The effects of acute Methylene Blue administration on cerebral blood flow and metabolism in humans and rats

Methylene Blue (MB) is a brain-penetrating drug with putative neuroprotective, antioxidant and metabolic enhancing effects. In vitro studies suggest that MB enhances mitochondrial complexes activity. However, no study has directly assessed the metabolic effects of MB in the human brain. We used in vivo neuroimaging to measure the effect of MB on cerebral blood flow (CBF) and brain metabolism in humans and in rats. Two doses of MB (0.5 and 1 mg/kg in humans; 2 and 4 mg/kg in rats; iv) induced reductions in global cerebral blood flow (CBF) in humans (F(1.74, 12.17)5.82, p = 0.02) and rats (F(1,5)26.04, p = 0.0038). Human cerebral metabolic rate of oxygen (CMRO2) was also significantly reduced (F(1.26, 8.84)8.01, p = 0.016), as was the rat cerebral metabolic rate of glucose (CMRglu) (t = 2.6(16) p = 0.018). This was contrary to our hypothesis that MB will increase CBF and energy metrics. Nevertheless, our results were reproducible across species and dose dependent. One possible explanation is that the concentrations used, although clinically relevant, reflect MB's hormetic effects, i.e., higher concentrations produce inhibitory rather than augmentation effects on metabolism. Additionally, here we used healthy volunteers and healthy rats with normal cerebral metabolism where MB's ability to enhance cerebral metabolism might be limited.

Investigating brain alterations in the Dp1Tyb mouse model of Down syndrome

Down syndrome (DS) is one of the most common birth defects and the most prevalent genetic form of intellectual disability. DS arises from trisomy of chromosome 21, but its molecular and pathological consequences are not fully understood. In this study, we compared Dp1Tyb mice, a DS model, against their wild-type (WT) littermates of both sexes to investigate the impact of DS-related genetic abnormalities on the brain phenotype. We performed in vivo whole brain magnetic resonance imaging (MRI) and hippocampal 1H magnetic resonance spectroscopy (MRS) on the animals at 3 months of age. Subsequently, ex vivo MRI scans and histological analyses were conducted post-mortem. Our findings unveiled the following neuroanatomical and biochemical alterations in the Dp1Tyb brains: a smaller surface area and a rounder shape compared to WT brains, with DS males also presenting smaller global brain volume compared with the counterpart WT. Regional volumetric analysis revealed significant changes in 26 out of 72 examined brain regions, including the medial prefrontal cortex and dorsal hippocampus. These alterations were consistently observed in both in vivo and ex vivo imaging data. Additionally, high-resolution ex vivo imaging enabled us to investigate cerebellar layers and hippocampal sub-regions, revealing selective areas of decrease and remodelling in these structures. An analysis of hippocampal metabolites revealed an elevation in glutamine and the glutamine/glutamate ratio in the Dp1Tyb mice compared to controls, suggesting a possible imbalance in the excitation/inhibition ratio. This was accompanied by the decreased levels of taurine. Histological analysis revealed fewer neurons in the hippocampal CA3 and DG layers, along with an increase in astrocytes and microglia. These findings recapitulate multiple neuroanatomical and biochemical features associated with DS, enriching our understanding of the potential connection between chromosome 21 trisomy and the resultant phenotype.

Mapping acute neuroinflammation in vivo with diffusion-MRI in rats given a systemic lipopolysaccharide challenge

It is becoming increasingly apparent that neuroinflammation plays a critical role in an array of neurological and psychiatric disorders. Recent studies have demonstrated the potential of diffusion MRI (dMRI) to characterize changes in microglial density and morphology associated with neuroinflammation, but these were conducted mostly ex vivo and/or in extreme, non-physiological animal models. Here, we build upon these studies by investigating the utility of well-established dMRI methods to detect neuroinflammation in vivo in a more clinically relevant animal model of sickness behavior. We show that diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) indicate widespread increases in diffusivity in the brains of rats given a systemic lipopolysaccharide challenge (n = 20) vs. vehicle-treated controls (n = 12). These diffusivity changes correlated with histologically measured changes in microglial morphology, confirming the sensitivity of dMRI to neuroinflammatory processes. This study marks a further step towards establishing a noninvasive indicator of neuroinflammation, which would greatly facilitate early diagnosis and treatment monitoring in various neurological and psychiatric diseases.

Erbb4 Deletion From Inhibitory Interneurons Causes Psychosis-Relevant Neuroimaging Phenotypes

BACKGROUND AND HYPOTHESIS

Converging lines of evidence suggest that dysfunction of cortical GABAergic inhibitory interneurons is a core feature of psychosis. This dysfunction is thought to underlie neuroimaging abnormalities commonly found in patients with psychosis, particularly in the hippocampus. These include increases in resting cerebral blood flow (CBF) and glutamatergic metabolite levels, and decreases in ligand binding to GABAA α5 receptors and to the synaptic density marker synaptic vesicle glycoprotein 2A (SV2A). However, direct links between inhibitory interneuron dysfunction and these neuroimaging readouts are yet to be established. Conditional deletion of a schizophrenia susceptibility gene, the tyrosine kinase receptor Erbb4, from cortical and hippocampal inhibitory interneurons leads to synaptic defects, and behavioral and cognitive phenotypes relevant to psychosis in mice.

STUDY DESIGN

Here, we investigated how this inhibitory interneuron disruption affects hippocampal in vivo neuroimaging readouts. Adult Erbb4 conditional mutant mice (Lhx6-Cre;Erbb4F/F, n = 12) and their wild-type littermates (Erbb4F/F, n = 12) were scanned in a 9.4T magnetic resonance scanner to quantify CBF and glutamatergic metabolite levels (glutamine, glutamate, GABA). Subsequently, we assessed GABAA receptors and SV2A density using quantitative autoradiography.

RESULTS

Erbb4 mutant mice showed significantly elevated ventral hippccampus CBF and glutamine levels, and decreased SV2A density across hippocampus sub-regions compared to wild-type littermates. No significant GABAA receptor density differences were identified.

CONCLUSIONS

These findings demonstrate that specific disruption of cortical inhibitory interneurons in mice recapitulate some of the key neuroimaging findings in patients with psychosis, and link inhibitory interneuron deficits to non-invasive measures of brain function and neurochemistry that can be used across species.

Pharmacological modulation of TSPO in microglia/macrophages and neurons in a chronic neurodegenerative model of prion disease

Neuroinflammation is an important component of many neurodegenerative diseases, whether as a primary cause or a secondary outcome. For that reason, either as diagnostic tools or to monitor progression and/or pharmacological interventions, there is a need for robust biomarkers of neuroinflammation in the brain. Mitochondrial TSPO (18 kDa Translocator protein) is one of few available biomarkers of neuroinflammation for which there are clinically available PET imaging agents. In this study, we further characterised neuroinflammation in a mouse model of prion-induced chronic neurodegeneration (ME7) including a pharmacological intervention via a CSF1R inhibitor. This was achieved by autoradiographic binding of the second-generation TSPO tracer, [3H]PBR28, along with a more comprehensive examination of the cellular contributors to the TSPO signal changes by immunohistochemistry. We observed regional increases of TSPO in the ME7 mouse brains, particularly in the hippocampus, cortex and thalamus. This increased TSPO signal was detected in the cells of microglia/macrophage lineage as well as in astrocytes, endothelial cells and neurons. Importantly, we show that the selective CSF1R inhibitor, JNJ-40346527 (JNJ527), attenuated the disease-dependent increase in TSPO signal, particularly in the dentate gyrus of the hippocampus, where JNJ527 attenuated the number of Iba1+ microglia and neurons, but not GFAP+ astrocytes or endothelial cells. These findings suggest that [3H]PBR28 quantitative autoradiography in combination with immunohistochemistry are important translational tools for detecting and quantifying neuroinflammation, and its treatments, in neurodegenerative disease. Furthermore, we demonstrate that although TSPO overexpression in the ME7 brains was driven by various cell types, the therapeutic effect of the CSF1R inhibitor was primarily to modulate TSPO expression in microglia and neurons, which identifies an important route of biological action of this particular CSF1R inhibitor and provides an example of a cell-specific effect of this type of therapeutic agent on the neuroinflammatory process.

