Anatomic and physiologic diagnostic discrepancies in fetuses with single ventricle congenital heart disease in a contemporary cohort

OBJECTIVE

Image quality of fetal echocardiography (FE) has improved in the recent era, but few recent studies have reported the accuracy of FE specifically in single ventricle congenital heart disease (SV). Our study aims to assess the ability of FE to correctly predict postnatal anatomy and physiology in SV in a contemporary cohort.

METHODS

The contemporary, clinical reports of FE with SV performed from 7/2017 to 7/2021 were compared with postnatal echocardiograms in a formal quality assurance program. SV were grouped by anatomic subtype. Diagnostic errors were designated as major if the error would have resulted in significant alteration in fetal counseling or postnatal management. Remaining errors were classified as minor. Physiologic discrepancies, including prostaglandin dependency (PGE-D), atrioventricular valve regurgitation (AVVR), pulmonary venous obstruction, and atrial septal restriction were assessed by review of postnatal course.

RESULTS

A total of 119 subjects were analyzed. SV subtypes in the cohort included hypoplastic left heart syndrome (HLHS) (n=68), tricuspid atresia (n=16), double inlet left ventricle (n=12), unbalanced atrioventricular canal (UAVC) (n=11), heterotaxy (n=9), and other (n=3). The rate of major anatomic and physiologic errors was low (n=6, 5.0%). A higher proportion of minor errors were noted in HLHS and tricuspid atresia but the differences were not statistically significant. Physiologic discrepancies were uncommon, with three major discrepancies including underestimation of degree of venous obstruction in one non-HLHS fetus with total anomalous pulmonary venous return, overestimation of atrial septal restriction in one HLHS fetus, and incorrect prediction of PGE-D with 1 false-negative for pulmonary blood flow. No discrepancy in degree of AVVR or atrial septal restriction affected postnatal care. Minor physiologic discrepancies included two false-positive predictions of PGE-D with 1 false-positive for ductal-dependent systemic flow, and 1 false-positive for pulmonary blood flow.

CONCLUSIONS

In this contemporary review of FE in SV at our center, there was high accuracy in describing anatomic and physiologic findings in fetuses with SV. Major physiologic discrepancies were uncommon but included important cases of false-negative prediction of PGE-dependence and underestimation of obstruction of total anomalous pulmonary venous return. These data can both inform more accurate counseling of families with SV fetuses and guide diagnostic improvement efforts. This article is protected by copyright. All rights reserved.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Clinical Acceptability of Artificial Intelligence-Screened Interstitial Lung Disease (AI-ILD) in Lung Cancer Patients Treated with Radiotherapy

PURPOSE/OBJECTIVE(S)

Patients with interstitial lung disease (ILD) treated with thoracic radiotherapy (RT) are at greater risk of pulmonary toxicity. Automatic universal screening for ILD allows radiation oncologists (ROs) to risk stratify patients and implement necessary modifications to their respiratory monitoring or treatment. Automatic screening however may affect RO workload and so it is imperative to assess the clinical acceptability of this tool.

MATERIALS/METHODS

We have developed a machine learning algorithm to identify patients who are at high risk of having ILD based on RT planning computed tomography (CT) images. A quality improvement (QI) project was initiated to test feasibility and acceptability of the machine learning algorithm. If positive, the results of the machine learning algorithm were made available to ROs via structured electronic reporting. ROs were prompted to review the patient and consider expert radiologist consultation if thought appropriate. All electronic surveys and qualitative comments were summarized to describe clinical acceptability. Expert radiologist established gold standard ILD status of all patients on the study. A formal review of RO feedback was collected for all screen-positive, true-positive cases.

RESULTS

Two hundred forty cases were screened of which 45 were flagged as AI-ILD positive and the responsible RO notified. Of these 45 screen-positive cases, all continued on to RT except for 3 patients with tumor progression. From these 45, 24 surveys were completed, 21 had no prior suspicion of ILD. There were 7 true-positives, of which 1 had a survey response. Based on the survey responses, 88% of cases underwent review by the responsible RO. In 16 cases this automatic notification prompted case consultation with an expert radiologist. Expert review was performed from 10 minutes up to 53 hours after the email prompt to the radiologist, with median response time of 1.5 hours. In the 7 screen-positive, true-positive cases, only 2 were not previously known to the responsible RO. In the two cases where true-positive ILD status was previously unknown, one was a mild case of ILD and the other had previously received thoracic RT at this institution without ILD being identified, in both cases the ROs were grateful that this diagnosis was identified prior to treatment. RO confidence in the machine learning prediction was moderate due to the high proportion of false positives.

CONCLUSION

Based on available survey results, more than 75% of the screen-positive cases were reviewed by the responsible RO and two-thirds of these involved expert radiology input. RO feedback was generally positive and this tool was rated as a net benefit despite the high rate of false-positives and the need for clarification.

Surgically Targeted Radiation Therapy (STaRT) for Brain Metastases: Initial Experience from a Prospective Multi-Institutional Registry

PURPOSE/OBJECTIVE(S)

Resection and intraoperative brachytherapy for patients with large, operable brain metastasis allows for both relief of mass effect and the delivery of radiotherapy (RT) to the resection cavity with a favorable dosimetric profile. The objective of this study was to analyze early patterns-of-care and treatment-related toxicity outcomes for brain metastasis patients treated with surgically targeted radiation therapy (STaRT) using a novel brachytherapy carrier.

