Molecular pathology in the cancer clinic - where are we now and where are we headed?

Molecular pathology is a developing sub-microscopic discipline of pathology that studies the effects of molecular variations and mutations on disease processes. The ultimate goal of molecular pathology in cancer is to predict risk, facilitate diagnosis and improve prognostication based on a complete understanding of the biological impact of specific molecular variations, mutations and dysregulations. This knowledge will provide the basis for customised cancer treatment, so-called precision medicine. Rapid developments in genomics have placed this field at the forefront of clinical molecular pathology and there are already a number of well-established genetic tests available for clinical use including PCR of antigen receptor rearrangement and KIT mutational analysis. Moving beyond tests assessing a single gene, there are significant research efforts utilising genomics to predict cancer risk, forecast aggressive behaviour and identify druggable mutations and therapeutic biomarkers. Researchers are also investigating the use of circulating cells and nucleic acid for clinically useful low morbidity genomic assessments. If we are to realise the full potential of molecular pathology and precision medicine there are a number of challenges to overcome. These include developing our understanding of the underlying biology (in particular intra-tumoural heterogeneity), methodological standardisation of assays, provision of adequate infrastructure and production of novel therapeutics backed by high-quality clinical data supporting the precision medicine approach. The era of molecular pathology holds the potential to revolutionise veterinary cancer care, but its impact on clinical practice will depend upon the extent to which the inherent challenges can be overcome.

Abstract P75: Cerebrovascular Events and Outcomes in Hospitalized Patients With Covid-19: The Society of Vascular and Interventional Neurology Multinational Registry

Background: Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has been associated with a significant risk of thrombotic events in critically ill patients.

Aims: To summarize the findings of a multinational observational cohort of patients with SARS-CoV-2 and cerebrovascular disease.

Methods: Retrospective observational cohort of consecutive adults evaluated in the emergency department and/or admitted with coronavirus disease 2019 (COVID-19) across 31 hospitals in 4 countries (2/1/2020 - 06/16/2020). The primary outcome was the incidence rate of cerebrovascular events, inclusive of acute ischemic stroke, intracranial hemorrhages (ICH), and cortical vein and/or sinus thrombosis (CVST).

Results: Of the 14,483 patients with laboratory-confirmed SARS-CoV-2, 172 were diagnosed with an acute cerebrovascular event (1.13% of cohort; 1130/100,000 patients, 95%CI 970-1320/100,000), 68/171 (40.5%) of whom were female and 96/172 (55.8%) were between the ages 60-79 years. Of these, 156 had acute ischemic stroke (1.08%; 1080/100,000 95%CI 920-1260/100,000), 28 ICH (0.19%; 190/100,000 95%CI 130 - 280/100,000) and 3 with CVST (0.02%; 20/100,000, 95%CI 4-60/100,000). The in-hospital mortality rate for SARS-CoV-2-associated stroke was 38.1% and for ICH 58.3%. After adjusting for clustering by site and age, baseline stroke severity, and all predictors of in-hospital mortality found in univariate regression (p<0.1: male sex, tobacco use, arrival by emergency medical services, lower platelet and lymphocyte counts, and intracranial occlusion), cryptogenic stroke mechanism (aOR 5.01, 95%CI 1.63-15.44, p<0.01), older age (aOR 1.78, 95%CI 1.07-2.94, p=0.03), and lower lymphocyte count on admission (aOR 0.58, 95%CI 0.34-0.98 p=0.04) were the only independent predictors of mortality among patients with stroke and COVID-19.

Conclusions: COVID-19 is associated with a small but significant risk of clinically relevant cerebrovascular events, particularly ischemic stroke. The mortality rate is high for COVID-19 associated cerebrovascular complications, therefore aggressive monitoring and early intervention should be pursued to mitigate poor outcomes.

Toxicity of cytarabine constant rate infusion in dogs with high-grade non-Hodgkin lymphoma with bone marrow or central nervous system involvement

OBJECTIVE

Cytarabine, a cell-cycle phase-specific antimetabolite, has been reported to improve outcomes in dogs with bone marrow (BM) or central nervous system (CNS) lymphoma involvement receiving combination chemotherapy. The objective of this study was to evaluate the incidence and severity of toxicity of cytarabine constant rate infusion (CRI) in dogs with high-grade non-Hodgkin lymphoma.

METHODS

Medical records of canine lymphoma patients with confirmed or suspected BM (group 1) or CNS (group 2) involvement, treated with a modified cyclophosphamide, epirubicin, vincristine and prednisolone protocol, including a single dose of cytarabine given as CRI, were reviewed and adverse events graded.

