Malignant ascites as a marker of peritoneal carcinomatosis burden in patients with colorectal and gastroesophageal cancer

455

Background: Malignant ascites occurs frequently in patients with gastric cancer (GC) and colorectal cancer (CRC) with peritoneal metastasis (PM). The presence of PM and malignant ascites have been independently reported to confer resistance to systemic therapy and poorer prognosis. However, the occurrence of malignant ascites as a function of increasing peritoneal carcinomatosis burden has been less studied and reported. Methods: We reviewed prospective cohorts of gastric cancer and colorectal cancer patients with PM. The first cohort was a prospective group of GCPM patients receiving bi-directional systemic and peritoneal-directed therapies (catheter-based intraperitoneal chemotherapy and/or pressurized intraperitoneal aerosol chemotherapy respectively) at a tertiary oncology center in Singapore. Clinico-pathological data, including Peritoneal Cancer Index (PCI) and the presence or absence of ascites based on diagnostic laparoscopy, was collected. To orthogonally validate the hypothesis of malignant ascites as a function of peritoneal carcinomatosis burden in gastrointestinal malignancies, we studied the relationship between ascites, PM and survival in an independent cohort of metastatic CRC patients eligible for first-line systemic treatment enrolled in two randomized clinical trials in different Italian cancer centers. Results: In the first cohort of 82 patients with GCPM, the median PCI was 19 (inter-quartile range (IQR) 8 – 26) in the group with ascites and 3 (IQR 1 – 12) in the group without ascites (p=0.005), suggesting ascites occurs with higher PM burden. The median overall survival (OS) was poorer in patients with ascites (13.4 vs 16.4 months, HR 1.6, 95% CI 0.9 – 2.8, p=0.082). The median OS in patients with PCI of <7 was 17.3 months (95% 12.0 – 22.7) and 13.8 months (95% CI 11.0 – 16.6) in those with PCI score >7. In the validation cohort of 900 CRC patients, presence of malignant ascites and PM resulted in poorer survival compared to patients with PM and no malignant ascites (HR for OS PM with ascites vs PM without ascites 2.01 (95% CI 1.37 - 2.96), p<0.001). Interestingly, those with PM and ascites had a poorer survival to those with stage IV disease without peritoneal involvement, while those with PM without ascites did not have a statistically significant difference (PM with malignant ascites vs. no peritoneal disease, HR for OS 2.14, 95% CI 1.57 – 3.01, p=0.007; PM without ascites vs no peritoneal disease, HR for OS 1.10, 95% CI 0.91 – 1.34). Conclusions: Our study of patients with colorectal or gastric cancer and peritoneal metastases suggest the presence of malignant ascites as a function of increased peritoneal carcinomatosis burden among patients with metastatic gastrointestinal malignancies, with correspondingly poorer survival outcomes.

73 Computed Tomography Imaging to Determine Reduction in Intracrainal Pressure Before & After Posterior Vault Expansion in Apert Syndrome

Introduction

Apert syndrome is an autosomal dominant malformation syndrome, accounting for 4.5% of all craniosynostoses. Raised intracranial pressure (ICP) in Apert syndrome has a multifactorial aetiology, with an incidence of up to 45% if left untreated [1, 2]. Raised ICP can be determined clinically, with non-invasive and invasive methods. In this study, we want to assess whether the use of CT scans is reliable in identifying changes in ICP.

Method

Pre and postoperative CT scans for 13 Apert syndrome patients who had posterior vault expansion were assessed and graded for severity of intracranial pressure (ICP). The grading system used was departmental specific and the assessment was carried out by a single clinician on different brain structures. This process was repeated on the same patients, using the same CT scans, 4 months later to determine consistency and repeatability. The relationship between the pre and postoperative scans was explored using the chi squared test. Intra-observer variability was assessed using Kappa statistics [SS1].

Results

There was no statistically significant difference between the pre and postoperative CT scan grading. Across instances, only one assessed structure had a p-value &lt;0.05. The Kappa interobserver reliability test did not identify a strong agreement in the comparison of the two instances of data analysis.

Conclusions

Assessment of CT scans is not a reliable method to determine changes in intracranial pressure in Apert syndrome patients who have had a posterior vault expansion.

1173 Airway and Breathing Problems in Pierre Robin Sequence: A Systematic Review Protocol

Aim

The primary aim is to systematically review the specific airway and/or breathing problems which have been reported in Pierre Robin Sequence (PRS). Secondary aims are to understand the prevalence and severity of these airway and breathing problems, and options for screening, assessment, and monitoring.

Method

A search strategy will be designed to search the following databases: MEDLINE, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials(CENTRAL) including a grey literature search, to identify publications on airway and/or breathing problems in Pierre Robin Sequence patients. Airway or breathing problems to be included are defined upper airway conditions (e.g., sleep apnoea) or clinically or objectively defined airway/breathing problems (e.g., increased respiratory rate, polysomnography). Screening will exclude non-English articles, abstracts, letters, editorials, expert opinions and breathing problems not anatomically related to craniofacial underdevelopment.