MATERIALS/METHODS

Patients with brain metastasis, de novo and recurrent disease, who enrolled onto a prospective multi-institutional observational study (NCT04427384) were the subject of this analysis. Patients underwent resection and immediate implantation of bioresorbable, conformable, 20 mm x 20 mm x 4 mm collagen tile brachytherapy device(s) containing four uniform-intensity Cesium-131 sources. Toxicities were categorized using the CTCAE v5.0 adverse event (AE) criteria.

RESULTS

From 10/2020 to 01/2023, 13 participating sites enrolled and treated 48 patients with 51 metastases (13 with de novo and 35 patients with recurrent brain metastases), and 3 patients had 2 lesions implanted at the same procedure. Median age was 61 years (range: 28-80), 52% were female, and the most common primary types were lung (56%) and breast (13%). The median maximum pre-operative dimension was 3.4 cm (range: 1.7-5.7) and median pre-operative tumor volume 13.7cm3 (range: 1.7-132). 64% had received prior RT with a median time from last RT to STaRT of 14.6 months range: 3.5-57.3). Median KPS at screening was 80 (range: 50-100), and remained stable at post op visit (80, range: 50-100), and at 3-months following treatment (80, range 50-100), respectively (p>0.05). The median time for implantation was 3 minutes (range: 0.4-30). At a median follow-up of 4 months (range: <1-18), no patient experienced a radiation-attributed AE, and only 1 attributable Gr >3 AE was noted (Gr 5 intracerebral hemorrhage deemed probably related to surgery and unrelated to the implanted device).

CONCLUSION

Early results from this prospective multi-center trial demonstrate the feasibility and safety of STaRT. The lack of radiation-related AE, even with short follow-up, is intriguing given the relatively large lesion size and proportion of patients treated for recurrent, previously irradiated disease. Additional follow-up will provide data on tumor control outcomes and radiation necrosis rates using this novel technique.

Association of Artificial Intelligence-Screened Interstitial Lung Disease with Radiation Pneumonitis and Mortality in Locally Advanced Non-Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

Radiation pneumonitis (RP) is a common and dose-limiting toxicity following radiotherapy for non-small cell lung cancer (NSCLC). Patients with interstitial lung disease (ILD) are believed to be at increased risk of developing complications including RP, ILD progression, or death. An automated method to identify patients prior to radiotherapy at high risk of developing toxicities or death may allow clinicians to mitigate risk through informed treatment planning and careful patient monitoring.

MATERIALS/METHODS

All locally advanced NSCLC patients treated with definitive radiation from 2006-2021 with a minimum 1 year of follow-up were assessed. RP and mortality data were prospectively collected and retrospectively reviewed. A convolutional neural network (CNN) was previously developed and validated to identify patients with radiographic ILD using planning computed tomography (CT) images, with an accuracy of 0.82. Planning CT scans for the retrospective cohort were used as input to the CNN, with artificial intelligence-screened ILD (AI-ILD) score as an output. AI-ILD scores above our established threshold were labeled as AI-ILD+. The association between AI-ILD score, AI-ILD+/-, mean lung dose (MLD), and the primary outcome of grade ≥2 (G2+) RP or mortality, as well as the secondary outcomes of G2+ RP and mortality were assessed using Wilcoxon rank sum test, univariate and multivariable logistic regression, and Kaplan-Meier survival analysis.

RESULTS

Of 799 patients reviewed, 745 eligible patients were included in the analysis; grade 0-5 RP was reported in 51.3%, 27.1%, 16.9%, 4.0%, 0.1%, and 0.5% of patients respectively. Overall, 22.9% of patients were AI-ILD+, and therefore at high risk (>20% chance) of having true ILD. On UVA, AI-ILD score, AI-ILD+ and MLD were significantly associated with the primary outcome of G2+ RP or mortality, as well as the secondary outcome of mortality. However, only MLD was significantly associated with the secondary outcome of G2+ RP. On MVA, both AI-ILD+ (OR 1.42, 95% CI 1.02-1.97, p = 0.04) and MLD (OR 1.13, 95% 1.05-1.21, p = 0.008) were significantly associated with G2+ RP or mortality. On Kaplan-Meier analysis, the median toxicity-free survival (TFS) time for AI-ILD+ and AI-ILD- patients were 1.7 and 3.4 years respectively, with a 2-year TFS of 48.3% vs. 59.3% (log-rank test: p = 0.02). There was no significant difference in rates of G2+ RP.

CONCLUSION

The AI-ILD algorithm can detect high risk patients with significantly decreased TFS following definitive treatment for NSCLC. AI-ILD classification was not associated with a significant difference in rates of RP when accounting for MLD. Future work will focus on improving the classification algorithm, expert radiologist validation of this dataset, and exploring reasons for the mortality difference in AI-ILD+ patients.