Tissue optimization strategies for high-quality ex vivo diffusion imaging

Ex vivo diffusion imaging can be used to study healthy and pathological tissue microstructure in the rodent brain with high resolution, providing a link between in vivo MRI and ex vivo microscopy techniques. Major challenges for the successful acquisition of ex vivo diffusion imaging data however are changes in the relaxivity and diffusivity of brain tissue following perfusion fixation. In this study we address this question by examining the combined effects of tissue preparation factors that influence signal-to-noise ratio (SNR) and consequently image quality, including fixative concentration, contrast agent concentration and tissue rehydration time. We present an optimization strategy combining these factors to manipulate theT 1 andT 2 of fixed tissue and maximize SNR efficiency. We apply this strategy in the rat brain, for a diffusion-weighted spin echo protocol with TE = 27 ms on a 9.4 T scanner with a 39 mm volume coil and 660 mT/m 114 mm gradient insert. We used a reduced fixative concentration of 2% paraformaldehyde (PFA), rehydration time more than 20 days, 15 mM Gd-DTPA in perfusate and TR 250 ms. This resulted in a doubling of SNR and an increase in SNR per unit time of 135% in cortical grey matter and 88% in white matter compared with 4% PFA and no contrast agent. This improved SNR efficiency enabled the acquisition of excellent-quality high-resolution (78 μ m isotropic voxel size) diffusion data with b = 4000 s/mm2 , 30 diffusion directions and a field of view of 40 × 13 × 18 mm3 in less than 4 days. It was also possible to achieve comparable data quality for a standard resolution (150 μ m) diffusion dataset in 2 1 4 h. In conclusion, the tissue optimization strategy presented here may be used to improve SNR, increase spatial resolution and/or allow faster acquisitions in preclinical ex vivo diffusion MRI experiments.

Non-Invasive measurement of the cerebral metabolic rate of oxygen using MRI in rodents

Malfunctions of oxygen metabolism are suspected to play a key role in a number of neurological and psychiatric disorders, but this hypothesis cannot be properly investigated without an in-vivo non-invasive measurement of brain oxygen consumption. We present a new way to measure the Cerebral Metabolic Rate of Oxygen (CMRO2) by combining two existing magnetic resonance imaging techniques, namely arterial spin-labelling and oxygen extraction fraction mapping. This method was validated by imaging rats under different anaesthetic regimes and was strongly correlated to glucose consumption measured by autoradiography.

Non-Invasive measurement of the cerebral metabolic rate of oxygen using MRI in rodents

Malfunctions of oxygen metabolism are suspected to play a key role in a number of neurological and psychiatric disorders, but this hypothesis cannot be properly investigated without an in-vivo non-invasive measurement of brain oxygen consumption. We present a new way to measure the Cerebral Metabolic Rate of Oxygen (CMRO 2) by combining two existing magnetic resonance imaging techniques, namely arterial spin-labelling and oxygen extraction fraction mapping. This method was validated by imaging rats under different anaesthetic regimes and was strongly correlated to glucose consumption measured by autoradiography.

Non-Invasive measurement of the cerebral metabolic rate of oxygen using MRI in rodents

Malfunctions of oxygen metabolism are suspected to play a key role in a number of neurological and psychiatric disorders, but this hypothesis cannot be properly investigated without an in-vivo non-invasive measurement of brain oxygen consumption. We present a new way to measure the Cerebral Metabolic Rate of Oxygen (CMRO2) by combining two existing magnetic resonance imaging techniques, namely arterial spin-labelling and oxygen extraction fraction mapping. This method was validated by imaging rats under different anaesthetic regimes and was strongly correlated to glucose consumption measured by autoradiography.

Relevance of sleep and associated structural changes in GBA1 mouse to human rapid eye movement behavior disorder

Rapid eye movement (REM) sleep behaviour disorder (RBD) is a REM parasomnia that often predicts the later occurrence of alpha-synucleinopathies. Variants in the gene encoding for the lysosomal enzyme glucocerebrosidase, GBA, strongly increase the risk of RBD. In a GBA1-mouse model recently shown to mimic prodromal stages of α-synucleinopathy, we now demonstrate striking REM and NREM electroencephalographic sleep abnormalities accompanied by distinct structural changes in the more widespread sleep neurocircuitry.

GABAA and NMDA receptor density alterations and their behavioral correlates in the gestational methylazoxymethanol acetate model for schizophrenia

Hippocampal hyperactivity driven by GABAergic interneuron deficits and NMDA receptor hypofunction is associated with the hyperdopaminergic state often observed in schizophrenia. Furthermore, previous research in the methylazoxymethanol acetate (MAM) rat model has demonstrated that repeated peripubertal diazepam administration can prevent the emergence of adult hippocampal hyperactivity, dopamine-system hyperactivity, and associated psychosis-relevant behaviors. Here, we sought to characterize hippocampal GABAA and NMDA receptors in MAM-treated rats and to elucidate the receptor mechanisms underlying the promising effects of peripubertal diazepam exposure. Quantitative receptor autoradiography was used to measure receptor density in the dorsal hippocampus CA1, ventral hippocampus CA1, and ventral subiculum. Specifically, [3H]-Ro15-4513 was used to quantify the density of α5GABAA receptors (α5GABAAR), [3H]-flumazenil to quantify α1-3;5GABAAR, and [3H]-MK801 to quantify NMDA receptors. MAM rats exhibited anxiety and schizophrenia-relevant behaviors as measured by elevated plus maze and amphetamine-induced hyperlocomotion (AIH), although diazepam only partially rescued these behaviors. α5GABAAR density was reduced in MAM-treated rats in all hippocampal sub-regions, and negatively correlated with AIH. Ventral hippocampus CA1 α5GABAAR density was positively correlated with anxiety-like behavior. Dorsal hippocampus CA1 NMDA receptor density was increased in MAM-treated rats, and positively correlated with AIH. [3H]-flumazenil revealed no significant effects. Finally, we found no significant effect of diazepam treatment on receptor densities, potentially related to the only partial rescue of schizophrenia-relevant phenotypes. Overall, our findings provide first evidence of α5GABAAR and NMDA receptor abnormalities in the MAM model, suggesting that more selective pharmacological agents may become a novel therapeutic mechanism in schizophrenia.

Age-Specific Adult Rat Brain MRI Templates and Tissue Probability Maps

Age-specific resources in human MRI mitigate processing biases that arise from structural changes across the lifespan. There are fewer age-specific resources for preclinical imaging, and they only represent developmental periods rather than adulthood. Since rats recapitulate many facets of human aging, it was hypothesized that brain volume and each tissue's relative contribution to total brain volume would change with age in the adult rat. Data from a longitudinal study of rats at 3, 5, 11, and 17 months old were used to test this hypothesis. Tissue volume was estimated from high resolution structural images using a priori information from tissue probability maps. However, existing tissue probability maps generated inaccurate gray matter probabilities in subcortical structures, particularly the thalamus. To address this issue, gray matter, white matter, and CSF tissue probability maps were generated by combining anatomical and signal intensity information. The effects of age on volumetric estimations were then assessed with mixed-effects models. Results showed that herein estimation of gray matter volumes better matched histological evidence, as compared to existing resources. All tissue volumes increased with age, and the tissue proportions relative to total brain volume varied across adulthood. Consequently, a set of rat brain templates and tissue probability maps from across the adult lifespan is released to expand the preclinical MRI community's fundamental resources.

MRI-guided histology of TDP-43 knock-in mice implicates parvalbumin interneuron loss, impaired neurogenesis and aberrant neurodevelopment in amyotrophic lateral sclerosis-frontotemporal dementia

Amyotrophic lateral sclerosis and frontotemporal dementia are overlapping diseases in which MRI reveals brain structural changes in advance of symptom onset. Recapitulating these changes in preclinical models would help to improve our understanding of the molecular causes underlying regionally selective brain atrophy in early disease. We therefore investigated the translational potential of the TDP-43Q331K knock-in mouse model of amyotrophic lateral sclerosis-frontotemporal dementia using MRI. We performed in vivo MRI of TDP-43Q331K knock-in mice. Regions of significant volume change were chosen for post-mortem brain tissue analyses. Ex vivo computed tomography was performed to investigate skull shape. Parvalbumin neuron density was quantified in post-mortem amyotrophic lateral sclerosis frontal cortex. Adult mutants demonstrated parenchymal volume reductions affecting the frontal lobe and entorhinal cortex in a manner reminiscent of amyotrophic lateral sclerosis-frontotemporal dementia. Subcortical, cerebellar and brain stem regions were also affected in line with observations in pre-symptomatic carriers of mutations in C9orf72, the commonest genetic cause of both amyotrophic lateral sclerosis and frontotemporal dementia. Volume loss was also observed in the dentate gyrus of the hippocampus, along with ventricular enlargement. Immunohistochemistry revealed reduced parvalbumin interneurons as a potential cellular correlate of MRI changes in mutant mice. By contrast, microglia was in a disease activated state even in the absence of brain volume loss. A reduction in immature neurons was found in the dentate gyrus, indicative of impaired adult neurogenesis, while a paucity of parvalbumin interneurons in P14 mutant mice suggests that TDP-43Q331K disrupts neurodevelopment. Computerized tomography imaging showed altered skull morphology in mutants, further suggesting a role for TDP-43Q331K in development. Finally, analysis of human post-mortem brains confirmed a paucity of parvalbumin interneurons in the prefrontal cortex in sporadic amyotrophic lateral sclerosis and amyotrophic lateral sclerosis linked to C9orf72 mutations. Regional brain MRI changes seen in human amyotrophic lateral sclerosis-frontotemporal dementia are recapitulated in TDP-43Q331K knock-in mice. By marrying in vivo imaging with targeted histology, we can unravel cellular and molecular processes underlying selective brain vulnerability in human disease. As well as helping to understand the earliest causes of disease, our MRI and histological markers will be valuable in assessing the efficacy of putative therapeutics in TDP-43Q331K knock-in mice.

