Comparison of actionable events detected in cancer genomes by whole-genome sequencing, in silico whole-exome and mutation panels

Background

Next-generation sequencing is used in cancer research to identify somatic and germline mutations, which can predict sensitivity or resistance to therapies, and may be a useful tool to reveal drug repurposing opportunities between tumour types. Multigene panels are used in clinical practice for detecting targetable mutations. However, the value of clinical whole-exome sequencing (WES) and whole-genome sequencing (WGS) for cancer care is less defined, specifically as the majority of variants found using these technologies are of uncertain significance.

Patients and methods

We used the Cancer Genome Interpreter and WGS in 726 tumours spanning 10 cancer types to identify drug repurposing opportunities. We compare the ability of WGS to detect actionable variants, tumour mutation burden (TMB) and microsatellite instability (MSI) by using in silico down-sampled data to mimic WES, a comprehensive sequencing panel and a hotspot mutation panel.

Results

We reveal drug repurposing opportunities as numerous biomarkers are shared across many solid tumour types. Comprehensive panels identify the majority of approved actionable mutations, with WGS detecting more candidate actionable mutations for biomarkers currently in clinical trials. Moreover, estimated values for TMB and MSI vary when calculated from WGS, WES and panel data, and are dependent on whether all mutations or only non-synonymous mutations were used. Our results suggest that TMB and MSI thresholds should not only be tumour-dependent, but also be sequencing platform-dependent.

Conclusions

There is a large opportunity to repurpose cancer drugs, and these data suggest that comprehensive sequencing is an invaluable source of information to guide clinical decisions by facilitating precision medicine and may provide a wealth of information for future studies. Furthermore, the sequencing and analysis approach used to estimate TMB may have clinical implications if a hard threshold is used to indicate which patients may respond to immunotherapy.

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Genome analysis revealed that treatment biomarkers are shared across solid tumours, highlighting repurposing opportunities.

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Comprehensive panels detect most known biomarkers; however, WGS detects more biomarkers for treatments in clinical trials.

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TMB is well correlated between sequencing methods, but absolute values vary and are dependent on mutation types considered.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Translation of Prognostic and Pharmacodynamic Biomarkers from Trial to Non-trial Patients with Metastatic Castration-resistant Prostate Cancer Treated with Docetaxel

AIMS

We conducted a pooled analysis of four randomised controlled trials and a non-trial retrospective dataset to study the changes in serum prostate-specific antigen (PSA) concentrations during treatment and its impact on survival in men treated with docetaxel for metastatic castration-resistant prostate cancer. We also compared the outcomes and pre-treatment prognostic factors between trial and non-trial patients.

MATERIALS AND METHODS

Data were obtained from four randomised controlled trials and a non-trial cohort from a tertiary cancer centre. The PSA kinetics covariates chosen were absolute value (PSAT), best percentage change (BPCH) and tumour growth rate (K). The association between the covariates collected and overall survival was assessed within a Cox proportional hazards model. How well a covariate captured the difference between trial and non-trial patients was assessed by reporting on models with or without trial status as a covariate.

RESULTS

We reviewed individual datasets of 2282 patients. The median overall survival for trial patients was 20.4 (95% confidence interval 19.6-22.2) months and for the non-trial cohort was 12.4 (10.7-14.7) months (P < 0.001). Of the pre-treatment factors, we found that only lactate dehydrogenase fully captured the difference in prognosis between the trial and non-trial cohorts. All PSA kinetic metrics appeared to be prognostic in both the trial and non-trial patients. However, the effect size was reduced in non-trial versus trial patients (interaction P < 0.001). Of the time-dependent covariates, we found that BPCH best captured the difference between trial and non-trial patient prognosis.

CONCLUSIONS

The analysis presented here highlights how data from open-source trial databases can be combined with emerging clinical practice databases to assess differences between trial versus non-trial patients for particular treatments. These results highlight the importance of developing prognostic models using both pre-treatment and time-dependent biomarkers of new treatments.

P-596 Comparative efficacy of Letrozole (5 mg) versus Clomiphene citrate (100 mg) for ovulation induction among infertile women

Study question

Does Letrozole have better offerings while being compared to Clomiphene citrate as an Ovulation inducing agent in infertile women?

Summary answer

Compared to clomiphene, Letrozole - an aromatase inhibitor, is associated with higher live-birth and ovulation rates among infertile women.

What is known already

Anovulatory dysfunction is a common problem and is responsible for about 40% of female infertility and among causes; PCOS (polycystic ovarian syndrome) is the leading cause.

Clomiphene citrate has been traditionally used as the drug of choice for treatment of women with anovulatory infertility. In the last decade, an aromatase inhibitor, letrozole, has emerged as an alternative ovulation induction agent among anovulatory women with polycystic ovarian syndrome. Letrozole has a definitive role in anovulatory women who have not responded to clomiphene citrate therapy, as confirmed by literature.

Study design, size, duration

Randomized double-blind study. Total 100 women were randomly assigned and divided into 2 groups of 50 patients each. The 2 groups were well matched at baseline. Study participants are of age 20 to 39 years. Study began in October 2019 and was completed in October 2021.

Participants/materials, setting, methods

Group 1: Clomiphene citrate (100 mg daily) and group 2: letrozole (5 mg daily), started from any day between 3-5 of the menstrual cycle and continued up to 5 consecutive days. Both groups have received Estradiol Valerate 4 mg on the 12th day of menstruation until 16th day of menstruation.

All patients had USG monitoring of follicular and endometrium size with perifollicular flow and uterine scoring system for reproduction (USSR) score with timed intercourse.

Main results and the role of chance

Women who received letrozole as compared to those who received clomiphene citrate had more cumulative live births (36 of 50 [72%] vs. 28 of 50 [56%]). Number of women ovulated in Letrozole group was – 42 (84%) while in Clomiphene citrate (CC) Group it was 39 (78%). The ovulation rate was significantly higher with letrozole than with clomiphene citrate. Among the study participants who ovulated, there was a significantly greater chance of singleton pregnancy with letrozole compared to clomiphene citrate.

The mean number of dominant follicles (18 mm) was 1.40 ± 0.58 for letrozole and 1.10 ± 0.86 for clomiphene citrate (P-value = &lt;0.05). The size of follicular development by day 14 was 17.6 ± 2.92 mm in Letrozole group while in Clomiphene citrate group it was 15.8 ± 3.84 mm (P-value = &lt;0.05). The mean endometrial thickness by day 14 was 7.2 ± 0.77 mm for Letrozole and 6.8 ± 0.92 mm for clomiphene citrate (P-value = &lt;0.05).