Evaluating the effect of child home safety training upon three family support practitioner groups: a mixed-methods study

AIMS

Unintentional injuries in the home contribute substantially to preschool child morbidity and mortality. Practitioners such as health visitors, family mentors and children's centre staff are well-positioned to facilitate child injury prevention by providing home safety advice to families, and training may enhance their ability to do so. We aimed to assess the impact of child home safety training for these practitioners.

METHODS

An explanatory mixed-methods design was used. Practitioners completed questionnaires before, and up to 7 months after, receiving child home safety training and took part in interviews. Seventy-eight health visitors, 72 family mentors and 11 children's centre staff members completed questionnaires. Items were used to calculate scores on home safety knowledge, confidence to provide home safety advice and belief that child home safety promotion is important. Thematic analysis of interviews with seven health visitors and nine family mentors, open-ended responses to the questionnaires and an additional evaluation form was conducted to explore attendees' perceptions of the training and its impact. In addition, seven health visitors and six children's centre staff who had received no training were interviewed.

RESULTS

Knowledge was greater post-training than pre-training across all participants (p < .001). When practitioner groups were analysed separately, there were significant increases in family mentors' knowledge (p < .001) and belief (p = .016), and health visitors' confidence (p = .0036). Qualitative findings indicated that most training session attendees valued the training, believed their practice relating to child home safety had improved as a result, and felt further similar training sessions would be beneficial. Those who had not attended the sessions described a need for more child home safety training.

CONCLUSIONS

Delivering training to practitioners providing child home safety promotion to families with preschool children can enhance injury prevention knowledge, beliefs and confidence and positively impact on home safety promotion by practitioners.

Abstract 6713: Myc-regulated miR17, 20a modulate RANK expression in osteosarcoma

Osteosarcoma (OS) is the most common primary bone tumor in children and adolescents. Approximately 25-30% of these tumors carry amplification of chromosome 8q24, which harbors the oncogene c-Myc, and correlates with a poor prognosis in patients with OS. To understand the mechanisms that underlie the ability of Myc to alter both the tumor and its surrounding tumor immune microenvironment (TiME), we generated and molecularly characterized an osteoblast-specific Cre-Lox-Stop-Lox;(LSL)-c-MycT58A;p53f/+ knockin genetically engineered mouse model (GEMM). Phenotypically, the Myc knockin-GEMM had rapid tumor development with a high incidence of metastasis. Myc-dependent gene signature in our murine model demonstrated significant homology to the human Myc-amplified OS.Interestingly, we noticed a significant reduction in the osteoclast (OCL) cell population in the Myc knockin OS tumor compared to the p53-driven. We found the expression of RANK was significantly downregulated in the Myc knockin tumor compared to the Non-knockin p53 heterozygous tumors. The RANK/RANKL pathway is vital in OCL maturation and bone modeling/remodeling. To understand the involvement of Myc in RANK regulation, we used murine-derived OS cell lines and transiently knocked down of Myc expression using siRNA. We observed a significant upregulation in RANK expression after Myc knockdown. To decipher the molecular mechanism behind the Myc-dependent regulation of RANK expression in OS, we looked into the Myc-mediated microRNAs. Myc regulates the expression of several microRNAs, including the polycistronic miR-17-92 cluster. The expression of miR17-5p and Mir20a-5p was significantly higher in the GEMM tumor tissue samples isolated from the Myc knockin compared to the p53-driven. Further, we validated the Myc-dependent regulation of miR-17-5p/20a-5p expression using transient knockdown of Myc in mouse Myc knockin-derived cell lines. To examine the role of miR17-5p/20a-5p on the RANK regulation, we performed both gain and loss-of-function studies using microRNA-17/20a mimics and inhibitors. After the treatment with miR-17-5p/20a-5p inhibitors, the expression of RANK was significantly upregulated whereas in

the case of miR17/20a mimics reversed these effects and led to a downregulation of RANK expression. We established that miR-17-5p/20a-5p is causally responsible for at least part of the mechanism by which Myc regulates the RANK expression in OS.We concluded that the Myc-regulated miR17/20a modulates the RANK expression that is involved in the OCL cell population regulation and function in the OS.

Citation Format: Bikesh Kumar Nirala, Lyazat Kurenbekova, Tajhal Patel, Ryan Lane Shuck, Atreyi Dasgupta, Nino Carlo Rainusso, Jason T. Yustein. Myc-regulated miR17, 20a modulate RANK expression in osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6713.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Outpatient management of uncomplicated enteric fever: A case series of 93 patients from the Hospital of Tropical Diseases, London

OBJECTIVES

Enteric fever is predominantly managed as an outpatient condition in endemic settings but there is little evidence to support this approach in non-endemic settings. This study aims to review the outcomes of outpatients treated for enteric fever at the Hospital of Tropical Diseases in London, UK.

METHODS

We conducted a retrospective analysis of all patients with confirmed enteric fever between August 2009 and September 2020. Demographic, clinical, laboratory and microbiological data were collected and compared between the inpatient and outpatient populations. Outcomes investigated were complicated enteric fever, treatment failure and relapse.

