Improving access to exome sequencing in a medically underserved population through the Texome Project

PURPOSE

Genomic medicine can end diagnostic odysseys for patients with complex phenotypes; however, limitations in insurance coverage and other systemic barriers preclude individuals from accessing comprehensive genetics evaluation and testing.

METHODS

The Texome Project is a 4-year study that reduces barriers to genomic testing for individuals from underserved and underrepresented populations. Participants with undiagnosed, rare diseases who have financial barriers to obtaining exome sequencing (ES) clinically are enrolled in the Texome Project.

RESULTS

We highlight the Texome Project process and describe the outcomes of the first 60 ES results for study participants. Participants received a genetic evaluation, ES, and return of results at no cost. We summarize the psychosocial or medical implications of these genetic diagnoses. Thus far, ES provided molecular diagnoses for 18/60 (30%) of Texome participants. Plus, in 11/60 (18%) participants, a partial or probable diagnosis was identified. Overall, five participants had a change in medical management.

CONCLUSIONS

To date, the Texome Project has recruited a racially, ethnically, and socioeconomically diverse cohort. The diagnostic rate and medical impact in this cohort support the need for expanded access to genetic testing and services. The Texome Project will continue reducing barriers to genomic care throughout the future study years.

Characterization of the prenatal renal phenotype associated with 17q12, HNF1B, microdeletions

OBJECTIVE

Recurrent deletions involving 17q12 are associated with a variety of clinical phenotypes, including congenital abnormalities of the kidney and urinary tract (CAKUT), maturity onset diabetes of the young, type 5, and neurodevelopmental disorders. Structural and/or functional renal disease is the most common phenotypic feature, although the prenatal renal phenotypes and the postnatal correlates have not been well characterized.

METHOD

We reviewed pre- and postnatal medical records of 26 cases with prenatally or postnatally identified 17q12/HNF1B microdeletions (by chromosomal microarray or targeted gene sequencing), obtained through a multicenter collaboration. We specifically evaluated 17 of these cases (65%) with reported prenatal renal ultrasound findings.

RESULTS

Heterogeneous prenatal renal phenotypes were noted, most commonly renal cysts (41%, n = 7/17) and echogenic kidneys (41%), although nonspecific dysplasia, enlarged kidneys, hydronephrosis, pelvic kidney with hydroureter, and lower urinary tract obstruction were also reported. Postnatally, most individuals developed renal cysts (73%, 11/15 live births), and there were no cases of end-stage renal disease during childhood or the follow-up period.

CONCLUSION

Our findings demonstrate that copy number variant analysis to assess for 17q12 microdeletion should be considered for a variety of prenatally detected renal anomalies. It is important to distinguish 17q12 microdeletion from other etiologies of CAKUT as the prognosis for renal function and presence of associated findings are distinct and may influence pregnancy and postnatal management.

Single Institute Experience Treating Uterine Carcinosarcoma: Outcome Analysis

PURPOSE/OBJECTIVE(S)

Uterine carcinosarcoma (UCS) is rare with a poor prognosis. We report over 10 years' experience, reporting prognostic and predictive factors for overall survival (OS) and disease-free survival (DFS).

MATERIALS/METHODS

Patient, tumor, treatment and relapse characteristics of 168 women with stages I-IVB UCS treated at our institute between 2010 and 2020 were analyzed. OS and DFS at 2 and 5 years were the primary outcomes, estimated with Kaplan-Meier. The benefit of adjuvant chemotherapy and radiotherapy in the curative cohort was estimated using the log rank test.

RESULTS

Median follow up was 23 months (range 1-137 months). 34% had FIGO stage IA disease, 10% IB, 8% II. 16% IIIA-IIIC1, and 10% IIIC2 and 22% IVB. The overall 2-year OS was 52% and 5-year OS 30%. 2-year OS by FIGO stage were: IA 66%; IB 63%; II 54%; IIIA-IIIC1 54%; IIIC2 45%; IVB 26%. Within the curative cohort who were surgically staged, 2-year DFS was 47% and 5-year was 30%. 2-year DFS were 61% in IA disease, 53% IB, 12% II, 51% IIIA-IIIC1, and 45% IIIC2 and 4% IVB. A greater risk of death was conferred by lack of adjuvant treatment (lack of chemo > lack of radiotherapy). The most common chemotherapy regimen used was Carboplatin Paclitaxel and pelvic radiotherapy 45Gy 25F over 5 weeks. The combination of surgery and chemotherapy +/- radiotherapy significantly improved OS compared to surgery +/- radiotherapy (HR 0.5 with CI 0.3 - 0.9) p<0.05. Radiotherapy improved OS compared to surgery only (HR 0.4 with CI 0.2 - 1.1) p<0.05. Relapse rate in all patients following curative treatment is 72% within year 1 and 86% within year 2 from diagnosis. In 52 patients with stage 1A disease treated with surgery +/- radiotherapy only, 42.4% relapsed, median time to relapse was 8 months from diagnosis. Relapse occurred despite 69.2 % stage 1A patients receiving adjuvant pelvic EBRT and in these patients relapse within the pelvis occurred in 50%.

CONCLUSION

This study constitutes the largest retrospective analyses of long-term mortality outcomes in UCS and confirms poor outcomes despite curative surgery and adjuvant therapy. Most patients relapse within the first year following curative treatment. The use of adjuvant chemotherapy improves OS in all stages. In stage 1A disease 42 % patients relapse locally and distantly. This is an area of controversy and this data would strongly suggest that the addition of adjuvant paclitaxel-carboplatin or cisplatin-doxorubicin chemotherapy to EBRT should be considered in all patients including earliest stage disease.