Limitations, reasons for caution

In our study, we have not considered lifestyle intervention before enrolment; although such interventions are recommended by experts, but there is currently no evidence from high quality clinical trials that they improve pregnancy outcomes in obese women.

Wider implications of the findings

Although Letrozole has still not gained universal acceptance as an ovulating agent for a variety of reasons, emerging evidences suggests that Letrozole could be an effective option and is non inferior to clomiphene citrate as an ovulating agent especially, in patients with non- responders to Clomiphene citrate and PCOS women.

Trial registration number

Not applicable

P-059 Effect of outcome of microfluidic sperm sorter and conventional swim-up technique on DNA integrity of the sperm

Study question

Does the approach of sperm preparation technique plays any role in sperm DNA Integrity

Summary answer

Outcome of the semen sample is directly proportional to the choice of preparation technique. Microfluidics improves sperm selection and results in better sperm DNA integrity

What is known already

Microfluidic systems are promising tools for fluid manipulation that can noninvasively separate motile sperm with higher hydrodynamics profile from the lower ones. It also enables to manipulate micro swimmers as compared to the traditional methods that to without centrifugation .As it is already known that Semen analysis and preparation is one of the most important aspects in andrology and microfluidics can improve sperm analysis and selection, therefore increasing the ART success rates

Study design, size, duration

Comparative study from July 2019 to Dec 2021 in IVF unit of IKDRC Hospital .A total number of 900 patients were enrolled in the study and were randomized by using computer generated list then divided into two groups, Group A contains 460 samples and Group B having 440 samples.

Participants/materials, setting, methods

Group A (n = 460) sample was prepared by using Microfluidic sperm Sorting technique and Group B (n = 440) sample was prepared by conventional Swim up technique. Samples were analyzed according to WHO 2010 laboratory manual for examination and processing of human sperm, including all normozoospermic samples. Primary outcomes of the study was DNA Fragmentation index (DFI) and it was evaluated by using sperm chromatin dispersion (SCD) test and secondary outcomes was Progressive motility .

Main results and the role of chance

DNA fragmentation index is significantly lower in group A where Microfluidic Sperm Sorting technique (MFSS )is used than in group B where conventional swim up technique is use (10.06% vs 34.2%, p&lt;0.0001) significant values implies that DNA integrity is better in group A than in group B and progressive motility was also found to be significantly higher in group A as compared to group B (57.6%vs16.9%, p &lt;0.001).

Limitations, reasons for caution

As sample size was smaller, larger randomized control studies are needed to strengthen these results and all normal samples were used for the analysis and preparation , abnormal parameters were not involved .

Wider implications of the findings

According to our study the samples prepared by Microfluidic technique have higher DNA integrity than samples prepared by Swim up technique. Lower DNA Fragmentation index in microfluidics outcome indicates lower DNA damage. Choice of technique for the preparation of semen sample also plays a key role in better sperm selection.

Trial registration number

N/A

Ultramini-percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of 10-30 mm calculi: a randomized controlled trial

The surgical management of renal stones 10-30 mm is usually performed with percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). Standard form of percutaneous nephrolithotomy has paved the way for miniaturized PCNL in many centres. We wanted to evaluate the efficacy, safety and the cost-effectiveness of ultramini-percutaneous nephrolithotomy (UMP) versus RIRS in the treatment of renal stones with stone burden 10-30 mm. Patients with renal stone burden 10-30 mm were prospectively randomized into either UMP or RIRS. The demographic data, stone characteristic, operative time and cost of the equipment were recorded. The stone free status, analgesic requirement, deterioration of the renal function and hemoglobin and the postoperative complications as per Clavein-Dindo grade were recorded. One hundred and fifty patients met inclusion criteria. Out of these 98 underwent UMP and 46 RIRS. Six withdrew the consent before the procedure. Mean stone size was comparable in either of the groups. Mean laser time and stone extraction time was significantly less for UMP compared to RIRS (41.17 min versus 73.58 min p < 0.0001). Mean consumable costs in the UMP group were considerably less at US$45.73 compared to the RIRS group at $423.11 (p < 0.0001). The stone free rates at 1 month of follow-up were 100% for UMP group and 73% for RIRS group. There were insignificant changes to mean hemoglobin and glomerular filtration rate (GFR) in all patients and the average length of the stay was similar in both the groups. The postoperative complications revealed Grade I and II rate of 10% in the UMP group and 35% in the RIRS group, respectively. We concluded that UMP to be safe, effective and more economical to the RIRS for renal stones up to 3 cm in size.Trial registered with ISRCTN registry ID ISRCTN20935105, Retrospective.

Hallux valgus surgery in children with cerebral palsy: A systematic review

BACKGROUND

Children with cerebral palsy are highly likely to develop foot deformities, some of which may require surgical intervention. Hallux valgus is a common forefoot deformity which can cause issues with pain, footwear, orthotic splints and soft tissues. It remains unclear what the optimal surgical treatment is for children with cerebral palsy and hallux valgus deformity.

OBJECTIVE

To systematically review studies reporting the clinical and radiological outcomes of surgical correction of hallux valgus deformity in children with cerebral palsy.

METHODS

A systematic review of studies published in electronic databases (Medline, Embase, Pubmed and Cochrane library) from inception until January 2021. Keywords related to hallux valgus and cerebral palsy were included.

RESULTS

58 studies were identified of which 7 met the criteria for inclusion. 200 feet in 134 patients with a mean age of 13.5 years were included, with a mean follow up period of 43 months. A range of clinical and radiographic outcomes were assessed. A treatment framework for the assessment and management of hallux valgus in children with cerebral palsy based on the published evidence is presented.

CONCLUSION

Non-ambulant children with cerebral palsy with symptomatic hallux valgus should primarily undergo first MTPJ arthrodesis whilst those who are ambulant should undergo first metatarsal osteotomy± soft tissue correction.

Bariatric surgery reduces ventricular repolarisation gradients in obese patients - results from an electrocardiographic imaging study

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health Research (NIHR) British Heart Foundation

Background

Obesity confers higher risks of atrial arrhythmias and is associated with abnormal ventricular repolarisation. Despite this, the proarrhythmic substrate in obesity and its reversibility with weight loss has not been studied in-depth.

