Response adaptive salvage with KTd and ASCT for functional high-risk multiple myeloma-The Australasian Leukemia and Lymphoma Group (ALLG) MM17 Trial

We evaluated re-induction incorporating carfilzomib-thalidomide-dexamethasone (KTd) and autologous stem cell transplantation (ASCT) for newly diagnosed multiple myeloma (NDMM) refractory, or demonstrating a suboptimal response, to non-IMID bortezomib-based induction. KTd salvage consisted of thalidomide 100 mg daily and dexamethasone 20 mg orally combined with carfilzomib 56 mg/m² days 1, 2, 8, 9, 15 and 16, of each 28-day cycle. Following four cycles, patients achieving a stringent complete response proceeded to ASCT whereas those who did not received a further two cycles then ASCT. Consolidation consisted of two cycles of KTd then Td to a total of 12 months post-ASCT therapy. Primary end-point was the overall response rate (ORR) with KTd prior to ASCT. Fifty patients were recruited. The ORR was 78% with EuroFlow MRD negativity of 34% in the intention-to-treat population and 65% in the evaluable population at 12 months post-ASCT. With follow-up >38 months median PFS and OS have not been reached with PFS and OS at 36 months of 64% and 80%, respectively. KTd was well tolerated with grade 3 and grade ≥4 adverse events rates of 32% and 10%, respectively. Response adaptive utilisation of KTd with ASCT is associated with both high-quality responses and durable disease control in functional high-risk NDMM.

Pseudoepitheliomatous keratotic and micaceous balanitis: a series of eight cases

BACKGROUND

Pseudoepitheliomatous keratotic and micaceous balanitis (PEKMB) is a clinicopathological entity characterized clinically by micaceous scale on the glans, and histologically by acanthosis, hyperkeratosis and pseudoepitheliomatous hyperplasia. We present a series of eight cases of this rare condition, the first series of more than two cases to be reported.

OBJECTIVES

To determine the clinical and histological characteristics of cases of PEKMB, and evaluate treatments used and clinical course.

METHODS

This monocentric case series was conducted at the University College London Hospitals tertiary male genital dermatology clinic between April 2018 and August 2020. Eight patients with PEKMB were evaluated. Data were collected on demographics, clinical presentation, histological features, presence of human papilloma virus (HPV), history of lichen sclerosus, treatment of PEKMB and subsequent response, and presence or development of squamous cell carcinoma (SCC) or penile intraepithelial neoplasia (PeIN) during follow-up.

RESULTS

Eight Caucasian males presented with clinical and histological evidence of PEKMB. Seven had a background of lichen sclerosus; two had failed treatment with superpotent topical steroids and four had symptoms for three or more years prior to circumcision. There was no clinical or histological relationship with HPV infection, and p16 staining was negative. HPV PCR, performed in two cases, was negative. Basal atypia, insufficient to amount to PeIN, was present in six patients. One patient progressed to PeIN during follow-up, and no patient progressed to invasive malignancy. Five patients were treated successfully with glans resurfacing and split skin graft reconstruction.

CONCLUSIONS

Our observations demonstrate that PEKMB represents a form of chronic, undiagnosed or misdiagnosed, inadequately treated or treatment refractory, unstable lichen sclerosus. The significant potential for squamous carcinogenesis (differentiated PeIN and verrucous carcinoma) can be mitigated by timely diagnosis and treatment. Glans resurfacing and split skin graft reconstruction appears to be a successful treatment modality in patients with refractory disease.

A systematic review and meta-analysis of disease burden of healthcare-associated infections in China: an economic burden perspective from general hospitals

BACKGROUND

Healthcare-associated infections (HAIs) are a global public health issue. However, the economic burden attributable to HAIs at a national level is unknown in China. The aim of this systematic review was to estimate the direct economic burden caused by HAIs in China.

METHODS

Medline, EMBASE and Chinese Journals Online databases were searched, including studies published from 2009 to 2019. The pooled estimates with 95% Confidential Interval were calculated with Quantile Estimation. The random effect model of the DerSimonian-Laird method was used. The statistical significance was set as P<0.05.

RESULTS

2,756 publications were identified; 6 studies were included in a meta-analysis to calculate the pooled estimates of direct economic burden, while 5 were included in the pooled estimates of the additional economic burden. The pooled median estimates of the total medical expenditure, the medicine expenditure and hospitalisation days per inpatient of patients with HAIs were ¥34,415.62, ¥20,065.21 and 34.01 days, respectively (P <0.0001). The pooled median estimates of the differences of the total medical expenditure, the medicine expenditure and hospitalisation days per inpatient between patients with HAIs and patients without HAIs were ¥24,881.37, ¥9,438.46 and 13.89 days, respectively (P < 0.01).