RESULTS

Overall, 93 patients (59% male, median age 31) were identified with blood and/or stool culture confirmed enteric fever and 49 (53%) of these were managed as outpatients. The commonest empirical treatment for outpatients was azithromycin (70%) and for inpatients was ceftriaxone (84%). Outpatients were more likely than inpatients to receive only one antibiotic (57% vs 19%, p < 0.01) and receive a shorter duration of antibiotics (median 7 vs 11 days, p <0.01). There were no cases of complicated disease or relapse in either the inpatient or outpatient groups. There was one treatment failure in the outpatient group. Azithromycin was well-tolerated with no reported side effects.

CONCLUSIONS

Our findings suggest that outpatient management of uncomplicated imported enteric fever is safe and effective with the use of oral azithromycin. Careful monitoring of patients is recommended as treatment failure can occur.

Abstract 6324: Development and characterization of Ewing Sarcoma lung metastasis model

Introduction: Ewing Sarcoma (EwS) is the second most common bone tumor in children. At diagnosis, approximately 20-25% of patients with EwS have metastatic disease. While systemic chemotherapy, along with surgery and/or radiotherapy, has significantly increased the survival rate of patients with localized disease, metastatic Ewing sarcoma (EwS) has an extremely poor overall survival with a 5-year survival rate of approximately 20-30%. This prognosis has not changed in the last several decades. Thus, there is an imperative need to focus particularly on mechanisms of metastatic growth and progression and to identify and target the underlying intrinsic and extrinsic molecular features. Unfortunately, presently there is no reliable engineered mouse model to functionally study EwS development and metastasis. Using two independent EwS cell lines, we have developed highly aggressive, lung-specific metastatic models that show mechanistic overlap with human patient tumor data and are valuable resources to further study and target metastatic EwS.

Approach: Using a serial transplantation approach, we generated lung specific metastatic lines by repeated intra-tibial injection of two commonly used EwS cell lines (A673 and TC71), allowing metastatic foci to form, followed by dissociation and subsequent re-injection into the tibia. We repeated this 5 times to generate highly aggressive lung-specific metastatic cell lines. As a proof of principle, when equal numbers of GFP+ parental cells and mCherry+ lung metastatic cells are injected into the tibia in NSG mice they form primary tumors with red and green cells, while the metastatic lesions in lungs are almost exclusively mCherry+. A multi-omics approach including glycoproteomics, secretome, and transcriptomic analysis were then used to characterize these cells and compare them with patient tumor samples.

Results: Integration of focused proteomics and glycoproteomics data revealed upregulation in AXL, MEK6, STAT1, and STAT3 proteins and phosphoproteins in metastatic lesions. Focused RNA profiling with Nanostring technologies using formalin-fixed paraffin-embedded (FFPE) slides of patient tumor samples revealed increased expression of several other upstream genes that signal through STAT1, including IL-6, IKK-β, TRAF-6, and Myd88. In addition, upregulation in factors involved in tumor invasive front such as Furin, TIMP-2, MMP-2, and MMP-14 were also noted. We are currently in the process of further validating some of the key regulators using larger set of patient derived tumors and by targeting them in orthotopic mouse models.

Citation Format: Atreyi Dasgupta, Lyazat Kurenbekova, Tajhal Patel, Jason T. Yustein. Development and characterization of Ewing Sarcoma lung metastasis model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6324.

Abstract 1668: Development and characterization of a c-Myc-driven preclinical mouse model of osteosarcoma to investigate the tumor immune microenvironment

Osteosarcoma (OS) is the most common bone tumor in pediatric patients, particularly in adolescents and young adults. Currently, no effective molecular targeted therapies are available for the OS, however, many OS patients possess genetically defined somatic DNA copy number alterations, including amplification of chromosome 8q24, which harbors the oncogene Myc, and correlates with a worse prognosis. To better understand the molecular pathogenesis, and identify targeted therapy for OS, a robust and reliable preclinical model is needed both for the primary and metastatic disease. We have developed a novel conditional, osteoblast-specific Myc knock-in murine model to understand the mechanisms that underlie the ability of Myc to drive the development and progression of OS and utilize it for the identification of Myc-dependent intrinsic and extrinsic molecular vulnerabilities. A tissue-specific Myc-in genetically engineered murine model was generated by crossing Col2.3-Cre; TP53Flox/+ mice with LSL-MycT58A mice and characterized integrating RNA-seq and Mass Spectrometry. Syngeneic murine OS cell lines were also generated and characterized. The molecular characterization of the GEMM model was compared with high and low Myc expressing human tumors using the OS-TARGET dataset. Differential gene expression in Myc-driven and non-driven-tumor tissue samples were quantified by RNA sequencing. The immune landscape of OS was evaluated using SymphonyFACS and IHC staining. Murine OS tumor type was confirmed by H&E staining. OS tumor was highly aggressive and metastatic in more than 60% of the mice. Myc expression was significantly higher both at the transcriptional and protein levels in the Myc-in tissue/cells compared to the non-Myc-driven model. Expression of 1479 genes (out of 13781 genes) were significantly altered in which 543 were upregulated and 936 were downregulated at transcriptional levels in Myc-in tumor tissue samples as compared to the low-Myc-driven OS tumor model analyzed by RNA sequencing. Myc-target-genes, splicing factor-related genes, E2F, G2M check-point, and DNA repair associated genes were significantly upregulated whereas the immune-related genes, oxidative phosphorylation, adipogenesis, and E2M transition genes were significantly downregulated when compared between two groups, which correlates to differential gene ontologies noted in high Myc human tumors. The total immune cell population, specifically the myeloid and macrophage populations were significantly diminished in the Myc-in tumor models, which could contribute to the poor prognosis in OS.Our murine model closely resembles human OS and will provide new opportunities for dissecting the molecular pathogenesis, identification of novel therapeutic strategies, and pre-clinical modeling for direct translational applications and targeting of Myc-driven OS.

