The comprehensive English National Lynch Syndrome Registry: development and description of a new genomics data resource

Background

Lynch Syndrome (LS) is a cancer predisposition syndrome caused by constitutional pathogenic variants in the mismatch repair (MMR) genes. To date, fragmentation of clinical and genomic data has restricted understanding of national LS ascertainment and outcomes, and precluded evaluation of NICE guidance on testing and management. To address this, via collaboration between researchers, the National Disease Registration Service (NDRS), NHS Genomic Medicine Service Alliances (GMSAs), and NHS Regional Clinical Genetics Services, a comprehensive registry of LS carriers in England has been established.

Methods

For comprehensive ascertainment of retrospectively identified MMR pathogenic variant (PV) carriers (diagnosed prior to January 1, 2023), information was retrieved from all clinical genetics services across England, then restructured, amalgamated, and validated via a team of trained experts in NDRS. An online submission portal was established for prospective ascertainment from January 1, 2023. The resulting data, stored in a secure database in NDRS, were used to investigate the demographic and genetic characteristics of the cohort, censored at July 25, 2023. Cancer outcomes were investigated via linkage to the National Cancer Registration Dataset (NCRD).

Findings

A total of 11,722 retrospective and 570 prospective data submissions were received, resulting in a comprehensive English National Lynch Syndrome Registry (ENLSR) comprising 9030 unique individuals. The most frequently identified pathogenic MMR genes were MSH2 and MLH1 at 37.2% (n = 3362) and 29.1% (n = 2624), respectively. 35.9% (n = 3239) of the ENLSR cohort received their LS diagnosis before their first cancer diagnosis (presumptive predictive germline test). Of these, 6.3% (n = 204) developed colorectal cancer, at a median age of initial diagnosis of 51 (IQR 40-62), compared to 73 years (IQR 64-80) in the general population (p < 0.0001).

Interpretation

The ENLSR represents the first comprehensive national registry of PV carriers in England and one of the largest cohorts of MMR PV carriers worldwide. The establishment of a secure, centralised infrastructure and mechanism for routine registration of newly identified carriers ensures sustainability of the data resource.

Funding

This work was funded by the Wellcome Trust, Cancer Research UK and Bowel Cancer UK. The funder of this study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.

Thrombosis with thrombocytopenia syndrome (TTS) following adenovirus vector COVID-19 vaccination in Canada

INTRODUCTION

Identifying and monitoring adverse events following vaccination contributed to the safety and effectiveness of COVID-19 mass vaccination campaigns. In March 2021, international reports emerged of an adverse event following vaccination with adenovirus vector COVID-19 vaccines (ChAdOx1-S [recombinant] and Ad26.COV2.S) of thrombosis with low platelet counts, referred to as thrombosis with thrombocytopenia syndrome (TTS). We described TTS reports in Canada following adenovirus vector COVID-19 vaccines and investigated whether the observed number of events were higher than expected.

METHODS

Reports of TTS following receipt of ChAdOx1-S [recombinant] or Ad26.COV2.S meeting the Canadian case definition for TTS and diagnostic certainty levels 1-3 of the Brighton Collaboration case definition, submitted to the Canadian Adverse Events Following Immunization Surveillance System and Canada Vigilance Database between February 26, 2021 and October 31, 2022 were included. Demographics and characteristics of the TTS reports are described along with an analysis comparing the observed number of reports to the expected number.

RESULTS

As of October 31, 2022, 56 reports of TTS following administration of ChAdOx1-S [recombinant] and no reports following Ad26.COV2.S vaccines were reported in Canada, of which 37 had functionally positive anti-PF4 antibodies. The median age was 56 years; males accounted for 54 % of reports. Five deaths were reported. The observed number of reports exceeded the expected for all ages and sexes combined, as well as for males aged 30-49 and 60-69 years, and females aged 40-59 years.

CONCLUSION

Based on international surveillance data, Canada evaluated a statistical signal of TTS following adenovirus vector vaccines. The investigation of this signal demonstrated how post-market vaccine safety surveillance systems were successful in investigating rare adverse events during the rollout of COVID-19 vaccines in Canada. As adenovirus vector vaccines continue to be administered, characterization of the association between the vaccine and TTS informs immunization programs and policies.