Real-World Experience of Intensity Modulated Radiation Therapy and Concurrent Chemotherapy for Anal Cancer with Long-Term Follow up and Clinical Outcomes

PURPOSE/OBJECTIVE(S)

The standard treatment for epidermoid anal cancer (AC) is concurrent chemoradiation (CRT). Here we present real world evidence of the safety and outcomes of AC patients managed by IMRT and concurrent chemotherapy at a single academic cancer center.

MATERIALS/METHODS

We retrospectively reviewed the outcomes of 180 AC patients treated with definitive CRT between 2011 and 2018. Patients were managed according to a prospectively designed protocol of IMRT with radiation dose escalated according to tumor stage: 50.4, 55.8 and 63 Gy for T1, T2 and T3/T4 disease respectively, and 36 Gy for elective nodal RT. Involved nodes were given the same dose based on T category. Concurrent chemotherapy consisted of two cycles of mitomycin C (MMC, 12 mg/m2) and 5-fluorouracil (5FU, 1000 mg/m2/day x 4 days) given on week 1 and 5. There was no planned treatment break. Univariate and multivariate analysis for outcomes were performed using Cox proportional hazard method and likelihood ratio statistics. Overall survival (OS) disease free (DFS), colostomy-free survival (CFS) and local failure rates (LFR) were described by Kaplan-Meier methods.

RESULTS

There were 128 female and 52 male patients with a median age of 64 (IQR 55-74). The median size of the primary was 4.0 cm (0.6-11.0 cm). There were 18 T1, 91 T2, 38 T3 and 33 T4 lesions; 50.6% (91/180) of the patients had N0 disease. Thirteen (7.2%) did not receive concurrent chemotherapy, and 16 (8.9%) failed to complete treatment as planned. Forty-three (23.9%) patients had a treatment gap >5 (6-33) days. Eighteen of 147 (12%) with T1-3 disease failed locally, LF was observed in 13/33 (39%) T4 lesions (P = 0.0002). The 5-year OS, DFS, CFS and LFR were 85.1%, 75.6%, 87.6% and 15.5% respectively. On multivariate analysis, increasing age and N+ disease were significant for worse OS, and increasing size of the primary tumor was the only significant factor for worse DFS, CFS and LFR. Grade ≥3 acute toxicities were observed in 42.8% of patients, with grade ≥3 neutropenia and febrile neutropenia observed in 18.9% and 13.9% of patients respectively. Six patients (3.3%) died of acute toxicities. Thirteen (7%) patients experienced grade ≥3 late toxicities.

CONCLUSION

Size of the primary appears to be the most important determinant of outcome following standard CRT using IMRT for AC. Despite IMRT, almost 1 in 4 patients required a treatment break, and over 40% experienced grade ≥3 acute toxicities including neutropenia and febrile neutropenia. Future studies with RT dose escalation or de-escalation, stratifying patients based on tumor size, HPV status and molecular markers are necessary to improve outcomes and decrease treatment related toxicity.

Brain Maturation Patterns on Normalized FLAIR MR Imaging in Children and Adolescents

BACKGROUND AND PURPOSE

Signal analysis of FLAIR sequences is gaining momentum for studying neurodevelopment and brain maturation, but FLAIR intensity varies across scanners and needs to be normalized. This study aimed to establish normative values for standardized FLAIR intensity in the pediatric brain.

MATERIALS AND METHODS

A new automated algorithm for signal normalization was used to standardize FLAIR intensity across scanners and subjects. Mean intensity was extracted from GM, WM, deep GM, and cortical GM regions. Regression curves were fitted across the pediatric age range, and ANOVA was used to investigate intensity differences across age groups. Correlations between intensity and regional volume were also examined.

RESULTS

We analyzed 429 pediatric FLAIR sequences in children 2-19 years of age with a median age of 11.2 years, including 199 males and 230 females. WM intensity had a parabolic relationship with age, with significant differences between various age groups (P < .05). GM and cortical GM intensity increased over the pediatric age range, with significant differences between early childhood and adolescence (P < .05). There were no significant relationships between volume and intensity in early childhood, while there were significant positive and negative correlations (P < .05) in WM and GM, respectively, for increasing age groups. Only the oldest age group showed significant differences between males and females (P < .05).

CONCLUSIONS

This work presents a FLAIR intensity standardization algorithm to normalize intensity across large data sets, which allows FLAIR intensity to be used to compare regions and individuals as a surrogate measure of the developing pediatric brain.

Budget impact of introducing subcutaneous vedolizumab as a maintenance therapy in biologic-naïve and biologic-experienced patients with ulcerative colitis in France

BACKGROUND

Inflammatory bowel disease poses significant social and economic burdens. We assessed the budget impact of including the recently approved subcutaneous (SC) formulation of vedolizumab as maintenance therapy (MT) in patients with ulcerative colitis (UC) in France.

METHODS

A decision-analytic model was developed from a French payer's perspective over 5 years to assess budget impact of including vedolizumab SC as MT for UC following induction therapy with vedolizumab intravenous (IV), by subtracting outcomes of a 'world without vedolizumab SC' from a 'world with vedolizumab SC.' Comparators included approved therapies: infliximab (branded/biosimilar), adalimumab (branded/biosimilar), golimumab, ustekinumab, and vedolizumab IV. The model predicts drug, medical, and total costs, including indirect costs in a scenario analysis. A one-way sensitivity analysis explored the impact of varying individual parameters.

RESULTS

Including vedolizumab SC as MT following vedolizumab IV induction yielded total cost savings of €59,176,842 (biologic-naïve) and €22,004,135 (biologic-experienced) versus a world without vedolizumab SC. Including indirect costs yielded cost savings in biologic-naïve (€62,600,716) and biologic-experienced (€24,314,915) populations in a world with vedolizumab SC.

CONCLUSIONS

Introducing vedolizumab SC as MT after IV induction is expected to have substantial cost savings to a health plan from a French payer's perspective versus a world without vedolizumab SC.