Citation Format: Bikesh K. Nirala, Lyazat Kurenbekova, Ryan L. Shuck, Tajhal Patel, Kimal Rajapakshe, Jason T. Yustein. Development and characterization of a c-Myc-driven preclinical mouse model of osteosarcoma to investigate the tumor immune microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1668.

Rhabdomyosarcoma in Ovary- Pathologist’s Diagnostic Dilemma

Introduction/Objective

Rhabdomyosarcoma is the most common pediatric soft tissue sarcoma. However, rhabdomyosarcoma in the ovary is exceptionally unusual and presents a diagnostic challenge. We report one such case and its clinical and pathological perspective.

Methods/Case Report

16-year-old female presented with an enlarging pelvic mass, abdominal distension, and pain. Imaging revealed a heterogeneous left ovarian mass, right axillary lymphadenopathy, and right-hand soft tissue mass. CA-125 was 1833.0 U/ml. Patient underwent left salphingo-oophorectomy, omentectomy, peritoneal and mesenteric biopsy for ovarian staging, incidental appendectomy, and right axillary lymph node excision with suspicion of ovarian epithelial tumor. Pathological evaluation revealed a 16-cm intact ovary with multiple solid and cystic nodules with areas of hemorrhage and necrosis. Microscopic examination of ovarian tumor showed a high-grade malignant tumor consisting of sheets of small round blue cells with severe cytologic atypia, increased mitoses, and features suggestive of rhabdoid morphology. The other specimens were positive for metastases. The tumor cells were immunopositive for Myogenin and MyoD1 while immunonegative for Cytokeratin AE1/AE3, SF-1, PLAP, SALL4, MelanA, and S-100. INI-1 and BRG-1 demonstrated intact nuclear expression. FISH testing identified rearrangement of the FOX01 gene at 13q14. Based on these findings, diagnosis of alveolar rhabdomyosarcoma was rendered. Currently, the patient is receiving rhabdomyosarcoma chemotherapy treatment and has responded well.

Results (if a Case Study enter NA)

NA

Conclusion

In cases with complex and urgent clinical presentation, where the existence of a primary tumor is unknown and where symptoms attributable to primary ovarian tumor dominate the clinical picture, rhabdomyosarcoma is rarely proposed in the differential diagnoses of small round blue cell tumors of the ovary. At present, the right-hand mass is under evaluation; thus, the true nature of the ovarian mass, primary or metastatic is unknown. Our case illustrates the importance of exact diagnoses, as treatment of rhabdomyosarcoma, is different from other ovarian tumors.

CHAF1A Blocks Neuronal Differentiation and Promotes Neuroblastoma Oncogenesis via Metabolic Reprogramming

Neuroblastoma (NB) arises from oncogenic disruption of neural crest (NC) differentiation. Treatment with retinoic acid (RA) to induce differentiation has improved survival in some NB patients, but not all patients respond, and most NBs eventually develop resistance to RA. Loss of the chromatin modifier chromatin assembly factor 1 subunit p150 (CHAF1A) promotes NB cell differentiation; however, the mechanism by which CHAF1A drives NB oncogenesis has remained unexplored. This study shows that CHAF1A gain-of-function supports cell malignancy, blocks neuronal differentiation in three models (zebrafish NC, human NC, and human NB), and promotes NB oncogenesis. Mechanistically, CHAF1A upregulates polyamine metabolism, which blocks neuronal differentiation and promotes cell cycle progression. Targeting polyamine synthesis promotes NB differentiation and enhances the anti-tumor activity of RA. The authors' results provide insight into the mechanisms that drive NB oncogenesis and suggest a rapidly translatable therapeutic approach (DFMO plus RA) to enhance the clinical efficacy of differentiation therapy in NB patients.

Abstract 405: The role of GALNT14 in chemoresistant and metastatic osteosarcoma

Introduction: Osteosarcoma is the most common bone tumor in children and adolescents. Many patients have disease progression through standard chemotherapy regimens of methotrexate, cisplatin, and doxorubicin. Presently, there are no salvage therapies that have added significant survival benefits, leaving minimal options for relapsed and resistant disease. Additionally, there are no clinically significant biomarkers for this disease that would predict treatment failures. N-acetylgalactosaminyltransferase 14 (GALNT14) is an enzyme that initiates O-linked glycosylation to outer membrane-bound and extracellular proteins. Using transcriptomic analyses, we identified GALNT14 overexpression correlated with poor tumor necrosis and survival outcomes. Therefore, we hypothesize that GALNT14 contributes to metastatic and chemoresistant phenotypes in pediatric osteosarcoma.