P-043 A RETROSPECTIVE OUTCOME REVIEW OF THE USE OF EGIS ACELLULAR DERMAL MATRIX DURING ABDOMINAL WALL RECONSTRUCTION

Aim

We aimed to demonstrate the relative safety profile of an established non-crosslinked porcine acellular dermal matrix (ADM) during abdominal wall reconstruction.

Material & Methods

Individual real-world safety data on specific mesh products are often lacking. With recent media scrutiny over the use of mesh, we sought to quantify outcomes and demonstrate the safety of a specific ADM (reference 1). A retrospective casenote-based outcome analysis was performed on patients who underwent mesh augmentation during abdominal wall reconstruction from two NHS institutions. Both elective and emergency patients were included from January 2018 to December 2021.

Results

Fifty-five patients were included in the study across two NHS specialist hernia centres. We identified a mean wound infection rate of 14.2% (range 2–22%) with a median follow up of 9 months (range 3–18 months). Hernia recurrence rate was 10.4% (range 5–22%). We found 7 patients (12%) developed a seroma, 1 of whom required seroma aspiration. Only 4 patients (7%) had post-operative dehiscence requiring further intervention, all of whom had Ventral Hernia Working Group (VHWG) Grade 3 or 4 wounds pre-operatively.

Conclusions

Our data supports the continued use of a widely available ADM for abdominal wall reconstruction in both elective and emergency cases, highlighting its positive relative safety profile.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Experiences of Multidisciplinary Working: Perspectives from the Wessex Ghana Stroke Partnership

INTRODUCTION

Substantial gaps remain in our understanding of stroke in Africa as well as in stroke care, practice and policy on the continent. The effective organization of preventative, therapeutic and rehabilitative stroke services continue to be challenging in many African countries.

METHODOLOGY

In this article we define the nature, function and benefits of effective multidisciplinary team (MDT) working. The experiences and perspectives of members of the MDT were collated by focus group discussions as well as individual and country specific contributions.

RESULTS

The experiences and perspectives of multidisciplinary team members from the United Kingdom and Ghana implementing these practices at the first stroke unit in Korle Bu Teaching Hospital, Accra, with a transparent discussion of successes and challenges faced throughout development of the service, is presented. MDT working has improved outcomes for patients and families who use the services, including encouraging better shared treatment planning and compliance. More stroke rehabilitation services are provided than previously, including greater self-management education and better secondary prevention care.

CONCLUSION

It is hoped that this article will provide an inspirational model for others working to provide stroke care in low-resource settings in Africa and worldwide.

Serial Clinical Scoring to Assess Transported Pediatric Patients

OBJECTIVES

The objective of this study was to evaluate serial Transport Risk Assessment in Pediatrics (TRAP) scoring during pediatric critical care transport as a potential measure for specialized pediatric transport teams (PTTs).

METHODS

This was a retrospective study with a provincial PTT from a tertiary hospital pediatric intensive care unit. All acutely ill children who were transported by the PTT between 2018 and 2019 were included in the study. The TRAP scores were measured at time of transport team arrival (TRAP1), time at arrival to tertiary center (TRAP2), and 4 hours postarrival to tertiary center (TRAP3).

RESULTS

A total of 300 transports were included. Patients' mean age was 54 months, with lower respiratory tract infection (40.7%) as the most common diagnosis. There were significant differences between TRAP1-TRAP2 (P < 0.01) and TRAP1-TRAP3 (P < 0.01), but not between TRAP2-TRAP3 (P = 0.67). The most significant improvements of ΔTRAP1-TRAP2 scores were seen in septic shock (mean, 2.0; SD, 1.7).

CONCLUSIONS

The TRAP scores improved following the PTTs' arrival to acutely ill children, particularly with sepsis. Serial TRAP scoring may present a system for evaluation of team performance and/or characterize disease states that are positively impacted by PTTs. Future prospective evaluation is needed to validate TRAP for this purpose.