A cross-sectional retrospective study comparing handwritten operation notes with electronic operation notes

INTRODUCTION

Electronically completed medical notes have been shown to be superior in legibility and completeness to handwritten ones. Despite this, surgeons continue to use handwritten operation notes. This paper aims to compare the quality of handwritten versus electronic operation notes.

METHODS

This is a retrospective cross-sectional single-centre study done at Darent Valley Hospital, a district general hospital at Dartford, UK. We looked at 405 operation notes of patients who had general surgery procedures between 1 January 2020 to 31 January 2021 checking for legibility and completeness of operation note criteria as given by the Royal College of Surgeons of England's Good Surgical Practice. Data were collated using an app that populates comparison criteria in an Excel sheet and were analysed using SPSS (Statistical Package for the Social Sciences). The results are presented in bar graphs and frequency table.

RESULTS

In 17 out of the 18 criteria in RCS England's Good Surgical Practice, electronic notes were better completed than handwritten ones (p<0.001). Signature as a criterion had comparable level of completeness in both handwritten and electronic notes, 95% versus 91% respectively. There was 8.3% illegibility in the handwritten note and none in the electronic ones.

CONCLUSIONS

Electronic notes are far better completed than handwritten notes in 17 out of the 18 criteria of a good operation note by RCS England. The difference between both forms of notes is far too much; we propose a complete shift in practice from handwritten to electronic format.

Recommendations for the management of advanced and metastatic renal cell carcinoma: joint consensus statements from the Hong Kong Urological Association and the Hong Kong Society of Uro-Oncology

INTRODUCTION

Kidney cancer, primarily renal cell carcinoma (RCC), ranks among the top 10 most common malignancies in the male population of Hong Kong. In 2019, members of two medical societies in Hong Kong formed an expert panel to establish a set of consensus statements for the management of metastatic RCC. On 22 June 2021, the same panel met to review recent evidence and reassess their positions regarding the management of advanced and metastatic RCC, with the aim of providing recommendations for physicians in Hong Kong.

PARTICIPANTS

The panel included 12 experts (6 clinical oncologists and 6 urologists) who had extensive experience managing patients with RCC in Hong Kong.

EVIDENCE

The panel reviewed randomised controlled trials, observational studies, systematic reviews/meta-analyses, and international clinical guidelines to address key clinical questions that were identified before the meeting.

CONSENSUS PROCESS

In total, 15 key clinical questions were identified before the meeting, covering the surgical and systemic treatment of advanced or metastatic clear cell, sarcomatoid, and non-clear cell RCCs. At the meeting, the panellists voted on these questions, then discussed relevant evidence and practical considerations.

CONCLUSIONS

The treatment landscape for advanced and metastatic RCC continues to evolve. More immune checkpoint inhibitor (ICI)-based combination regimens will be indicated for the treatment of metastatic clear cell RCC. There is increasing evidence concerning the benefit of adjuvant ICI treatment for resected advanced RCC. This article summarises recent evidence and expert insights regarding a series of key clinical questions about the management of advanced and metastatic RCC.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

396 Rotator Cuff Assessment Following Traumatic Anterior Shoulder Dislocation

Aim

Glenohumeral joint dislocation is the most common traumatic joint dislocation with a high recurrence rate correlating with age at first dislocation. There is an associated increased incidence in concurrent rotator cuff tears with increasing age affecting 40% aged 40–60. Patient care was assessed against BESS/BOA standard: These patients should have rotator cuff assessment and those aged 40–60 should undergo routine MRI/Ultrasound imaging.

Method

All patients admitted to the emergency departments of the 3 Lanarkshire hospitals undergoing first time traumatic anterior dislocation of the shoulder in February 2021 were included. This was the third cycle of this audit. Previous interventions were presentation at a CPD meeting after cycle one and an NHS Lanarkshire regional meeting after cycle two.

Results

Cycle one (2018)-14 patients. 3/14 underwent rotator cuff assessment. 5/14 aged 40–60. 1/5 underwent rotator cuff imaging.

Cycle two (2020)-11 patients. 0/9 underwent rotator cuff assessment (Two excluded as managed operatively). 4/11 aged 40–60. 0/4 underwent rotator cuff imaging.

Cycle three (2021)-13 patients. 3/11 underwent rotator cuff assessment (Two excluded as managed operatively). 3/13 aged 40–60. 0/3 underwent rotator cuff imaging.

Conclusions

Although a slight improvement has been made over the 3 cycles with rotator cuff assessment the BOA standard is not being met. There has been no improvement in the additional imaging required in traumatic anterior shoulder dislocations in those aged 40–60 over the 3 cycles. These patients may develop pain, reduced function, and rotator cuff arthropathy. There is now an aim to introduce a pathway for these patients across the health board.

795 Adequacy of Surgical Excision Margins in Lentigo Maligna: An Audit

Aim

The optimal excision margin for Lentigo Maligna (LM) lesions has been a frequent topic of debate. An audit was carried out to compare the excision margins used for LM excisions with current NICE guidelines, and to assess the adequacy of these excision margins.

Method

A retrospective study was carried out to analyse all excisions of LM lesions in 2018. 33 patients were identified from the plastic surgery departmental database. Patient demographics, the site and distribution of LM lesions, and any history of previous skin cancer were analysed. Patient electronic records, operative notes, and histopathological reports were examined to determine the number of excisions done for each LM lesion along with the peripheral and deep surgical excision margins, and the histological clearance achieved. Complete histological clearance was determined by the Multidisciplinary team for each lesion.

Results

60 cases were identified. 60% of cases were located on the head and neck. The average peripheral surgical excision margin at first excision was 2.3mm. 55% of patients had a 2nd excision. The average peripheral surgical excision margin at 2nd excision was 5.4mm. 70.6% of cases achieved complete histological clearance at 2nd excision. 72.7% of lesions excised at 2nd excision with a 5mm or less surgical excision margin achieved complete histological clearance.