Non-Invasive measurement of the cerebral metabolic rate of oxygen using MRI in rodents

Malfunctions of oxygen metabolism are suspected to play a key role in a number of neurological and psychiatric disorders, but this hypothesis cannot be properly investigated without an in-vivo non-invasive measurement of brain oxygen consumption. We present a new way to measure the Cerebral Metabolic Rate of Oxygen (CMRO2) by combining two existing magnetic resonance imaging techniques, namely arterial spin-labelling and oxygen extraction fraction mapping. This method was validated by imaging rats under different anaesthetic regimes and was strongly correlated to glucose consumption measured by autoradiography.

Time to re-engage psychiatric drug discovery by strengthening confidence in preclinical psychopharmacology

BACKGROUND

There is urgent need for new medications for psychiatric disorders. Mental illness is expected to become the leading cause of disability worldwide by 2030. Yet, the last two decades have seen the pharmaceutical industry withdraw from psychiatric drug discovery after costly late-stage trial failures in which clinical efficacy predicted pre-clinically has not materialised, leading to a crisis in confidence in preclinical psychopharmacology.

METHODS

Based on a review of the relevant literature, we formulated some principles for improving investment in translational neuroscience aimed at psychiatric drug discovery.

RESULTS

We propose the following 8 principles that could be used, in various combinations, to enhance CNS drug discovery: (1) consider incorporating the NIMH Research Domain Criteria (RDoC) approach; (2) engage the power of translational and systems neuroscience approaches; (3) use disease-relevant experimental perturbations; (4) identify molecular targets via genomic analysis and patient-derived pluripotent stem cells; (5) embrace holistic neuroscience: a partnership with psychoneuroimmunology; (6) use translational measures of neuronal activation; (7) validate the reproducibility of findings by independent collaboration; and (8) learn and reflect. We provide recent examples of promising animal-to-human translation of drug discovery projects and highlight some that present re-purposing opportunities.

CONCLUSIONS

We hope that this review will re-awaken the pharma industry and mental health advocates to the opportunities for improving psychiatric pharmacotherapy and so restore confidence and justify re-investment in the field.

Projecting effects of land use change on human well-being through changes in ecosystem services

Changing patterns of land use, temperature, and precipitation are expected to impact ecosystem services, including water quality and quantity, buffering of extreme events, soil quality, and biodiversity. Scenario analyses that link such impacts on ecosystem services to human well-being may be valuable in anticipating potential consequences of change that are meaningful to people living in a community. Ecosystem services provide numerous benefits to community well-being, including living standards, health, cultural fulfillment, education, and connection to nature. Yet assessments of impacts of ecosystem services on human well-being have largely focused on human health or monetary benefits (e.g. market values). This study applies a human well-being modelling framework to demonstrate the potential impacts of alternative land use scenarios on multi-faceted components of human well-being through changes in ecosystem services (i.e., ecological benefits functions). The modelling framework quantitatively defines these relationships in a way that can be used to project the influence of ecosystem service flows on indicators of human well-being, alongside social service flows and economic service flows. Land use changes are linked to changing indicators of ecosystem services through the application of ecological production functions. The approach is demonstrated for two future land use scenarios in a Florida watershed, representing different degrees of population growth and environmental resource protection. Increasing rates of land development were almost universally associated with declines in ecosystem services indicators and associated indicators of well-being, as natural ecosystems were replaced by impervious surfaces that depleted the ability of ecosystems to buffer air pollutants, provide habitat for biodiversity, and retain rainwater. Scenarios with increases in indicators of ecosystem services, however, did not necessarily translate into increases in indicators of well-being, due to covarying changes in social and economic services indicators. The approach is broadly transferable to other communities or decision scenarios and serves to illustrate the potential impacts of changing land use on ecosystem services and human well-being.

Does the time from diagnostic biopsy to neoadjuvant chemotherapy affect the rate of pathologic complete response in stages I-III breast cancer?

Background

Studies in the adjuvant setting suggest that the timing of breast cancer diagnosis, surgery, and chemotherapy might affect outcomes. In the neoadjuvant setting, data exploring whether expeditious neoadjuvant chemotherapy (nac) after diagnosis improves the rate of pathologic complete response (pcr) in breast cancer are limited.

Methods

Patients who received nac and completed treatment between May 2012 and December 2018 were identified from a prospectively collected database at BC Cancer. Time from diagnosis to start of nac was calculated. Patients were grouped into those who did and did not experience a pcr, and those who started nac within 28 days or after 28 days [time to nac (ttn)]. The association between pcr and ttn was tested using logistic regression.

Results

In the time period studied, 482 patients who received nac were identified. After exclusions, 421 patients met the eligibility criteria. Median time from biopsy to chemotherapy was 33 days (range: 7-140 days). In 149 patients (35.4%), nac was received within 28 days of diagnosis (range: 7-28 days); in 272 patients (64.6%), it was received after more than 28 days (range: 29-140 days). The overall pcr rate was 31.8%. A trend toward a higher pcr rate, although not statistically significant, was observed in the group that initiated chemotherapy within 28 days (34.2% vs. 30.5%, p = 0.43). In the logistic regression model, rates of pcr were associated with receptor status, but not age, stage, or ttn.

Conclusions

In the neoadjuvant setting, we observed no difference in the rate of pcr in patients who started nac within 28 days or after 28 days.

Update on Systemic Therapy for Advanced Soft Tissue Sarcoma

Background: Soft tissue sarcoma (STS) is a rare group of mesenchymal neoplasms which contains over 50 heterogenous subtypes.  There have been great efforts to increase the understanding of treatment of advanced STS (unresectable or metastatic disease). We wished to determine if outcomes for patients with advanced STS have improved over time, and to assess the current evidence for systemic therapy. Methods: We performed a scoping review to evaluate the contemporary evidence for systemic treatment of advanced soft tissue in adults (>18 years old). Phase I, II, and III studies of systemic therapy for advanced STS published in the English language were included. After abstract and full text review of 77 studies, 62 trials met inclusion criteria.  Results: The number of clinical trials conducted and published in advanced STS has increased over the last 30 years. Although median OS has increased, attempts at improving first line therapy through dose intensification, doublet chemotherapy or alternative backbones have not been successful. The optimal therapy beyond anthracyclines remains a challenge, especially given the inherent heterogeneity of grouping multiple STS subtypes within clinical trials. However, increasing numbers of agents are being studied and several studies had shown isolated PFS or OS benefit.  Conclusions: First line anthracycline systemic therapy remains the standard of care for advanced STS.  However, choice of subsequent therapy beyond anthracyclines remains challenging. Novel systemic therapies, using molecular diagnostics to direct therapy, subtype specific trials and learning from real world retrospective data are all important in improving outcomes for patients with advanced STS.

Update on systemic therapy for advanced soft-tissue sarcoma

Background

Soft-tissue sarcoma (sts) represents a rare group of mesenchymal neoplasms comprising more than 50 heterogeneous subtypes. Great efforts have been made to increase the understanding of the treatment of advanced sts (unresectable or metastatic disease). We set out to determine whether outcomes for patients with advanced sts have improved over time and to assess the current evidence for systemic therapy.

Methods

In a scoping review, we evaluated the contemporary evidence for systemic treatment of advanced sts in adults (>18 years of age). Phase i, ii, and iii studies of systemic therapy for advanced sts published in the English language were included. After abstract and full-text review of seventy-seven studies, sixty-two trials met the inclusion criteria.