CONCLUSIONS

The cost of care for patients with HAIs was significantly higher than that for those without HAIs. This excess economic burden is likely to impact on patients and their families as well as health service providers and the health care system as a whole. Effective surveillance systems and cost-effective interventions are needed to control HAIs.

Biomechanical regulation of breast cancer metastasis and progression

Physical activity has been consistently linked to decreased incidence of breast cancer and a substantial increase in the length of survival of patients with breast cancer. However, the understanding of how applied physical forces directly regulate breast cancer remains limited. We investigated the role of mechanical forces in altering the chemoresistance, proliferation and metastasis of breast cancer cells. We found that applied mechanical tension can dramatically alter gene expression in breast cancer cells, leading to decreased proliferation, increased resistance to chemotherapeutic treatment and enhanced adhesion to inflamed endothelial cells and collagen I under fluidic shear stress. A mechanistic analysis of the pathways involved in these effects supported a complex signaling network that included Abl1, Lck, Jak2 and PI3K to regulate pro-survival signaling and enhancement of adhesion under flow. Studies using mouse xenograft models demonstrated reduced proliferation of breast cancer cells with orthotopic implantation and increased metastasis to the skull when the cancer cells were treated with mechanical load. Using high throughput mechanobiological screens we identified pathways that could be targeted to reduce the effects of load on metastasis and found that the effects of mechanical load on bone colonization could be reduced through treatment with a PI3Kγ inhibitor.

Detection of SARS-CoV-2 within the healthcare environment: a multi-centre study conducted during the first wave of the COVID-19 outbreak in England

BACKGROUND

Understanding how severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is spread within the hospital setting is essential in order to protect staff, implement effective infection control measures, and prevent nosocomial transmission.

METHODS

The presence of SARS-CoV-2 in the air and on environmental surfaces around hospitalized patients, with and without respiratory symptoms, was investigated. Environmental sampling was undertaken within eight hospitals in England during the first wave of the coronavirus disease 2019 outbreak. Samples were analysed using reverse transcription polymerase chain reaction (PCR) and virus isolation assays.

FINDINGS

SARS-CoV-2 RNA was detected on 30 (8.9%) of 336 environmental surfaces. Cycle threshold values ranged from 28.8 to 39.1, equating to 2.2 x 105 to 59 genomic copies/swab. Concomitant bacterial counts were low, suggesting that the cleaning performed by nursing and domestic staff across all eight hospitals was effective. SARS-CoV-2 RNA was detected in four of 55 air samples taken <1 m from four different patients. In all cases, the concentration of viral RNA was low and ranged from <10 to 460 genomic copies/m3 air. Infectious virus was not recovered from any of the PCR-positive samples analysed.

CONCLUSIONS

Effective cleaning can reduce the risk of fomite (contact) transmission, but some surface types may facilitate the survival, persistence and/or dispersal of SARS-CoV-2. The presence of low or undetectable concentrations of viral RNA in the air supports current guidance on the use of specific personal protective equipment for aerosol-generating and non-aerosol-generating procedures.

Genome wide analysis of gene expression changes in skin from patients with type 2 diabetes

Non-healing chronic ulcers are a serious complication of diabetes and are a major healthcare problem. While a host of treatments have been explored to heal or prevent these ulcers from forming, these treatments have not been found to be consistently effective in clinical trials. An understanding of the changes in gene expression in the skin of diabetic patients may provide insight into the processes and mechanisms that precede the formation of non-healing ulcers. In this study, we investigated genome wide changes in gene expression in skin between patients with type 2 diabetes and non-diabetic patients using next generation sequencing. We compared the gene expression in skin samples taken from 27 patients (13 with type 2 diabetes and 14 non-diabetic). This information may be useful in identifying the causal factors and potential therapeutic targets for the prevention and treatment of diabetic related diseases.

Therapeutic strategies for enhancing angiogenesis in wound healing

The enhancement of wound healing has been a goal of medical practitioners for thousands of years. The development of chronic, non-healing wounds is a persistent medical problem that drives patient morbidity and increases healthcare costs. A key aspect of many non-healing wounds is the reduced presence of vessel growth through the process of angiogenesis. This review surveys the creation of new treatments for healing cutaneous wounds through therapeutic angiogenesis. In particular, we discuss the challenges and advancement that have been made in delivering biologic, pharmaceutical and cell-based therapies as enhancers of wound vascularity and healing.