Conclusions

Taking &gt;5mm surgical excision margins did not increase the rate of complete histological clearance for Lentigo Maligna lesions.

Cardiopulmonary and metabolic physiology during hemodialysis and inter/intradialytic exercise

Hemodialysis is associated with numerous symptoms and side effects that, in part, may be due to subclinical hypoxia. However, acute cardiopulmonary and metabolic physiology during hemodialysis is not well defined. Intradialytic and interdialytic exercise appear to be beneficial and may alleviate these side effects. To better understand these potential benefits, the acute physiological response to exercise should be evaluated. The aim of this study was to compare and characterize the acute physiological response during hemodialysis, intradialytic exercise, and interdialytic exercise. Cardiopulmonary physiology was evaluated during three conditions: 1) hemodialysis without exercise (HD), 2) intradialytic exercise (IDEx), and 3) interdialytic exercise (Ex). Exercise consisted of 30-min constant load cycle ergometry at 90% V̇O₂AT (anaerobic threshold). Central hemodynamics (via noninvasive bioreactance) and ventilatory gas exchange were recorded during each experimental condition. Twenty participants (59 ± 12 yr, 16/20 male) completed the protocol. Cardiac output (Δ = -0.7 L/min), O₂ uptake (Δ = -1.4 mL/kg/min), and arterial-venous O₂ difference (Δ = -2.0 mL/O₂/100 mL) decreased significantly during HD. Respiratory exchange ratio exceeded 1.0 throughout HD and IDEx. Minute ventilation was lower (P = 0.001) during IDEx (16.5 ± 1.1 L/min) compared with Ex (19.8 ± 1.0 L/min). Arterial-venous O₂ difference was partially restored further to IDEx (4.6 ± 1.9 mL/O₂/100 mL) compared with HD (3.5 ± 1.2 mL/O₂/100 mL). Hemodialysis altered cardiopulmonary and metabolic physiology, suggestive of hypoxia. This dysregulated physiology contributed to a greater physiological demand during intradialytic exercise compared with interdialytic exercise. Despite this, intradialytic exercise partly normalized cardiopulmonary physiology during treatment, which may translate to a reduction in the symptoms and side effects of hemodialysis.NEW & NOTEWORTHY This study is the first, to our knowledge, to directly compare cardiopulmonary and metabolic physiology during hemodialysis, intradialytic exercise, and interdialytic exercise. Hemodialysis was associated with increased respiratory exchange ratio, blunted minute ventilation, and impaired O₂ uptake and extraction. We also identified a reduced ventilatory response during intradialytic exercise compared with interdialytic exercise. Impaired arterial-venous O₂ difference during hemodialysis was partly restored by intradialytic exercise. Despite dysregulated cardiopulmonary and metabolic physiology during hemodialysis, intradialytic exercise was well tolerated.

3 Estimating the Burden of Dementia in Latin America and the Caribbean: A Systematic Review and Meta-Analysis

Background and Objectives

Rapid increase in life expectancy has resulted in an increase in the global burden of dementia that is expected to become a leading cause of morbidity in the future. Low- and middle-income countries are expected to bear an increasing majority of the burden, but lack data for accurate burden estimates that are key for informing policy and planning. Bayesian methods have recently gained recognition over traditional frequentist approaches for modelling disease burden for their superiority in dealing with severely limited data. This study provides updated estimates of dementia prevalence in Latin America and the Caribbean (LAC) for the years 2015, 2020 and 2030. Given the paucity of data, estimates were developed using a Bayesian methodology and confirmed by the traditional frequentist approach, with the aim of providing methodological insights for future disease burden estimates.

Methods

A comprehensive systematic literature search was conducted to identify all relevant primary studies published between the years 2010–2018. The quality of the included studies was critically assessed. A random-effects model (REM) and a Bayesian normal-normal hierarchical model (NNHM) were used to obtain the pooled prevalence estimate of dementia for people aged 60 and above. The latter model was also developed to estimate age-specific dementia prevalence. Using UN population estimates, total and age-specific projections of the burden of dementia were calculated.

Results

The prevalence of dementia in LAC was found to be 14% (10–21%) in those above age 60 based on REM, and 8% (5–11.5%) based on NNHM. The prevalence increased from 2% (1–4%) in people aged 60–69 to 29% (20–37%) in people above the age of 80. The number of people living with dementia in LAC in 2015 was estimated at 5.68 million, with future projections of 6.86 million in 2020 and 9.94 million in 2030.

Conclusions

The findings of this review found that burden of dementia in LAC is substantial and continues to rapidly grow. The projected rise in dementia cases in the future should prompt urgent governmental response to address this growing public health issue. We were also able to demonstrate that given the overall paucity of data, a Bayesian approach was superior for estimating disease prevalence and burden.

Pulmonary pressure-to-longitudinal strain ratio by echocardiography: a rapid surrogate to magnetic resonance for right ventricular failure assessment

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): United Christian Hospital Ruttonjee and Tang Siu Kin Hospitals

Background

Better risk stratification in pulmonary hypertension (PH) by echocardiography (echo) to detect ventricular vascular uncoupling may act as gate-keeper for downstream management, such as MRI and expensive therapies. Studies showed modest correlation found between RV peak global longitudinal strain (RVGLS), which is afterload dependent, and right ventricular ejection fraction (RVEF)

Purpose

To test the accuracy and optimal cut-off of echo derived mean PA pressure-to-RVGLS ratio against MRI detected severe RV dysfunction (defined as RVEF&lt; 35%), RV dilatation (defined as RVEDVi &gt;87ml), and correlate native T1-values (nT1)