Results

The number of clinical trials conducted and published in advanced sts has increased over the last 30 years. Although median overall survival has increased, attempts at improving first-line therapy through dose intensification, doublet chemotherapy, or alternative backbones have not been successful. The optimal therapy beyond anthracyclines remains a challenge, especially given the heterogeneity that grouping multiple sts subtypes within clinical trials creates. However, increasing numbers of agents are being studied, and several studies had shown isolated benefit in progression-free or overall survival.

Summary

First-line systemic therapy with an anthracycline remains the standard of care for advanced sts. However, choice of subsequent therapy beyond anthracyclines remains challenging. Novel systemic therapies, use of molecular diagnostics to direct therapy, subtype-specific trials, and learnings from real-world retrospective data are all important for improving outcomes in patients with advanced sts.

Evolving Practice Patterns Over Two Decades (1993-2013) in the Management of Desmoid-type Fibromatosis in British Columbia

AIMS

Due to the rarity and varied natural history of desmoid-type fibromatosis, evidence-based treatment standards for this disease remain lacking. This study evaluated outcomes in patients with desmoid-type fibromatosis managed at a Canadian institution over two decades.

MATERIALS AND METHODS

Records of 227 patients with desmoid-type fibromatosis referred from 1990 to 2013 were retrospectively reviewed to investigate management strategies including active surveillance, surgery, radiation therapy, cryoablation, and systemic therapy, including tamoxifen and chemotherapy.

RESULTS

Thirty-two per cent of cases were men, median age 40 years, median tumour size 5.4 cm. Initial treatments were surgery (79%), tamoxifen (13%), radiation therapy (5.0%), chemotherapy (1.8%) and cryoablation (1.2%). Active surveillance was used upfront in 26% of cases, most after 2005. At a median follow-up of 77 months, one patient died of disease, 13 died of unrelated causes and the remainder were alive with no evidence of disease (56%), stable/responding disease (33%) or progressive disease (4%). The recurrence rate was 25% after upfront surgery. Response rates and disease control rates were 40% and 76% for active surveillance; 68% and 96% for radiation therapy; 31% and 67% for tamoxifen; and 53% and 80% for chemotherapy. On univariable analysis, factors associated with a higher recurrence after initial surgery were young age (P = 0.012), male gender (P = 0.012) and extremity location (P = 0.005). On multivariable analysis, only young age was significantly associated with recurrence risk (P = 0.010).

CONCLUSIONS

Active surveillance was associated with spontaneous regression and long-term disease control consistent with other studies. Primary radiation therapy appeared to provide a similar response and disease control compared with systemic treatments and may be a viable option for patients who are not candidates for surgery or active surveillance.

Sarm1 deletion suppresses TDP-43-linked motor neuron degeneration and cortical spine loss

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative condition that primarily affects the motor system and shares many features with frontotemporal dementia (FTD). Evidence suggests that ALS is a 'dying-back' disease, with peripheral denervation and axonal degeneration occurring before loss of motor neuron cell bodies. Distal to a nerve injury, a similar pattern of axonal degeneration can be seen, which is mediated by an active axon destruction mechanism called Wallerian degeneration. Sterile alpha and TIR motif-containing 1 (Sarm1) is a key gene in the Wallerian pathway and its deletion provides long-term protection against both Wallerian degeneration and Wallerian-like, non-injury induced axonopathy, a retrograde degenerative process that occurs in many neurodegenerative diseases where axonal transport is impaired. Here, we explored whether Sarm1 signalling could be a therapeutic target for ALS by deleting Sarm1 from a mouse model of ALS-FTD, a TDP-43Q331K, YFP-H double transgenic mouse. Sarm1 deletion attenuated motor axon degeneration and neuromuscular junction denervation. Motor neuron cell bodies were also significantly protected. Deletion of Sarm1 also attenuated loss of layer V pyramidal neuronal dendritic spines in the primary motor cortex. Structural MRI identified the entorhinal cortex as the most significantly atrophic region, and histological studies confirmed a greater loss of neurons in the entorhinal cortex than in the motor cortex, suggesting a prominent FTD-like pattern of neurodegeneration in this transgenic mouse model. Despite the reduction in neuronal degeneration, Sarm1 deletion did not attenuate age-related behavioural deficits caused by TDP-43Q331K. However, Sarm1 deletion was associated with a significant increase in the viability of male TDP-43Q331K mice, suggesting a detrimental role of Wallerian-like pathways in the earliest stages of TDP-43Q331K-mediated neurodegeneration. Collectively, these results indicate that anti-SARM1 strategies have therapeutic potential in ALS-FTD.

CSF1R inhibitor JNJ-40346527 attenuates microglial proliferation and neurodegeneration in P301S mice

Neuroinflammation and microglial activation are significant processes in Alzheimer's disease pathology. Recent genome-wide association studies have highlighted multiple immune-related genes in association with Alzheimer's disease, and experimental data have demonstrated microglial proliferation as a significant component of the neuropathology. In this study, we tested the efficacy of the selective CSF1R inhibitor JNJ-40346527 (JNJ-527) in the P301S mouse tauopathy model. We first demonstrated the anti-proliferative effects of JNJ-527 on microglia in the ME7 prion model, and its impact on the inflammatory profile, and provided potential CNS biomarkers for clinical investigation with the compound, including pharmacokinetic/pharmacodynamics and efficacy assessment by TSPO autoradiography and CSF proteomics. Then, we showed for the first time that blockade of microglial proliferation and modification of microglial phenotype leads to an attenuation of tau-induced neurodegeneration and results in functional improvement in P301S mice. Overall, this work strongly supports the potential for inhibition of CSF1R as a target for the treatment of Alzheimer's disease and other tau-mediated neurodegenerative diseases.

Abstract P1-13-02: Real world outcomes of adjuvant FECD, ddACT and ACT for the treatment of early stage breast cancer - A multicenter retrospective analysis

Background: Adjuvant chemotherapy combining anthracyclines and taxanes for early stage breast cancer (ESBC) have demonstrated disease-free survival (DFS) and overall survival (OS) benefits. Among the 3rd generation regimens, 2 options have been favoured: FEC-Docetaxel (FECD) and AC-Paclitaxel (ACT). ACT may be delivered with dose-dense (ddACT) or weekly taxane scheduling (ddACWT), compared to traditional every 3-weekly (q3ACT) scheduling. Despite literature supporting both FECD and (dd)ACT regimens in the management of ESBC, no direct prospective trial has evaluated their comparative effectiveness.

Methods: A retrospective review of the BC Cancer Breast Cancer Outcomes Unit (BCOU) and the Alberta Health Services (AHS) databases was performed to identify patients with HER2 negative, stage 1-3 ESBC, who received adjuvant chemotherapy between 2007-2014. The primary endpoint was OS and the secondary endpoint was RFS, defined as freedom from local (invasive), regional or distant recurrence or breast cancer death. Outcome comparisons were made between FECD, ddACT/ddACWT and q3ACT using the Kaplan Meier method. Treatment arms were compared using a log-rank test for univariate analysis. A multivariate analysis was also conducted for OS comprising age, stage, grade, receptor status and type of chemotherapy received (FECD vs combined ACT group).

Results: A total of 4047 patients met inclusion criteria, including 2685 FECD, 1259 ddACT and 103 ACT. Median age was 53 (24-77) in the FECD group vs 52 (26-68) in the ddACT/ddACWT group and 58 (43-78) in the q3ACT group. The majority had stage 2 disease, 51.3%, 53.5% and 50.5% in the FECD, ddACT/ddACWT and q3ACT groups, respectively. Most were HR+, 84.5% in the FECD group vs 66.9% in both the ddACT/ddACWT and q3ACT groups. In the FECD group, 42.8% had a grade 2 tumour and 48.2% a grade 3 tumour vs 35.4% and 56.4% in the ddACT/ddACWT group and 35.0% and 58.3% in the q3ACT group. Lymphovascular invasion (LVI) was present in 40.7% of patients who received FECD vs 39.7% for ddACT/ddACWT and 26.2% for ACT. 5-year OS, for the FECD group was 90.3% (95%CI 89.1,91.4) vs 87.0% (95%CI 84.3,89.2) for the ddACT/ddACWT and 84.9% (95%CI 75.5,90.8) for the q3ACT groups, p=0.0907. 5-year RFS was 85.5% (95%CI 84.0-86.8) with FECD vs 84.4% (95% 81.9,86.6) for ddACT/ddACWT and 87.7% (95%CI 79.2,92.8) with q3ACT,p=0.4200. In multivariate analysis: age, stage and grade were significantly associated with OS whereas type of chemotherapy received (FECD vs ACT) was not (p=0.165). Finally, OS rates were compared across provinces and no significant differences were identified, 87.0% vs 88.0% (p=0.6294). Subgroup analyses by receptor type, comparing HR+ and TNBC are ongoing.