* Glioblastoma Exosomes for Therapeutic Angiogenesis in Peripheral Ischemia

Peripheral ischemia as a result of occlusive vascular disease is a widespread problem in patients older than the age of 65. Angiogenic therapies that can induce microvascular growth have great potential for providing a long-lasting solution for patients with ischemia and would provide an appealing alternative to surgical and percutaneous interventions. However, many angiogenic therapies have seen poor efficacy in clinical trials, suggesting that patients with long-term peripheral ischemia have considerable therapeutic resistance to angiogenic stimuli. Glioblastoma is one of the most angiogenic tumor types, inducing robust vessel growth in the area surrounding the tumor. One major angiogenic mechanism used by the tumor cells to induce blood vessel growth is the production of exosomes and other extracellular vesicles that can carry pro-angiogenic and immunomodulatory signals. Here, we explored whether the pro-angiogenic aspects of glioblastoma-derived exosomes could be harnessed to promote angiogenesis and healing in the context of peripheral ischemic disease. We demonstrate that the exosomes derived from glioblastoma markedly enhance endothelial cell proliferation and increase endothelial tubule formation in vitro. An analysis of the microRNA expression using next generation sequencing identified that exosomes contained a high concentration of miR-221. In addition, we found that glioblastoma exosomes contained significant amounts of the proteoglycans glypican-1 and syndecan-4, which can serve as co-receptors for angiogenic factors, including fibroblast growth factor-2 (FGF-2). In a hindlimb ischemia model in mice, we found that the exosomes promoted enhanced revascularization in comparison to control alginate gels and FGF-2 treatment alone. Taken together, our results support the fact that glioblastoma-derived exosomes have powerful effects in increasing revascularization in the context of peripheral ischemia.

Syndecan-1 in mechanosensing of nanotopological cues in engineered materials

The cells of the vascular system are highly sensitive to biophysical cues from their local cellular microenvironment. To engineer improved materials for vascular devices and delivery of cell therapies, a key challenge is to understand the mechanisms that cells use to sense biophysical cues from their environment. Syndecans are heparan sulfate proteoglycans (HSPGs) that consist of a protein core modified with heparan sulfate glycosaminoglycan chains. Due to their presence on the cell surface and their interaction with cytoskeletal and focal adhesion associated molecules, cell surface proteoglycans are well poised to serve as mechanosensors of the cellular microenvironment. Nanotopological cues have become recognized as major regulators of cell growth, migration and phenotype. We hypothesized that syndecan-1 could serve as a mechanosensor for nanotopological cues and can mediate the responsiveness of vascular smooth muscle cells to nanoengineered materials. We created engineered substrates made of polyurethane acrylate with nanogrooves using ultraviolet-assisted capillary force lithography. We cultured vascular smooth muscle cells with knockout of syndecan-1 on engineered substrates with varying compliance and nanotopology. We found that knockout of syndecan-1 reduced alignment of vascular smooth muscle cells to the nanogrooves under inflammatory treatments. In addition, we found that loss of syndecan-1 increased nuclear localization of Yap/Taz and phospho-Smad2/3 in response to nanogrooves. Syndecan-1 knockout vascular smooth muscle cells also had elevated levels of Rho-associated protein kinase-1 (Rock1), leading to increased cell stiffness and an enhanced contractile state in the cells. Together, our findings support that syndecan-1 knockout leads to alterations in mechanosensing of nanotopographical cues through alterations of in rho-associated signaling pathways, cell mechanics and mediators of the Hippo and TGF-β signaling pathways.

Abstract A38: Biophysical Regulation of Breast Cancer Metastasis

Introduction: Despite many advances in our understanding of breast cancer biology over the last decades, there are no therapies that can effectively prevent or treat metastatic cancer. During the growth of the primary tumor mass and its dissemination through the body during metastasis, cancer cells are exposed to a host of mechanical environments generated by the local matrix compliance, pressure and tension from tumor mass expansion, and fluidic shear stresses from interstitial and vascular fluid flow. These biophysical forces are emerging as powerful regulators of cancer growth, quiescence and metastasis; however, our understanding of the mechanisms of the biomechanical regulation of tumor biology remains very limited. The overall goal was to identify the role of mechanical forces in regulating key steps in tumor metastasis and progression.

Results: We recently developed a mesofluidic system that allows the high throughput study of tumor cell interactions under flow. This device allows us to simulate the adhesion of cancer cells to endothelial cells under physiological flow conditions to model this step of the metastatic cascade and to apply shear forces to cells in a 96-well format. In addition, we have designed a system to apply mechanical stretch to cells in a high throughput format (576 wells simultaneously). Using these two systems, we examined the interplay between mechanical cues and the propensity of breast cancer cells to metastasize and undergo epithelial-to-mesenchymal transition (EMT).