Method

Strain analyses by echo and volumetric assessment by 1.5 tesla MRI were performed in all patients. Contoured MRI short axis images provided RVEF. In a subgroup of pulmonary arterial hypertension (PAH), right heart catheterization and MRI non-contrast native T1 mapping were performed (Figure 1). Using previous study data, to identify a difference of 1.8 pressure-to-strain ratio between mild and severe PH with a variance  of 2.2 , power of 80% and a significance level of 0.05, a total of 11 participants per group were needed

Result

Thirty-one PH patients (13 female, age 60 ± 14y, 13 had PAH) were recruited prospectively. Strong correlation was demonstrated between the mean PA pressure-to-RVGLS ratio to MRI derived RVEF (r = 0.80, p &lt; 0.01), and to catheterization derived pulmonary vascular resistance and indexed cardiac output (r = -0.80, p= 0.001; r= -0.75, p = 0.003 respectively). The cut-off value of -2.5 had best accuracy in ROC analyses (Table 1)

In PAH patients, this ratio correlated with global nT1 at basal short-axis level (r= -0.91, p = 0.004), but not at the mid short-axis level. Their basal posterior interventricular insertion regions had significantly higher nT1 than those of age-matched normal controls at the same region on the same scanner (1256 ± 217 ms vs. 932 ± 25 ms, p = 0.04)

Conclusion

In terms of detection of severe right ventricular dysfunction by echocardiography, mean PA pressure-to-RVGLS ratio performed better than RVGLS alone, and a ratio cutoff of -2.5 predicts MRI determined ventricular vascular uncoupling in pulmonary hypertension

Table 1 Echo detect MRI AUC standard error 95% CI sens (%) spec (%) p Mean PA pressure -to-RVGLS ratio RVEF &lt; 35% 0.86 0.073 0.71-1.00 72 83 0.007 RVEDVi &gt; 87ml 0.81 0.081 0.65-0.97 83 70 0.004 RVGLS RVEF &lt; 35% 0.76 0.100 0.57-0.96 60 83 0.048 RVEDVi &gt; 87ml 0.73 0.090 0.55-0.91 67 70 0.032 PA pulmonary artery; RVGLS: RV global longitudinal strain; RVEDVi: indexed RV end-diastolic volume Abstract Figure 1

A matching-adjusted indirect comparison of combination nivolumab plus ipilimumab with BRAF plus MEK inhibitors for the treatment of BRAF-mutant advanced melanoma☆

Background

Approved first-line treatments for patients with BRAF V600–mutant advanced melanoma include nivolumab (a programmed cell death protein 1 inhibitor) plus ipilimumab (a cytotoxic T lymphocyte antigen-4 inhibitor; NIVO+IPI) and the BRAF/MEK inhibitors dabrafenib plus trametinib (DAB+TRAM), encorafenib plus binimetinib (ENCO+BINI), and vemurafenib plus cobimetinib (VEM+COBI). Results from prospective randomized clinical trials (RCTs) comparing these treatments have not yet been reported. This analysis evaluated the relative efficacy and safety of NIVO+IPI versus DAB+TRAM, ENCO+BINI, and VEM+COBI in patients with BRAF-mutant advanced melanoma using a matching-adjusted indirect comparison (MAIC).

Patients and methods

A systematic literature review identified RCTs for DAB+TRAM, ENCO+BINI, and VEM+COBI in patients with BRAF-mutant advanced melanoma. Individual patient-level data for NIVO+IPI were derived from the phase III CheckMate 067 trial (BRAF-mutant cohort) and restricted to match the inclusion/exclusion criteria of the comparator trials. Treatment effects for overall survival (OS) and progression-free survival (PFS) were estimated using Cox proportional hazards and time-varying hazard ratio (HR) models. Safety outcomes (grade 3 or 4 treatment-related adverse events) with NIVO+IPI and the comparators were compared.

Results

In the Cox proportional hazards analysis, NIVO+IPI showed improved OS compared with DAB+TRAM (HR = 0.53; 95% confidence interval [CI], 0.39-0.73), ENCO+BINI (HR = 0.60; CI, 0.42-0.85), and VEM+COBI (HR = 0.50; CI, 0.36-0.70) for the overall study period. In the time-varying analysis, NIVO+IPI was associated with significant improvements in OS and PFS compared with the BRAF/MEK inhibitors 12 months after treatment initiation. There were no significant differences between NIVO+IPI and BRAF/MEK inhibitor treatment from 0 to 12 months. Safety outcomes favored DAB+TRAM over NIVO+IPI, whereas NIVO+IPI was comparable to VEM+COBI.

Conclusion

Results of this MAIC demonstrated durable OS and PFS benefits for patients with BRAF-mutant advanced melanoma treated with NIVO+IPI compared with BRAF/MEK inhibitors, with the greatest benefits noted after 12 months.

•

First-line treatments for BRAF V600-mutant melanoma include NIVO+IPI and BRAF/MEK inhibitors.

•

Results from prospective RCTs comparing NIVO+IPI and BRAF/MEK inhibitors have not yet been reported.

•

This MAIC evaluated NIVO+IPI versus BRAF/MEK inhibitors for BRAF-mutant advanced melanoma.

•

OS and PFS benefits were noted with NIVO+IPI versus BRAF/MEK inhibitors beginning at 12 months.

•

These findings may provide information relevant to the selection of treatments for BRAF-mutant advanced melanoma.