Purpose

To characterise the proarrhythmic substrate in obese patients, and its reversibility with bariatric surgery, using electrocardiographic imaging (ECGi).

Methods

ECGi was performed in 8 obese patients before (PreOb) and after (PostOb) bariatric surgery (mean age 39+/-11years, 7 female), and in 8 age- and sex-matched non-obese controls (NOb) (40+/-11 years). ECGi recordings were made at rest, on exercise, and during recovery from exercise. For ECGi analysis, &gt;2000 atrial and ventricular epicardial electrograms were calculated from body surface potential recordings from 256 sites and information from cardiac magnetic resonance imaging, by solving the inverse problem. Local atrial and ventricular epicardial activation times (AT) were calculated as the steepest downslope of their respective activation complexes, and local ventricular repolarisation times (RT) as the steepest upslope of the T-wave. Atrial activation gradients (ATG) and ventricular repolarisation gradients (RTG) were calculated as the maximum difference within 10mm radius divided by the corresponding Euclidean distance.

Results

BMI was greater in PreOb vs NOb (46.6+/-4.8 vs 23.8+/-2.6kg/m2, p&lt;0.0001) and decreased with surgery (PostOb 35.3+/-4.2kg/m2, p&lt;0.0001). Total atrial AT was prolonged in PreOb vs NOb (68+/-12 vs 45+/-10ms, p=0.016) and did not change post-surgery (PreOb vs PostOb: 68+/-12 vs 67+/-16ms, p=0.81). Atrial ATG were also greater in PreOb vs NOb: max 254+/-111 vs 106+/-58ms, p=0.035; mean 24+/-6 vs 12+/-6ms, p=0.0087) and did not change with weight loss (PreOb vs PostOb: max 254+/-111 vs 222+/-69ms/mm, p=0.61; mean 24+/-6 vs 21+/-7ms/mm, p=0.52). Ventricular RTG were greater in PreOb vs NOb (max: 287+/-73 vs 131+/-89ms/mm, p=0.012; mean: 33+/-10 vs 17+/-9ms/mm, p=0.0052). Ventricular RTG decreased with weight loss (PreOb vs PostOb: max 287+/-73 vs 151+/-54ms/mm, p=0.0070; mean: 33+/-10 vs 21+/-8ms/mm, p=0.018), and were similar between PostOb and NOb (max, p=0.81; mean p=0.58). Ventricular AT and RT were non-different in NOb, PreOb and PostOb.

Conclusion

Obesity is associated with pro-arrhythmic electrophysiological remodelling, including steeper ventricular repolarisation gradients and slower atrial activation. At 6 months post-bariatric surgery, there was a reduction in ventricular repolarisation gradients though atrial conduction abnormalities persisted. These findings provide a mechanistic insight into obesity-related arrhythmic risks and its potential reversibility with weight loss surgery.

Textbook outcome following oesophagectomy for cancer: international cohort study

Background

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

Methods

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

Results

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter ‘no major postoperative complication’ had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P &lt; 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P &lt; 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

Conclusion

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Textbook outcome following oesophagectomy for cancer: international cohort study

BACKGROUND

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

METHODS

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

RESULTS

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter 'no major postoperative complication' had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

CONCLUSION

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Characterization of Lung Transplant COVID19+ Patients and Mortality Outcomes

Purpose

The aim of this study is to report the characteristic and mortality outcomes of lung transplant patients that contracted COVID19.

Methods

A retrospective chart review was conducted of lung transplant recipients who tested positive for COVID19 from 6/1/2020 to 9/1/2021.

Results

Forty-five patients were included for mortality incidence review with 2 patients who were admitted to outside facilities during their COVID diagnosis with limited treatment data. Mortality incidence was 15.5% with cohort mean age of 62 (±11.7). Median time from transplant to infection was 1281 days (223-5800). Five patients required O2 and n=5 were intubated with 80% mortality (n=4) among those intubated. Baseline demographics of age, gender, indication for transplant or race were not statistically different among patients that died vs those that survived. Vaccinations (2 doses) prior to infection were evident in n=35 (77.8%) of the patients. Maintenance immunosuppressants and covid therapies (table 1) did not have an associated difference in survival from infection. A significant association with mortality was found from the time of reported symptoms to triage or hospitalization in those that survived vs died, 3.3 vs 9.4 days (p=0.003).

Conclusion

This is one of the largest cohorts reporting lung transplant recipients who contracted COVID19, and despite lungs being the organ directly affected by COVID19, mortality rates are comparable to rates reported in other solid organ transplants. Time to triage from symptom onset to clinic management or hospital admission for COVID appears to be associated with improved mortality rates.

A220 THE IMPACT OF DIABETES AND AGE ON PERFORMANCE OF NON-INVASIVE SERUM-BASED TESTS FOR PREDICTION OF ADVANCED FIBROSIS IN BIOPSY-PROVEN NAFLD

Background

Non-alcoholic fatty liver disease (NAFLD) is now a leading cause of end-stage liver disease. Advanced stage F3-4 fibrosis predicts liver-related mortality in NAFLD patients. Simple non-invasive serum-based tests (NIT) for F3-4 are limited by indeterminate scores, necessitating secondary tests or liver biopsy. Diagnostic NIT cut-offs may vary in NAFLD patients with diabetes mellitus (DM) and the elderly. Identifying appropriate thresholds in populations in which these tests can be applied will reduce indeterminates and facilitate their broader use.

Aims

The aim of this study was to assess the impact of DM status and age on the performance of NIT for prediction of advanced fibrosis in patients with biopsy-proven NAFLD.

Methods

Patients presenting to two Canadian tertiary care centers between 2010–2018 for liver biopsy to diagnose NAFLD were included in this study. NIT including NFS, FIB4, BARD, AST-to-platelet ratio index (APRI), and AST to ALT ratio (AST/ALT) were calculated for each patient using validated cut-offs.

Results

457 patients were included in this study. Mean age was 48.8±12.9 years, 56% male, mean BMI 32.3 ± 6.7kg/m2, 69% with DM, and F3-4 prevalence 48%. Indeterminate rates for NIT were generally higher for older patients, with or without DM (27–49% and 37–52%, vs. 33–42% and 20–37%, respectively). FIB-4 and NFS both had high specificity &gt;0.9 in DM patients &lt;60 years (Table 1). There were no differences in AUROC for individual NITs between patients with and without DM, and those &lt; 60 vs. ≥ 60, nor between individual NIT within these groups.