Results

This systematic review has been successfully registered on the PROSPERO International Prospective Register of Systematic Reviews (CRD42020210572)

Conclusions

PRS is a rare craniofacial condition which presents at birth, consisting of micrognathia, glossoptosis and airway problems, and is usually, but not always, associated with a cleft palate. There is no consensus on the type of airway problems that affect patients with PRS. The findings of this systematic review will help to develop a consensus on the airway and breathing problems in PRS and options for assessment and monitoring of the airway and breathing problem. This data may also contribute to development of a standardized guideline for management of airway and breathing problems in PRS.

Parametrizing the genioplasty: a biomechanical virtual study on soft tissue behavior

Purpose

Sliding genioplasty is used to surgically correct a retruded or misaligned chin: in this procedure, an osteotomy is performed and the bony segment is repositioned. In this study we investigate the effect of surgical parameters (bony segment movement, osteotomy design) on postop soft tissue changes in a patient cohort.

Methods

Seven patients were retrospectively recruited. Cone beam computed tomography data were obtained and soft tissue and bone shape reconstructions were performed. 3D models were created and surgical cuts were replicated according to postop scans. Each model was imported in ANSYS 2019R1 (Ansys Inc, USA) for simulation: the effect of variation in osteotomy plane as well as extent of bony segment movement were assessed by means of design of experiment: surgical parameters were varied in a surgically acceptable range and the soft tissue predictions were evaluated as displacement output of five craniometric landmarks.

Results

Simulation results show the overall changes of the lower third of the face are sensitive to changes in horizontal and vertical displacement of the bony segment as well as segment rotation. No significant changes in the soft tissue response were to attribute to the osteotomy design.

Conclusions

Our results are consistent with experimental findings reported in the literature: when planning genioplasty in orthognathic surgery, particular focus on the segment movement (horizontal translation, vertical translation and rotation), rather than on the design of the osteotomy itself, should be considered.

Treatment of gastrointestinal tumor (GIST) of the rectum requiring abdominoperineal resection following neoadjuvant imatinib: a cost-effectiveness analysis

Background

Neoadjuvant imatinib for gastrointestinal stromal tumors (GIST) of the rectum can reduce, but may not eliminate, risk of surgical morbidity from permanent bowel diversion. We sought to evaluate the cost-effectiveness of alternative strategies in rectal GIST patients requiring abdominoperineal resection following neoadjuvant imatinib.

Methods

We developed a Markov model using a healthcare payers' perspective to estimate costs in 2017 Singapore dollars (SGD) and quality adjusted life years (QALYs) for upfront abdominoperineal resection (UAPR) versus continued imatinib until progression (CIUP) following 1 year of neoadjuvant imatinib. Transition probabilities and utilities were obtained from published data, and costs were estimated using data from the National Cancer Centre Singapore. Deterministic and probabilistic sensitivity analyses were conducted to probe model uncertainty. Incremental cost-effectiveness ratio below SGD 50,000 per QALY gained was considered cost-effective.

Results

In the base case, UAPR dominates CIUP being both more effective (8.66 QALYS vs 5.43 QALYs) and less expensive (SGD 312,627 vs SGD 339,011). These estimates were most sensitive to 2 variables, utility of abdominoperineal resection and annual recurrence probability post-abdominoperineal resection. However, simultaneously varying the values of these variables to maximally favor CIUP did not render it the more cost effective strategy at willingness to pay (WTP) of SGD 50,000. In probabilistic sensitivity analysis, UAPR had probability of being cost-effective compared with CIUP greater than 95%, reaching 100% at WTP SGD 10,000.

Conclusion

UAPR is more effective and less costly than CIUP for patients with rectal GIST requiring abdominoperineal resection following neoadjuvant imatinib, and is the strategy of choice in this setting.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

0143 Vigilance Declines Following Sleep Deprivation are Associated with Two Previously Identified Dynamic Connectivity States

Introduction

Dynamic functional connectivity (DFC) analysis of resting-state fMRI data has been successfully used to track fluctuations in arousal in the human brain. Changes in DFC have also been reported with acute sleep deprivation. Here, we demonstrate that dynamic connectivity states (DCS) previously related to arousal are reproducible, and are associated with individual differences in sustained attention declines after one night of total sleep deprivation.

Methods

32 participants underwent two counterbalanced resting-state fMRI scans: during rested wakefulness (RW) and following total sleep deprivation (SD). They also completed the Psychomotor Vigilance Test (PVT), a sustained attention task that is highly sensitive to the effects of sleep loss. SD vulnerability was computed as the decrease in response speed (∆RS) and increase in lapses (∆lapse) in SD compared with RW.

Dynamic functional connectivity analysis was conducted on rs-fMRI data. Connectivity matrices were clustered to obtain 5 prototypical DCS. We calculated the proportion of time participants spent in each of these DCS, as well as how often participants transitioned between DCSs. Relationships between SD vulnerability and connectivity metrics were then correlated.

Results

We recovered two DCS that were highly similar (ρ = .89-.91) to arousal-related DCS observed in previous work (high arousal state (HAS); low arousal state (LAS)).