Ventilatory and chronotropic incompetence during incremental and constant load exercise in end-stage renal disease: a comparative physiology study

Maximal O₂ uptake is impaired in end-stage renal disease (ESRD), reducing quality of life and longevity. While determinants of maximal exercise intolerance are well defined, little is known of limitation during submaximal constant load exercise. By comparing individuals with ESRD and healthy controls, the aim of this exploratory study was to characterize mechanisms of exercise intolerance in participants with ESRD by assessing cardiopulmonary physiology at rest and during exercise. Resting spirometry and echocardiography were performed in 20 dialysis-dependent participants with ESRD (age: 59 ± 12 yr, 14 men and 6 women) and 20 healthy age- and sex-matched controls. Exercise tolerance was assessed with ventilatory gas exchange and central hemodynamics during a maximal cardiopulmonary exercise test and 30 min of submaximal constant load exercise. Left ventricular mass (292 ± 102 vs. 185 ± 83 g, P = 0.01) and filling pressure (E/e': 6.48 ± 3.57 vs. 12.09 ± 6.50 m/s, P = 0.02) were higher in participants with ESRD; forced vital capacity (3.44 ± 1 vs. 4.29 ± 0.95 L/min, P = 0.03) and peak O₂ uptake (13.3 ± 2.7 vs. 24.6 ± 7.3 mL·kg^-1·min^-1, P < 0.001) were lower. During constant load exercise, the relative increase in the arterial-venous O₂ difference (13 ± 18% vs. 74 ± 18%) and heart rate (32 ± 18 vs. 75 ± 29%) were less in participants with ESRD despite exercise being performed at a higher percentage of maximum minute ventilation (48 ± 3% vs. 39 ± 3%) and heart rate (82 ± 2 vs. 64 ± 2%). Ventilatory and chronotropic incompetence contribute to exercise intolerance in individuals with ESRD. Both are potential targets for medical and lifestyle interventions.

Abstract B60: Functional genomic landscape of T-cell mediated cytotoxicity

The direct killing of cancer cells by cytotoxic T-lymphocytes (CTL) is critical for achieving effective antitumor immune responses. While several tumor-intrinsic mutations have been identified that promote evasion to CTL killing, there remains a paucity of data cataloging how individual genetic perturbations impact cancer cell fitness under immunotherapeutic selection pressure. Towards this, genetic screens using the CRISPR-Cas9 system have recently been employed, identifying novel intrinsic genetic regulators of cancer immunotherapy fitness. While these initial studies demonstrate the significant potential of unbiased genetic screens for discovery of novel immunotherapy targets, they have been limited in application to a small number of disease models. As such, the degree to which intrinsic genetic perturbations robustly modulate immunotherapy fitness across diverse cancer genotypes remains largely unexplored. To circumvent this knowledge gap, we performed genetic screens across a panel of commonly utilized syngeneic murine cancer cell lines to identify a core set of genes that render cancer cells more sensitive or resistant to CTL killing across diverse genetic backgrounds. An optimized genome-scale gRNA library targeting ~19,000 protein-coding genes in the murine genome (termed mTKO; mouse Toronto Knockout) was created in an analogous manner to our human library. Screens were performed in multiple murine cell lines engineered to express model tumor-associated antigens. Cells were propagated in the presence or absence of preactivated antigen-specific CTLs, and gRNA abundance was quantified by illumina sequencing to identify perturbed genes enriched or depleted in CTL treated versus untreated populations. These screens uncovered known genetic regulators of CTL killing including immune checkpoints (Cd274), antigen presentation machinery (B2m, Tap1/2) and interferon signaling components (Socs1, Jak1/2, Ifngr1/2), benchmarking the utility of this approach. Importantly, we leveraged this dataset to derive a core list of genes whose perturbation significantly modulates cancer-cell fitness to CTL killing across the majority of genotypes screened. Gene set enrichment analysis revealed critical roles for cytokine and TLR signaling, the NF-κB and MAPK pathways as well as the antiviral and antigen presentation machineries. As such, our dataset represents the first step towards a comprehensive understanding of the functional genomic landscape of CTL-mediated cytotoxicity.

Citation Format: Keith Lawson, Xiaoyu Zhang, Cris Sousa, Rummy Akthar, Zi Fan, Eiru Kim, Medina Colic, Amy Tong, Katie Chan, Qian Huang, Xiaowei Wang, Kevin Brown, Michael Aregger, Antonio Finelli, Laurie Ailles, Traver Hart, Gillian Kingsbury, Charles Kung, Jason Moffat. Functional genomic landscape of T-cell mediated cytotoxicity [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr B60.

A systematic review and network meta-analysis of adjuvant therapy for curatively resected biliary tract cancers

Background

Recent randomized controlled trials (rcts) have contributed high-quality data about adjuvant therapy in curatively resected biliary tract cancer (btc); however, a standard approach to treating those patients still has not been developed.

Methods

We conducted a systematic review of published studies and abstracts up to and including June 2018, choosing rcts involving patients with btc receiving adjuvant chemotherapy after complete surgical resection. Network meta-analysis methods were used for indirect comparisons of overall survival (os) and relapse-free survival (rfs) for various adjuvant therapies.

Results

Five rcts were included in qualitative synthesis, and three rcts (bilcap, prodige 12-accord 18, and bcat) had data sufficient for inclusion in the meta-analysis. Results from the indirect comparison demonstrated no significant improvement in os for capecitabine compared with gemcitabine or with gemcitabine-oxaliplatin (gemox), the hazard ratios (hrs) being 0.82 [95% confidence interval (ci): 0.53 to 1.27] and 0.86 (95% ci: 0.56 to 1.34) respectively. Similarly, no significant improvement in rfs was observed for capecitabine compared with gemcitabine or gemox.

Conclusions

Although in the present analysis, we found no statistically significant improvements in os or rfs for capecitabine compared with gemox or gemcitabine, capecitabine can-until further prospective trials are completed-be considered the standard of care in the adjuvant setting based on a single randomized phase iii study.

Vismodegib for periocular basal cell carcinoma: an international multicentre case series

INTRODUCTION

Vismodegib (Erivedge, Genentech) is a first-in-class inhibitor of the hedgehog (Hh) pathway, which is licensed for use in locally advanced basal cell carcinoma (BCC) and metastatic BCC. The National Institute for Health and Care Excellence withdrew recommendation for use of vismodegib secondary to a lack of data comparing vismodegib to standard supportive care. The purpose of this multicentre, international case series is to report outcomes of patients with locally advanced periocular BCC who have been treated with vismodegib.