Conclusions

DM status and age, ≥ 60 vs. &lt; 60, do not appear to have a significant impact on diagnostic performance of serum-based NIT in our cohort. Older patients had higher indeterminate results and reduced specificity, but T2DM status and age did not appear to have an impact on rate of misclassified patients. Serum-based NIT thresholds need to be optimized for older patients to reduce indeterminates and improve specificity.

Funding Agencies

None

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND

The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting.

METHODS

Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups.

RESULTS

Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005).

CONCLUSION

Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.

A practical approach to bladder preservation with hypofractionated radiotherapy for localised muscle-invasive bladder cancer

Bladder preservation with trimodality treatment (TMT) is an alternative strategy to radical cystectomy (RC) for the management of localised muscle invasive bladder cancer (MIBC). TMT comprises of transurethral resection of the bladder tumour (TURBT) followed by radiotherapy with concurrent radiosensitisation. TMT studies have shown neo-adjuvant chemotherapy with cisplatin-based regimens is often given to further improve survival outcomes. A hypofractionated radiotherapy regimen is preferable due to its non-inferiority in local control and late toxicities. Radiosensitisation can comprise concurrent chemotherapy (with gemcitabine, cisplatin or combination fluorouracil and mitomycin), CON (carbogen and nicotinomide) or hyperthermic treatment. Radiotherapy techniques are continuously improving and becoming more personalised. As the bladder is a mobile structure subject to volumetric changes from filling, an adaptive approach can optimise bladder coverage and reduce dose to normal tissue. Adaptive radiotherapy (ART) is an evolving field that aims to overcome this. Improved knowledge of tumour biology and advances in imaging techniques aims to further optimise and personalise treatment.

Epstein-Barr Virus associated gastric carcinoma in a patient with germline STAT3 gain-of-function mutation

Introduction/Objective

Signal transducer and activator of transcription 3 (STAT3) is a transcription factor involved in inflammation, proliferation, differentiation and survival. STAT3 gain-of-function (GoF) disorders are characterized by immune dysregulation and present with polyendocrinopathy, enteropathy, X-linked syndrome (IPEX)- or autoimmune lymphoproliferative syndrome (ALPS)-like features. While patients with STAT-3 GoF are known to have an increased risk for hematologic malignancies, neither solid tumors nor an increased risk for EBV-associated disorders have been described. We report the first case of an EBV-associated solid organ tumor in a patient with STAT-3 GoF.

Methods/Case Report

A 21-year-old male with germline mutation in STAT3 (variant p. M329K) presented with early satiety, abdominal pain and worsening of chronic anemia. Serology showed high EBV DNA PCR levels. Endoscopy showed multiple nodular lesions in the stomach, which were biopsied to reveal EBV-associated high-grade dysplasia and intramucosal adenocarcinoma. Initiation of chemotherapy with a poor response led to a total gastrectomy. Gross examination of the specimen showed a 7.9 x 6.5 x 1.8 cm tan-brown, exophytic mass in the posterior wall of the body and antrum, involving the greater curvature. Histology revealed an adenocarcinoma with tubulovillous morphology extending into the lamina propria, without invasion into the muscularis mucosa or submucosa. EBER in-situ hybridization was diffusely positive in the tumor cells. The background mucosa showed severe chronic active and atrophic gastritis with intestinal metaplasia and low-grade dysplasia. All the seventy examined lymph nodes were negative for metastasis. Helicobacter-like organisms were not seen.

Results (if a Case Study enter NA)

NA

Conclusion

This is the first report of a solid tumor in a patient with STAT3 GoF mutation. The role of the patient’s underlying immune dysregulation disorder in the development of EBV-associated gastric adenocarcinoma is unclear and warrants further investigation. The case also highlights the importance of a close clinical follow-up in this patient population, as unexpected malignancies can develop at younger ages.

Computed tomography vs cardiovascular magnetic resonance imaging derived extracellular volume fraction in patients with stable new-onset chest pain

Background

Computed tomography (CT) is increasingly recognised as a diagnostic modality across a range of cardiovascular conditions and is now first-line for the investigation of stable new-onset chest pain. Determination of the myocardial extracellular volume fraction (ECV) has been shown to correlate well with the identification and prognostication of disease. Cardiovascular magnetic resonance (CMR) imaging remains the gold standard for the measurement of myocardial ECVCMR using T1-mapping, but there is increasing evidence for the use of ECV by cardiac CT (ECVCT).

Purpose

To assess the performance of ECVCT against the reference standard of ECVCMR.

Methods

Patients with a history of chest pain and no previously documented coronary disease referred for invasive angiography were recruited as part of the EVINCI Heart-QIT study. A cohort of these patients (n=33) underwent CMR at 1.5T (Siemens Aera, Siemens Healthcare, Erlangen/Germany) with T1 mapping of a mid-ventricular short axis slice (by MOdified Look-Locker Inversion recovery [MOLLI]) before and 15 minutes after a bolus of gadolinium contrast (0.1 mmol/kg gadoterate meglumine), followed by whole-heart ECVCT quantification (Somatom Force, Siemens Healthcare, Erlangen/Germany) using a 5-min post-iodine-contrast acquisition protocol. To account for data clustering on a patient level and volumetric discrepancy on a modality level, comparisons were made using mid-ventricular pooled ECVCT and ECVCMR. Bland-Altman analysis was used to determine the limits of agreement and identify systematic differences between both measures.

Results

A total of 33 patients (70% male, mean age 56.8±12.6yr) underwent the combined CMR and CT. ECVCMR and ECVCT were then analysed retrospectively (Figure 1). The average pooled ECV for the 6 mid-ventricular segments for CMR and CT were (27.6±2.4 and 26.8±2.2 respectively). Bland-Altman analysis demonstrated a marginally higher CMR-ECV (0.8±2.1) vs CT-ECV, which is in keeping with the longer delay-time encountered in CMR protocols (Figure 2).

Conclusions

ECVCT obtained from 5-minute post-contrast CT protocols show good agreement with ECVCMR in a stable chest pain patient cohort.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Siemens Helthineers Educational Grant Figure 1. CMR (L) and CT (R) ECV mapsFigure 2. Bland-Altman plot

The management of severe aortic stenosis during the COVID-19 pandemic: an observational study comparing TAVI and SAVR

Introduction

Outcomes and characteristics of patients with severe aortic stenosis (AS) treated during the COVID-19 pandemic is unknown.