748 Case Series: Experience of Using External Fixation as An Adjunct in The Management of MRONJ Affecting the Mandible

Introduction

External fixation was first described by Malgaigne and Rigaud in 1870 for use on long bones, then adapted for OMFS in 1934 and used for treating comminuted fractures. In recent times, popularity of external fixators has decreased with the use of mini-plates, often only used in major trauma, for example gunshot wounds. This is a case series of patients who have been treated by external fixation for medication related osteonecrosis (MRONJ) of the jaw and could be a fairly simple alternative to major reconstructive surgery in such cases. This method of treatment has been particularly useful during the Covid-19 pandemic as a non-aerosol generating procedure.

Method

A single centre, retrospective study of 5 cases between December 2018 - December 2020. The MRONJ cases were graded using the AAOMS classification. All cases treated with external fixation of mandible were included. Pre-operative condition, medical history, treatment complications, pain management, length of treatment and follow-up results were recorded.

Results

Of the 5 cases treated for MRONJ, 4 of these had pathological fractures. All were AAOMS stage 3. The mean duration of treatment was 78 days, with regular clinical reviews monitoring progress. Of these cases, 4 cases healed well with significant improvement or closure of intraoral and extra-oral wounds.

Conclusions

In this small case series the technique has shown positive results; being well received by patients and allowing function while in situ. It allows treatment of pathological fractures as well as stabilising the mandible as a preventative measure whilst debriding severely atrophic mandibles.

The importance of neurology and genetic testing in the patient with non-cleft velopharyngeal dysfunction

OBJECTIVE

A significant proportion of the referrals made to a speech investigation clinic in a cleft unit include patients with non-cleft velopharyngeal dysfunction (VPD). This study aims to quantify the underlying diagnoses of these patients and describe the investigative pathway and diagnostic information subsequent to presentation in our clinic.

MATERIALS AND METHODS

The case notes of 136 consecutive patients with non-cleft VPD who attended our Velopharyngeal Investigation (VPI) clinic from July 2014-December 2019 were reviewed.

RESULTS

In the paediatric group (n = 118) the most common cause was 22q11 chromosomal anomalies (n = 46), while post palatal tumour resection was the commonest cause of acquired non-cleft VPD in adults (n = 8). Fifty-nine patients were referred to the clinic with a known underlying pathology such as a syndromic diagnosis. Of those presenting without a known aetiology, fifty-eight were referred onto our genetics and/or neurology colleagues. Although a genetic or neurological cause could not be identified in some of those patients, thirty-one patients received a new diagnosis, with subsequent implications for ongoing care.

CONCLUSION

There are a wide range of diagnoses resulting in non-cleft VPD, but there are very few large-scale studies focusing on investigating these patients for an underlying aetiology. This study highlights the role of genetics and neurology in the diagnosis and management plan for this cohort of patients.

Continuous-flow electrocoagulation (EC) process for iron removal from water: Experimental, statistical and economic study

The process of Electrocoagulation (EC), the in-situ production of coagulants by passing an electric current through sacrificial electrodes, is free of chemical additives and cost-effective. This makes it the most widely used water and wastewater treatment method. However, the literature highlights some significant drawbacks of this method including EC unit design limitations. This research therefore aimed to develop a new EC unit design using drilled plates (electrodes) to mix the solution being treated without using external mixers, this minimising power consumption. The performance of the new EC unit was validated by applying it to remove iron from water taking into account the effects of applied current density (ACD), the pH of the water (PoW), iron concentration (IC) and treatment time (TT). The effects of these parameters were optimised using the Box-Behnken model. Synthetic water samples containing different concentrations of iron (10-30 mg/l), were treated in a continuous flow, using the new EC reactor at different ACD (1.5-4.5 mA/cm²), PoW (4-10) and TT (10-50 min). The results revealed that the removal of 99.9% of iron was achieved by keeping PoW, ACD, IC and TT at 7, 3 mA/cm², 10 mg/l and 50 min, respectively. The effects of ACD, POW, IC and TT on iron removal could be successfully simulated with R² = 0.9788. The cost of removing iron using the proposed EC unit was 0.623 £/m³.

