Fluoropyrimidine type, patient age, tumour sidedness and mutation status as determinants of benefit in patients with metastatic colorectal cancer treated with EGFR monoclonal antibodies: individual patient data pooled analysis of randomised trials from the ARCAD database

BACKGROUND

KRAS mutations in metastatic colorectal cancer (mCRC) are used as predictive biomarkers to select therapy with EGFR monoclonal antibodies (mAbs). Other factors may be significant determinants of benefit.

METHODS

Individual patient data from randomised trials with a head-to-head comparison between EGFR mAb versus no EGFR mAb (chemotherapy alone or best supportive care) in mCRC, across all lines of therapy, were pooled. Overall survival (OS) and progression-free survival (PFS) were compared between groups. Treatment effects within the predefined KRAS biomarker subsets were estimated by adjusted hazard ratio (HRadj) and 95% confidence interval (CI). EGFR mAb efficacy was measured within the KRAS wild-type subgroup according to BRAF and NRAS mutation status. In both KRAS wild-type and mutant subgroups, additional factors that could impact EGFR mAb efficacy were explored including the type of chemotherapy, line of therapy, age, sex, tumour sidedness and site of metastasis.

RESULTS

5675 patients from 8 studies were included, all with known mCRC KRAS mutation status. OS (HRadj 0.90, 95% CI 0.84-0.98, p = 0.01) and PFS benefit (HRadj 0.73, 95% CI 0.68-0.79, p < 0.001) from EGFR mAbs was observed in the KRAS wild-type group. PFS benefit was seen in patients treated with fluorouracil (HRadj 0.75, 95% CI 0.68-0.82) but not with capecitabine-containing regimens (HRadj 1.04, 95% CI 0.86-1.26) (pinteraction = 0.002). Sidedness also interacted with EGFR mAb efficacy, with survival benefit restricted to left-sided disease (pinteraction = 0.038). PFS benefits differed according to age, with benefits greater in those under 70 (pinteraction = 0.001). The survival benefit was not demonstrated in those patients with mutations found in the KRAS, NRAS or BRAF genes. The presence of liver metastases interacted with EGFR mAb efficacy in patients with KRAS mutant mCRC (pinteraction = 0.004).

CONCLUSION

The benefit provided by EGFR mAbs in KRAS WT mCRC is associated with left-sided primary tumour location, younger patient age and absence of NRAS or BRAF mutations. Survival benefit is observed with fluorouracil but not capecitabine. Exploratory results support further research in KRAS mutant mCRC without liver metastases.

A Phase 1 Trial of the Safety, Tolerability, and Biological Effects of Intravenous Enadenotucirev (EnAd), a Novel Oncolytic Virus, in Combination with Chemoradiotherapy in Locally Advanced Rectal Cancer (CEDAR)

PURPOSE/OBJECTIVE(S)

Novel treatment combinations are required to increase response rates in rectal cancer. EnAd is an intravenous, tumor selective, oncolytic adenovirus with high affinity for malignant colorectal epithelial cells. Pre-clinical evidence of synergy with radiation warranted further clinical evaluation and assessment of safety in combination with chemoradiation (CRT), 25 × 2Gy and concurrent capecitabine.

MATERIALS/METHODS

EnAd was escalated using 2 dose levels of viral particles (1 × 1012, 3 × 1012), given Monday, Wednesday, Friday over 3 schedules (pre-CRT, pre & post CRT). Toxicity and efficacy were used as dual end points in escalation decisions. A 2-parameter and 3-parameter logistic Time to Event Continual Reassessment Method (TiTE-CRM) were used estimate the dose-toxicity and dose-efficacy relationship, respectively. Results are shown as probability and 95% credible interval (Cr.I). The dose limiting toxicity (DLT) window was 13 weeks. Patients who had not completed their DLT window at the time of a dose decision were included in the safety analysis but down-weighted according to their follow-up time and amount of IMP received. Efficacy was assessed at 13 weeks using MRI Tumor Regression Grade (mrTRG), where mrTRG 1-2 equals response. The trial (NCT03916510) was conducted in 4 UK centers.

RESULTS

A total of 13 patients were enrolled, 12 of whom were evaluable. Median age was 57 (range 31-84), and 10/13 were male. One patient had two G3 adverse events (AE); diarrhea, acute kidney injury. All other adverse events (AEs) were G1 or 2, with no G4/5 events. The most common AE by organ system was gastrointestinal (20.8%, G1). There were two observed DLTs on Dose schedule 3; leg swelling and acute kidney injury. Responses and toxicities increased with escalating schedules of EnAd (Table 1).