After sleep deprivation, the proportion of time spent in the LAS increased significantly (t29=3.16, p=.0039), while there was no significant change in HAS (t29=-1.43, p=.16). We observed significantly more state transitions in RW compared with SD. Change in LAS and HAS across sleep conditions correlated significantly with SD vulnerability (ΔLASxΔRS: r=-0.64, p&lt;.0001; ΔLASxΔlapse: r=0.43, p=.018; ΔHASxΔRS; r=0.43, p=.019; ΔHASxΔlapse; r=-0.39, p=.033). Finally, Δ%transitions was correlated with ΔRS but not Δlapse.

Conclusion

This study adds to the evidence that two specific reproducible DCS are robust markers of arousal and attention, and may be useful indicators of SD vulnerability.

Support

This work was supported by the National Medical Research Council, Singapore (STaR/0015/2013), and the National Research Foundation Science of Learning (NRF2016-SOL002-001).

0092 A Daytime Nap Restores Hippocampal Function and Improves Declarative Learning

Introduction

Daytime naps have been shown to improve learning outcomes. One theory underlying enhanced encoding following a nap is via the synaptic downscaling of neurons potentiated during wake - a process facilitated by slow oscillations. In this study, we sought to investigate neural mechanisms underlying enhanced encoding following a nap compared to a waking period using a combination of PSG and fMRI methods.

Methods

40 healthy undergraduates (M=23.3y, SD=2.96y; 10 males) who slept normally the previous night encoded word pair lists across 2 runs in an MRI scanner at 1PM and 4.30PM. In between encoding sessions, participants either stayed awake and watched a documentary (Wake group; N=20), or napped for 90-min while undergoing polysomnography (Nap group; N=20). Approximately 40min after each encoding session, memory of these word lists were assessed in a cued-recall fashion. Performance in each session was measured by percentage of correct responses.

Results

There were no baseline differences in encoding performance. However, a Session x Group interaction effect (p&lt;0.001) was observed whereby performance significantly improved only in the Nap group in the second encoding session (Nap:20±19% vs. Wake:-1±13%). Concurrent to this, fMRI analyses revealed a Session x Run x Group interaction effect in the hippocampus (p=0.002) whereby hippocampal activation during encoding of the word lists increased only in the Nap group. In addition, although there was no association between degree of performance improvement in the nap group with duration of sleep or the various sleep stages (N1,N2,N3,REM), spindle count (12-15Hz) in the Nap group correlated significantly with both performance improvement (rs=0.46) and increase in hippocampal activation (rs=0.46).

Conclusion

These results confirm the benefit of a nap on encoding processes. Hippocampal activation also increased following the nap, which could indicate renewed hippocampal capacity to store new information. While we hypothesized that slow wave sleep would aid in this transfer, we instead found a relationship between spindle count and both degree of performance improvement and increase in hippocampal activation. The interplay between NREM sleep oscillations, hippocampal downscaling and encoding performance could be more complex than originally thought.

Support

National Medical Research Council, Singapore (NMRC/STaR/015/2013) and the Far East Organization.

0519 Mindfulness Based Therapy for Insomnia Improves Objective Markers of Sleep in the Elderly: Preliminary Data from the Mindfulness Sleep Therapy (MIST) Study

Introduction

Mindfulness-based treatment for insomnia (MBTI) is a viable intervention for improving poor sleep. We report preliminary data from an ongoing pre-registered, randomized controlled trial which investigates the effect of MBTI on elderly adults.

Methods

Participants above 50 years old with PSQI ≥ 5 were recruited and randomised into either MBTI or an active control group (Sleep hygiene education and exercise program, SHEEP) in sequential cohorts with about 20 participants per cohort (10 per group). Before and after the intervention, 1 night of portable polysomnography (PSG) and 1 week of actigraphy (ACT) and sleep diary (DIARY) data were collected. We report the ACT and DIARY results of the first 3 cohorts (n = 46, male = 23, mean age = 62.3, std = 6.3) and PSG data of the first 2 cohorts (n = 29, male = 12, mean age = 62.5, std = 5.7). Time in bed (TIB), total sleep time (TST), sleep onset latency (SOL), wake after sleep onset (WASO), and sleep efficiency (SE) were analysed with mixed-model repeated-measures ANOVA.

Results

We observed increases in TIBDIARY (F1,44 = 5.151, p &lt; .05) and SEDIARY (F1,44 = 22.633, p &lt; .0001), and significant reductions in SOLDIARY (F1,44 = 7.031, p &lt; .05) and WASODIARY (F1,39 = 7.411, p &lt; .05). In the actigraphy data, we found a significant interaction in SOLACT (F1,39 = 4.273, p &lt; .05) with an increase in SHEEP SOLACT (t18= 2.36, p &lt; .05). Significant reductions were also observed in WASOACT (F1,44 = 16.459, p &lt; .0001) Finally, we observed a reduction in SOLPSG (F1,26 = 5.037, p &lt;. 05). All other tests were non-significant.

Conclusion

Preliminary results suggest that both interventions lead to improvements in sleep with more pronounced effects in subjective sleep reports. Objective sleep data suggest that improvements in sleep is a result of improved sleep quality and not simply extending sleep opportunity. These preliminary data shows that MBTI may be a promising intervention for elderly individuals with sleep difficulties.