RESULTS

Twenty-six dogs were included. Gastrointestinal toxicity occurred in 17 dogs (65.3%), with 5 (19.2%) experiencing grade III or IV toxicity. Neutropenia occurred in nine dogs (34.6%), but was grade I or II in most cases. Three dogs (11.5%) had thrombocytopenia: one grade III and two grade IV. Four dogs (15.3%) experienced increases in alanine amino transferase: one each grade I and II and two grade III. Five dogs (19.2%) required hospitalisation to manage toxicity after completing cytarabine CRI, and haematological toxicity resulted in treatment delays in five dogs (median delay of 4 days, range: 3-7 days).

CONCLUSION

Our findings suggest that gastrointestinal toxicity should be expected in lymphoma patients undergoing cytarabine CRI.

Results of induction chemotherapy in children older than 18 months with stage-4 neuroblastoma treated with an adaptive-to-response modified N7 protocol (mN7)

PURPOSE

We report the response rate in children older than 18 months with stage 4 Neuroblastoma, using a modified dose-intensive, response-adaptive, induction mN7 protocol.

METHODS

From 2005 to 2012, 24 patients were treated with the mN7 protocol. Phase 1 included five MSKCC N7 cycles and surgery and two high-dose cyclophosphamide-topotecan (HD-CT) cycles for those who did not achieve complete remission (CR) and negative bone marrow (BM) minimal residual disease (MRD) status (CR+MRD-). Phase 2 consisted of myeloablative doses of topotecan, thiotepa and carboplatin plus hyperfractionated RT. Phase 3 included isotretinoin and 3F8 immunotherapy plus GM-CSF. BM MRD was monitored using GD2 synthase, PHOX2B and cyclin D1 mRNAs.

RESULTS

After 3 cycles, all patients showed BM complete histological clearance and 6 (25 %) were MRD-. Twenty of 21 s-look surgeries achieved macroscopic complete resection. After 5 cycles and surgery, (123)I-MIBG scan was negative in 15 (62.5 %) cases, BM disease by histology was negative in 23 (96 %) and 10 (42 %) patients were MRD-. Twelve (50 %) pts were in CR, 2 in very good partial response (VGPR), 9 partial response (PR) and one had progressive disease. With 2 HD-CT extra cycles, 17 (71 %) pts achieved CR+MRD- status moving to phase 2. Overall and event-free survival at 3 years for the 17 patients who achieved CR+MRD- is 65 and 53 %, respectively, median follow-up 47 months. Seven (29 %) patients never achieved CR+MRD-. Univariate Cox regression analysis shows CR+MRD- status after mN7 induction as the only statistically significant prognostic factor to predict overall survival.

CONCLUSIONS

mN7 induction regimen produced a CR+MRD- rate of 71 %. CR+MRD- status following induction was the only predictive marker of long-term survival.

Evidence of the harmonic Faraday instability in ultrasonic atomization experiments with a deep, inviscid fluid

A popular method for generating micron-sized aerosols is to submerge ultrasonic (ω~MHz) piezoelectric oscillators in a water bath. The submerged oscillator atomizes the fluid, creating droplets with radii proportional to the wavelength of the standing wave at the fluid surface. Classical theory for the Faraday instability predicts a parametric instability driving a capillary wave at the subharmonic (ω/2) frequency. For many applications it is desirable to reduce the size of the droplets; however, using higher frequency oscillators becomes impractical beyond a few MHz. Observations are presented that demonstrate that smaller droplets may also be created by increasing the driving amplitude of the oscillator, and that this effect becomes more pronounced for large driving frequencies. It is shown that these observations are consistent with a transition from droplets associated with subharmonic (ω/2) capillary waves to harmonic (ω) capillary waves induced by larger driving frequencies and amplitudes, as predicted by a stability analysis of the capillary waves.

Treatment of childhood glial tumors with cisplatin and irinotecan

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Background: Childhood glial tumors are heterogeneous neoplasias for which non-surgical management is controversial. After a pilot study suggesting that irinotecan/cisplatin (I/C) may be effective in children (Mora et al, Neuro Oncol 2007), we initiated a phase II prospective trial with the aim of avoiding radiation therapy for low grade's (LG) and improve outcome for high grade's (HG). Methods: The indication for adjuvant therapy was based upon histology, the extent of surgical resection, and the presence of clinical or neuroradiological signs of progression. Weekly Irinotecan (50 mg/m2 and 65 mg/m2 the last 2 cycles) and Cisplatin (30 mg/m2) for four consecutive weeks (1 cycle), and a total of 4 cycles was used. Results: From January 2004 to December 2007, 30 children aged 6 months to 17 years were treated, 21 at diagnosis, 7 at progression and 2 at relapse. Fourteen tumors were WHO grades I-II gliomas (LGG), 10 grade III (6 gliomas, 2 anaplastic ependymomas and 2 AT/RT), and 6 had no biopsy (3 brainstem (BST) and 3 optic-pathway tumors (OPT)). Two patients had type-1 neurofibromatosis and OPT. Primary sites included: 4 supratentorial, 8 BST, 9 OPT, 2 cerebellar, and 7 spinal. Prior to the I/C regimen, gross total resection was performed in 7 and biopsy in 14 tumors; 9 patients received chemotherapy and 5 radiotherapy. All but 6 patients, 2 because of C allergy and 4 BST because of progression, completed the protocol, with no grade 3–4 side effects. Vomiting was the main side effect. Twenty (90%) of 22 patients with evaluable clinical symptoms had a complete and rapid response, with objective functional recovery. With a median follow-up of 25 months, 14 (47%) patients had a complete/partial response (7 out of 10 HG), 10 (40%) had stable disease (8 out of 14 LG), and 6 (20%) progressed (all BST). Five patients died of disease, all BST. Twenty-five (83%) patients remain progression-free, median 27 months from protocol entry. Conclusions: Seventy percent objective response rate for HG and avoidance of radiotherapy for 93% of LG was obtained using the I/C regimen. Remarkable fast clinical responses and functional recoveries occurred.