CONCLUSION

CEDAR is the first trial to successfully combine an intravenous oncolytic adenovirus with radiation, demonstrating the feasibility and acceptability of this approach, and a new paradigm in radiosensitization in rectal cancer. Within this small Phase I study, EnAd demonstrated an acceptable safety profile with evidence of a higher-than-expected rate of response by mrTRG. Translation analysis of tissue, blood and microbiome for biological correlates of radiation synergy is underway.

FUNDING

PsiOxus, CRUK (A24474).

SPONSOR

University of Oxford.

Accuracy and economic evaluation of screening tests for undiagnosed COPD among hypertensive individuals in Brazil

In Brazil, prevalence of diagnosed COPD among adults aged 40 years and over is 16% although over 70% of cases remain undiagnosed. Hypertension is common and well-recorded in primary care, and frequently co-exists with COPD because of common causes such as tobacco smoking, therefore we conducted a cross-sectional screening test accuracy study in nine Basic Health Units in Brazil, among hypertensive patients aged ≥40 years to identify the optimum screening test/combinations to detect undiagnosed COPD. We compared six index tests (four screening questionnaires, microspirometer and peak flow) against the reference test defined as those below the lower limit of normal (LLN-GLI) on quality diagnostic spirometry, with confirmed COPD at clinical review. Of 1162 participants, 6.8% (n = 79) had clinically confirmed COPD. Peak flow had a higher specificity but lower sensitivity than microspirometry (sensitivity 44.3% [95% CI 33.1, 55.9], specificity 95.5% [95% CI 94.1, 96.6]). SBQ performed well compared to the other questionnaires (sensitivity 75.9% [95% CI 65.0, 84.9], specificity 59.2% [95% CI 56.2, 62.1]). A strategy requiring both SBQ and peak flow to be positive yielded sensitivity of 39.2% (95% CI 28.4, 50.9) and specificity of 97.0% (95% CI 95.7, 97.9). The use of simple screening tests was feasible within the Brazilian primary care setting. The combination of SBQ and peak flow appeared most efficient, when considering performance of the test, cost and ease of use (costing £1690 (5554 R$) with 26.7 cases detected per 1,000 patients). However, the choice of screening tests depends on the clinical setting and availability of resources.ISRCTN registration number: 11377960.

Pressurised intraperitoneal aerosolised chemotherapy (PIPAC) for gastric cancer with peritoneal metastases: A systematic review by the PIPAC UK collaborative

INTRODUCTION

Gastric cancer with peritoneal metastases (GCPM) carries a poor prognosis. Pressurised Intraperitoneal Aerosolised Chemotherapy (PIPAC) offers pharmacokinetic advantages over intravenous therapy, resulting in higher chemotherapy concentrations in peritoneal deposits, and potentially reduced systemic absorption/toxicity. This review evaluates efficacy, tolerability and impact on quality of life (QOL) of PIPAC for GCPM.

METHODS

Following registration with PROSPERO (CRD42021281500), MEDLINE, EMBASE and The Cochrane Library were searched for PIPAC in patients with peritoneal metastases, in accordance with PRISMA standards RESULTS: Across 18 included reports representing 751 patients with GCPM (4 prospective, 11 retrospective, 3 abstracts, no phase III studies), median overall survival (mOS) was 8 - 19.1 months, 1-year OS 49.8-77.9%, complete response (PRGS1) 0-35% and partial response (PRGS2/3) 0-83.3%. Grade 3 and 4 toxicity was 0.7-25% and 0-4.1% respectively. Three studies assessing QOL reported no significant difference.

CONCLUSION

PIPAC may offer promising survival benefits, toxicity, and QOL for GCPM.

P09.04.B The importance of treatment tolerability for people with glioma: registry review and qualitative findings from the COBra Study

Background

Gliomas are the commonest form of primary brain tumour, accounting for 80% of malignant brain tumours. Gliomas represent a heterogeneous group of cancers with variable outcomes, traditionally graded from I to IV (least to most aggressive). The poor prognosis of some glioma patients and high symptom burden has led to a growing emphasis on their quality of survival. Maintaining cognitive function, physical function and other health-related quality of life aspects throughout the disease trajectory are key considerations, particularly for patients with aggressive forms of glioma. It is therefore important that glioma intervention studies collect data aligned with patient priorities that enables assessment of the net clinical benefit of treatments and facilitates informed decision-making. In particular, and of increasing recognition, is the importance of monitoring the incidence of adverse events during and after the course of an intervention, and understanding their impact upon patients, and patients’ own assessment of, tolerability.