Support

This study was supported by an award from the 7th grant call of the Singapore Millennium Foundation Research Grant Programme

A 24-month cost and outcome analysis comparing traditional fronto-orbital advancment and remodeling with endoscopic strip craniectomy and molding helmet in the management of unicoronal craniosynostosis: A retrospective bi-institutional review

Introduction

Endoscopic strip craniectomy with helmeting (ESCH) has been shown to be a safe and efficacious alternative to fronto-orbital remodeling (FOR) for selected children with craniosynostosis. In addition to clinical factors, there may be economic benefits from the use of ESCH instead of FOR.

Methods

A retrospective review of 23 patients with nonsyndromic unicoronal craniosynostosis (UCS) treated with FOR was carried out at Great Ormond Street Hospital (GOSH) for Children in London, UK. Secondary data were used for the ESCH cohort from a paper published by Jimenez and Barone (2013). Data were collected on surgical time, transfusion rates, length of hospital stay, adverse event rates, reintervention rates, and overall costs. Costs were categorized and then assigned to the appropriate data sets.

Results

The mean age of patients undergoing FOR (vs. ESCH) was 17.4 mo (vs. 3.1 mo) with a mean surgical time of 234 min (vs. 55 min), mean transfusion volume of 221.6 mL (vs. 80.0 mL), mean transfusion rate of 14/23 (vs. 2/115), and a total immediate overnight stay of 3.13 days (vs. 97% next-day discharge). The FOR group had a higher adverse event rate (5/23 vs. 4/115, p=<0.005) and a higher number requiring extraocular muscle surgery (4/23 vs. 7/109, p=0.16). There was a substantial difference in overall costs between the two groups. Total variance cost for the FOR group was £7436.5 vs. £4951.35, representing a cost difference of £2485.15 over the 24-month study period.

Conclusion

ESCH, in comparison to FOR, appears as a more economical method in the management of USC patients, as well as having clinical benefits including reduced adverse event rate and improved ophthalmic outcomes.

The importance of synchronicity in the management of colorectal peritoneal metastases with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

Background

Colorectal peritoneal metastases (CPM) occur in up to 13% of patients with colorectal cancer, presenting either synchronously or metachronously. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS and HIPEC) have been increasingly utilised for selected CPM patients with favourable outcomes, though its benefits may differ for synchronous (s-CPM) and metachronous CPM (m-CPM).

Methods

A retrospective analysis of CPM patients treated with CRS and HIPEC at the National Cancer Centre Singapore over 15 years was performed. In the s-CPM group, CPM was diagnosed at primary presentation with CRS and HIPEC performed at the time of or within 6 months from primary surgery. In the m-CPM group, patients developed CPM > 6 months after primary curative surgery.

Results

One hundred two patients with CPM were treated with CRS and HIPEC. Twenty (19.6%) patients had s-CPM and 82 (80.4%) had m-CPM. Recurrences occurred in 45% of s-CPM and in 54% of m-CPM (p = 0.619). Median overall survival was significantly prolonged in patients with m-CPM (45.2 versus 26.9 months, p = 0.025). In a subset of m-CPM patients with limited PCI in whom ICU stay was not required, a survival advantage was seen (p = 0.031).

Conclusion

A survival advantage was seen a subset of m-CPM patients, possibly representing differences in disease biology.

P847 Echocardiographic imaging in primary cardiac tumour-leiomyosarcoma

Funding Acknowledgements

N.A

Primary cardiac tumours are rare entities with an incidence rate of 0.0017% to 0.019% of which 25% are malignant. Leiomyosarcomas, a form of primary cardiac sarcoma, accounts for 8-9% of all the cardiac sarcomas (1). Primary cardiac sarcomas typically present late with either quite advanced local cardiac symptoms or non-specific symptoms arising from metastasis (2). We herein report a rare presentation of leiomyosarcoma in a sixty-seven year old female Caucasian female, originally suspected following transthoracic echocardiogram.

A large mass filling the Left Atrium(L.A) with a degree obstruction to the Mitral Valve (M.V) was firstly noted on transthoracic echocardiogram. This mass had a broad base, appeared to be originating from the pulmonary veins and was not encapsulated. A small circumferential pericardial effusion was noted. Overall biventricular function was preserved and there was no evidence of pulmonary hypertension. A contrast-enhanced computed tomography scan of the chest, abdomen and pelvis was performed for staging which in addition to known cardiac mass revealed widespread bony metastases. A core biopsy of one of the lumbar paravertebral metastatic deposit was carried out to establish the diagnosis.

We hope to add to the pool of increasing overall understanding of primary cardiac sarcomas and share our fascinating echocardiogram findings. In addition, we believe this case supports our recommendation for general practitioners in the United Kingdom to have open access to requesting echocardiograms in order to identify such aggressive cardiac malignancies at an earlier stage, with the hope to improve prognosis.