Methods: Transcriptomic data from the Therapeutically Applicable Research for Generating Effective Treatments (TARGET) database and RNA-sequencing of institutional patient-derived xenografts (PDXs) revealed that overexpression of GALNT14 correlated to poor necrosis rates. Gene Set Enrichment Analysis (GSEA) also identified upregulation of glycosylation pathways. Aberrant expression of GALNT14 was confirmed using quantitative polymerase chain reaction (qPCR) and Western blot analyses in various osteosarcoma cell lines. Transient GALNT14 knockdown and overexpression were then analyzed for effects on proliferation, invasion, migration, and chemotherapy response in vitro. Kaplan-Meier curves demonstrating overall survival (OS) and event-free survival (EFS) were established using data from the TARGET database.

Results: GALNT14 expression was higher in both commercial and PDX cell lines that were known to be more prone for chemoresistance and invasiveness. The highest quartile of patients based on GALNT14 overexpression had 40% OS and 25% EFS, compared to 80% (p=0.002) and 75% (p&lt;0.001) for the lowest quartile of expression, respectively.

Summary: GALNT14 shows promise as a predictive marker of chemoresistance and metastasis for pediatric osteosarcoma. Future functional genomic studies through gain and loss-of-function assays will evaluate the role of GALNT14 in osteosarcoma chemoresistance and metastatic potential.

Citation Format: Zachary D. Prudowsky, Tajhal Patel, Kimal Rajapakshe, Christian Coarfa, Ryan Shuck, Nino Rainusso, Jason Yustein. The role of GALNT14 in chemoresistant and metastatic osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 405.

Sex disparity in skin carcinogenesis and potential influence of sex hormones

Background

Sex or gender disparity in skin cancer has been documented for a long time at the population level. UV radiation (UVR) is a common environmental risk for all three major types of skin cancer: cutaneous melanoma (CM), basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC). The underlying mechanism for sex disparity has been largely attributed to sex‐differentiated behaviour patterns related to UVR. Non‐UVR factors such as intrinsic physiological differences have been suggested but remain understudied.

Aims, Materials and Methods

This review summarizes and compares the known sex differences in three skin cancer types with regard to body site distribution and age influence.

Results

We found a similar age‐dependent sex difference pattern in CM and BCC. Specifically, CM and BCC tend to show higher incidence in young women and old men, with a switching age around menopause. The switching age suggests involvement of sex hormones, which has shown controversial influence on skin cancers at epidemiological level. Literatures regarding sex hormone receptors for oestrogen, androgen and progesterone are summarized for potential explanations at molecular level.

Discussion

Overall, more and more evidence suggests non‐UVR factors such as sex hormones play critical roles in skin cancer (especially CM and BCC), yet solid population and molecular evidence are required. Incidences of skin cancer are increasing which suggests limited effect for the current UVR‐avoidance prevention methods.

Conclusion

Fully understanding the causes of sex disparities in incidence is necessary for developing a comprehensive prevention strategy.

Targeting PAK4 Inhibits Ras-Mediated Signaling and Multiple Oncogenic Pathways in High-Risk Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most prevalent pediatric soft-tissue sarcoma. Multimodal treatment, including surgery and traditional chemotherapy with radiotherapy, has contributed to improvements in overall survival rates. However, patients with recurrent or metastatic disease have 5-year survival rates of less than 30%. One reason for the lack of therapeutic advancement is identification and targeting of critical signaling nodes. p21-activated kinases (PAK) are a family of serine/threonine kinases downstream of multiple critical tumorigenic receptor tyrosine kinase receptors and oncogenic regulators, including IGFR and RAS signaling, that significantly contribute to aggressive malignant phenotypes. Here, we report that RMS cell lines and tumors exhibit enhanced PAK4 expression levels and activity, which are further activated by growth factors involved in RMS development. Molecular perturbation of PAK4 in multiple RMS models in vitro and in vivo resulted in inhibition of RMS development and progression. Fusion-positive and -negative RMS models were sensitive to two PAK4 small-molecule inhibitors, PF-3758309 and KPT-9274, which elicited significant antitumor and antimetastatic potential in several primary and metastatic in vivo models, including a relapsed RMS patient-derived xenograft model. Transcriptomic analysis of PAK4-targeted tumors revealed inhibition of the RAS-GTPase, Hedgehog, and Notch pathways, along with evidence of activation of antitumor immune response signatures. This PAK4-targeting gene signature showed prognostic significance for patients with sarcoma. Overall, our results show for the first time that PAK4 is a novel and viable therapeutic target for the treatment of high-risk RMS. SIGNIFICANCE: These data demonstrate a novel oncogenic role for PAK4 in rhabdomyosarcoma and show that targeting PAK4 activity is a promising viable therapeutic option for advanced rhabdomyosarcoma.