Material and Methods

A trial registry review, a systematic review of the qualitative literature and semi-structured interviews with patients and caregivers were undertaken. Outcomes were extracted from these sources to formulate a longlist during the development of a core outcome set for glioma interventional trials (the COBra study).

Results

The registry review (n=91), systematic review (n=21) and semi-structured interviews (n=19) identified many important outcomes and concepts, one of which was tolerability. Tolerability, adverse events, toxicity or safety was reported to be collected as an outcome in 46 trials. Outcomes related to tolerability were identified from 7 articles included in the systematic review. Themes related to tolerability emerged from the qualitative interviews. These included tolerability of side effects of treatment; trade-offs of side effects versus potential benefits in deciding on, and willingness to, undertake further treatment; and self-directed strategies for coping.

Conclusion

There is a growing acknowledgement of the importance of treatment tolerability in the wider field of cancer research. In glioma research specifically, its significance is yet to be reflected in outcomes collected in trials. Our qualitative findings indicate tolerability is of high significance to patients and those close to them. Participants reported how their preconceptions and experience of tolerability influenced treatment decisions and treatment uptake. However, outcomes related to tolerability were collected in just over half of trials in our sample. Tolerability and items relating to the patients’ experience of adverse events should be collected and reported in trial findings to reflect patients’ priorities and enable informed treatment decisions.

Rectal cancer management during the COVID-19 pandemic (ReCaP): multicentre prospective observational study

Concerns over unacceptable high mortality in patients with rectal cancer undergoing surgery or systemic therapy who contract COVID-19 have led to widespread adoption of alternative treatment strategies.The ReCaP study aimed to study these variations and associated outcomes.

Outcome following surgery to treat septic peritonitis in 95 cats in the United Kingdom

OBJECTIVES

To review the cause, management and outcome in cats with septic peritonitis within the United Kingdom (2008 to 2018) and to identify if previously identified prognostic factors were associated with survival in this population.

MATERIALS AND METHODS

Clinical records from 10 referral hospitals in United Kingdom were reviewed. Data collected included signalment, clinicopathological data and management techniques. Serum albumin, glucose, lactate and ionised calcium concentration; presence of intraoperative hypotension and correct empirical antibiosis were analysed via logistic regression for association with survival.

RESULTS

Ninety-five cats were included. The overall survival rate was 66%. Lethargy (89%) and anorexia (75%) were the most common clinical signs, with abdominal pain and vomiting in 44% and 27% of cases, respectively. Gastro-intestinal leakage was the most common source of contamination. The presence of an abdominal mass on clinical examination was not strongly predictive of the presence of neoplasia on histology and did not confer a worse prognosis. Cats presenting with dehiscence of a previous enterotomy/enterectomy did not have a worse prognosis than those presenting with other aetologies. Intraoperative hypotension (adjusted odds ratio 0.173, 95% confidence intervals 0.034 to 0.866, P=0.033) was associated with non-survival. Cats that survived beyond 1 day postoperatively had an improved likelihood of survival (87.5%). All cats that survived beyond 6 days were successfully discharged.

CLINICAL SIGNIFICANCE

This study describes the largest group of cats with septic peritonitis with an overall survival rate of 66%. The presence of an abdominal mass on clinical examination or having dehiscence of a previous gastrointestinal surgery did not confer a worse prognosis.

Tracking and Assessing Oil Spill Toxicity to Aquatic Organisms: A Novel Approach

An in situ exposure and effects bioassay system was developed for assessing the toxicity of oil spills to aquatic organisms. The assessment tool combines components of 2 previously developed systems, the sediment ecotoxicity assessment ring (SEA Ring) and the drifting particle simulator. The integrated drifting exposure and effects assessment ring (DEEAR) is comprised of a Global Positioning System (GPS) float, a drifter drogue, the SEA Ring, and the Cyclops-7 fluorescent sensor. Polyethylene passive sampling devices (PED) were mounted for an additional means to characterize water quality conditions and exposures. The DEEAR is optimized for evaluating oil exposure and toxicity in the shallow surface mixing layer of marine waters. A short-term preliminary test was conducted in San Diego, California, USA, to verify the operation of the GPS tracking, the iridium communications, and the integrated SEA Ring exposure system. Further, a proof-of-concept demonstration was conducted offshore in the Santa Barbara Channel, where natural oil seeps produce surface slicks and sheens. Two DEEAR units were deployed for 24 h-one within the oil slick and one in an area outside observable slicks. An aerial drone provided tracking of the surface oil and optimal sites for deployment. The DEEAR proof-of-concept demonstrated integrated real-time tracking and characterization of oil exposures by grab samples, PED, and fluorescent sensors. Oil exposures were directly linked to toxic responses in fish and mysids. This novel integrated system shows promise for use in a variety of aquatic sites to more accurately determine in situ oil exposure and toxicity. Environ Toxicol Chem 2021;40:1452-1462. © 2021 SETAC.

