogen in breast cancer cells and we have earlier shown that ERβ inhibits cell-cycle progression in vitro. Estrogens are well known stimulators of in vivo breast cancer cell growth as well as angiogenesis, and the effect is mediated through ERα. The function of ERβ in this context is not well understood. Methods: We have used ERα-positive T47D breast cancer cells stably transfected with a Tet/Off regulated ERβ expression vector system. The ERβ-inducible tumor cells are studied in vitro as well as in vivo. Results: By transplanting ERβ-inducible breast cancer cells into SCID-mice, we show that ERβ inhibits tumor growth and reduces the volume of established tumors. Furthermore, we show by immunohistochemistry, that the number of blood microvessels in the tumor periphery is decreased by ERβ expression, counteracting the well-known pro-angiogenic effect of ERα. By Western blot analysis on tumor extracts, we show that the concentration of the important pro-angiogenic growth factors VEGF and bFGF, normally expressed by breast tumor cells, is decreased in the ERβ-expressing tumors compared to the normal tumors. To exclude that the observed anti-angiogenic effect is just a result of reduced tumor growth, we incubated Tet/Off regulated ERβ expressing cells in vitro, during non-hypoxic conditions. We found that the expression of ERβ leads to decreased expression of VEGF and PDGFβ at the mRNA and protein-levels. In transient transfection assays, we found estrogen-ERα mediated up regulation of VEGF, PDGFβ and bFGF-promoter activities in T47D cells, and these activities were all suppressed following co-transfection with an ERβ-expression vector. Conclusions: We conclude that ERβ inhibits growth factor expression at transcriptional level in breast cancer cells; taken together, our data indicates that ERβ inhibits growth and angiogenesis of tumors formed by T47D breast cancer cells. This makes ERβ an interesting therapeutic target in breast cancer and perhaps treatment with the newly designed ERβ-selective ligands might work as a new anti-proliferative and anti-angiogenic therapy.

No significant financial relationships to disclose.

Characteristics of sudden death in hemodialysis patients

Hemodialysis (HD) is an intermittent procedure during which large fluid and electrolyte shifts occur. We hypothesized that sudden death occurrences in HD patients are related to the timing of HD, and that they occur more frequently in the 12 h period starting with dialysis and in the 12 h period at the end of the dialysis-free weekend interval. In a retrospective study, 228 patient deaths were screened to determine if they met the criteria for sudden death. Information was obtained from clinic charts, dialysis center records, and interview of witnesses of the death event. There were 80 HD patients who met the criteria for sudden death. A bimodal distribution of death occurrences was present, with a 1.7-fold increased death risk occurring in the 12 h period starting with the dialysis procedure and a threefold increased risk of death in the 12 h before HD at the end of the weekend interval (P=0.011). Patients with sudden death had a high prevalence of congestive heart failure and coronary artery disease. Only 40% of patients experiencing sudden death were receiving beta-blockers, and the prior monthly serum potassium value was less than 4 mEq/l in 25%. Sudden death is temporally related to the HD procedure. Every other day HD could be beneficial in preventing sudden death. Careful attention to the usage of beta-blockers and to the maintenance of normal serum potassium values is indicated in HD patients at risk for sudden death.