Mechanical strain increases circulating tumor cell adhesion to endothelial cells and extracellular matrix (ECM). We applied cyclic mechanical strain (5% maximal strain) to MDA-MB-231 and MCF-7 cancer cells for 24 hours and then performed adhesion assays of the cancer cells to activated and non-activated endothelial cells (ECS) and purified ECM proteins. We found that cyclic strain increased cancer cell adhesion to activated ECs in comparison to non-strained cells. In addition cancer cells exposed to mechanical strain adhered more to collagen I, laminin, and vitronectin, while they adhered less to collagen II and fibronectin in comparison to non-strained control cells. To determine which integrins were involved in the strain-induced change in adhesion, we treated the cells with a library of integrin inhibitors while applying strain for 24 hours. Cilengitide, P11, ATN-161, Bio 1211, and RGDS peptides reduced the adhesion of cancer cells back to the level of non-strained cancer cells, indicating the role of αvβ3, αvβ5, α5β1, and α4β1 integrins in the biophysical regulation of circulating tumor cell adhesion.

Cyclic strain alters the ability of breast cancer cells to invade through an endothelial monolayer. We next used the high throughput system to apply multiple levels of strain to the cancer cell lines (0, 2.5, 5, 7.5, 10, 12.5, 15 and 17.5% strain). We then trypsinized the cells and measured their invasion in a Transwell assay with a confluent layer of endothelial cells cultured on a porous membrane. We found that the mid-level strains ranging from 7.5-15% strain decreased the invasiveness of the MDA-MB-231 cells compared to the non-strained control cells. For the MCF-7 cells, mechanical strain of 5% or higher led to decreased invasion through the endothelial layer.

Mechanical forces alter signaling through the TGF-β and Yap/Taz pathways as well the expression of markers of epithelial-to-mesenchymal transition (EMT). We applied cyclic strain at multiple levels (2.5-17.5% strain) to breast cancer cells for 24 hours then immunostained for various signaling proteins. In MDA-MB-231 cells, we saw a significant decrease in the intensity of Smad2/3 and nuclear phospho-Smad2/3 at mid-range strains (5-12.5% strain) as well as an increase in the nuclear localization of Yap/Taz using fluorescent immunostaining. At high levels of strain (15 and 17.5% strain), there was increased nuclear p-Smad2/3 intensity. Consistent with these findings, we found increased Smad activity in the cells using a luciferase reporter assay. An analysis of EMT markers using PCR, western blotting and immunostaining showed a reduction in mesenchymal markers including α−SMA, Slug, ZEB, fibronectin and vimentin with mid-range mechanical strain levels.

Conclusion: Together, our studies demonstrate that mechanical forces can profoundly alter the propensity of cancer cells to adhere and invade during metastasis. Moreover, the response to mechanical strain is dependent on the magnitude of the strain and cancer cell type. These effects are mediated, in part, through integrin interactions and the differential regulation of the TGF-β and Hippo pathways by biophysical forces.

Citation Format: Adrianne Spencer, Jason Lee, Katerina Lee, Darshil Choksi, Jerry Wang, Christopher Spruell, Aaron Baker. Biophysical Regulation of Breast Cancer Metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Engineering and Physical Sciences in Oncology; 2016 Jun 25-28; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2017;77(2 Suppl):Abstract nr A38.

Autologous transplant vs oral chemotherapy and lenalidomide in newly diagnosed young myeloma patients: a pooled analysis

In newly diagnosed myeloma patients, upfront autologous transplant (ASCT) prolongs progression-free survival 1 (PFS1) compared with chemotherapy plus lenalidomide (CC+R). Salvage ASCT at first relapse may still effectively rescue patients who did not receive upfront ASCT. To evaluate the long-term benefit of upfront ASCT vs CC+R and the impact of salvage ASCT in patients who received upfront CC+R, we conducted a pooled analysis of 2 phase III trials (RV-MM-209 and EMN-441). Primary endpoints were PFS1, progression-free survival 2 (PFS2), overall survival (OS). A total of 268 patients were randomized to 2 courses of melphalan 200 mg/m² and ASCT (MEL200-ASCT) and 261 to CC+R. Median follow-up was 46 months. MEL200-ASCT significantly improved PFS1 (median: 42 vs 24 months, HR 0.53; P<0.001), PFS2 (4 years: 71 vs 54%, HR 0.53, P<0.001) and OS (4 years: 84 vs 70%, HR 0.51, P<0.001) compared with CC+R. The advantage was noticed in good and bad prognosis patients. Only 53% of patients relapsing from CC+R received ASCT at first relapse. Upfront ASCT significantly reduced the risk of death (HR 0.51; P=0.007) in comparison with salvage ASCT. In conclusion, these data confirm the role of upfront ASCT as the standard approach for all young myeloma patients.

Recreational physical activity in natural environments and implications for health: A population based cross-sectional study in England

BACKGROUND

Building on evidence that natural environments (e.g. parks, woodlands, beaches) are key locations for physical activity, we estimated the total annual amount of adult recreational physical activity in England's natural environments, and assessed implications for population health.