Intensity-modulated Radiotherapy for Rectal Cancer in the UK in 2020

AIMS

Preoperative (chemo)radiotherapy followed by total mesorectal excision is the current standard of care for patients with locally advanced rectal cancer. The use of intensity-modulated radiotherapy (IMRT) for rectal cancer is increasing in the UK. However, the extent of IMRT implementation and current practice was not previously known. A national survey was commissioned to investigate the landscape of IMRT use for rectal cancer and to inform the development of national rectal cancer IMRT guidance.

MATERIALS AND METHODS

A web-based survey was developed by the National Rectal Cancer IMRT Guidance working group in collaboration with the Royal College of Radiologists and disseminated to all UK radiotherapy centres. The survey enquired about the implementation of IMRT with a focus on the following aspects of the workflow: dose fractionation schedules and use of a boost; pre-treatment preparation and simulation; target volume/organ at risk definition; treatment planning and treatment verification. A descriptive statistical analysis was carried out.

RESULTS

In total, 44 of 63 centres (70%) responded to the survey; 30/44 (68%) and 36/44 (82%) centres currently use IMRT to treat all patients and selected patients with rectal cancer, respectively. There was general agreement concerning several aspects of the IMRT workflow, including patient positioning, use of intravenous contrast and bladder protocols. Greater variation in practice was identified regarding rectal protocols; use of a boost to primary/nodal disease; target volume delineation; organ at risk delineation and dose constraints and treatment verification. Delineation of individual small bowel loops and daily volumetric treatment verification were considered potentially feasible by most centres.

CONCLUSION

This survey identified that IMRT is already used to treat rectal cancer in many UK radiotherapy centres, but there is heterogeneity between centres in its implementation and practice. These results have been a valuable aid in framing the recommendations within the new National Rectal Cancer IMRT Guidance.

Population-based analysis of sociodemographic predictors, health-related quality of life and health service use associated with obstructive sleep apnoea and insomnia in Australia

Although there is growing recognition of the effects of living with sleep disorders and the important role of primary care in their identification and management, studies indicate that the detection of sleep apnoea (OSA) and insomnia may still be low. This large representative community-based study (n=2977 adults) used logistic regression models to examine predictors of self-reported OSA and current insomnia and linear regression models to examine the association of these sleep conditions with both mental and physical components of health-related quality of life (HRQoL) and health service use. Overall, 5.6% (95% confidence interval (CI) 4.6-6.7) and 6.8% (95% CI 5.7-7.9) of subjects self-reported OSA (using a single-item question) and current insomnia (using two single-item questions) respectively. Many sociodemographic and lifestyle predictors for OSA and insomnia acted in different directions or showed different magnitudes of association. Both disorders had a similar adverse relationship with physical HRQoL, whereas mental HRQoL was more impaired among those with insomnia. Frequent consultations with a doctor were associated with a lower physical HRQoL across these sleep conditions; however, lower mental HRQoL among those frequently visiting a doctor was observed only among individuals with insomnia. The adverse relationship between sleep disorders and physical and mental HRQoL was substantial and should not be underestimated.

Trends in complications and mortality following catheter ablation of atrial fibrillation: results from 22,582 ablations in Australia and New Zealand from 2010 to 2015

Background

Recent studies from the United States report rising rates of in-hospital complications and mortality following catheter ablation of atrial fibrillation (AF) but whether such a trend is observed in other populations is uncertain.

Purpose

To examine the trends in complications and mortality following AF ablations up to 30 days after discharge in Australia and New Zealand (ANZ) using nationwide data.

Methods

All patients ≥18y undergoing catheter ablation of AF from 2010–2015 were identified using hospitalisation data from all public and most private hospitals in ANZ. The primary endpoint was one or more procedural complications during the hospital stay or within 30 days of discharge. The secondary endpoints were mortality and other specific complications. Unadjusted trend was evaluated using Cochran-Armitage test while that of complications, adjusting for differences in other characteristics, was evaluated using multivariate logistic regression with the year of ablation modelled as a continuous variable. Results are reported as odd ratios (OR) and 95% confidence intervals (CI).