METHODS

The medical records of all patients treated with vismodegib were retrospectively reviewed across seven institutions in the United Kingdom, Australia, and New Zealand.

RESULTS

Thirteen patients were identified. Seven (54%) patients were male. All BCCs were ill-defined, with seven (58%) having orbital involvement at presentation. Median treatment time was 7 months (range 2-36 months). Eleven out of 13 patients developed side effects, the most common being fatigue in six patients (46%). Median follow-up was 24 months (range 12-48 months). Complete response was found in 5/13 patients (38%) and a partial response in 8/13 patients (62%). Six patients had further surgery after vismodegib, with three classed as globe-sparing operations. Three patients developed recurrence (23%). Three patients (23%) ultimately underwent exenteration.

DISCUSSION

This study demonstrates vismodegib to be a well-tolerated treatment which may, in some cases, facilitate globe-sparing surgery and hence avoid disfiguring operations such as exenteration. Uncertainty does remain regarding the long-term outcomes of patients treated with vismodegib.

The Application of Non-linear Flow Resistance in Cerebral Artery: Compared with Windkessel Model based on Genetic Algorithm

Continuous blood pressure is measured from various extracranial body sites, with difference in amplitude and phase with intracranial blood pressure. Consequent influences on the accuracy of Windkessel model need further investigation. Between blood pressure and intracranial flow rate, a model with non-linear flow resistance (R-DT) was proposed and compared with the 3-element Windkessel (RCR) model. From the measured blood flow velocity in middle cerebral artery, the blood pressure was estimated by R-DT and RCR models respectively. The parameters in the models were optimized by genetic algorithm. The accuracies of R-DT and RCR models were compared based on their estimation errors to the measured blood pressure. The capacitance element in RCR model indicated limited ability to take the time shift into account. Compared with RCR model, R-DT model had less error (averaged relative error: 5.19% and 2.49% for RCR and RDT models). The non-linear flow resistance was applicable in simulating cerebral arteries.

P5604Combining aortic size with measures of aortic stiffness and pulsatile hemodynamics enhances prediction of future thoracic aortic aneurysm expansion

Introduction

Thoracic aortic aneurysm (TAA) is a clinically silent disease which can lead to significant morbidity when complicated by an acute aortic syndrome. Although TAA size is the only variable used in decision-making, it is an imperfect predictor of risk. Conversely, hemodynamic measures that reflect the aorta's function, such as aortic stiffness and pulsatile hemodynamics, may provide additional insights into risk of TAA expansion.

Purpose

We hypothesized that combining aortic size with measures of arterial function (stiffness and pulsatile hemodynamics) would improve prediction of TAA expansion, as compared to aortic size alone.

Methods

105 unoperated participants with TAA were recruited between 2014 and 2017 and followed prospectively for ≥1 yr. TAA size was measured at enrolment and at the latest imaging study according to published consensus; TAA expansion was calculated as mm/year. Arterial function was non-invasively assessed at baseline with validated methods that integrate arterial tonometry with echocardiography. Multivariable linear regression assessed independent associations of baseline TAA size and each arterial function measure, initially separately and then in combination (by multiplying them when direction of association was the same, and dividing them when direction of association was opposite), with future TAA expansion. Standardized beta coefficients were calculated to allow direct comparisons. Models were adjusted for age, sex, body size, aneurysm location and etiology, type of imaging modality, follow-up time, mean arterial pressure, and history of hypertension, diabetes and smoking.

Results

Seventy-seven percent of participants were men, and the ratio of degenerative to heritable TAAs was 62/43. Mean ± SD age, baseline TAA size, and follow-up time were 62.8±11.3yrs, 46.3±3.9cm, and 2.2±0.7 years, respectively. Results of the multivariable linear regression models are summarized in the Table. While baseline TAA size and each arterial function measure were independently associated with TAA expansion, some of the arterial function measures were superior in predicting TAA growth (Table, left). In addition, combining aortic size and function further improved the prediction of TAA growth beyond each variable alone (Table, right).

Conclusion(s)

Combining aortic size with arterial function improved prediction of TAA expansion over any individual variable alone, independently of confounders. Assessing arterial function may confer a clinical advantage, when compared to current practice, in determining TAA disease activity and estimating one's TAA-related risk.

Acknowledgement/Funding

Canadian Institute of Health Research, Canadian Vascular Network, and Heart and Stroke Foundation of Canada

P4427Cardiovascular outcomes among runners of a marathon race - a 17 years' experience

Introduction

Over the past 17 years (2002–2018), 898,831 people participated in the Hong Kong Standard Chartered Marathon (HKSCM).

Purpose

We aim to study the incidence of marathon-related sudden cardiac arrest (SCA) and non-fatal myocardial injury (NFMI).

Methods

All the HKSCM related admissions between 2002 and 2017 were retrieved from the accident and emergency department admission records. We reviewed the data of HKSCM runners admitted for SCA and NFMI.

Results

Fourteen and thirty-nine runners were admitted for SCA (Mean age 38±13 years-old, 12 men) and NFMI (Mean age 42±12 years-old; 34 men) respectively.

Among the SCA runners, the arrest rhythms could not be retrieved in 3 cases. In the remaining 11 SCA runners, the arrest rhythms were ventricular fibrillation (VF) (N=6), pulseless-electrical activity (PEA) (N=3), and asystole (N=2). Nine of the 14 SCA runners were successfully resuscitated. Only 2 out of the 14 SCA runners had significant atherosclerotic coronary artery disease (CAD) requiring coronary angioplasty. Among the SCA runners, the etiologies of cardiac arrest were myocardial infarction (MI) (N=2), ischemic cardiomyopathy with VF (N=1), idiopathic VF (N=3), malignant coronary anomaly (N=1), and idiopathic (N=5). Percutaneous coronary intervention (PCI) was performed in 2 SCA runner with MI. Implantable cardioverter-defibrillators were implanted in 1 resuscitated runner with VF. Postmortem examination of the 3 deceased runners showed significant CAD in two and was unrevealing in one.