Methods

This was a single-centre observational study of patients undergoing AS treatment with transcatheter (TAVI) or surgical (SAVR) therapy during the first-wave of the UK COVID-19 pandemic compared to a control cohort undergoing treatment in 2019.

Demographics, baseline echocardiogram, CT, procedural characteristics and outcome data were collated. The primary outcome was 30-day all-cause mortality. The secondary endpoint was duration of post-procedural hospitalisation.

Results

319 patients were recruited - 122 underwent intervention during the pandemic [73 TAVI; 49 SAVR] and 197 in 2019 [127 TAVI; 70 SAVR].

In 2020, TAVI patients had a higher Euroscore II (p&lt;0.001) but there were no differences in procedural complications or mortality [p=0.16] compared to TAVI 2019 cases. Duration from TAVI to discharge was shorter in 2020 (p&lt;0.001).

SAVR 2020 patients had similar baseline profile [p=0.48], surgical characteristics, mortality (p=0.68) and duration from SAVR to discharge compared to those in 2019.

During the pandemic, TAVI patients were older (p&lt;0.001) and had a higher Euroscore II (p&lt;0.001) than SAVR counterparts. TAVI patients had reduced 30-day mortality [0 (0%) vs 3 (6%); p=0.06] and were discharged more rapidly post-intervention than SAVR patients [median 1 [1] vs 7 [4] days; p&lt;0.001) translating into shorter hospitalization (p&lt;0.001).

Conclusions

TAVI and SAVR can be safely delivered with predictable resource utilisation during a pandemic. Despite the TAVI cohort incorporating higher risk, older patients, outcomes were at least as good as SAVR with a shorter length of post-procedural hospitalisation.

Funding Acknowledgement

Type of funding sources: None. Procedural Complications TAVI/SAVRDuration to discharge post TAVI/SAVR

198 Immediate Post-Operative PDE5i Therapy Improves Early Erectile Function Outcomes after Robot-Assisted Radical Prostatectomy (RARP)

Aim

To assess whether the timing of post-operative Phosphodiesterase Inhibitor (PDE5i) therapy after Robot Assisted Radical Prostatectomy (RARP) is associated with a change in early erectile function, continence, or safety outcomes.

Method

Data was prospectively collected from a single surgeon in one tertiary centre and retrospectively evaluated. 158 patients were treated with PDE5i therapy post RARP over a two-year period.

Results

There were no significant differences in pre-operative characteristics between the therapy groups. Patients that had bilateral nerve sparing had a mean drop in Erectile Function (EF) score by 5.4 compared to 8.8 in the unilateral group. Additionally, 34.9% of bilateral nerve sparing patients returned to baseline compared to 12.1% of unilateral. Drop in EF scores and percentage return to baseline for unilateral nerve sparing was respectively 9 and 11.1% of immediate (day 1-2), 7 and 14.8% of early (day 3-14) and 9.7 and 9.5% of late (day &gt;14) therapy (p = 0.9 and p = 0.6). For bilateral nerve sparing this was respectively 3.5 and 42.9% immediate therapy, 5.5 and 35.5% early therapy and 7.3 and 25% late therapy (p = 0.017 and p = 0.045). Pad free and social continence was achieved in 54% and 37% of those receiving immediate therapy, 60% and 33% for early therapy and 26% and 54% for late therapy. There were no differences in compliance, complication, or readmission outcomes.

Conclusions

Immediate PDE5i therapy should be considered in patients following nerve sparing RARP in order to maximise functional outcomes, especially in those undergoing bilateral nerve spare.

614 Elective Bariatric and Metabolic Surgery in United Kingdom During the Coronavirus Pandemic

Aim

Elective Bariatric and Metabolic Surgery (BMS) was halted in the UK during the first wave of the Coronavirus (COVID-19) pandemic. Obesity is a predictor of poor outcome in those infected with this virus. This study reports our experience resuming elective weight loss surgery safely amidst the pandemic.

Method

Guidance from national bodies (BOMSS/NICE) were reviewed and a Standard Operating Procedure (SOP) was drafted to accommodate local considerations. Data were prospectively collected on patients undergoing BMS following commencement of elective surgery after the first national lockdown.

Results

A total of 50 patients underwent BMS at our institution within six weeks of resuming the services. The median age was 41 years old and BMI was 43.8(IQR 40.0-48.8 kg/m2). Equal number of patients underwent laparoscopic Sleeve Gastrectomy (SG) and Roux en-Y Gastric Bypass (RYGB). Of these, 9 patients (18%) had revisional surgery and 48 patients (96%) were discharged within 24 hours of their surgery. The rate of readmission within thirty days of surgery was 6% (n = 3) and 1 patient returned to theatre with an obstruction proximal to the jejuno-jenunal anastomosis. None of the patients exhibited symptoms or tested positive for the COVID-19 virus.

Conclusions

With appropriate precautions and protocols, it is feasible and safe to resume BMS, with no increased risk to bariatric patients during the COVID-19 pandemic. This is particularly encouraging for other units in UK to offer BMS after the current lockdown.

684 The Standard of Emergency Operation Note Documentation at A District General Hospital Compared Against The Royal College of Surgeons of England (RCSEng) Standard

Introduction

Meticulous operation note documentation is essential for seamless, safe continuity of care in postoperative surgical patients. This study evaluated the standard of emergency operation note documentation at a district general hospital, when compared to the Royal College of Surgeons of England (RCSEng) guidelines and assessed the impact of a new operation note proforma.

Method

A retrospective review of 50 emergency operation notes was conducted between December 2019 and March 2020 and compared to RCSEng guidelines. Initial findings were presented at a local clinical governance meeting and a new electronic operation note was introduced. A further 50 emergency operation notes using the new proforma were analysed between August 2020 and December 2020.

Results

RCSEng mentions 19 main points that all operation notes must include. A total of 100 operation notes were reviewed and each given a score out of 19. Intervention of the new proforma showed significant improvement to the average score (15.64 vs 17.94; p &lt; 0.0001) when compared to RCSEng guidelines. In particular, there was significant improvement in the documentation of assistants involved in the procedure (58% vs 98%; p &lt; 0.0001), estimated blood loss (2% vs 63%; p &lt; 0.0001) and specific mention whether the operation was emergency or elective (20% vs 86%; p &lt; 0.0001).