Results

A total of 22,582 AF ablations were included (mean age 62.2±11.6y, 29.1% female, 94.4% elective procedures). The number of ablations increased by 26.4% during the study period (3,097 in 2010 to 3,915 in 2015). Rates of heart failure (8.98% to 10.09%, p for trend=0.010), diabetes (4.52% to 12.46%, p&lt;0.001), chronic kidney disease (2.36% to 4.29%, p&lt;0.001) significantly increased over time but that of hypertension decreased (15.27% to 12.29%, p&lt;0.001). The incidence of overall complications (6.55% in 2010 to 6.67% in 2015, OR 0.99, 95% CI 0.96–1.03) was unchanged during the study period (Figure 1A). When individual complications were considered, mortality rate was low with no statistically significant change with time (0.19% to 0.15%, OR 1.03, 95% CI 0.84–1.28) (Figure 1A) while the rate of acute kidney injury (0.23% to 0.51%, OR 1.17, 95% CI 1.02–1.34) increased and that of venous thromboembolism (0.16% to 0.0%, OR 0.71, 95% CI 0.54–0.94) decreased (Figure 1B). Though the incidence of any bleeding (4.49% to 3.98%, OR 0.97, 95% CI 0.93–1.01) was unchanged, that of major bleeding requiring blood transfusion (0.97% to 0.64%, OR 0.87, 95% CI 0.79–0.96) declined significantly (Figure 1B). No significant trend was observed in other complications or when in-hospital (5.13% to 5.21%, OR 1.00, 95% CI 0.97–1.04) and post-discharge (1.55% to 1.63%, OR 0.97, 95% CI 0.91–1.03) complications were separately evaluated.

Conclusions

Though more patients with heart failure, diabetes and chronic kidney disease underwent catheter ablation of AF over time in ANZ, the overall complication rate was unchanged with a significant decrease in the incidences of major bleeding and venous thromboembolism. However, rate of acute kidney injury nearly doubled, and this could be a potential target for efforts to further improve procedural safety.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The National Heart Foundation of Australia

Differences between public and private hospitals in complications following catheter ablation of atrial fibrillation: a cohort study in Australia

Background

Comparing outcomes of care between public and private hospitals is critical to inform patients and improve care quality.

Purpose

To compare complication rates following catheter ablation of atrial fibrillation (AF) up to 30-days post discharge between public and private hospitals.

Methods

We included patients ≥18 years who underwent AF ablation in the Australian states of New South Wales, Queensland, Victoria, and Western Australia from 2010–2015. The primary outcome was the occurrence of any complication up to 30-days after discharge. The association between provider type and the risk of complications was examined using logistic regression with inverse probability of treatment weighting (IPTW) propensity scores to account for differences in measured confounders. The minimum strength of association required for an unmeasured confounder to nullify any observed association was estimated using the E value.

Results

We identified 18,074 AF ablations during the study period (mean age 62.3±11.4y, 28.8% female, 78.4% performed in private hospitals). Patients ablated at public hospitals were younger (59.3 vs. 63.1y, p&lt;0.001) but had higher rates of heart failure (10.3% vs. 7.7%, p&lt;0.001), diabetes (10.9% vs. 7.9%, p&lt;0.001), chronic kidney disease (4.9% vs. 2.2%, p&lt;0.001), and chronic lung diseases (4.2% vs. 3.6%, p=0.046) than those at private hospitals. The unadjusted rate of complications was higher in publics hospitals compared with private ones (7.59% vs. 5.26%, p&lt;0.001). After IPTW, there was good covariate balance with a median standardised difference of 0.006 (range 0.0–0.032) and the adjusted difference in procedural complication rates between two sectors remained significant (OR=1.46, 95% CI 1.24–1.73). The difference was mainly driven by an elevated risk of complications requiring cardiac surgery (OR=3.85, 95% CI 1.35–10.98), acute kidney injury (OR=2.95, 95% CI 1.12–7.74), cardiorespiratory failure (OR=2.69, 95% CI 1.19–6.04), postprocedural infection (OR=2.50, 95% CI 1.28–4.86), and bleeding (OR=1.26, 95% CI 1.02–1.56) (Figure 1). The disparity in the complication rates persisted when in-hospital (OR=1.41, 95% CI 1.16–1.70) and post-discharge (OR=1.52, 95% CI 1.12–2.07) complications were analysed separately. The E value was 1.79, suggesting that the disparity might plausibly be explained by unmeasured confounders.