Conclusions: The use of FECD as compared to ACT based chemotherapy did not reveal significant differences in OS or RFS in this population-based study. Further, chemotherapy regimen was not associated with differences in overall survival, as compared to other well recognized prognostic factors. While the results were obtained from a retrospective analysis, conclusive prospective data is lacking. These results may therefore reassure physicians and patients alike on a comparable efficacy of these regimens in a real-life setting.

Citation Format: LeVasseur N, Veitch Z, Diocee RM, Gondara L, Cheung W, Khan O, Cossetti R, Gelmon KA, King K, Lupichuk S, Chia SK, Tang P, Simmons C. Real world outcomes of adjuvant FECD, ddACT and ACT for the treatment of early stage breast cancer - A multicenter retrospective analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-13-02.

Abstract P6-16-09: What research questions matters most to patients? Final results of the metastatic breast cancer priority setting partnership

Background: Research is fundamental to the management of cancer, however many studies are primarily researcher or industry led, with minimal input and involvement from the people most affected by the outcomes- the patients and caregivers. The James Lind Alliance (JLA) is a not for profit initiative that brings patients, caregivers and clinicians together in priority setting partnerships (PSPs) to determine key priorities in research. Breast cancer remains the most common cancer among women, with an estimated third of women diagnosed developing metastatic disease. With advances in treatment, women are living longer with metastatic breast cancer (MBC), in some cases many years. Objectives: The aims of this study are to utilize the JLA approach to (1) identify the unanswered questions about treatment of MBC from patient and clinical perspectives, and (2) to prioritize those that patients and clinicians agree are the most important. Methods: Following the established JLA approach, MBC patients, caregivers, and health professionals were surveyed to elicit their questions pertaining to MBC. Research questions were generated from the survey responses, and following literature review that the questions were currently not completely answered, an interim prioritization survey was conducted to identify a shortlist of questions to take to a final consensus meeting. Results: One thousand, one-hundred and ninety-four responses were collected from 668 individuals(49% patients; 13% physicians; 9% caregivers; 4% allied health care professionals; 2% patient organization representatives; 23% other), which were refined into 62 unique unanswered research questions. The interim prioritization survey was completed by 174 individuals, and the top 27 questions were taken to a final meeting where MBC patients, caregivers, and health care professionals prioritized all the questions, and reached consensus on the top 10. Conclusion: The top 10 questions cover a wide range of research questions, identified by valuable stakeholders as being priorities. These priorities can be used to fund and inform future MBC research.

List of final top 10 ranked prioritiesRankQuestion1What biomarkers or intrinsic features of the tumour can be used to identify response to specific treatments and dosing schedules?2What is the role of immunotherapy for MBC?3How can treatment resistance be delayed and minimized?4What causes (i.e. cellular, genomic) breast cancer cells to metastasize, and what changes allow them to penetrate the blood brain barrier?5What is the right sequence of therapy in MBC?6Does local therapy (radiation or surgery to sites of metastatic disease) improve survival outcomes in MBC?7Is continuous treatment with systemic therapy (including HER2-targeted therapy and chemotherapy) better than intermittent?8Does early palliative care improve outcomes for MBC patients?9What are the best methods of education for patients around treatment options and decision making that can lead to improved patient outcomes?10Can safer, more accurate methods, including blood tests of detecting spread of disease (including following curative treatment) be developed?

Citation Format: Nixon NA, Simmons C, Lemieux J, Verma S. What research questions matters most to patients? Final results of the metastatic breast cancer priority setting partnership [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-16-09.

Abstract P5-13-04: Needle-to-knife wait time and impact on pCR in patients undergoing neoadjuvant chemotherapy for breast cancer

Introduction: In the setting of pre-operative neoadjuvant chemotherapy (NAC) for the treatment of breast cancer, it is important to ensure coordination between medical and surgical oncology. A study by Sanford et al. show that patients receiving surgery >8 weeks after NAC have worse overall survival. As NAC continues to expand its role in breast cancer treatment, a closer look at the maximal acceptable time between NAC and surgery becomes more important. We wished to assess the impact of time between last dose of chemotherapy and surgery on pathological complete response (pCR), disease free survival (DFS), overall survival (OS), and surgical complications.

Methods: A cohort study was conducted utilizing the BC Cancer Agency's prospective neoadjuvant database, located in Vancouver, BC. Patients were selected if they had undergone NAC with curative intent for treatment of breast cancer, followed by surgical resection. Patients who received neoadjuvant radiation and/or hormone therapy were excluded. Patients were divided into three groups: those who had surgery <4 weeks from last dose of chemo, 4-8 weeks from last dose, and >8 weeks from last dose. Charts were audited for demographic data, tumour characteristics, and complications from surgery. Data was analyzed using a Chi Squared test to determine any differences in pCR, OS, DFS, and surgical complications, between the three different time intervals.

Results: 347 patients were identified and included in this study. The median time to surgery after last dose of chemotherapy was 4.86 weeks (range 0.86-22.86 weeks). The percentage of patients that achieved pCR was 31.3%, 30.5%, and 28.6% in the <4 weeks, 4-8 weeks, and >8 weeks groups respectively (p= NS for all comparisons). There was no difference in pCR observed between the three groups based on receptor status. At the median follow up of 3 years, DFS was 85%, 85.8%, and 85.7% in all three groups. Likewise OS was 95%, 90%, and 89% respectively. The rate of surgical complications are 16%, 23.4%, and 21.4% for the three groups respectively (p=NS).

Conclusions: This study demonstrated no difference between receiving surgery <4 weeks, 4-8 weeks, or >8 weeks after last dose of NAC on pCR, survival, or surgical complications. This finding was preserved in all receptor subtypes. This has important implications for resource allocation. This data may also help in counselling and easing patient anxiety in terms of the urgency (or lack thereof) and wait times for surgery. Subsequent studies with larger sample sizes will help to ensure that clinical differences in outcomes are not affected by wait times.

Comparison of outcome measures based on needle to knife time < 4 weeks (n=80)4-8 weeks (n=239)>8weeks (n=28)p (<4 weeks vs. < 8 weeks)pCR31.3% (25)30.5% (73)28.6% (8)0.791HR+Her2-4.5% (1/22)6.5% (6/92)0% (0/5)--TNBC31.5% (6/19)42.1% (24/57)0% (0/6)--Her2+46.1% (18/39)48.8% (44/90)47.1% (8/17)--3 year DFS85%85.5%85.7%0.9273 year OS95%90%89%0.290Surgical Complication16.3%23.4%21.4%0.536

Citation Format: Lai V, Hajjaj O, Chia S, Simmons C. Needle-to-knife wait time and impact on pCR in patients undergoing neoadjuvant chemotherapy for breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-13-04.

Abstract P4-08-27: The 21-gene Recurrence® (RS) Score assay in estrogen receptor positive node negative breast cancer: Real-world chemotherapy usage and patient characteristics within the intermediate and high-risk RS category

Background:

The Oncotype Dx, a 21-gene recurrence score (RS) assay, has been validated as a prognostic tool in early-stage, hormone receptor-positive, HER2-negative breast cancer. A RS of ≥ 31 is predictive for chemotherapy benefit. However, it has not been clearly established whether more intensive chemotherapy regimens for these patients provide further benefit and whether higher RS stratifications (≥41) influence treatment decisions.

Methods:

From the prospective British Columbia (BC) Breast Cancer Outcomes Unit database, we identified patients with N0 disease who received Oncotype Dx testing from May 2010 to December 2016. Patients with previous or synchronous breast cancer, and patients treated with neoadjuvant chemotherapy were excluded. Groups were defined that had an Oncotype Dx RS of 31-40 and ≥ 41. Demographic characteristics and type of chemotherapy received were collected. Additional subgroups were defined for patients who had a RS of 21-25 and who were ≤ 50 years old and > 50 years old.