Conclusions

Implementation of the new proforma showed significant improvement in operation note documentation when compared to the RCSEng standard. Therefore, this study emphasises the need for surgeons to familiarise themselves with the current guidelines and highlights the importance of tailoring local operation note proformas to match this national standard closely.

1384 Managing Peri-Orbital and Orbital Cellulitis: A New Multi-Specialty Care Pathway

Aim

1) To review current practice in the diagnosis and management of peri-orbital and orbital cellulitis in children at a London University Teaching Hospital. 2) To design and implement a streamlined, multi-specialty care pathway to improve the quality of care.

Background

Clinical differentiation between peri-orbital cellulitis and orbital cellulitis is often difficult, especially in young children. Early recognition and aggressive, multi-specialty treatment are required in order to prevent any vision and life-threatening sequelae.

Method

A retrospective case note analysis was performed for all paediatric patients with suspected peri-orbital or orbital cellulitis over a nineteen-month period. Extensive literature review was undertaken to ascertain current best practice in diagnosis and management. A streamlined, multi-specialty care pathway was developed, ratified by specialist departments, and introduced to optimise safety and quality of care.

Results

The results correlate with trends found in recent literature. 94.3% of patients had a blood culture taken with only 9.1% being positive. There were inadequate eye (37.1%) and endonasal (17.1%) cultures. Wide variation was noted in the criteria for imaging and in the antibiotic regimen used. 25.7% of patients received any nasal treatment. Suboptimal specialist review was identified in both orbital (60%) and peri-orbital (50.0%) cellulitis.

Conclusions

The new care pathway clearly informs investigation and empiric treatment based on initial risk stratification. The paediatric team is now the main, named care provider responsible for coordinating specialist input.

P–082 Effect of semen hyper viscosity (SHV) on blastocyst formation rate and implantation rate

Study question

Does semen hyper viscosity effects blastocyst formation rate

Summary answer

Hyper viscosity of semen sample later results in poor blastocyst formation rate and lower implantation rate.

What is known already

Normal range of semen hyper viscosity ranges between 12–29%.Highly viscous semen samples impairs the physical and chemical characteristics of seminal fluid and due to which seminal oxidative damage increases which further increases the ROS and reduces the sperm motility there are some factors that can affect the seminal viscosity out of which one is Male accessory gland infection, Hypo function of prostate seminal vesicles and varicoceles. SHV create hindrance in semen preparation.

Study design, size, duration

Retrospective study was conducted from June 2019 to Oct 2020 at IVF unit IKDRC hospital.

Participants/materials, setting, methods

142 patients were enrolled from June 2019 to Oct 2020 in IVF unit IKDRC hospital and divided into two groups. Group A (n = 83) patients with hyper semen viscosity and Group B (n = 69) patients with normal semen viscosity, inclusion and exclusion criteria’s were same for both the groups, only patient with normozoospermia were taken. Semen analysis was done by using WHO manual 2010.

Main results and the role of chance

In group A with hyper semen viscosity fertilization rate was (49.2% vs. 70% p = &lt;0.001) vs in group B with normal semen viscosity which is significantly higher in group B, Blastocyst formation rate ( 18.4% vs 35% p = &lt;0.01) and implantation rate (9.4% vs 20% p = &lt;0.005) both are significantly higher in group B . Which implies fertilization rate , blastocyst formation rate and implantation rate is significantly lower in patients with semen hyper viscosity.

Limitations, reasons for caution

Larger randomized control studies are needed to strengthen these results.

Wider implications of the findings: Our study demonstrates that patients having higher semen viscosity have poor blastocyst formation rate and implantation rate due to oxidative stress.

Trial registration number

Not applicable

P–109 Comparison between the outcome of sperm vitrification protocol and conventional slow freezing protocol for semen cryopreservation

Study question

Does sperm vitrification technique helps in increasing sperm survival and low DNA fragmentation index post warming.

Summary answer

Sperm vitrification protocol results in better motility, high progression and low DNA fragmentation index as compared to slow freezing.

What is known already

Cryopreservation is ceasing and resuming the cell metabolism, which can be achieved by different techniques like slow freezing and vitrification .Vitrification allows solidification of the cells and extracellular milieu into a glass like state without formation of ice which protects intracellular and extracellular ice formation, and further helps in avoiding different types of cryo-injuries and cellular damage. Study design, size, duration: Comparative study from July 2019 to Oct 2020 in IVF unit of IKDRC Hospital. Two hundred and ten patients were randomized by computer generated list and divided into two groups. Group 1 (n = 110) samples cryopreserved by vitrification and Group 2 (n = 100) samples cryopreserved by conventional slow freezing.

Participants/materials, setting, methods

Semen sample were analyzed by WHO 2010 laboratory manual, including all normozoospermic samples , other abnormal samples were excluded from the study . Method of semen preparation before cryopreservation is similar for both the groups, double density gradient method of preparation was used . Semen sample with high viscosity, hypo and hyper-spermia were also excluded. Similar cryovials of 2ml volume were used for both groups.

Main results and the role of chance

In group 1 where samples were cryopreserved by vitrification sperm motility was (54.3% vs 49.2%)vs in group 2 where samples were cryopreserved by slow freezing , non- significant difference were observed , but progressive motility was significantly higher in group 1 as compared to group 2 (36.8%vs17.9%) and DNA fragmentation index is significantly lower in group 1 vitrification than in group 2slow freezing ( 9.7% vs 20%).

Limitations, reasons for caution

Technical proficiency of the operator to avoid human errors and still larger randomized control studies are needed to strengthen these results

Wider implications of the findings: Our study demonstrates that vitrification is better than slow freezing of human sperm, improved survival rates with high progression were found with vitrification and low DNA fragmentation index were also observed in samples cryopreserved with vitrification protocol.

Trial registration number

Not applicable

O41 Quantifying the burden of survivorship associated with infra-renal abdominal aortic aneurysm repair: a systematic review

Introduction

Survivorship encompasses the physical, psychological, social, functional and economic experience of living with a chronic condition for both patients and their caregivers. It comprises 9 distinct domains and remains understudied in non-oncological pathologies, including infra-renal abdominal aortic aneurysmal disease (IRAAA). This review aims to quantify the extent to which existing IRAAA literature addresses the burden of survivorship in patients following surgical intervention.