Conclusion

AF ablation at a public hospital was associated with a 46% higher risk of complications compared with ablation at a private hospital, mainly driven by a higher risk of complications requiring cardiac surgery, acute kidney injury, cardiorespiratory failure, infections, and bleeding. The disparity could be due to differences in care quality between two sectors or explained by unmeasured confounders such as higher procedural complexity in public hospitals.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The National Heart Foundation of Australia

Impact of compliance to chemoradiation on long-term outcomes in squamous cell carcinoma of the anus: results of a post hoc analysis from the randomised phase III ACT II trial

BACKGROUND

Concurrent chemoradiation is standard-of-care for patients with squamous cell carcinoma of the anus. Poor compliance to chemotherapy, radiotherapy treatment interruptions and unplanned breaks may impact adversely on long-term outcomes.

METHODS

The ACT II trial recruited 940 patients with localised squamous cell carcinoma of the anus, and assigned patients to mitomycin (week 1) or cisplatin (weeks 1 and 5), with fluorouracil (weeks 1 and 5) and radiotherapy (50.4 Gy in 28 fractions over 38 days). This post hoc analysis examined the association between baseline factors (age, gender, site, T stage and N stage), and compliance to treatment (radiotherapy and chemotherapy), and their effects on locoregional failure-free survival, progression-free survival (PFS) and overall survival (OS). Compliance was categorised into groups. Radiotherapy: six groups according to total dose and overall treatment time (OTT). Chemotherapy: three groups (A = per-protocol; B = dose reduction or delay; C = omitted).

RESULTS

A total of 931/940 patients were assessable for radiotherapy and 936 for chemotherapy compliance. Baseline glomerular filtration rate <60 ml/min and cisplatin were significantly associated with poor week 5 compliance to chemotherapy (P = 0.003 and 0.02, respectively). Omission of week 5 chemotherapy was associated with significantly worse locoregional failure-free survival [hazard ratio (HR) 2.53 (1.33-4.82) P = 0.005]. Dose reductions/delays or omission of week 5 chemotherapy were associated with significantly worse PFS {HR: 1.56 [95% confidence interval (CI): 1.18-2.06], P = 0.002 and HR: 2.39 (95% CI: 1.44-3.98), P = 0.001, respectively} and OS [HR: 1.92 (95% CI: 1.41-2.63), P < 0.001 and HR: 2.88 (95% CI: 1.63-5.08), P < 0.001, respectively]. Receiving the target radiotherapy dose in >42 days is associated with worse PFS and OS [HR: 1.72 (95% CI: 1.17-2.54), P =0.006].

CONCLUSION

Poor compliance to chemotherapy and radiotherapy were associated with worse locoregional failure-free survival, PFS and OS. Treatment interruptions should be minimised, and OTT and total dose maintained.

CLINICAL TRIAL NUMBER

ISRCTN 26715889.

Expansion of off-site percutaneous coronary intervention centres significantly reduces ambulance driving time to primary PCI in the Netherlands

Introduction

In patients with ST-elevation myocardial infarction (STEMI), percutaneous coronary intervention (PCI)-mediated reperfusion is preferred over pharmacoinvasive reperfusion with fibrinolysis if transfer to a PCI centre can be ensured in ≤120 min. We evaluated the ambulance driving time to primary PCI centres in the Netherlands and assessed to what extent ambulance driving times were impacted by the expansion of off-site PCI centres.

Methods and results

We calculated the driving routes from every Dutch postal code to the nearest PCI centre with (on-site) or without (off-site) surgical back-up. We used data from ambulance records to estimate the ambulance driving time on each route. There were 16 on-site and 14 off-site PCI centres. The median (interquartile range) time to on-site PCI centres was 18.8 min (12.2–26.3) compared with 14.9 min (8.9–20.9) to any PCI centre (p < 0.001). In postal code areas that were impacted by the initiation of off-site PCI, the median driving time decreased from 25.4 (18.2–33.1) to 14.7 min (8.9–20.9) (p < 0.001). Ambulance driving times of >120 min were only seen in non-mainland areas.

Conclusion

Based on a computational model, timely ambulance transfer to a PCI centre within 120 min is available to almost all STEMI patients in the Netherlands. Expansion of off-site PCI has significantly reduced the driving time to PCI centres.

UK national cohort of anal cancer treated with intensity-modulated radiotherapy: One-year oncological and patient-reported outcomes

BACKGROUND

Concurrent chemoradiotherapy is the standard treatment for anal cancer. Following national UK implementation of intensity-modulated radiotherapy (IMRT), this prospective, national cohort evaluates the one-year oncological outcomes and patient-reported toxicity outcomes (PRO) after treatment.