Results:

We identified 1,202 patients who received Oncotype Dx testing over the time period studied, with 14.8% (n=178) having a RS of ≥ 31. Among these high-risk patients, the median age was 58 (range 34-79), 90% received hormonal therapy and 85% received chemotherapy. In this cohort, 46% received docetaxel and cyclophosphamide for 4 cycles and 28% received 3rd generation chemotherapy. The use of 3rd generation chemotherapy in patients with a RS of ≥ 41 was significantly higher than in patients with RS between 31-40 (39% vs 22%, p = 0.006). Among patients who had a RS of 21-25 and who were ≤ 50 years old (n = 49), 53% received chemotherapy. Of patients who had a RS of 21-25 and who were > 50 years old (n = 127), 16% received chemotherapy.

Conclusions:

Among patients with a RS ≥ 31, decisions regarding chemotherapy usage were heterogeneous with docetaxel and cyclophosphamide for 4 cycles being the most commonly used regimen. However, in those with a RS ≥ 41, 3rd generation chemotherapy was preferred. Patients with a RS between 21-25 and who were ≤ 50 years old received more chemotherapy than patients who were > 50 years old.

 RS 31-40 (n=116)RS ≥ 41 (n=62)RS ≥ 31 (n=178)Median age58.0 (range, 36-79)57.5 (range 34-78)58.0 (range 34-79)Pre-menopausal28.4%29.0%28.7%Hormonal therapy93.1%83.9%89.9%Chemotherapy86.2%82.3%84.8%DCx4 (1)54.3% (n=63/116) Median age 59.0 (range, 36 – 78)30.6% (n=19/62) Median age 64.0 (range, 42 – 78)46.1% (n=82/178) Median age 59.5 (range, 36 – 78)3rd generation chemo (2)21.6% (n=25/116) Median age 56.0 (range, 39 – 79)38.7% (n=24/62) Median age 52.0 (range, 34 – 76)27.5% (n=49/178) Median age 54.0 (range, 34 – 79)Other chemo10.3% (n=12/116) Median age 57.5 (range, 52 – 78)12.9% (n=8/62) Median age 64.0 (range, 42 – 72)11.2% (n=20/178) Median age 58.5 (range, 42 – 78)(1) Docetaxel and cyclophosphamide, 4 cycles (2) Anthracycline and Taxane containing regimens, 6 cycles or 8 cycles

Citation Format: Le D, Chia S, Simmons C, Speers C, Gondara L, Nichol A, Lohrisch C, Gelmon KA. The 21-gene Recurrence® (RS) Score assay in estrogen receptor positive node negative breast cancer: Real-world chemotherapy usage and patient characteristics within the intermediate and high-risk RS category [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-27.

Intranasal midazolam and fentanyl for procedural sedation and analgesia in infants in the neonatal intensive care unit

BACKGROUND

The intranasal route is a minimally invasive method for rapidly delivering midazolam and fentanyl to provide short-term analgesia and sedation in infants. However, intranasal use of midazolam and fentanyl is not labeled for infants and safety data are sparse. The objective of this study is to evaluate the safety of intranasal midazolam and intranasal fentanyl in infants admitted to the Neonatal Intensive Care Unit (NICU).

METHODS

We retrospectively identified all infants receiving intranasal midazolam or fentanyl in the NICU from 2009 to 2015. We recorded indication for use and vital signs and determined the proportion of infants experiencing the following adverse events: death within 24 hours, hypotension, bradycardia, worsening respiratory status, and chest wall rigidity. Vital signs 4 hours before and after each dose were compared using the Wilcoxon signed-rank test.

RESULTS

We identified 17 infants (gestational ages 23- 41 weeks) receiving 25 intranasal doses. None of the infants died or developed hypotension, bradycardia, or chest wall rigidity. Intranasal delivery was most commonly used for sedation during magnetic resonance imaging studies. Other indications include analgesia or sedation for retinopathy of prematurity surgery, intubation, and peripherally inserted central catheter placement. One infant receiving intranasal midazolam experienced worsening respiratory status. Vital signs before and after dosing were not significantly different.

CONCLUSIONS

Intranasal midazolam and fentanyl use in term and preterm infants appeared safe and well-tolerated in this small cohort of infants. Larger, prospective studies evaluating the safety and efficacy of intranasal midazolam and fentanyl use in infants are warranted.

Stroke Recovery in Rats after 24-Hour-Delayed Intramuscular Neurotrophin-3 Infusion

Objective

Neurotrophin‐3 (NT3) plays a key role in the development and function of locomotor circuits including descending serotonergic and corticospinal tract axons and afferents from muscle and skin. We have previously shown that gene therapy delivery of human NT3 into affected forelimb muscles improves sensorimotor recovery after stroke in adult and elderly rats. Here, to move toward the clinic, we tested the hypothesis that intramuscular infusion of NT3 protein could improve sensorimotor recovery after stroke.

Methods

Rats received unilateral ischemic stroke in sensorimotor cortex. To simulate a clinically feasible time to treatment, 24 hours later rats were randomized to receive NT3 or vehicle by infusion into affected triceps brachii for 4 weeks using implanted catheters and minipumps.

Results

Radiolabeled NT3 crossed from the bloodstream into the brain and spinal cord in rodents with or without strokes. NT3 increased the accuracy of forelimb placement during walking on a horizontal ladder and increased use of the affected arm for lateral support during rearing. NT3 also reversed sensory impairment of the affected wrist. Functional magnetic resonance imaging during stimulation of the affected wrist showed spontaneous recovery of peri‐infarct blood oxygenation level–dependent signal that NT3 did not further enhance. Rather, NT3 induced neuroplasticity of the spared corticospinal and serotonergic pathways.

Interpretation

Our results show that delayed, peripheral infusion of NT3 can improve sensorimotor function after ischemic stroke. Phase I and II clinical trials of NT3 (for constipation and neuropathy) have shown that peripheral high doses are safe and well tolerated, which paves the way for NT3 as a therapy for stroke. ANN NEUROL 2019;85:32–46.

Neoadjuvant Therapy for Breast Cancer: Updates and Proceedings From the Seventh Annual Meeting of the Canadian Consortium for Locally Advanced Breast Cancer

Therapy for breast cancer involves a complex interplay of three main treatment modalities: surgery, systemic therapy, and radiation therapy. The Canadian Consortium for Locally Advanced Breast Cancer (LABC) was established with the goal to convene a strong multidisciplinary team of breast oncology clinicians and scientists who are dedicated to the advancement of LABC research and treatment, with a vision to drive progress through increased collaboration across disciplines and throughout Canada. The most recent meeting in May 2017 highlighted the latest evidence and literature about the optimal use of neoadjuvant systemic therapy in breast cancer. There is a need for increased clinical and scientific collaboration and the development of guidelines for the use of emerging treatment strategies. The interactive meeting sessions fostered unique opportunities for academic debate and nurtured collaboration between the attendees.

Assessing the feasibility of intranasal radiotracer administration for in brain PET imaging

Introduction

The development of clinically useful tracers for PET imaging is enormously challenging and expensive. The intranasal (IN) route of administration is purported to be a viable route for delivering drugs to the brain but has, as yet, not been investigated for the delivery of PET tracers. If the intranasal (IN) pathway presents a viable option, it extends the PET imaging field by increasing the number of tracers available for human use.

Here we report the results of a rodent study testing the feasibility of the IN route to administer radiotracers for brain PET imaging.

Methods

We used two different, well characterised, brain penetrant radiotracers, [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) and [¹⁸F]fallypride, and aimed to evaluate the pharmacokinetics after administration of the tracers via the intranasal route, and contrast this to intravenous administration. Image acquisition was carried out after tracer administration and arterial blood samples were collected at different time intervals, centrifuged to extract plasma and gamma counted. We hypothesised that [brain region]:[plasma] ratios would be higher via the intranasal route as there are two inputs, one directly from the nose to the brain, and another from the peripheral circulation. To assess the feasibility of using this approach clinically, we used these data to estimate radiation dosimetry in humans.

Results

Contrary to our hypothesis, in case of both radiotracers, we did not see a higher ratio in the expected brain regions, except in the olfactory bulb, that is closest to the nose. It appears that the radiotracers move into the olfactory bulb region, but then do not progress further into other brain regions. Moreover, as the nasal cavity has a small surface area, the extrapolated dosimetry estimations for intranasal human imaging showed an unacceptably high level (15 mSv/MBq) of cumulative skin radiation exposure.

Conclusions

Therefore, although an attractive route for brain permeation, we conclude that the intranasal route would present difficulties due to non-specific signal and radiation dosimetry considerations for brain PET imaging.