Method

The databases; MEDLINE, EMBASE and PsychINFO, were searched from 1989 through to July 2020. Randomised controlled trials, observational studies and case series studies were included. Eligible studies had to detail outcomes related to survivorship following IRAAA surgery. Due to heterogeneity between studies and outcomes, no meta-analysis was conducted. Study quality was assessed with specific risk of bias tools.

Result

112 studies were included and only 4 of the 9 domains of survivorship have been previously studied—treatment complications, physical functioning, co-morbidities and caregivers. The available evidence is of variable quality; the majority of studies display a moderate to high risk of bias, are of an observational study design, are based within a limited number of countries and consist of an insufficient follow up period.

Conclusion

This review highlights the absence of robust evidence regarding survivorship following IRAAA surgery, regardless of repair modality. Consequently, contemporary treatment guidelines are reliant upon historic quality of life data that is narrow in scope and non-representative of contemporary clinical practice. As such, there is an urgent need to re-evaluate the scope and methodology associated with this research theme moving forwards.

Take-home Message

There is an urgent need to re-evaluate the scope and methodology associated with traditional quality of life centred IRAAA studies moving forwards in order to better empower patient decision making as well as inform treatment guidelines and health policy initiatives.

Safety and feasibility of resuming bariatric surgery under the cloud of COVID-19

INTRODUCTION

Because of the COVID-19 pandemic, numerous bariatric surgical units globally have halted weight loss surgery. Obesity itself has been shown to be a predictor of poor outcome in people infected with the virus. The aim of this study was to report our experience as a high-volume bariatric institution resuming elective weight loss surgery safely amidst emergency admissions of COVID-19-positive patients.

METHODS

A standard operating procedure based on national guidance and altered to accommodate local considerations was initiated across the hospital. Data were collected prospectively for 50 consecutive patients undergoing bariatric surgery following recommencement of elective surgery after the first national lockdown in the UK.

RESULTS

Between 28 June and 5 August 2020, a total of 50 patients underwent bariatric surgery of whom 94% were female. Median age was 41 years and median body mass index was 43.8 (interquartile range 40.0-48.8)kg/m2. Half of the patients (n = 25/50) underwent laparoscopic sleeve gastrectomy and half underwent Roux-en-Y gastric bypass (RYGB). Of these 50 patients, 9 (18%) had revisional bariatric surgery. Overall median length of hospital stay was 1 day, with 96% of the study population being discharged within 24h of surgery. The overall rate of readmission was 6% and one patient (2%) returned to theatre with an obstruction proximal to jejuno-jejunal anastomosis. None of the patients exhibited symptoms or tested positive for COVID-19.

CONCLUSION

With appropriately implemented measures and precautions, resumption of bariatric surgery during the COVID-19 pandemic appears feasible and safe with no increased risk to patients.

Mortality from esophagectomy for esophageal cancer across low, middle, and high-income countries: An international cohort study

BACKGROUND

No evidence currently exists characterising global outcomes following major cancer surgery, including esophageal cancer. Therefore, this study aimed to characterise impact of high income countries (HIC) versus low and middle income countries (LMIC) on the outcomes following esophagectomy for esophageal cancer.

METHOD

This international multi-center prospective study across 137 hospitals in 41 countries included patients who underwent an esophagectomy for esophageal cancer, with 90-day follow-up. The main explanatory variable was country income, defined according to the World Bank Data classification. The primary outcome was 90-day postoperative mortality, and secondary outcomes were composite leaks (anastomotic leak or conduit necrosis) and major complications (Clavien-Dindo Grade III - V). Multivariable generalized estimating equation models were used to produce adjusted odds ratios (ORs) and 95% confidence intervals (CI95%).

RESULTS

Between April 2018 to December 2018, 2247 patients were included. Patients from HIC were more significantly older, with higher ASA grade, and more advanced tumors. Patients from LMIC had almost three-fold increase in 90-day mortality, compared to HIC (9.4% vs 3.7%, p < 0.001). On adjusted analysis, LMIC were independently associated with higher 90-day mortality (OR: 2.31, CI95%: 1.17-4.55, p = 0.015). However, LMIC were not independently associated with higher rates of anastomotic leaks (OR: 1.06, CI95%: 0.57-1.99, p = 0.9) or major complications (OR: 0.85, CI95%: 0.54-1.32, p = 0.5), compared to HIC.

CONCLUSION

Resections in LMIC were independently associated with higher 90-day postoperative mortality, likely reflecting a failure to rescue of these patients following esophagectomy, despite similar composite anastomotic leaks and major complication rates to HIC. These findings warrant further research, to identify potential issues and solutions to improve global outcomes following esophagectomy for cancer.

Increasing adiposity and metabolic dysfunction prolong QTc interval and increase risk of ventricular arrhythmias: results from the UK Biobank

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health Research

Background/purpose: Small-scale studies have associated obesity and metabolic ill-health with QTc interval prolongation. Whether these associations are modulated by an underlying genetic predilection and translate into higher risks of ventricular arrhythmias (VA) is unknown.

Methods

 Using the UK Biobank and adjusted multivariate regression analysis, we studied the associations between QTc and clinical measures of adiposity and metabolic ill-health. A polygenic risk score was used to determine whether these associations are modulated by a genetic predilection for QTc prolongation. We compared QTc between four clinical phenotypes defined according to presence (+) or absence (-) of obesity (Ob), and metabolic ill-health (MU). Logistic regression was used to calculate odds ratios (OR) for VA amongst these groups.

Results

 23,683 individuals (11,563 male, mean age 61.0 + 7.5years) had ECG and clinical data available. QTc prolongs with increasing body mass index (0.76ms/kg/m2, 95%CI: 0.68-0.83ms/kg/m2), body fat (0.45ms/%, 95%CI:0.39-0.50ms/%), hip girth (0.35ms/cm, 95%CI:0.31-0.39ms/cm) and waist girth (0.32ms/cm, 95%CI:0.29-0.35ms/cm); all p &lt; 0.001. Genetically determined repolarisation reserve has no significant modulatory effect on the QTc-prolonging effects of increasing adiposity. Referenced to Ob-MU-, Ob + MU- and Ob-MU+ independently prolong QTc to a comparable extent, and Ob + MU+ has an additive effect on QTc prolongation. With reference to Ob-MU-, OR for VA in Ob-MU+ males and females were 5.96 (95%CI:4.70-7.55) and 5.10 (95%CI:3.34-7.80), respectively. OR for Ob + MU+ were 6.99 (95%CI:5.72-8.54) and 3.56 (95%CI:2.66-4.77) in males and females, respectively, (all p &lt; 0.001, see Table).