MATERIALS AND METHODS

A national cohort of UK cancer centers implementing IMRT was carried out between February to July 2015. Cancer centers provided data on oncological outcomes, including survival, and disease and colostomy status at one-year. EORTC-QLQ core (C30) and colorectal (CR29) questionnaires were completed at baseline and one-year followup. The PRO scores at baseline and one year were compared.

RESULTS

40 UK Cancer Centers returned data with a total of 187 patients included in the analysis. 92% received mitomycin with 5-fluorouracil or capecitabine. One-year overall survival was 94%; 84% were disease-free and 86% colostomy-free at one-year followup. At one year, PRO results found significant improvements in buttock pain, blood and mucus in stools, pain, constipation, appetite loss, and health anxiety compared to baseline. No significant deteriorations were reported in diarrhea, bowel frequency, and flatulence. Urinary symptom scores were low at one year. Moderate impotence symptoms at baseline remained at one year, and a moderate deterioration in dyspareunia reported.

CONCLUSIONS

With national anal cancer IMRT implementation, at this early pre-defined time point, one-year oncological outcomes were reassuring and resulted in good disease-related symptom control. one-year symptomatic complications following CRT for anal cancer using IMRT techniques appear to be relatively mild. These PRO results provide a basis to benchmark future studies.

P347Complications of catheter ablation for atrial fibrillation: a nation-wide study in Australia and New Zealand

Background

It is important to investigate complications of catheter ablation for atrial fibrillation (AF) - an increasingly common procedure - to inform patients and guide efforts to improve procedural quality. However, clinical trials and registries are limited by selection bias, while existing population-based studies either lack nation-wide data, or fail to report post-discharge complications. The timing and impact of these complications are also poorly understood.

Purpose

To obtain unbiased and comprehensive estimates of complications of AF ablations using national data from Australia and New Zealand. We also evaluated the impact of in-hospital complications on the length of stay and assessed the timing of post-discharge complications.

Methods

We included patients aged ≥18 years undergoing catheter ablation with a primary diagnosis of AF between 2010–2015 in all public and most private hospitals in Australia and New Zealand. The primary outcome was the occurrence of major complications in-hospital or up to 30-days after discharge. We identified major complications based on a literature review and expert clinical opinion and defined these using International Classification of Diseases – 10th revision, Australian Modification diagnoses codes and Australian Classification of Health Interventions procedure codes. We determined the impact of in-hospital complications on the length of stay, adjusting for other covariates, by using negative binomial regression, and reported results as incident rate ratio (IRR) and 95% confidence intervals (CI). Time to first post-discharge complication was evaluated using Kaplan Meier survival analysis.

Results

A total of 20,057 AF ablations were included (mean age 62.1±11.6 y, 56.7% ≤65 years old; 29.2% female; median length of stay 1 day). Of these, major complications occurred in 6.3% procedures (4.6% occurring in-hospital and a further 2.0% occurring in the 30-day post discharge). The most common complications were bleeding or haematoma formation and perforation (primarily pericardial effusion), which accounted to 60.3% and 14.3% of all complications, respectively. Rate of procedure-related deaths was 0.1%. Occurrence of an in-hospital complication more than doubled the length of stay (IRR: 2.3, 95% CI 2.2–2.4) with complications requiring cardiac surgery (IRR 4.5, 95% CI 3.2–6.4) and vascular injuries (IRR 3.9, 95% CI 3.1–4.9) having the length of stay prolonged the most (Figure 1A). In the first-week, 67.3% of post-discharge complications had occurred, and this number reached 95% within three-weeks (Figure 1B).

Conclusions

Major complications after AF ablation were common. In-hospital complications doubled the length of stay. Approximately 30% of complications occurred after discharge with the risk highest in the first seven days. Efforts to reduce complications should focus on reducing the incidence of bleeding and pericardial effusions which counted for more than 75% of all complications.

Acknowledgement/Funding

National Heart Foundation of Australia, The Hospital Research Foundation

Autism spectrum disorder in children with Type 1 diabetes

AIM

Links between autism spectrum disorder (ASD) and autoimmune diseases, including Type 1 diabetes have been proposed. This study assessed the frequency of ASD in children with Type 1 diabetes in the T1D Exchange (T1DX) registry and the impact of ASD on characteristics of children with Type 1 diabetes.

METHODS

Analysis included 10 032 participants aged < 18 years (median Type 1 diabetes duration 6.5 years, 48% female, 77% non-Hispanic White). Diagnosis of ASD was defined as autism, Asperger's or pervasive developmental disorder.