METHODS

A cross-sectional analysis of six waves (2009/10-2014/5) of the nationally representative, Monitor of Engagement with the Natural Environment survey (n=280,790). The survey uses a weekly quota sample, and population weights, to estimate nature visit frequency across England, and provides details on a single, randomly selected visit (n=112,422), including: a) duration; b) activity; and c) environment type.

RESULTS

Approximately 8.23 million (95% CIs: 7.93, 8.54) adults (19.5% of the population) made at least one 'active visit' (i.e. ≥30min, ≥3 METs) to natural environments in the previous week, resulting in 1.23 billion (1.14, 1.32) 'active visits' annually. An estimated 3.20 million (3.05, 3.35) of these also reported meeting recommended physical activity guidelines (i.e. ≥5×30min a week) fully, or in part, through such visits. Active visits by this group were associated with an estimated 109,164 (101,736, 116,592) Quality Adjusted Life Years (QALYs) annually. Assuming the social value of a QALY to be £20,000, the annual value of these visits was approximately £2.18 billion (£2.03, £2.33). Results for walking were replicated using WHO's Health Economic Assessment Tool.

CONCLUSIONS

Natural environments provide the context for a large proportion of England's recreational physical activity and highlight the need to protect and manage such environments for health purposes.

Recreational physical activity in natural environments and implications for health: A population based cross-sectional study in England

BACKGROUND

Building on evidence that natural environments (e.g. parks, woodlands, beaches) are key locations for physical activity, we estimated the total annual amount of adult recreational physical activity in England's natural environments, and assessed implications for population health.

METHODS

A cross-sectional analysis of six waves (2009/10-2014/5) of the nationally representative, Monitor of Engagement with the Natural Environment survey (n=280,790). The survey uses a weekly quota sample, and population weights, to estimate nature visit frequency across England, and provides details on a single, randomly selected visit (n=112,422), including: a) duration; b) activity; and c) environment type.

RESULTS

Approximately 8.23 million (95% CIs: 7.93, 8.54) adults (19.5% of the population) made at least one 'active visit' (i.e. ≥30min, ≥3 METs) to natural environments in the previous week, resulting in 1.23 billion (1.14, 1.32) 'active visits' annually. An estimated 3.20 million (3.05, 3.35) of these also reported meeting recommended physical activity guidelines (i.e. ≥5×30min a week) fully, or in part, through such visits. Active visits by this group were associated with an estimated 109,164 (101,736, 116,592) Quality Adjusted Life Years (QALYs) annually. Assuming the social value of a QALY to be £20,000, the annual value of these visits was approximately £2.18 billion (£2.03, £2.33). Results for walking were replicated using WHO's Health Economic Assessment Tool.

CONCLUSIONS

Natural environments provide the context for a large proportion of England's recreational physical activity and highlight the need to protect and manage such environments for health purposes.

Abstract PR08: Biomechanical preconditioning of circulating tumor cell adhesion during metastasis

Introduction: Mechanical forces may greatly affect the ability and propensity of cancer cells to metastasize. Tumor cells are subject to many mechanical forces within their microenvironment in vivo. These mechanical forces may play a role in cancer cell regulation in combination with biochemical signals. However, much less is known about the role of mechanical forces in regulation of cancer cells. We have recently developed a novel high throughput mechanofluidic platform for assaying cancer cell adhesion under flow in a 96-well format. This device functions like a cone and plate viscometer in each well by inducing shear stress on cells cultured in a standard 96-well plate. We have used this device to study how the mechanics of the tumor microenvironment or applied mechanical forces alter a cancer cells propensity to adhere during metastatic extravasation.

Mechanical compliance of the microenvironment regulates circulating tumor cell adhesion. We first examined how the compliance of the tumor environment can alter the adhesion of cancer cells during metastasis. MDA-MB-231 breast cancer cells were cultured on hydrogels with stiffnesses ranging from 0.2-50 kPa for the Young's modulus. Using the high throughput flow system we conducted adhesion assays to endothelial cells under flow followed by a detachment assay in which we increased the applied shear stress to determine the strength of attachment. We found that the compliance of the substrate cancer cells were grown on did not alter the initial adhesion to activated endothelial cells but markedly altered the strength of adhesion. The cells grown on 0.2 kPa substrates remained adhered under high stress (20 dynes/cm2) five-fold more than cells grown on 50 kPa substrates. We also examined whether compliance of the microenvironment of the endothelial cells could regulate their ability to recruit circulated tumor cells. We grew endothelial cells on substrates of varying compliance and then examined the adhesion of cancer cells grown on standard culture plates. In endothelial cells grown on compliant substrates (0.2 and 0.5 kPa) we found that cancer cells adhered less than to endothelial cells on stiffer substrates.