No significant financial relationships to disclose.

Successful treatment of childhood astrocytomas with cisplatin and irinotecan

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Background: Childhood astrocytomas are a heterogeneous group of neoplasms for which non-surgical management is controversial. After a pilot study suggesting that irinotecan/cisplatin (I/C) may be effective for spinal cord astrocytomas in children (Mora et al, Neuro-Oncol 2007), we initiated a phase II trial for progressing astrocytomas with the aim of avoiding radiation therapy for low grade's and improve outcome for high grade's. Methods: The indication for adjuvant therapy was based upon histology, the extent of surgical resection, and the presence of clinical or neuroradiological signs of progression. Weekly Irinotecan (50 mg/m2 and 65 mg/m2 the last 2 cycles) and Cisplatin (30 mg/m2) for four consecutive weeks (1 cycle), and a total of 4 cycles was used. Results: Since 2004, 17 children aged 7m-17y were treated including 5 WHO grade I, 6 grade II, 3 grade III, and 3 non biopsied tumors: 2 intrinsic brain-stem tumors (BST) and 1 optic-pathway (OP) tumor. No patient had clinical signs of neurofibromatosis. Primary sites included 4 supratentorial, 3 BST, 3 OP, 1 cerebellar, and 6 spinal tumors. Gross total resection was performed in 1 case, subtotal in 4 and only biopsy in 9. Six patients received chemotherapy and one radiotherapy prior to the I/C regimen. Vomiting was easily controlled except for patients with BST. All but 2 patients, because of C allergy, completed the protocol with no documented ototoxic, renal, or GI side effects. Eleven (65%) pts had a complete clinical response, including 1 BST and all the spinal cord cases. Remarkably all the clinical responses were rapid, within the first 1–2 weeks of treatment. Twelve (70%) pts had a <25 [O1] % reduction of the tumor size at the end of therapy including 2 spinal cord cases that achieved complete radiological responses 10 months after the end of therapy. One BST patient progressed on therapy. Thus far, none of the low grade cases have received radiotherapy, although median f/u is only 1 year. All pts are alive and well. Conclusions: Remarkable clinicoradiological responses and avoidance of radiotherapy was obtained using the I/C regimen for childhood astrocytoma.

No significant financial relationships to disclose.

[Short form 36 health questionnaire in hemiplegic patients 2 years after stroke]

INTRODUCTION

Many studies show that subjects with sequelae after stroke have a worse health perception in western societies. Due to the shortage of papers on the Spanish population in this regard, a study was carried out to assess health perception in hemiplegic patients 2 years after stroke in comparison with that of the general population and correlate health perception with demographic, clinical and functional variables.

METHODS

Cross-sectional study of 212 community stroke survivors. The main variables collected were: health perception assessed with the Short Form 36 (SF-36), disability assessed with the motor Functional Independence Measure (FIM) and Geriatric Depression Scale (GDS). Statistical tests used: chi2, Student t test and Spearman correlation coefficient.

RESULTS

In comparison with the Spanish general population, health perception in hemiplegic male stroke patients is diminished in all areas. In hemiplegic female patients, physical function is the only subscale significantly affected in all age groups. Variables related to worse health perception are: presence of depression, dependence and the belief of the need for kind of social support, A significant correlation was observed between SF-36 values and the motor FIM (r = 0.737 with physical function) and the GDS (r = -0.821 with mental health).

CONCLUSIONS

Health perception in hemiplegic patients 2 years after stroke is diminished in comparison with that 348 of the general population. Factors which determine worst health perception are depression, motor dependence, need of caregiver assistance and need of social support.