RESULTS

A diagnosis of ASD was recorded for 159 (1.58%) participants. Those with ASD were predominantly male (88% vs. 51% of those without ASD, P < 0.001) and slightly older (median 14 vs. 13 years, P = 0.022). Occurrence of diabetic ketoacidosis at Type 1 diabetes diagnosis was similar (35% vs. 41%, P = 0.161). Pump use was lower in those with ASD (51% vs. 63%, P = 0.005) but continuous glucose monitor use was similar (24% vs. 27%, P = 0.351). Median HbA_1c was slightly lower in those with ASD [68 vs. 69 mmol/mol (8.4% vs. 8.5%), P = 0.006]. This difference was more pronounced after adjusting for confounders.

CONCLUSIONS

The frequency of ASD in the T1DX registry was similar to that in the general population. These data show that despite deficits in communication, occurrence of diabetic ketoacidosis was similar in youth with and without ASD. Pump use was less frequent in those with ASD, possibly due to sensory issues, although CGM use did not differ. The lower HbA_1c may be due to a more regimented routine with ASD. Because comorbidities such as ASD complicate care of patients with Type 1 diabetes, further research is needed to support these children.

Controls on nitrogen transformation rates on restored floodplains along the Cosumnes River, California

Levee construction results in the systematic replumbing of river systems and reduces the frequency of floodplain inundation, which impacts nutrient delivery and transformations in floodplains. Floodplain restoration via levee removal affects downstream water quality by restoring soil microbial metabolic pathways such as denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA). Although these metabolisms are important for the nitrogen cycle, few studies have quantified the contribution of all three pathways to nitrate retention or loss in restored floodplains. The objectives of this study were to quantify the relevance of denitrification, anammox and DNRA to nitrogen retention, characterize the hydrologic conditions most favorable to each pathway, and estimate the potential for floodplain restoration to improve nitrogen cycling in the Cosumnes River watershed. To address these goals, we simulated flood conditions in soil mesocosms collected from two floodplains where levees were breached in 1997 and 2014 along the Lower Cosumnes River in the San Joaquin Basin of California. River water enriched with K¹⁵NO₃ tracer was pumped into each mesocosm at a constant rate for a period of 3 months. Samples were collected from the surface water and soil pore water for measurements of NO₃^-, NO₂^-, and NH₄⁺ concentrations, and δ¹⁵N of dissolved gases (N₂ and N₂O). To the best of our knowledge, this study reports the highest relative contribution to N₂ production due to anammox for freshwater systems (41 to 84%) to date. High anammox rates were associated with heterogeneous grain size distribution across depth and high nitrification rates. We quantify the capacity of restored floodplain soils with distinct textural and chemical characteristics to retain or release nitrogen during large and small floods in a particular water year.

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.

Session 4: What should we do for poor responders after chemoradiotherapy: bad biology or should the fight go on?

Just over 50% of patients with advanced rectal cancer have a poor response to chemoradiotherapy with resultant poor outcomes. Professor Glimelius reviews the evidence base for defining such patients and the potential role, if any, of further treatment.

A paradigm for understanding trust and mistrust in medical research: The Community VOICES study

BACKGROUND

To promote justice in research practice and rectify health disparities, greater diversity in research participation is needed. Lack of trust in medical research is one of the most significant obstacles to research participation. Multiple variables have been identified as factors associated with research participant trust/mistrust. A conceptual model that provides meaningful insight into the interplay of factors impacting trust may promote more ethical research practice and provide an enhanced, actionable understanding of participant mistrust.

METHODS

A structured survey was developed to capture attitudes toward research conducted in emergency situations; this article focuses on items designed to assess respondents' level of trust or mistrust in medical research in general. Community-based interviews were conducted in English or Spanish with 355 New York City residents (white 42%, African American 29%, Latino 22%).

RESULTS

Generally favorable attitudes toward research were expressed by a majority (85.3%), but many respondents expressed mistrust. Factor analysis yielded four specific domains of trust/mistrust, each of which was associated with different demographic variables: general trustworthiness (older age, not disabled); perceptions of discrimination (African American, Latino, Spanish language preference); perceptions of deception (prior research experience, African American); and perceptions of exploitation (less education).

CONCLUSIONS

The four domains identified in the analysis provide a framework for understanding specific areas of research trust/mistrust among disparate study populations. This model offers a conceptual basis for the design of tailored interventions that target specific groups to promote trust of individual researchers and research institutions as well as to facilitate broader research participation.