Abstract P847 Figure. Depicting LA mass occupying the whole of

Marked TGF-β-regulated miRNA expression changes in both COPD and control lung fibroblasts

COPD is associated with disturbed tissue repair, possibly due to TGF-β-regulated miRNA changes in fibroblasts. Our aim was to identify TGF-β-regulated miRNAs and their differential regulation and expression in COPD compared to control fibroblasts. Small RNA sequencing was performed on TGF-β-stimulated and unstimulated lung fibroblasts from 15 COPD patients and 15 controls. Linear regression was used to identify TGF-β-regulated and COPD-associated miRNAs. Interaction analysis was performed to compare miRNAs that responded differently to TGF-β in COPD and control. Re-analysis of previously generated Ago2-IP data and Enrichr were used to identify presence and function of potential target genes in the miRNA-targetome of lung fibroblasts. In total, 46 TGF-β-regulated miRNAs were identified in COPD and 86 in control fibroblasts (FDR < 0.05). MiR-27a-5p was the most significantly upregulated miRNA. MiR-148b-3p, miR-589-5p and miR-376b-3p responded differently to TGF-β in COPD compared to control (FDR < 0.25). MiR-660-5p was significantly upregulated in COPD compared to control (FDR < 0.05). Several predicted targets of miR-27a-5p, miR-148b-3p and miR-660-5p were present in the miRNA-targetome, and were mainly involved in the regulation of gene transcription. In conclusion, altered TGF-β-induced miRNA regulation and differential expression of miR-660-5p in COPD fibroblasts, may represent one of the mechanisms underlying aberrant tissue repair and remodelling in COPD.

Does the gene matter? Genotype-phenotype and genotype-outcome associations in congenital melanocytic naevi

Background

Genotype–phenotype studies can identify subgroups of patients with specific clinical features or differing outcomes, which can help shape management.

Objectives

To characterize the frequency of different causative genotypes in congenital melanocytic naevi (CMN), and to investigate genotype–phenotype and genotype–outcome associations.

Methods

We conducted a large cohort study in which we undertook MC1R genotyping from blood, and high‐sensitivity genotyping of NRAS and BRAF hotspots in 156 naevus biopsies from 134 patients with CMN [male 40%; multiple CMN 76%; projected adult size (PAS) > 20 cm, 59%].

Results

Mosaic NRAS mutations were detected in 68%, mutually exclusive with BRAF mutations in 7%, with double wild‐type in 25%. Two separate naevi were sequenced in five of seven patients with BRAF mutations, confirming clonality. Five of seven patients with BRAF mutations had a dramatic multinodular phenotype, with characteristic histology distinct from classical proliferative nodules. NRAS mutation was the commonest in all sizes of CMN, but was particularly common in naevi with PAS > 60 cm, implying more tolerance to that mutation early in embryogenesis. Facial features were less common in double wild‐type patients. Importantly, the incidence of congenital neurological disease, and apparently of melanoma, was not altered by genotype; no cases of melanoma were seen in BRAF‐mutant multiple CMN, however, this genotype is rare.

Conclusions

CMN of all sizes are most commonly caused by mutations in NRAS. BRAF is confirmed as a much rarer cause of multiple CMN, and appears to be commonly associated with a multinodular phenotype. Genotype in this cohort was not associated with differences in incidence of neurological disease in childhood. However, genotyping should be undertaken in suspected melanoma, for guidance of treatment.

What's already known about this topic?

Multiple congenital melanocytic naevi (CMN) have been shown to be caused by NRAS mosaic mutations in 70–80% of cases, by BRAF mosaicism in one case report and by inference in some previous cases.

There has been debate about genotypic association with different sizes of CMN, and no data on genotype–outcome.

What does this study add?

NRAS mosaicism was found in 68%, BRAF in 7% and double wild‐type in 25% of cases of CMN.

NRAS was the commonest mutation in all sizes of CMN, but was nearly universal in projected adult size > 60 cm.

BRAF is often associated with a distinct multinodular clinical/histological phenotype.

Adverse outcomes did not differ between genotypes on current numbers.

https://doi.org/10.1111/bjd.18747 available online

WPI-13 Lack of association of cranial lacunae with intracranial hypertension in children with crouzon syndrome and apert syndrome: a 3D morphometric quantitative analysis

Objectives

Cranial lacunae on CT is equivalent to the plain X-ray ‘copper beating’ seen in craniosynostosis. Copper beating has not been shown to correlate to intracranial hypertension (IH). However it is a purely quantitative assessment – can qualitative measurement of CT cranial lacunae more accurately predict IH in children with craniosynostosis?

Design

Retrospective cohort study.

Subjects

18 consecutive children with Crouzon and 17 with Apert syndrome were identified.

Methods

Patients were divided into IH and non-IH groups defined on an intention to treat basis. 3D software was used to analyse% of calvarial lacunae.