Applied mechanical forces regulate circulating tumor cell adhesion to endothelial cells and extracellular matrix (ECM). We next examined how application of a cyclic stretching force to cancer cells would alter their adhesion to endothelial cells (ECs) and ECM. We applied a cyclic physiological strain to cancer cells for 24 hours and then performed adhesion assays with breast cancer cells to activated ECs, non-activated ECs, and purified ECM. We found that cyclic strain caused more cancer cells to adhere to activated ECs than their non-strained counterparts, however the strained cancer cells did not adhere as strongly to the activated ECs. Strained cancer cells adhered more to collagen I, laminin, and vitronectin, while they adhered less to collagen II and fibronectin than non-strained cells. The strength of adhesion to ECM was increased for collagen II, fibronectin, and laminin, but not for collagen I or vitronectin. To determine which integrins were involved in the strain-induced change in adhesion, a small library of integrin inhibitors was used to treat cancer cells while applying strain for 24 hours. Cilengitide, P11, ATN-161, Bio 1211, and RGDS peptides reduced the adhesion of cancer cells back to the level of non-strained cancer cells, indicating the role of αvβ3, αvβ5, α5β1, and α4β1 integrins in cancer cell sensing and reaction to the applied cyclic strain.

Conclusion: Our studies have shown that application of mechanical forces such as the stiffness of the substrate that cancer cells and endothelial cells are cultured on or the application of cyclic strain can alter the adhesiveness and strength of adhesion of cancer cells to an endothelial monolayer or ECM under shear stress.

Citation Format: Adrianne Spencer, Zhiying Zhu, Katerina Lee, Jason Lee, Chris Spruell, Chad Williams, Peter Voyvodic, Ashwin Ramaswami, Ning Jiang, Aaron Baker. Biomechanical preconditioning of circulating tumor cell adhesion during metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr PR08.

Abstract B46: Biomechanical preconditioning of circulating tumor cell adhesion during metastasis

This abstract is being presented as a short talk in the scientific program. A full abstract is printed in the Proffered Abstracts section (PR08) of the Conference Proceedings.

Citation Format: Adrianne Spencer, Zhiying Zhu, Katerina Lee, Jason Lee, Chris Spruell, Chad Williams, Peter Voyvodic, Ashwin Ramaswami, Ning Jiang, Aaron Baker. Biomechanical preconditioning of circulating tumor cell adhesion during metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr B46.

High Throughput Label Free Measurement of Cancer Cell Adhesion Kinetics Under Hemodynamic Flow

The kinetics of receptor-mediated cell adhesion to extracellular matrix and adherent cell monolayers plays a key role in many physiological and pathological processes including cancer metastasis. Within this process the presence of fluidic shear forces is a key regulator of binding equilibrium and kinetics of cell adhesion. Current techniques to examine the kinetics of cell adhesion are either performed in the absence of flow or are low throughput, limiting their application to pharmacological compound screening or the high throughput investigation of biological mechanisms. We developed a high throughput flow device that applies flow in a multi-well format and interfaced this system with electric cell-substrate impedance sensing (ECIS) system to allow label free detection of cell adhesion. We demonstrate that this combined system is capable of making real time measurements of cancer cell adhesion to extracellular matrix and immobilized platelets. In addition, we examined the dependence of the kinetics of binding of cancer cells on the level of shear stress and in the presence of small molecule inhibitors to adhesion-related pathways. This versatile system is broadly adaptable to the high throughput study of cell adhesion kinetics for many applications including drug screening and the investigation of the mechanisms of cancer metastasis.

Management of systemic AL amyloidosis: recommendations of the Myeloma Foundation of Australia Medical and Scientific Advisory Group

Systemic AL amyloidosis is a plasma cell dyscrasia with a characteristic clinical phenotype caused by multi-organ deposition of an amyloidogenic monoclonal protein. This condition poses a unique management challenge due to the complexity of the clinical presentation and the narrow therapeutic window of available therapies. Improved appreciation of the need for risk stratification, standardised use of sensitive laboratory testing for monitoring disease response, vigilant supportive care and the availability of newer agents with more favourable toxicity profiles have contributed to the improvement in treatment-related mortality and overall survival seen over the past decade. Nonetheless, with respect to the optimal management approach, there is a paucity of high-level clinical evidence due to the rarity of the disease, and enrollment in clinical trials is still the preferred approach where available. This review will summarise the Clinical Practice Guidelines on the Management of Systemic Light Chain (AL) Amyloidosis recently prepared by the Medical Scientific Advisory Group of the Myeloma Foundation of Australia. It is hoped that these guidelines will assist clinicians in better understanding and optimising the management of this difficult disease.