Abstract P4-11-01: Effects of high anxiety scores on surgical and overall treatment plan in breast cancer patients treated with neoadjuvant therapy

Introduction:

Anxiety is a common symptom in patients with newly diagnosed cancer. Patients with high levels of anxiety have been shown to choose more invasive surgeries in various cancer settings. Rates of contralateral prophylactic mastectomy in the adjuvant setting remain high, despite offering no survival advantage. In the neoadjuvant setting, patients have more time for decisions regarding final surgery. If anxiety is playing a role in their decisions, this could be addressed while on neoadjuvant therapy (NAT). However, the impact of anxiety at initial diagnosis on surgical decision making in this setting has not yet been studied.

Methods:

Data collected from a prospective institutional database of breast cancer patients treated with NAT at the British Columbia Cancer Agency (BCCA) were utilized to identify all patients. Information was extracted from this database with regards to patient and tumour characteristics, initial surgical plan, and final surgery performed. This was cross referenced with patient self-reported anxiety, which was extracted from the Edmonton Symptom Assessment System (ESAS) and the Psychosocial Screen for Cancer (PSSCAN) forms administered at initial consultation. Patients were assigned a score of 0 to 3 based on their answers to the ESAS anxiety scale and the PSSCAN anxiety questions, and whether or not they had any concerns related to their care. Patients were excluded if they had bilateral breast cancer, BRCA mutation or referral to the Hereditary Cancer Program, did not receive NAT or undergo breast surgery, or did not complete the forms. Fisher's exact tests were applied for statistical analysis.

Results:

From 2012-2016, 361 potential patients were identified for this study. A total of 203 patients met eligibility criteria. 93 patients (46%) had low anxiety (score 0 or 1) and 110 patients (54%) had high anxiety (score 2 or 3). Patients with high self-reported anxiety at initial consultation were significantly more likely to undergo bilateral mastectomy for unilateral disease and mastectomy for breast conserving surgery (BCS) eligible disease than those with low self-reported anxiety at initial consultation (37.3% VS 18.3%; p=0.003). No significant differences in treatment times (time interval between biopsy to chemotherapy, chemotherapy to surgery, and surgery to radiation) or investigations were identified when comparing high and low anxiety patients.

Anxiety level and type of surgery performedType of SurgeryAnxiety Level  Low (n=93)High (n=110) Bilateral Mastectomy and Mastectomy for BCS eligible disease17 (18.3%)41 (37.3%) BCS and Mastectomy for non-BCS eligible disease76 (81.7%)69 (62.7%)    p = 0.0031

Conclusion:

High anxiety scores lead to a 19% increase in bilateral mastectomies in patients without bilateral disease and mastectomies in patients eligible for BCS compared to patients with low anxiety (p = 0.003). These findings suggest that self-reported anxiety levels can inform and assist physicians to identify patients who are more likely to undergo aggressive surgery and may need further counselling and support services. Future work should examine the effects of counselling intervention in patients with high anxiety on surgical decisions.

Citation Format: Li H, Cheung W, Myers P, McKevitt E, Willemsma K, Deruchie Tan A, Chia S, Simmons C. Effects of high anxiety scores on surgical and overall treatment plan in breast cancer patients treated with neoadjuvant therapy [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 P4-11-01.

Abstract P5-19-07: Defining priorities for research: Interim results of the Canadian metastatic breast cancer priority setting partnership

Background: Research priorities are generally determined by funders and researchers without direct involvement and input from patients and caregivers. Certain disease areas have incorporated the patient voice to determine patient driven priorities. In this study, this approach was employed to better understand the needs and priorities of metastatic breast cancer patients and their caregivers.

Methods: This study was conducted using methodology outlined by the James Lind Alliance. A steering committee of patients, physicians, patient advocates, and allied health care professionals was assembled to oversee the research study. The initial survey collected unanswered research questions from patients, caregivers, and clinicians. Responses were collected and categorized by consensus of the steering committee. Here we present the results from the national survey.

Results: Between November 2016 and April 2017, 733 responses from 311 individuals were collected (62% patients, 11% physicians, 9% caregivers or relatives, 5% nurses/allied health professionals, 2% patient organization representatives, and 10% other). The main themes for key patient priorities are: 136 (19%) related to treatment and monitoring, 78 (11%) linked lifestyle and alternative therapy, 58 (8%) regarded tumour biology, 53 (7%) regarded psychosocial aspects, 46 (6%) to diagnosis, 35 (5%) to toxicity, 24 (3%) to prevention, and 17 (2%) to young or pre-menopausal population. Two hundred and eighty-six (39%) were considered out of scope. The most frequently identified priorities included the role of alternative therapies for improving survival, the role of immune therapy for treating metastatic breast cancer, and the potential for improving outcomes with early detection/surveillance with modern treatment and diagnostic modalities.

Conclusion: Patient derived research priorities in advanced breast cancer point to an improved understanding of alternative therapies, integration of immune therapy and a focus on early detection of relapse. These priorities should be addressed by the research community to meet the needs of our patients with advanced breast cancer.

Citation Format: Nixon N, Simmons C, Lemieux J, Verma S. Defining priorities for research: Interim results of the Canadian metastatic breast cancer priority setting partnership [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 P5-19-07.

Neoadjuvant systemic therapy in breast cancer: use and trends in radiotherapy practice

BACKGROUND

The use of neoadjuvant systemic therapy (nast) in the treatment of breast cancer is increasing, and the role of adjuvant radiation therapy (rt) in that setting is uncertain. We sought to review and report the use of nast, its trends over time, and its relationship with the prescribing patterns of locoregional rt in a provincial cancer system.

METHODS

Patients with stages i-iii breast cancer diagnosed during 2007-2012 were identified using a provincial database. Patient, tumour, and treatment characteristics were extracted. Multivariable logistic regression analyses were used to assess associations with the use of nast. Kaplan-Meier and Cox regression were used for survival analyses.

RESULTS

Of the 11,658 patients who met the inclusion criteria, 602 (5%) had received nast. Use of nast was more frequent in stage iii patients (53%) than in stages i and ii patients (2%). In clinically lymph-node positive patients, a pathology assessment was made approximately 50% of the time. Higher clinical tumour stage and increasing clinical nodal stage predicted for increasing use of nast and of nodal rt after nast, but pathologic nodal status after nast was not associated with use of nodal rt. A statistically significant survival difference was observed between patients in the nast and no-nast groups, but that significance disappeared in a multivariable Cox regression analysis.

CONCLUSIONS

This population-based study demonstrated 5% use of nast for breast cancer. Most patients received nodal rt after nast, and nodal rt was not associated with pathologic stage after nast. Findings likely reflect the realities of clinical practice and show that reliance on clinical nodal staging results in outcomes similar to those reported in the literature.

A randomized phase II study of weekly paclitaxel with or without pelareorep in patients with metastatic breast cancer: final analysis of Canadian Cancer Trials Group IND.213

BACKGROUND

Pelareorep, a serotype 3 reovirus, has demonstrated preclinical and early clinical activity in breast cancer and synergistic cytotoxic activity with microtubule targeting agents. This multicentre, randomized, phase II trial was undertaken to evaluate the efficacy and safety of adding pelareorep to paclitaxel for patients with metastatic breast cancer (mBC).

METHODS

Following a safety run-in of 7 patients, 74 women with previously treated mBC were randomized either to paclitaxel 80 mg/m² intravenously on days 1, 8, and 15 every 4 weeks plus pelareorep 3 × 10¹⁰ TCID₅₀ intravenously on days 1, 2, 8, 9, 15, and 16 every 4 weeks (Arm A) or to paclitaxel alone (Arm B). Primary endpoint was progression-free survival (PFS). Secondary endpoints were objective response rate, overall survival (OS), circulating tumour cell counts, safety, and exploratory correlative analyses. All comparisons used a two-sided test at an alpha level of 20%. Survival analyses were adjusted for prior paclitaxel.

RESULTS

Final analysis was performed after a median follow-up of 29.5 months. Pelareorep was well tolerated. Patients in Arm A had more favourable baseline prognostic variables. Median adjusted PFS (Arm A vs B) was 3.78 mo vs 3.38 mo (HR 1.04, 80% CI 0.76-1.43, P = 0.87). There was no difference in response rate between arms (P = 0.87). Median OS (Arm A vs B) was 17.4 mo vs 10.4 mo (HR 0.65, 80% CI 0.46-0.91, P = 0.1).

CONCLUSIONS

This first, phase II, randomized study of pelareorep and paclitaxel in previously treated mBC did not show a difference in PFS (the primary endpoint) or RR. However, there was a significantly longer OS for the combination. Further exploration of this regimen in mBC may be of interest.