Results

Mean age at CT scan was 380 days (range 6–1778). Of the 35 children, 21 required surgery for raised ICP (17 posterior vault expansion 2 ventriculo-peritoneal shunts (VPS), 1 spring-assisted cranioplasty and 1 fronto-orbital advancement) at mean age of 512 days (range 38–1710). Of the 21 children with raised ICP, 15 had lacunae with mean lacuna/calvarium percentage of 3% (0%–28%). Of the 14 non-raised ICP children, 8 had lacunae with mean lacuna/calvarium percentage of 2% (0%–8%). T-test demonstrated no significant difference between the 2 groups. For both groups, parietal bones were most likely to show lacunae (IH 14/21, non-IH 9/14), followed by occipital (IH 8/21, non-IH 3/14), followed by frontal (IH 6/21, non-IH 2/14).

Conclusions

Results suggest that cranial lacunae, measured using quantitative 3D methods, do not predict IH, in agreement with evidence from qualitative plain skull radiograph studies.

Factors influencing patient decision-making between simple mastectomy and surgical alternatives

Background

Despite similar survival rates, breast‐conserving therapy (BCT) remains a distant second choice after simple mastectomy for patients with early‐stage breast cancer in Singapore. Uptake of reconstruction after mastectomy is also low (18 per cent). The aim of this study was to explore the factors influencing a patient's choice for mastectomy when eligible for BCT, and why patients decline reconstruction after mastectomy.

Methods

Patients from the National Cancer Centre Singapore, who were eligible for BCT but chose mastectomy without reconstruction, between December 2014 and December 2015 were included. An interviewer‐administered questionnaire focusing on patients' reasons for choosing mastectomy over BCT and not opting for immediate breast reconstruction after mastectomy was used. Tumour characteristics were retrieved from medical records. Spearman's rank correlation coefficient, Mann–Whitney U and Kruskal–Wallis tests were used to analyse the correlation between the patient's self‐rated influential factors and variables. Statistical significance was taken as P < 0·050.

Results

Ninety‐one patients were included (90·1 per cent response rate). The main reasons for choosing mastectomy over BCT were: fear of cancer recurrence (considered very important in 74 per cent), the perception that health outweighs breast retention (49 per cent) and the possibility of second surgery for margins (40 per cent). Key factors for rejecting immediate reconstruction after mastectomy were: patient‐perceived ‘old age’ (very important in 53 per cent), concern about two sites of surgery (42 per cent) and financial cost (29 per cent). Given a second chance, 19·8 per cent of patients would undergo BCT instead of mastectomy.

Conclusion

This study has identified the considerations that women in Singapore have when deciding on breast cancer surgery. Some perceptions need to be addressed for women to make a fully informed decision, especially as one‐fifth regret their initial choice.

Treatment and outcomes of melanoma in Asia: Results from the National Cancer Centre Singapore

BACKGROUND

Acral melanoma (AM) and mucosal melanoma (MM) make up more than half of melanomas in Asia but comprise only 5% of cases in Caucasians, where cutaneous melanoma (CM) predominates. AM and MM are thought to be genetically and biologically distinct from CM. We report the characteristics and outcomes of melanoma patients from the National Cancer Centre Singapore.

METHODS

Case records of 210 patients treated between 2002 and 2014 were reviewed.

RESULTS

Median follow-up was 2.5 years. CM, AM and MM made up of 37.6%, 33.8% and 16.2% of cases, respectively, with 6.2% each having ocular melanoma and unknown primary. Caucasians made up 16.2% of patients, accounting for 36.7% of CM but only 2.8 of AM and 2.9% of MM. Patients with MM (2.9% stage I, 14.7% stage IV) presented with higher American Joint Committee on Cancer (AJCC) stage than those with AM (16.9% stage I, 5.6% stage IV) or CM (24.1% stage I, 8.9% stage IV) (P = 0.01). Median overall survival (OS) was 5.7 years for all patients, and 1.0 year for metastatic disease. Considering stage I-III disease, multivariable Cox regression analysis demonstrated age ≥60 years and higher stage to be independent adverse prognostic factors for RFS and OS. Sentinel lymph node biopsy, undertaken for 56 stage I-III patients (25 AM, 31 CM) did not influence outcome.

CONCLUSION

Our study reinforces the known unique clinicopathologic features of melanomas in Asians where AM and MM predominate. Age and stage remain the most critical prognostic factors across all subtypes.

A smoking cessation programme for current and recent ex-smokers following diagnosis of a potentially curable cancer

BACKGROUND

Cancer patients who quit smoking have improved survival rates. The time of diagnosis provides a 'teachable moment' when healthcare providers can offer smoking-cessation treatment.

AIMS

To assess the impact on quit rates of a tailored smoking-cessation intervention for patients diagnosed with a potentially curable cancer.

METHODS

A prospective, one-arm cohort study of current smokers and recent quitters (<30 days) who had commenced treatment for a potentially curable cancer was performed. Intervention involved an initial motivational interview, regular follow up and pharmacotherapy when appropriate. Quit rates were measured at 1, 3, 6 and 12 months by self-reported abstinence and biochemical confirmation. The primary end point was prolonged abstinence at 12 months. Changes in quality of life parameters and distress were also assessed.