A high-throughput mechanofluidic screening platform for investigating tumor cell adhesion during metastasis

The metastatic spread of cancer is a major barrier to effective and curative therapies for cancer. During metastasis, tumor cells intravasate into the vascular system, survive in the shear forces and immunological environment of the circulation, and then extravasate into secondary tumor sites. Biophysical forces are potent regulators of cancer biology and are key in many of the steps of metastasis. In particular, the adhesion of circulating cells is highly dependent upon competing forces between cell adhesion receptors and the shear stresses due to fluid flow. Conventional in vitro assays for drug development and the mechanistic study of metastasis are often carried out in the absence of fluidic forces and, consequently, are poorly representative of the true biology of metastasis. Here, we present a novel high-throughput approach to studying cell adhesion under flow that uses a multi-well, mechanofluidic flow system to interrogate adhesion of cancer cell to endothelial cells, extracellular matrix and platelets under physiological shear stresses. We use this system to identify pathways and compounds that can potentially be used to inhibit cancer adhesion under flow by screening anti-inflammatory compounds, integrin inhibitors and a kinase inhibitor library. In particular, we identify several small molecule inhibitors of FLT-3 and AKT that are potent inhibitors of cancer cell adhesion to endothelial cells and platelets under flow. In addition, we found that many kinase inhibitors lead to increased adhesion of cancer cells in flow-based but not static assays. This finding suggests that even compounds that reduce cell proliferation might also enhance cancer cell adhesion during metastasis. Overall, our results validate a novel platform for investigating the mechanisms of cell adhesion under biophysical flow conditions and identify several potential inhibitors of cancer cell adhesion during metastasis.

Modifying chemotherapeutic management of a patient with Burkitt's lymphoma and pre-existing motor neurone disease

WHAT IS KNOWN AND OBJECTIVE

Intensive chemotherapy for treatment of Burkitt's lymphoma (BL) - a high-grade lymphoproliferative disorder (LPD) - can cause neurotoxicity. An association between motor neurone disease (MND) and LPDs has previously been described, but there is a lack of recommendations available to guide management of such patients. This report aims to describe suitable management of BL in a patient with MND.

CASE DESCRIPTION

A 66-year-old woman with a history of MND affecting her limbs was diagnosed with bulky, extranodal, high-risk gastric BL. Standard chemotherapy is with multiple non-cross-resistant cytotoxic agents. To avoid exacerbation of neuropathy, six cycles of a modified regimen was planned, aiming to minimize exposure to the most neurotoxic agents. A PET-FDG-negative remission was obtained at 12 months, without the signs of central neurotoxicity, peripheral neuropathy or muscle weakness.

WHAT IS NEW AND CONCLUSION

High-intensity chemotherapy, minimizing known neurotoxic agents, was delivered safely and effectively in a patient with BL and pre-existing MND. More case descriptions are required to guide management decisions.

Changing microbial epidemiology in hematopoietic stem cell transplant recipients: increasing resistance over a 9-year period

Infections remain important contributors to mortality in hematopoietic stem cell transplantation (HSCT).

METHOD

We studied the evolving epidemiology and trends in susceptibility of bacterial and Candida isolates at an Australian HSCT center. A total of 528 HSCTs in 508 patients were performed from April 2001 to May 2010. A total of 605 isolates were eligible for study inclusion; 318 (53%) were gram-positive, 268 (44%) were gram-negative, and 19 (3%) were Candida species.

RESULTS

The most common site for isolates was blood (380 isolates, 63%). Staphylococcus aureus was the most common gram-positive organism (n = 107, 34%), but trends to increasing coagulase-negative staphylococci (P = 0.002) and vancomycin-resistant Enterococcus (P < 0.001) were observed. Escherichia coli was the most common gram-negative isolate (n = 74, 28%). Fluoroquinolone resistance increased with widespread use of protocol fluoroquinolone prophylaxis (P = 0.001). Carbapenem resistance was found in 44% of Pseudomonas or Acinetobacter isolates. Bloodstream infection with a multidrug-resistant organism (odds ratio 3.61, 95% confidence interval: 1.40-9.32, P = 0.008) was an independent predictor of mortality at 7 days after a positive blood culture.

CONCLUSIONS

Antimicrobial resistance is an increasing problem in this vulnerable patient population, and not only has an impact on choice of empiric therapy for febrile neutropenia but also on mortality.

Metastatic spinal cord compression as a result of the unknown primary tumour

PURPOSE

Patients presenting with metastatic spinal cord compression (MSCC) due to an unknown primary tumour (UPT) present an interesting problem with limited literature available to provide guidance on management. Our aim was twofold-first, to analyse all our patients with MSCC due to a UPT pre-operatively, to review their treatment and outcome; second, make comparisons with those patients who presented with MSCC due to a known primary tumour (KPT) during the same period.