Conclusion

 Adiposity and metabolic perturbation prolong QTc to a similar extent, and their co-existence exerts an additive effect. These effects are independent of genetically determined repolarisation reserve. Despite their comparable QTc prolonging effects, metabolic ill-health is associated with higher OR for VA than obesity. VA in obesity and metabolic dysfunctionReference phenotypeOb + MU-Ob-MU+Ob + MU+Ob-MU+male1.10(0.87-1.39)ns5.96 (4.70-7.55)***6.99(5.72-8.54)***female0.87(0.64-1.18)ns5.10(3.34-7.80)***3.56(2.66-4.77)***Ob + MU-male--6.01(4.98-7.26)***female--5.61(4.18-7.52)***Ob + MU+male--1.25(1.05-1.49)*female--1.16(0.80-1.68)nsOb, obese; MU, metabolically unhealthy; +, presence; -, absence; ns, non-significant; *p &lt; 0.05; ***p &lt; 0.001. Abstract Figure. QTc in obesity and metabolic dysfunction

TimiRGeN: R/Bioconductor package for time series microRNA-mRNA integration and analysis

Motivation

The analysis of longitudinal datasets and construction of gene regulatory networks (GRNs) provide a valuable means to disentangle the complexity of microRNA (miRNA)–mRNA interactions. However, there are no computational tools that can integrate, conduct functional analysis and generate detailed networks from longitudinal miRNA–mRNA datasets.

Results

We present TimiRGeN, an R package that uses time point-based differential expression results to identify miRNA–mRNA interactions influencing signaling pathways of interest. miRNA–mRNA interactions can be visualized in R or exported to PathVisio or Cytoscape. The output can be used for hypothesis generation and directing in vitro or further in silico work such as GRN construction.

Availability and implementation

TimiRGeN is available for download on Bioconductor (https://bioconductor.org/packages/TimiRGeN) and requires R v4.0.2 or newer and BiocManager v3.12 or newer.

Supplementary information

Supplementary data are available at Bioinformatics online.

A proposed "Radiological Evaluation Score for Bone Tumors" (REST): An objective system for assessment of a radiograph in patients with suspected bone tumor

BACKGROUND

Although radiographs have been widely used in the evaluation of patients with suspected bone tumors, the lack of an objective radiological assessment method leads to a challenge in reaching correct diagnosis. The study aimed to propose a Radiological Evaluation Score for Bone Tumors (REST) which includes eight radiological factors [characteristics, content, cortical breach, distinctiveness, distribution, periosteal reaction, fracture, and soft tissue swelling] to form a single score along with its validation by multidisciplinary observers.

METHODS

We reviewed the radiographs of 100 patients with a primary bone tumor which were selected at random from the database between January 2017 and January 2019 of a tertiary cancer center. Four reviewers (two orthopedic oncologists and two surgical oncologists) independently assessed the radiographs, based on the reporting system of REST. We constituted two groups according to the probable diagnosis of bone tumor (suspected benign tumor and suspected malignant tumor).

RESULTS

The mean score in the suspected benign tumor group was 1.1 (range 0-3, 95% CI 0.8-1.3) and in malignant tumor group was 6.1 (range 2-8, 95% CI 5.8-6.4). A receiver operator characteristic (ROC) curve for REST was with a cutoff of 3.5, with the most diagnostic value area under curve (AUC) of 0.99. The sensitivity was 98% and specificity was 100% with a positive predictive value of 100% and a negative predictive value of 98%. The inter-observer correlation coefficient was 0.985 (p value < 0.05), and Fleiss kappa value for the prediction of the benign or malignant lesion was 0.97 (p value < 0.05). The characteristics and content of tumor, cortical erosion, distinctiveness, distribution, periosteal reaction, and soft tissue mass had a significant correlation with the aggressiveness of bone lesion p value < 0.05.

CONCLUSIONS

The Radiological Evaluation Score for Bone Tumors (REST) is a structured reporting and objective method for the assessment of radiographs in patients with suspected bone tumors. This method is a reliable and helpful tool for clinicians in their outdoor patient department to differentiate a radiograph of a suspected benign tumor from a malignant bone tumor.

Comparison of short-term outcomes from the International Oesophago-Gastric Anastomosis Audit (OGAA), the Esophagectomy Complications Consensus Group (ECCG), and the Dutch Upper Gastrointestinal Cancer Audit (DUCA)

BACKGROUND

The Esophagectomy Complications Consensus Group (ECCG) and the Dutch Upper Gastrointestinal Cancer Audit (DUCA) have set standards in reporting outcomes after oesophagectomy. Reporting outcomes from selected high-volume centres or centralized national cancer programmes may not, however, be reflective of the true global prevalence of complications. This study aimed to compare complication rates after oesophagectomy from these existing sources with those of an unselected international cohort from the Oesophago-Gastric Anastomosis Audit (OGAA).

METHODS

The OGAA was a prospective multicentre cohort study coordinated by the West Midlands Research Collaborative, and included patients undergoing oesophagectomy for oesophageal cancer between April and December 2018, with 90 days of follow-up.

RESULTS

The OGAA study included 2247 oesophagectomies across 137 hospitals in 41 countries. Comparisons with the ECCG and DUCA found differences in baseline demographics between the three cohorts, including age, ASA grade, and rates of chronic pulmonary disease. The OGAA had the lowest rates of neoadjuvant treatment (OGAA 75.1 per cent, ECCG 78.9 per cent, DUCA 93.5 per cent; P < 0.001). DUCA exhibited the highest rates of minimally invasive surgery (OGAA 57.2 per cent, ECCG 47.9 per cent, DUCA 85.8 per cent; P < 0.001). Overall complication rates were similar in the three cohorts (OGAA 63.6 per cent, ECCG 59.0 per cent, DUCA 62.2 per cent), with no statistically significant difference in Clavien-Dindo grades (P = 0.752). However, a significant difference in 30-day mortality was observed, with DUCA reporting the lowest rate (OGAA 3.2 per cent, ECCG 2.4 per cent, DUCA 1.7 per cent; P = 0.013).

CONCLUSION

Despite differences in rates of co-morbidities, oncological treatment strategies, and access to minimal-access surgery, overall complication rates were similar in the three cohorts.