RESULTS

Seventy-one patients were recruited, with a median age of 56 years. Forty-one patients (58%) had a smoking-related cancer. The prolonged abstinence rate at 12 months was 24% (95% confidence interval 14-36%). Factors associated with successful quitting included being in the preparation or action phase of readiness to change at study entry (P = 0.012) and having complications of treatment requiring hospitalisation (P = 0.024). Between baseline and 12 months, quitters reported improvement in self-control (P < 0.001) and reduced levels of distress (P = 0.03) compared to non-quitters.

CONCLUSION

Patients who continue to smoke after being diagnosed with cancer require intensive support to quit. An individualised behavioural and pharmacological intervention can be successful in helping patients quit smoking, with quality of life improvements seen amongst successful quitters. Population measures to stop people starting smoking remain essential.

Abstract 2253: 5 Gene prognostic signature for dedifferentiated liposarcomas

Introduction: Liposarcomas, despite being rare consist of a number of entities spanning low to high grade sarcomas. De-differentiated liposarcoma (DDLS) is associated with increased frequency of recurrence and lower overall survival. We aimed to identify gene expression changes associated with OS in DDLS. Secondary aims was to postulate a mechanism for DDLS.

Methods: We analysed data from gene expression omnibus (GEO, ID = GSE30929) to identify genes associated with DDLS (n=39). A signature representing genes overexpressed in DDLS was then applied to an independent dataset, utilising data from The Cancer Genome Atlas (TCGA, n=58 DDLS) to segregate samples based on gene expression and groupings compared for survival.

Results: A 5 gene signature was generated consisting of genes with increased expression in DDLS and its relation to OS. The signature was significantly enriched for genes involved in lipid metabolism (AQP7, PRKAR2B, FABP4 p&lt;0.01) and genes involved in the cell cycle and cell proliferation (FBN2, CEBPA p&lt;0.01). Segregation of DDLS in the TCGA cohort on the basis of median gene signature score gave a significant difference in overall survival. High score (stronger DDLS signature) was associated with a lower median survival(33.5 vs 76.4 months, p = 0.027), and poorer 2 year (63.4% vs 89.2%) and 5 year survival (20.6% vs 71.1%). The survival difference remained significant when applied to retroperitoneal DDLS only (n=51, median survival 34.5 vs 54.2 months, p = 0.034) and poorer 2 year survival (. A postulated mechanism is that DDLS have gained deficiency in AQP7, PRKAR2B and FABP4 leading to fatty acid and glycerol accumulation in cells, increasing cancer cell replication. CEBPA inhibits CDK4 and a deficiency of CEBPA in DDLS leads to up regulation of CDK4, increasing cell proliferation. An upregulation of FBN2 in DDLS up regulates TGF-β1, increasing cell proliferation.

Conclusion: Gene expression changes associated with dedifferentiated liposarcomas include changes in cell cycle checkpoint regulation. The signature is associated with poorer overall survival in DDLS and can be used to prognosticate patients.

Citation Format: Deanna Ng, Nicholas Shannon, Johnny Ong, Melissa Teo. 5 Gene prognostic signature for dedifferentiated liposarcomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2253. doi:10.1158/1538-7445.AM2017-2253

Safety, efficacy and pharmacokinetics of rVIII-SingleChain in children with severe hemophilia A: results of a multicenter clinical trial

Essentials rVIII-SingleChain is a novel recombinant factor VIII with covalently bonded heavy and light chains. Efficacy, safety and pharmacokinetics were studied in pediatric patients with severe hemophilia A. Across all prophylaxis regimens, the median annualized spontaneous bleeding rate was 0.00. rVIII-SingleChain showed excellent hemostatic efficacy and a favorable safety profile.

SUMMARY

Background rVIII-SingleChain is a novel B-domain truncated recombinant factor VIII (rFVIII) comprised of covalently bonded FVIII heavy and light chains, demonstrating a high binding affinity to von Willebrand factor. Objectives This phase III study investigated the safety, efficacy and pharmacokinetics of rVIII-SingleChain in previously treated pediatric patients < 12 years of age with severe hemophilia A. Patients/Methods Patients could be assigned to prophylaxis or on-demand therapy by the investigator. For patients assigned to prophylaxis, the treatment regimen and dose were based on the bleeding phenotype. For patients receiving on-demand therapy, dosing was guided by World Federation of Hemophilia recommendations. The primary endpoint was treatment success, defined as a rating of 'excellent' or 'good' on the investigator's clinical assessment of hemostatic efficacy for all treated bleeding events. Results The study enrolled 84 patients (0 to < 6 years, n = 35; ≥ 6 to < 12 years, n = 49); 81 were assigned to prophylaxis and three to an on-demand regimen. Patients accumulated a total of 5239 exposure days (EDs), with 65 participants reaching > 50 EDs. In the 347 bleeds treated and evaluated by the investigator, hemostatic efficacy was rated as excellent or good in 96.3%. The median annualized spontaneous bleeding rate was 0.00 (Q1, Q3: 0.00, 2.20), and the median annualized bleeding rate was 3.69 (Q1, Q3: 0.00, 7.20) across all prophylaxis regimens. No participant developed an inhibitor. Conclusions rVIII-SingleChain is a novel rFVIII molecule showing excellent hemostatic efficacy and a favorable safety profile in a clinical study in children < 12 years of age with severe hemophilia A.