Spontaneous resolution of a Chiari I malformation associated syringomyelia in one child

A child with complete spontaneous resolution of a Chiari I malformation associated Syringomyelia without surgical intervention is presented. The child was followed clinically by serial magnetic resonance imaging (MRI) and remains neurologically stable after 8-years of follow-up. To our knowledge, only 6 pediatric cases with spontaneous resolution of a spinal cord syrinx documented by MRI without surgical intervention have been reported. This case is of interest in the light of the postulated theories to explain spontaneous resolution of syringomyelia.

The futility of common firewall policies: an experimental demonstration

Many healthcare organizations utilize network "firewalls" to protect their networks from being accessed by unauthorized external entities. These same firewalls are also often configured to deny access to certain external services from within the internal network. The latter policy can be subverted through a "protocol tunneling" strategy, which has been implemented as a set of programs called "Firehole." Organizations should be aware of this potential weakness in their network security designs. Policies that deny external services to users should be carefully evaluated in light of clearly defined organizational goals.

Cellular interactions during heart morphogenesis in the Drosophila embryo

The formation of the dorsal vessel or heart in a Drosophila melanogaster embryo can be divided into three main steps: i) the determination step allows individualization of heart precursor cells from the dorsal mesoderm. They are arranged in clusters of seven to nine cells, located in each of the eleven segments of the trunk. Preliminary observations suggest that the gene Notch could participate in the choice of fate that the cardioblasts and the pericardial cells will adopt within the cardiogenic region. In the same line, a new gene, whose expression, as revealed by a P-lacZ insertion, is initiated at gastrulation in the developing mesoderm and becomes restricted within the mesoderm to the myogenic lineages, could participate in the determination of the cardioblasts identity; ii) once the cardioblasts have separated from the dorsal mesoderm, they reorganize to form an epithelial monolayer. The gene coding for the alpha-subunit of the transduction protein Go, which is expressed in the cardioblasts shortly before this step, could be involved in this process. Indeed, mutants in the Go alpha gene are affected in the formation of the cardiac endothelium; and iii) the last step consists of the migration of the cardiac epithelium towards the dorsal midline of the embryo to form the dorsal vessel by apposition of the two layers of cardioblasts. We show that an extracellular matrix component is specifically expressed at the surface of the dorsal vessel and could participate in the interaction between the dorsalmost ectodermal cells and the heart during this migration step.

Ceratitis capitata brain adenylate cyclase and its membrane environment

Adenylate cyclase activation by GTP and octopamine as well as basal activity (in the presence of Mg2+) have been studied as a function of membrane structure in plasma membranes from brain of the dipterous Ceratitis capitata. Benzyl alcohol and lidocaine, but not phenobarbital, inhibited the three activities to the same extent. Triton X-100-solubilized adenylate cyclase was also inhibited by benzyl alcohol and lidocaine, but not by phenobarbital. Results could be explained by an effect on the catalytic unit lipid environment, which would be maintained after solubilization, counteracting the effect of these drugs to facilitate lateral diffusion and coupling of adenylate cyclase components in the lipid bilayer. The observation that the insect adenylate cyclase is relatively insensitive to changes in bulk bilayer fluidity is strengthened by the absence of effect of phenobarbital on enzyme activities. Indeed, this compound was as active as lidocaine or benzyl alcohol in increasing bulk membrane fluidity. The response of C. capitata adenylate cyclase to changes in membrane fluidity is different from that recorded in mammalian systems. This may be functionally important and result from the fact that insects are not warm-blooded.

Regulation by forskolin of octopamine-stimulated adenylate cyclase from brain of the dipterous Ceratitis capitata

Forskolin, a diterpene that exerts several pharmacological effects, activates adenylate cyclase in brain and in some other mammalian tissues. Properties of forskolin activation of adenylate cyclase from central nervous system of the dipterous Ceratitis capitata are described. The interaction of forskolin with the insect adenylate cyclase system was studied by evaluating its effect on metal-ATP kinetics, protection against thermal inactivation, membrane fluidity and enzyme modulation by fluoride, guanine nucleotides, octopamine, and ADP-ribosylation by cholera toxin. The diterpene stimulated basal enzyme activity both in membranes and Triton X-100-solubilized preparations, apparently devoid of functional regulatory unit, this effect being rapidly reversed by washing the membranes. An increase of Vmax accounts for the activation of soluble and membrane adenylate cyclase preparations by forskolin, whereas the affinity of the enzyme for the substrate was not affected. Forskolin apparently protects the membrane enzyme from thermal inactivation, and at concentrations that promote the enzyme activity the diterpene does not alter membrane microviscosity. Forskolin does not appear to alter the sensitivity of insect adenylate cyclase to sodium fluoride, guanine nucleotide, or regulatory subunit ADP ribosylated by cholera toxin, the combined effect of these factors with the diterpene resulting in a nearly additive enzymatic activation. However, forskolin blocks the octopamine stimulatory input. Results obtained with the insect adenylate cyclase system are discussed and compared to what is known about mammalian systems to propose a mechanism of enzyme activation by forskolin.