Kavain Interference with Amphetamine Immunoassay

INTRODUCTION

We encountered unexpected false positive urine results in three patients for amphetamine-type substances by immunoassay, measured as part of community drug prevention programmes. Kavain was identified in all three urine samples by gas chromatography mass spectrometry (GC-MS). No other potential cross-reactants were found.Kavain is a kava-lactone present in kava, a ceremonial and recreational drink derived from roots and stem of the plant Piper Methysticum. It is consumed regularly by many indigenous Pacific and Australian Aboriginal communities.

METHODS

Urine immunoassay was performed on a Beckman Coulter AU480 Analyser using CEDIA amphetamine-type substances reagent and DRI ethanol reagent. Three different kava powders were purchased from local kava clubs and dissolved in ethanol, then evaporated and reconstituted in blank urine and analysed by immunoassay, GC-MS for amphetamine-type substances. Additionally authentic kavain standard was also tested for cross reactivity by immunoassay and analysed by GC-MS to compare the mass fragmentation pattern and retention time with the kava powder and patient specimens.

RESULTS AND DISCUSSION

The patient urine samples tested positive by CEDIA immunoassay for amphetamines. However, when analysed by GCMS they were negative for amphetamine-type but contained kavain.The kava powders and kavain standard all cross reacted with the amphetamine immunoassay to give falsely detected results. GCMS did not identify any amphetamine-type compounds in any of the Kava powders nor in the kavain standard.

CONCLUSION

To our knowledge, this is the first report of false positive amphetamine measurements due to kavain, a component of the kava drink, widely consumed in Oceania and Australasia.

Current videofluoroscopy practice in the United Kingdom: A survey of imaging professionals

INTRODUCTION

Videofluoroscopy (VFSS) is a frequently used radiological investigation for dysphagia and is conducted within a radiology setting by speech and language therapists (SLTs) working alongside imaging personnel (radiologists and/or radiographers). Previous surveys of SLT practice have reported variability in VFSS protocols and procedures. The aim of this study was to explore current clinical practice for VFSS from the perspective of imaging personnel engaged in VFSS within the United Kingdom.

METHODS

A comprehensive online survey enabled exploration of current practices of imaging professionals. Target participants were diagnostic imaging personnel (radiographers and radiologists) with experience of working in VFSS clinics. Descriptive statistics describe and summarise the data alongside inferential statistics where appropriate.

RESULTS

54 survey participants represented 40 unique acute healthcare organisations in the UK, in addition to two respondents from the Republic of Ireland. The survey demonstrated high variance in clinical practice across all stages of the VFSS procedure. Clinicians were not always compliant with current UK guidelines and the roles and responsibilities of different professionals working within the clinics were often not clearly defined.

CONCLUSION

Further research is required to develop new international, interprofessional VFSS guidelines to standardise service delivery for VFSS, improving diagnostic accuracy, efficiency and patient experience.

IMPLICATIONS FOR PRACTICE

In the absence of VFSS guidelines for imaging personnel, practitioners should familiarise themselves with the UK Royal College of Speech and Language Therapists VFSS Position paper; IR (ME)R guidelines and DRLs for the client groups with which they work to guide clinics and improve practice. Clinicians should revisit protocols and clinical governance regarding safe practice in order to improve the quality of care within the VFSS clinic.

Abstract 6147: Myc-driven osteosarcoma murine model for dissecting the molecular genetics and novel therapeutic strategies for OS

Osteosarcoma (OS) is the most common bone tumor in pediatric patients, particularly in adolescents and young adults. Unfortunately, over the past four decades, there has been minimal progress towards improving patient outcomes, especially for those with metastatic disease. Currently, no effective molecular targeted therapies are available for the OS, however many OS patients possess genetically defined somatic DNA copy number alterations (SCNAs), including amplification of chromosome 8q24. 8q24.2 region harbors the oncogene c-Myc, and the SCNA is associated with decreased overall survival rates. Furthermore, enhanced c-Myc transcript levels are significantly correlated with worse prognosis. There is a scarcity of reliable and reproducible in vivo animal models that mimic SCNAs and can be used to provide both intrinsic and extrinsic molecular insights into c-Myc-osteosarcoma biology. We have developed a novel conditional c- Myc knock-in mouse model to understand the mechanisms that underlie the ability of c-Myc to drive development and progression of OS and utilize for identification of c-Myc-dependent molecular vulnerabilities. A tissue-specific GEMM for osteosarcoma was developed by altering p53 (f/+) and c-Myc (c- Myc-in) genes in the osteoblast derived cells. Either c-Myc WT or the c-Myc T58A phosphorylation mutant was knocked-in from the constitutively active ROSA26 locus in response to Cre-recombinase. Differential gene expression in c-Myc-driven and non-driven-tumor tissue samples were quantified by RNA sequencing. The protein expression profiles were evaluated for both groups by comprehensive mass spectrometry (MS) analysis and reverse phase proteome analysis (RPPA). Osteosarcoma was confirmed for GEMM tumors by histopathological (H&E) staining. The spontaneous tumor development was significantly accelerated and more aggressive in c-Myc- driven GEMMs as compared to the non-c-Myc-driven. c-Myc expression was significantly higher both at the transcriptional and protein levels in the c-Myc-driven tissue/cells. Expression of 1479 genes (out of 13781 genes) were significantly altered at transcriptional levels in c-Myc driven tumor tissue samples, analyzed by RNA sequencing. Myc-target, E2F, G2M check-point, KRAS and DNA repair associated genes were significantly upregulated whereas the protein secretion, oxidative phosphorylation, adipognenesis, myhogenesis, and E2M transition genes were significantly downregulated when compared with the non-c-Myc-driven group. A significant alteration was observed in the protein expression levels of ribosome biogenesis, DNA replication, nucleotide excision repair, mismatch repair and RNA degradation associated genes in MS data analysis. Our mouse model has high penetrance, short latency, closely resembles human OS and will provide new opportunities for dissecting the molecular genetics of OS and developing novel therapeutic strategies. This model has also provided syngeneic cell lines for future in vivo studies.