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.

Sporadic vestibular schwannoma: a molecular testing summary

OBJECTIVES

Cases of sporadic vestibular schwannoma (sVS) have a low rate of association with germline pathogenic variants. However, some individuals with sVS can represent undetected cases of neurofibromatosis type 2 (NF2) or schwannomatosis. Earlier identification of patients with these syndromes can facilitate more accurate familial risk prediction and prognosis.

METHODS

Cases of sVS were ascertained from a local register at the Manchester Centre for Genomic Medicine. Genetic analysis was conducted in NF2 on blood samples for all patients, and tumour DNA samples when available. LZTR1 and SMARCB1 screening was also performed in patient subgroups.

RESULTS

Age at genetic testing for vestibular schwannoma (VS) presentation was younger in comparison with previous literature, a bias resulting from updated genetic testing recommendations. Mosaic or constitutional germline NF2 variants were confirmed in 2% of patients. Pathogenic germline variants in LZTR1 were found in 3% of all tested patients, with a higher rate of 5% in patients <30 years. No pathogenic SMARCB1 variants were identified within the cohort. Considering all individuals who received tumour DNA analysis, 69% of patients were found to possess two somatic pathogenic NF2 variants, including those with germline LZTR1 pathogenic variants.

CONCLUSIONS

Undiagnosed schwannoma predisposition may account for a significant minority of apparently sVS cases, especially at lower presentation ages. Loss of NF2 function is a common event in VS tumours and may represent a targetable common pathway in VS tumourigenesis. These data also support the multi-hit mechanism of LZTR1-associated VS tumourigenesis.

Understanding and optimising patient and public involvement in trial oversight: an ethnographic study of eight clinical trials

BACKGROUND

Trial oversight is important for trial governance and conduct. Patients and/or lay members of the public are increasingly included in trial oversight committees, influenced by international patient and public involvement (PPI) initiatives to improve the quality and relevance of research. However, there is a lack of guidance on how to undertake PPI in trial oversight and tokenistic PPI remains an issue. This paper explores how PPI functions in existing trial oversight committees and provides recommendations to optimise PPI in future trials. This was part of a larger study investigating the role and function of oversight committees in trials facing challenges.

METHODS

Using an ethnographic study design, we observed oversight meetings of eight UK trials and conducted semi-structured interviews with members of their trial steering committees (TSCs) and trial management groups (TMGs) including public contributors, trial sponsors and funders. Thematic analysis of data was undertaken, with findings integrated to provide a multi-perspective account of how PPI functions in trial oversight.

RESULTS

Eight TSC and six TMG meetings from eight trials were observed, and 66 semi-structured interviews conducted with 52 purposively sampled oversight group members, including three public contributors. PPI was reported as beneficial in trial oversight, with public members contributing a patient voice and fulfilling a patient advocacy role. However, public contributors were not always active at oversight meetings and were sometimes felt to have a tokenistic role, with trialists reporting a lack of understanding of how to undertake PPI in trial oversight. To optimise PPI in trial oversight, the following areas were highlighted: the importance of planning effective strategies to recruit public contributors; considering the level of oversight and stage(s) of trial to include PPI; support for public contributors by the trial team between and during oversight meetings.

CONCLUSIONS

We present evidence-based recommendations to inform future PPI in trial oversight. Consideration should be given at trial design stage on how to recruit and involve public contributors within trial oversight, as well as support and mentorship for both public contributors and trialists (in how to undertake PPI effectively). Findings from this study further strengthen the evidence base on facilitating meaningful PPI within clinical trials.

Ex vivo specimen MRI and pathology confirm a rectosigmoid mesenteric waist at the junction of the mesorectum and mesocolon

AIM

Continuity of the mesentery has recently been established and may provide an anatomical basis for optimal colorectal resectional surgery. Preliminary data from operative specimen measurements suggest there is a tapering in the mesentery of the distal sigmoid. A mesenteric waist in this area may be a risk factor for local recurrence of colorectal cancer. This study aimed to investigate the anatomical characteristics of the mesentery at the colorectal junction.