Pharmacokinetics of oxycodone after subcutaneous administration in a critically ill population compared with a healthy cohort

This study aimed to characterise and compare the absorption pharmacokinetics of a single subcutaneous dose of oxycodone in critically ill patients and healthy subjects. Blood samples taken at intervals from two minutes to eight hours after a subcutaneous dose of oxycodone in patients (5 mg) and healthy volunteers (10 mg) were assayed using high performance liquid chromatography. Data were analysed using a non-compartmental approach and presented as mean (SD). Parameters were corrected for dose differences between the groups assuming linear kinetics. Ten patients (eight male, two female) and seven healthy male subjects were included. Maximum venous concentration and area under the concentration curve were approximately two-fold lower in the patient group for an equivalent dose, suggesting either reduced bioavailability or increased clearance: maximum venous concentration 0.14 ± 0.06 vs 0.05 ± 0.02 µg/ml (P <0.0001); area under the concentration curve 19.50 ± 9.15 vs 9.72 ± 2.71 µg/ml/minute (P <0.001) respectively. However, time to maximum venous concentration and mean residence time were not different, suggesting similar absorption rates: time to maximum venous concentration 22.10 ± 18.0 vs 20.50 ± 16.10 minutes (P=0.81); mean residence time 353 ± 191 vs 291 ± 80 minutes (P=0.26). Kinetic parameters were less variable in patients than in volunteers. The patients therefore had reduced exposure to subcutaneous oxycodone. This warrants further model-based analysis and experimentation. Dose regimens for subcutaneous oxycodone developed in healthy volunteers cannot be directly translated to critically ill patients.

Diagnosing the doctors' departure: survey on sources of dissatisfaction among Irish junior doctors

There has been a significant decline in the number of applications for non-consultant hospital doctor (NCHD) posts in Ireland over the last 18 months. We conducted an online, anonymous survey of Irish NCHDs to establish levels of satisfaction, sources of dissatisfaction and the major reasons for junior doctors seeking work abroad. 522 NCHDs took the survey, including 64 (12.3%) currently working outside of the Republic. 219 (45.8%) were slightly dissatisfied and 142 (29.7%) were extremely dissatisfied with practising medicine in Ireland. Major sources of dissatisfaction included the state of the health care system, staffing cover for leave and illness, the dearth of consultant posts and the need to move around Ireland. The most important reason for NCHDs wishing to leave was to seek better training and career opportunities abroad.

Computer-assisted gap balancing technique improves outcome in total knee arthroplasty, compared with conventional measured resection technique

PURPOSE

The objective of this prospective study was to compare the functional outcome of conventional measured resection technique and computer-assisted gap balancing technique in TKA.

METHODS

140 patients were randomized into two groups. The conventional measured resection technique without computer navigation was performed in Group 1 and the computer-assisted gap balancing technique in Group 2. Range of motion, clinical laxity assessment with KT-1000 arthrometer, postoperative radiological films and various functional knee scores were documented at 6 months and 2 years.

RESULTS

At 2 years, there were significantly more patients (five patients, 7%) in the Group 1 with flexion contractures of more than 5° (P = 0.05). There were significantly more outliers in the Group 1 (eight patients, 11%), who demonstrated anterior tibial translation >5 mm, than Group 2 (two patients, 3%) (P = 0.041). The total excursion at 20° was significantly higher in Group 1 at 6 months (P = 0.012) and after 2 years (P = 0.031). Group 2 was able to demonstrate significantly better limb alignment with fewer outliers (more than 3° varus/valgus) than Group 1. At 6-month follow-up, Group 2 demonstrated better outcomes in Function Score (P = 0.040) and Total Oxford Score (P = 0.031). At 2-year review, Group 2 had better outcome in the Total Oxford Score (0.030).

CONCLUSION

Computer-assisted gap balancing technique was able to achieve more precise soft tissue balance and restoration of limb alignment with better knee scores as compared to the conventional measured resection technique in total knee arthroplasty.

Solitary caecal ulcer syndrome: our experience with this benign condition

AIM

Solitary caecal ulcer syndrome is rare. We describe our experience of 10 patients with the condition.

METHOD

A prospectively collected database of patients undergoing colonoscopy or surgery with histology reporting a solitary caecal ulcer was reviewed from 1999 to 2008. Patients with known carcinoma of the colon, cytomegalovirus infection, amoebiasis, inflammatory bowel disease, immunosuppression and history of nonsteroidal anti-inflammatory drug use were excluded.

RESULTS

Ten patients were found to have a solitary caecal ulcer. All were of Chinese ethnicity, of median age 61 years. The most common presenting symptoms were haematochezia and right-sided abdominal pain. Histological findings included ulceration sharing some features of solitary rectal ulcer syndrome, but with differences to suggest a different aetiology.

CONCLUSION

Solitary caecal ulcer syndrome should be included in the differential diagnosis of lower gastrointestinal haemorrhage, right iliac fossa pain or when computed tomography imaging demonstrates caecal wall thickening. The diagnosis can only be made on histopathological examination.