METHODS

All data was collected retrospectively from October 2004 to October 2009, then prospectively from October 2009 to October 2012 (8 years). We reviewed all patient records held on the database, including patient demographics, primary tumour, neurological outcome (Frankel grade), complications and survival.

RESULTS

During the 8-year study period, out of the 382 patients who underwent emergency surgery for MSCC, 285 patients were included in whom complete information was available. Of these, 17 patients presented with MSCC due to a UPT (6 %; mean age 61 years, 5 M, 12 F). When compared to those with a known primary, the UPT group trended to a longer duration of symptoms prior to surgery (200 vs. 156 days, p = 0.86). They had a similar neurological outcome (88 % remained the same or improved post-operatively vs. 90 % in KPT group; p = 0.42), similar complication rate (23.5 vs. 33.6 %; p = 0.32) and survival (222 vs. 251 days, p = 0.42). The primary site in the UPT group was confirmed in 10/17 (58.8 %)-all 10 were adenocarcinoma [lung (6) and GI (4)].

DISCUSSION

In our series, the incidence of MSCC due to an unknown primary was 6 %. They had similar overall outcome (neurology post-operatively, complications and survival) to those patients with MSCC from a known primary. Our experience would suggest that we need to treat these patients expeditiously with thorough evaluation and urgent treatment.

Exercise for depression in care home residents: a randomised controlled trial with cost-effectiveness analysis (OPERA)

BACKGROUND

Many older people living in care homes (long term residential care or nursing homes) are depressed. Exercise is a promising non-drug intervention for preventing and treating depression in this population.

OBJECTIVE

To evaluate the impact of a 'whole-home' intervention, consisting of training for residential and nursing home staff backed up with a twice-weekly, physiotherapist-led exercise class on depressive symptoms in care home residents.

DESIGN

A cluster randomised controlled trial with a cost-effectiveness analysis to compare (1) the prevalence of depression in intervention homes with that in control homes in all residents contributing data 12 months after homes were randomised (cross-sectional analysis); (2) the number of depressive symptoms at 6 months between intervention and control homes in residents who were depressed at pre-randomisation baseline assessment (depressed cohort comparison); and (3) the number of depressive symptoms at 12 months between intervention and control homes in all residents who were present at pre-randomisation baseline assessment (cohort comparison).

SETTING

Seventy-eight care homes in Coventry and Warwickshire and north-east London.

PARTICIPANTS

Care home residents aged ≥ 65 years.

INTERVENTIONS

Control intervention: Depression awareness training programme for care home staff. Active intervention: A 'whole-home' exercise intervention, consisting of training for care home staff backed up with a twice-weekly, physiotherapist-led exercise group.

MAIN OUTCOME MEASURES

Geriatric Depression Scale-15, proxy European Quality of Life-5 Dimensions (EQ-5D), cost-effectiveness from an National Health Service perspective, peripheral fractures and death.

RESULTS

We recruited a total of 1054 participants. Cross-sectional analysis: We obtained 595 Geriatric Depression Scale-15 scores and 724 proxy EQ-5D scores. For the cohort analyses we obtained 765 baseline Geriatric Depression Scale-15 scores and 776 proxy EQ-5D scores. Of the 781 who we assessed prior to randomisation, 765 provided a Geriatric Depression Scale-15 score. Of these 374 (49%) were depressed and constitute our depressed cohort. Resource-use and quality-adjusted life-year data, based on proxy EQ-5D, were available for 798 residents recruited prior to randomisation. We delivered 3191 group exercise sessions with 31,705 person attendances and an average group size of 10 (5.3 study participants and 4.6 non-study participants). On average, our participants attended around half of the possible sessions. No serious adverse events occurred during the group exercise sessions. In the cross-sectional analysis the odds for being depressed were 0.76 [95% confidence interval (CI) 0.53 to 1.09] lower in the intervention group at 12 months. The point estimates for benefit for both the cohort analysis (0.13, 95% CI -0.33 to 0.60) and depressed cohort (0.22, 95% CI -0.52 to 0.95) favoured the control intervention. There was no evidence of differences in fracture rates or mortality (odds ratio 1.07, 95% CI 0.79 to 1.48) between the two groups. There was no evidence of differences in the other outcomes between the two groups. Economic analysis: The additional National Health Service cost of the OPERA intervention was £374 per participant (95% CI -£655 to £1404); the mean difference in quality-adjusted life-year was -0.0014 (95% CI -0.0728 to 0.0699). The active intervention was thus dominated by the control intervention, which was more effective and less costly.

CONCLUSION

The results do not support the use of a whole-home physical activity and moderate-intensity exercise programme to reduce depression in care home residents.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN43769277.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 18. See the Health Technology Assessment programme website for further project information.