Characterization of the resting-state brain network topology in the 6-hydroxydopamine rat model of Parkinson's disease

Resting-state functional MRI (rsfMRI) is an imaging technology that has recently gained attention for its ability to detect disruptions in functional brain networks in humans, including in patients with Parkinson's disease (PD), revealing early and widespread brain network abnormalities. This methodology is now readily applicable to experimental animals offering new possibilities for cross-species translational imaging. In this context, we herein describe the application of rsfMRI to the unilaterally-lesioned 6-hydroxydopamine (6-OHDA) rat, a robust experimental model of the dopamine depletion implicated in PD. Using graph theory to analyse the rsfMRI data, we were able to provide meaningful and translatable measures of integrity, influence and segregation of the underlying functional brain architecture. Specifically, we confirm that rats share a similar functional brain network topology as observed in humans, characterised by small-worldness and modularity. Interestingly, we observed significantly reduced functional connectivity in the 6-OHDA rats, primarily in the ipsilateral (lesioned) hemisphere as evidenced by significantly lower node degree, local efficiency and clustering coefficient in the motor, orbital and sensorimotor cortices. In contrast, we found significantly, and bilaterally, increased thalamic functional connectivity in the lesioned rats. The unilateral deficits in the cortex are consistent with the unilateral nature of this model and further support the validity of the rsfMRI technique in rodents. We thereby provide a methodological framework for the investigation of brain networks in other rodent experimental models of PD, as well as of animal models in general, for cross-comparison with human data.

Abstract P3-02-05: Does MRI influence surgical planning more than clinical outcome? A cohort study of breast cancer patients receiving neoadjuvant therapy

Background: While magnetic resonance imaging (MRI) is a powerful diagnostic tool, there is currently no consensus on its role for breast cancer patients prior to the initiation of neoadjuvant therapy (NAT). In the adjuvant setting, there is evidence that the use of MRI is correlated with an increase the rate of mastectomies performed. There is currently no data describing how MRI is influencing treatment decisions or surgical management in the neoadjuvant setting. This study aimed to determine the impact of MRI on patients' surgical plan, and to understand the demographic differences in patients who had an MRI compared to those that did not in the neoadjuvant setting.

Methods: A secure database containing all potential NAT patients seen by medical oncologists at the BC Cancer Agency Vancouver Centre since 2012 was searched. Breast cancer patients who were treated with NAT and had undergone breast surgery before March 30, 2016 were identified. Tumour characteristics, surgical plan and surgical outcome were assessed retrospectively and compared between patients who had an MRI and patients who did not have an MRI.

Results: 270 patients were identified who met the inclusion criteria. Of those, 107 patients had a breast MRI and 163 patients did not. The two groups showed no significant pre-treatment differences with regards to type of breast cancer, receptor status, or clinical stage. The median age was 10 years younger in the MRI group (47 years) compared to the non-MRI group (57 years), p < 0.0001. Patients who had an MRI had a non-significant higher rate of pathological complete response (pCR) than those who did not (30.8% and 21.5%, respectively, p=0.08). The surgical treatment did differ between these two groups; those who had MRI were more likely to have bilateral mastectomy (36.4% vs 23.3%, p=0.019) and less likely to have breast conserving surgery (BCS) (19.6% vs 31.9%, p=0.026). In the cohort that had an MRI, there was no significant difference in percentage of patients whose surgical plan was changed compared to the patients who did not have an MRI (33.6% and 28.8%, respectively). A change in surgical plan from a mastectomy to a BCS was more common in patients who did not have an MRI than those that did (31.9% and 13.9%, respectively). 45% of the surgeons who dictated a follow-up surgery consultation stated that the MRI was used to inform the surgical plan.

Discussions/Conclusions: In this real-world cohort, patients who had an MRI were more likely to undergo a bilateral mastectomy and less likely to have a BCS than the patients who did not have an MRI, despite having a higher rate of pCR. Age was the only baseline demographic difference between the two groups. These findings suggest that the role of MRI in the neoadjuvant setting needs to be refined further in order to avoid over-treatment.Background: While magnetic resonance imaging (MRI) is a powerful diagnostic tool, there is currently no consensus on its role for breast cancer patients prior to the initiation of neoadjuvant therapy (NAT). In the adjuvant setting, there is evidence that the use of MRI is correlated with an increase the rate of mastectomies performed. There is currently no data describing how MRI is influencing treatment decisions or surgical management in the neoadjuvant setting. This study aimed to determine the impact of MRI on patients' surgical plan, and to understand the demographic differences in patients who had an MRI compared to those that did not in the neoadjuvant setting.

Methods: A secure database containing all potential NAT patients seen by medical oncologists at the BC Cancer Agency Vancouver Centre since 2012 was searched. Breast cancer patients who were treated with NAT and had undergone breast surgery before March 30, 2016 were identified. Tumour characteristics, surgical plan and surgical outcome were assessed retrospectively and compared between patients who had an MRI and patients who did not have an MRI.

Results: 270 patients were identified who met the inclusion criteria. Of those, 107 patients had a breast MRI and 163 patients did not. The two groups showed no significant pre-treatment differences with regards to type of breast cancer, receptor status, or clinical stage. The median age was 10 years younger in the MRI group (47 years) compared to the non-MRI group (57 years), p < 0.0001. Patients who had an MRI had a non-significant higher rate of pathological complete response (pCR) than those who did not (30.8% and 21.5%, respectively, p=0.08). The surgical treatment did differ between these two groups; those who had MRI were more likely to have bilateral mastectomy (36.4% vs 23.3%, p=0.019) and less likely to have breast conserving surgery (BCS) (19.6% vs 31.9%, p=0.026). In the cohort that had an MRI, there was no significant difference in percentage of patients whose surgical plan was changed compared to the patients who did not have an MRI (33.6% and 28.8%, respectively). A change in surgical plan from a mastectomy to a BCS was more common in patients who did not have an MRI than those that did (31.9% and 13.9%, respectively). 45% of the surgeons who dictated a follow-up surgery consultation stated that the MRI was used to inform the surgical plan.

Discussions/Conclusions: In this real-world cohort, patients who had an MRI were more likely to undergo a bilateral mastectomy and less likely to have a BCS than the patients who did not have an MRI, despite having a higher rate of pCR. Age was the only baseline demographic difference between the two groups. These findings suggest that the role of MRI in the neoadjuvant setting needs to be refined further in order to avoid over-treatment.

Citation Format: McDermott M, Wilson C, Xu J, Illmann C, Simmons C. Does MRI influence surgical planning more than clinical outcome? A cohort study of breast cancer patients receiving neoadjuvant therapy [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 P3-02-05.

Whole-brain ex-vivo quantitative MRI of the cuprizone mouse model

Myelin is a critical component of the nervous system and a major contributor to contrast in Magnetic Resonance (MR) images. However, the precise contribution of myelination to multiple MR modalities is still under debate. The cuprizone mouse is a well-established model of demyelination that has been used in several MR studies, but these have often imaged only a single slice and analysed a small region of interest in the corpus callosum. We imaged and analyzed the whole brain of the cuprizone mouse ex-vivo using high-resolution quantitative MR methods (multi-component relaxometry, Diffusion Tensor Imaging (DTI) and morphometry) and found changes in multiple regions, including the corpus callosum, cerebellum, thalamus and hippocampus. The presence of inflammation, confirmed with histology, presents difficulties in isolating the sensitivity and specificity of these MR methods to demyelination using this model.

Impact of a palliative care program on end-of-life care in a neonatal intensive care unit

OBJECTIVE

Evaluate changes in end-of-life care following initiation of a palliative care program in a neonatal intensive care unit.

STUDY DESIGN

Retrospective study comparing infant deaths before and after implementation of a Palliative Care Program comprised of medication guidelines, an individualized order set, a nursing care plan and staff education.

RESULT

Eighty-two infants died before (Era 1) and 68 infants died after implementation of the program (Era 2). Morphine use was similar (88% vs 81%; P =0.17), whereas benzodiazepines use increased in Era 2 (26% vs 43%; P=0.03). Withdrawal of life support (73% vs 63%; P=0.17) and do-not-resuscitate orders (46% vs 53%; P=0.42) were similar. Do-not-resuscitate orders and family meetings were more frequent among Era 2 infants with activated palliative care orders (n=21) compared with infants without activated orders (n=47).

CONCLUSION

End-of-life family meetings and benzodiazepine use increased following implementation of our program, likely reflecting adherence to guidelines and improved communication.