Citation Format: Bikesh Kumar Nirala, Kurenbekova Lyazat, Tajhal Patel, Ryan Lane Shuck, Rajapakshe Kimal, Jason T. Yustein. Myc-driven osteosarcoma murine model for dissecting the molecular genetics and novel therapeutic strategies for OS [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6147.

Evaluating the role of dithiolane rich fraction of Ferula asafoetida (apiaceae) for its antiproliferative and apoptotic properties: in vitro studies

Asafoetida resin has been reported for various biological activities but its use has been widely restricted owing to its pungent smell and pool water solubility.

AIM

In vitro study of the anticancer potential of microwave-extracted essential oil (EO) of Ferula asafoetida.

MATERIALS AND METHODS

The phytochemical investigation and in vitro cytotoxicity assessment was carried out in two human liver cancer cell lines. The expression of NFKB1, TGFB1, TNF, CASP3 was analyzed by reverse transcription polymerase chain reaction.

RESULTS

Ferula asafoetida EO contains high concentrations of dithiolane, which possess antiproliferative activity in human liver carcinoma cell lines (HepG2 and SK-Hep1) in a dose-dependent manner. The bioactive compounds in F. asafoetida are capable of induction of apoptosis and altered NF-kB and TGF-β signalling with increase in caspase-3 and TNF-α expression.

CONCLUSION

Further elucidation of bioactive molecules and underlying mechanisms could lead to potential intervention in liver cancer in animal models. The safety and efficacy as well as the mode of EO action in animal models would be highly crucial.

Abstract OT3-08-01: A phase Ib/II clinical trial investigating the efficacy of nitric oxide deprivation and docetaxel in triple negative breast cancer

Triple negative breast cancer (TNBC) is an aggressive disease that currently lacks an efficacious form of therapy. Although chemotherapy is the current standard of care for metastatic TNBC, the 5-year prognosis remains grim with a high rate of disease recurrence. Cancer relapse is thought to be initiated by chemotherapy-resistant breast cancer stem cells (BCSCs). These BCSCs give rise to a diverse clonal population that results in a heterogeneous cancer, which complicates targeted therapeutic strategies. Our previous studies revealed that BCSCs utilize inducible nitric oxide synthase (iNOS)-derived nitric oxide to promote their proliferation, migration, and self-renewal capacity. In an effort to target the BCSC population, we found that iNOS inhibition with NG-monomethyl-L-arginine (L-NMMA) sensitized BCSCs to docetaxel in vivo in TNBC xenograft models, leading to decreased BCSC viability and tumor burden. These findings suggest that BCSC resist conventional therapy in a nitric oxide-dependent manner and that combination of L-NMMA with docetaxel will effectively target BCSCs to prevent further relapse. A phase Ib/II clinical trial was conducted to determine the maximum tolerated dose, recommended phase 2 dose (R2PD), dose-limiting toxicities (DLTs), and efficacy of the L-NMMA and docetaxel combination in TNBC patients with chemotherapy-refractory locally advanced or metastatic disease. For the phase Ib portion of the study, a standard Bayesian continual reassessment method is being used to investigate 7 dose levels of L-NMMA (5, 7.5, 10, 12.5, 15, 17.5, and 20 mg/kg) and two dose levels of docetaxel (75 and 100 mg/m2). Sixteen patients have been recruited to date, and based on current pharmacokinetics, pharmacodynamics, and safety data, the RP2D is expected to be docetaxel 100 mg/m2 (Day 1) and L-NMMA 20 mg/kg (Days 1-5) every 3 weeks. Two and three patients received 15 mg/kg L-NMMA + 75 mg/m2 docetaxel and 17.5 mg/kg L-NMMA + 100 mg/m2 docetaxel, respectively. Of these 5 patients, one partial responder completed 8 cycles before discontinuing treatment due to taxane-associated neuropathy. Among the five patients treated at the RP2D, only one taxane-associated DLT occurred. The overall response rate for patients treated at the higher doses was 22.2%. Early results of the phase Ib/II trial indicate the safety, tolerability, and promising activity of the first-in-class pan-NOS inhibitor L-NMMA in combination with chemotherapy in the treatment of chemotherapy-refractory TNBC.

Citation Format: Chung AW, Ensor JE, Darcourt J, Belcheva A, Patel T, Chang JC, Niravath PA. A phase Ib/II clinical trial investigating the efficacy of nitric oxide deprivation and docetaxel in triple negative 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 OT3-08-01.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.