METHOD

In this cross-sectional study, 20 patients were recruited. After planned colorectal resection, the surgical specimens were scanned in a MRI system and subsequently dissected and photographed as per national pathology guidelines. Mesenteric surface area and linear measurements were compared between MRI and pathology to establish the presence and location of a mesenteric waist.

RESULTS

Specimen analysis confirmed that a narrowing in the mesenteric surface area was consistently apparent at the rectosigmoid junction. Above the anterior peritoneal reflection, the surface area and posterior distance of the mesentery of the upper rectum initially decreased before increasing as the mesentery of the sigmoid colon. These anatomical properties created the appearance of a mesenteric 'waist' at the rectosigmoid junction. Using the anterior reflection as a reference landmark, the rectosigmoid waist occurred at a mean height of 23.6 and 21.7 mm on MRI and pathology, respectively.

CONCLUSION

A rectosigmoid waist occurs at the junction of the mesorectum and mesocolon, and is a mesenteric landmark for the rectum that is present on both radiology and pathology.

Noninvasive ventilation for pediatric interfacility transports: a retrospective study

BACKGROUND

To characterize pediatric patients supported with continuous positive airway pressure and bilevel positive airway pressure (CPAP/BiPAP) or high-flow nasal cannula (HFNC) during interfacility transport (IFT).

METHODS

A retrospective study with a provincial pediatric transport team from a tertiary hospital pediatric intensive care unit. Pediatric patients aged 28 days to < 17 years, who required IFT between January 2017 and December 2018, were identified through a transport registry and were included in the study.

RESULTS

A total of 118 (26.7%) patients received CPAP/BIPAP or HFNC support for IFT. The most common respiratory diagnosis was bronchiolitis (46%). These patients were placed on respiratory support, 31.4 minutes after the transport team's arrival. None required intubation during their IFT, despite mean transport times of 163 minutes.

CONCLUSIONS

This study may provide important information for programs with large catchment areas, in which large distances and transport times should not be barriers to NIV implementation.

Chronic Dyrk1 Inhibition Delays the Onset of AD-Like Pathology in 3xTg-AD Mice

There is a critical need for new treatment approaches that can slow or prevent the progression of Alzheimer's disease (AD). Targets that act simultaneously on multiple relevant pathways could have significant therapeutic potential. Dual-specificity tyrosine phosphorylation-regulated kinase 1A (Dyrk1a) phosphorylates both amyloid precursor protein (APP) and tau. Dyrk1a is upregulated in post-mortem brains of AD patients, and such elevated expression is associated with cognitive deficits. We previously demonstrated that small molecule inhibition of Dyrk1 is well-tolerated and reduces amyloid plaques and pathological forms of tau in 3xTg-AD mice if administered after formation of these pathologies. However, while insoluble forms of hyperphosphorylated tau were reduced by Dyrk1 inhibition, overt neurofibrillary tangle (NFT) pathology remained unchanged. Herein, we specifically test the hypothesis that inhibition of Dyrk1 prior to NFT formation will delay the onset of pathology. 3xTg-AD mice were treated chronically, beginning at 6 months of age, prior to NFT pathology. Mice were dosed daily for either 3 or 6 months and amyloid and tau pathology were assessed. We show that chronic Dyrk1 inhibition reduces insoluble forms of amyloid beta peptides (Aβ) and hyper-phosphorylated tau long-term and that these reductions are associated with dramatic delay in the onset of both amyloid plaques and NFTs. In addition, we show that DYR219, a potent and selective small molecule Dyrk1 inhibitor, induces degradation of Dyrk1a protein, likely contributing to the efficacy of this small molecule approach in vivo. Collectively, these results suggest that therapeutic strategies targeting tau phosphorylation will show the greatest effect if administered very early in the pathogenesis of AD.

Hypokalaemia with flaccid paralysis following high-voltage electrical injury in an adolescent patient

The authors present a case report of a previously healthy 15-year-old male who experienced global weakness in the presence of profound hypokalaemia following a high-voltage electrical arc injury. The clinical picture is discussed in the context of our evolving understanding of electrical injuries and potassium homeostasis.