Among the 39 NFMI runners, coronary angiograms (CAG) or CT coronary angiogram were performed in 14 cases (36%), which showed minor CAD or unremarkable findings in 7 runners, and significant CAD in 7 runners. PCI and coronary artery bypass were performed in 5 and 2 NFMI runners respectively. Only 8 out of 39 NFMI runners reported chest pain. Significant ischemic ECG changes were detected in 9 out of 39 NFMI runners. Invasive CAGs were not performed in the remaining NFMI runners due to low pre-test likelihood of CAD and normal non-invasive test results.

Conclusions

The incidence of SCA and mortality among HKSCM runners was 1.56 per 100,000 and 0.56 per 100,000 respectively. The incidence of NFMI was 4.3 per 100,000. Coronary artery disease, coronary anomaly and idiopathic VF were the commonest etiologies of SCA.

2378Blunted stress myocardial oxygenation and not myocardial perfusion reserve is associated with arrhythmic risk in hypertrophic cardiomyopathy

Background

In hypertrophic cardiomyopathy (HCM), myocardial ischaemia is believed to play a role in fatal life-threatening ventricular arrhythmias and caused by microvascular dysfunction manifesting as impaired myocardial perfusion. However, previous studies suggest that myocardial oxygenation during vasodilator stress may also be blunted when perfusion is normal, due to increased metabolic demands conferred by energy-costly sarcomeric mutations, left ventricular hypertrophy and outflow obstruction. Whether or not impaired myocardial perfusion reserve or blunted stress oxygenation on cardiac magnetic resonance (CMR) predict the risk of ventricular arrhythmia in HCM is unknown.

Purpose

We sought to investigate if impaired myocardial perfusion reserve or stress oxygenation is associated with an increased risk of ventricular arrhythmia in HCM.

Methods

103 genotyped HCM patients (mean age 47±15 years) and 32 age- and sex-matched healthy controls underwent adenosine stress blood oxygen level dependent (BOLD) imaging, first pass perfusion and late gadolinium imaging (LGE) on CMR to assess stress oxygenation (BOLD ΔSI), myocardial perfusion reserve index (MPRI), and fibrosis respectively. All HCM patients were monitored for ventricular tachycardia (≥3 beats, ≥120 beats per minute) on a 24-hour Holter.

Results

As expected, MPRI was significantly reduced in HCM (1.5±0.4 vs 2.0±0.3, p<0.0001) compared to controls. Stress oxygenation response was blunted in HCM versus controls (9.1±4.1% vs 17.0±1.6%, p<0.0001, Figure 1B). Twenty-six (25%) patients developed ventricular tachycardia on Holter monitoring. On univariate analysis, only stress oxygenation and not MPRI associated with ventricular tachycardia. The prevalence of ventricular tachycardia in HCM increased with decreasing quartiles of stress oxygenation (Figure 1D). HCM patients in the lowest quartile of oxygenation (BOLD ΔSI <6.5%) were at a three-fold risk of ventricular tachycardia (OR 3.04, 95% confidence interval 1.02–9.05, p=0.04) on multivariable analysis (after adjusting for sudden cardiac death risk factors and LGE mass) compared to other patients. Sarcomeric mutation status was an independent determinant of stress oxygenation on multivariable analysis. Stress oxygenation was impaired in phenotype-negative sarcomeric mutation carriers (Sarc+P-, n=16) despite normal perfusion (Figure 1C, E). Sarcomeric HCM (Sarc+HCM) had more severe impairment in stress oxygenation than genotype negative HCM (G-HCM) and controls (Figure 1E).

Figure 1

Conclusion

In HCM, blunted stress-induced oxygenation is associated with an increased risk of ventricular arrhythmia and may represent a novel biomarker of arrhythmic risk. Sarcomeric mutation status is an important determinant of stress oxygenation response.

Acknowledgement/Funding

National Institute for Health Research Oxford Biomedical Centre and British Heart Foundation.

Impact of a novel prioritization framework on clinician-led oncology drug submissions

Background

In Canada, requests for public reimbursement of cancer drugs are predominately initiated by pharmaceutical manufacturers. Clinician-led submissions provide a mechanism to initiate the drug funding process when industry does not submit a request for funding consideration. Although such requests are resource-intensive to produce, Cancer Care Ontario (cco) has the capacity to facilitate clinician-led submissions. In 2014, cco began developing a cancer drug prioritization framework that allocates resources to systematically address a growing number of clinician-identified funding gaps with clinician-led submissions.

Methods

Cancer site-specific drug advisory committees established by cco consist of health care practitioners whose roles include identifying and prioritizing funding gaps. The committees submit their identified gaps to a cross-cancer-site prioritization exercise in which the requests are ranked based on a set of guiding principles derived from health technology assessment. The requests are then sequentially allocated the resources needed to meet submission requirements. Whether the funding gap is of provincial or pan-Canadian relevance determines where the submission is filed for assessment.

Results

Since its inception, the cco framework has identified 17 funding gaps in 9 cancer sites. In 4 prioritizations, the framework supported 6 submissions. As of June 2018, the framework had contributed to the eventual funding of more than 9 new drug-indication pairs, with more awaiting funding consideration.

Conclusions

The cco prioritization framework has enabled clinicians to effectively and systematically identify, prioritize, and fill funding gaps not addressed by industry. Ultimately, the framework helps to ensure that patients can access evidence-informed and cost-effective therapies. The framework will continue to evolve as it encounters new challenges, including funding requests for rare indications.