Variation in landmarks for the rectum: an MRI study

AIM

This study aimed to assess the reliability of measurements and bony landmarks for the rectosigmoid junction on MRI.

METHOD

The staging MRI scans for 100 patients were reviewed. The junction of the mesorectum and mesocolon was used to identify the rectum and sigmoid. The performance of current metric measurements or bony landmarks was then compared against the actual anatomical bowel segment.

RESULTS

The mean distance of the sigmoid take-off from the anal verge was 12.6 cm (SD 1.8 cm, range 9.4-19.0 cm). At a cutoff of 12 cm, the anatomical bowel segment was found to be sigmoid colon rather than rectum in 35% of patients. At 15 and 16 cm the bowel segment was sigmoid in 84% and 96% of patients, respectively. At the sacral promontory and the third sacral segment, the bowel segment was sigmoid in 28% and 100% of patients, respectively.

CONCLUSION

Current definitions of the rectum that rely on arbitrary measurements or bony landmarks will not locate the correct point of transition between the rectum and sigmoid in the majority of patients. The sigmoid take-off offers an alternative, anatomically bespoke, landmark.

Deep urban groundwater vulnerability in India revealed through the use of emerging organic contaminants and residence time tracers

Demand for groundwater in urban centres across Asia continues to rise with ever deeper wells being drilled to avoid shallow contamination. The vulnerability of deep alluvial aquifers to contaminant migration is assessed in the ancient city of Varanasi, India, using a novel combination of emerging organic contaminants (EOCs) and groundwater residence time tracers (CFC and SF₆). Both shallow and intermediate depth private sources (<100 m) and deep (>100 m) municipal groundwater supplies were found to be contaminated with a range of EOCs including pharmaceuticals (e.g. sulfamethoxazole, 77% detection frequency, range <0.0001-0.034 μg L^-1), perfluoroalkyl substances (e.g. PFOS, range <0.0001-0.033 μg L^-1) as well as a number of pesticides (e.g. phenoxyacetic acid, range <0.02-0.21 μg L^-1). The profile of EOCs found in groundwater mirror those found in surface waters, albeit at lower concentrations, and reflect common waste water sources with attenuation in the subsurface. Mean groundwater residence times were found to be comparable between some deep groundwater and shallow groundwater sources with residence times ranging from >70 to 30 years. Local variations in aquifer geology influence the extent of modern recharge at depth. Both tracers provide compelling evidence of significant inputs of younger groundwater to depth >100 m within the aquifer system.

Rapid disease progression in a patient with mismatch repair-deficient and cortisol secreting adrenocortical carcinoma treated with pembrolizumab

CONTEXT

Metastatic adrenocortical carcinoma (ACC) is an aggressive malignancy with a poor prognosis and limited therapeutic options. A subset of ACC is due to Lynch syndrome, an inherited tumor syndrome resulting from germline mutations in mismatch repair (MMR) genes. It has been demonstrated that several cancers characterized by MMR deficiency are sensitive to immune checkpoint inhibitors that target PD-1. Here, we provide the first report of PD-1 blockade with pembrolizumab in a patient with Lynch syndrome and progressive cortisol-secreting metastatic ACC.

CASE REPORT

A 58-year-old female with known Lynch syndrome presented with severe Cushing's syndrome and was diagnosed with a cortisol-secreting ACC. Three months following surgical resection and adjuvant mitotane therapy the patient developed metastatic disease and persistent hypercortisolemia. She commenced pembrolizumab, but her second cycle was delayed due to a transient transaminitis. Computed tomography performed after 12 weeks and 2 cycles of pembrolizumab administration revealed significant disease progression and treatment was discontinued. After 7 weeks, the patient became jaundiced and soon died due to fulminant liver failure.

CONCLUSION

Treatment of MMR-deficient cortisol-secreting ACC with pembrolizumab may be ineffective due to supraphysiological levels of circulating corticosteroids, which may in turn mask severe drug-induced organ damage.