Citations

e18911 Background: Stool-based colorectal cancer (CRC) screening with the multi-target stool DNA (mt-sDNA) test is a guideline endorsed strategy for average-risk individuals age ≥45 years and provides a reference for value-based pricing (VBP); maximum price at which a willingness-to-pay threshold is reached. Blood-based tests (BT) are an emerging screening option. Using recent reported BT performance data from the ECLIPSE study (Guardant Health, Inc.)1, the potential VBP of BT compared with multi-target stool DNA (mt-sDNA) was analyzed. Methods: Using the validated CRC-AIM model, we simulated a cohort of 2 million average-risk individuals who received screening with BT at 1, 2, or 3-year intervals or triennial mt-sDNA between the ages of 45-75 years. For BT, CRC sensitivity, advanced adenoma sensitivity, and specificity were based on reported clinical trial data (83%, 13%, and 90%, respectively). Adherence assumptions for BT and mt-sDNA screening were modeled at perfect (100%) or real-world mt-sDNA adherence (RWE). Key outcomes were life-years gained (LYG) per 1000 individuals vs no screening, and VBP of BT vs mt-sDNA ($895 vs $508) was assessed at a willingness-to-pay (WTP) threshold of $50,000 per quality-adjusted life-year. Results: The triennial mt-sDNA was more effective and less costly vs BT at all intervals with both perfect and RWE adherence at the current price. Compared with mt-sDNA screening, LYG of screening with BT was lower (320 vs. 241-314) and the VBP should be at most $49 and $11 and no-cost at the 1-, 2-, and 3-year intervals, respectively (Table), when perfect adherence is assumed. With RWE adherence, the LYG with mt-sDNA was 306 compared to 229-284 with BT across all intervals. To be comparable to RWE triennial mt-sDNA screening, the maximum VBP for BT would need to be $13 at the 1-year interval and no cost for 2- and 3-year interval. Conclusions: Compared to annual, biannual, and triennial BT, triennial mt-sDNA was more effective at all intervals and 44% to 102% less costly. The maximum price of BT should not exceed $49 to be considered a cost-effective option compared to mt-sDNA when WTP is 50,000. [Table: see text]

6642 Background: Although follow up colonoscopy (COL) after a positive stool-based colorectal cancer (CRC) screening test is necessary to complete the CRC screening process, follow-up COL rates remain suboptimal, especially among underserved populations. As of January 2023, federal policies require commercial insurers and Medicare to eliminate out of pocket costs for follow-up COL. To estimate the implications of this policy change, we compared the clinical and fiscal outcomes for a simulated cohort receiving a follow-up COL after a non-invasive CRC test ($0 cost sharing), compared to the same cohort not completing follow-up COL (status quo). Methods: Using the validated CRC-AIM model, we simulated a cohort of 6 million average-risk individuals who received mt-sDNA (commercial patients at age 45 and Medicare patients at age 65) and further analyzed only the population with positive mt-sDNA. Life-years gained, CRC incidence, CRC-related mortality and total costs of care (inclusive of CRC screening and treatment) were calculated for a cohort that underwent follow-up COL and compared these outcomes to that same cohort that did not complete follow-up COL. The cost of follow-up COL was assumed to be $1,576 for Medicare and $3,086 for commercially insured patients ($0 out of pocket costs for all). Results: Patients undergoing follow-up COL after a positive mt-sDNA experienced more life-years (83 per 1,000 commercially insured patients and 80 per 1,000 Medicare beneficiaries) compared to those who did not undergo follow-up COL. The follow-up COL resulted in reductions in CRC incidence and CRC mortality by 14% and 16% for commercial and 19% and 23% for Medicare beneficiaries, respectively. Compared to those patients with a mt-sDNA positive test result and did not complete follow-up COL, the total cost per patient for those receiving follow-up COL was $3,339 less for commercially insured ($15,690 – no follow up vs. $12,351 – follow up) and $4,382 less for Medicare beneficiaries ($19,337 – no follow up vs. $14,955 – follow up). Total spending for patients receiving follow-up COL was cost-saving when compared to no follow-up as long as the COL costs were less than $6,269 for commercial plans and $5,753 for Medicare. Conclusions: Completing a follow-up COL after a positive mt-sDNA screening saves lives, enhances equity, and lowers total expenditures. Thus, health care stakeholders should invest in efforts to identify and reduce barriers that ultimately lead to an increase uptake of this potentially lifesaving and cost-reducing intervention.

e17009 Background: Decreased circulating levels of ether lipids (glycerophospholipids with an ether-linked fatty alcohol, e.g. plasmalogens) have been observed in obesity, diabetes and cardiovascular disease. In vitro and in vivo studies suggest that ether lipids are anti-inflammatory and protective against obesity. A recent landmark study revealed that ether lipids can kill cancer cells through ferroptosis. However, the role of ether lipids in prostate cancer has not been thoroughly investigated despite the known association of dysregulated lipid metabolism with poorer clinical outcomes. The aim of this study was to assess the relationship between the circulating profiles of ether lipids and clinical outcomes in localised and metastatic prostate cancer. Methods: The profiles of ~150 ether lipids (8 lipid classes) in plasma lipidomic data from localised prostate cancer (389 men in Australia) and metastatic castration-resistant prostate cancer (mCRPC)(2 cohorts –147 men in USA, 128 men in Australia) were analysed for associations with disease progression or overall survival (OS). Open-access genomic data of mCRPC tumours (108 men, CbioPortal) were analysed for aberrations in genes associated with ether lipid metabolism in relation to clinical outcome. Results: Previously in these study cohorts, we had identified men with poorer prognosis based on their plasma lipidome and our validated sphingolipid signature. These men with poorer prognosis have lower plasma levels of ether lipids than those with better prognosis (t-test p < 0.05, localised disease – 110 ether lipids, mCRPC – 54 ether lipids). Decreased plasma levels of up to 46 ether lipid species were associated with higher rates of clinical relapse in localised disease (hazard ratio (HR) range 0.37-0.73, p-value range 0.006-0.049), shorter radiological progression-free survival in mCRPC (HR range 0.35-0.73, p-value range 0.00009-0.049), and shorter OS in mCRPC (HR range 0.33-0.79, p-value range 0.000004-0.0497). Chromosomal loss of tumour GNPAT, an essential gene in ether lipid synthesis, was associated with shorter OS in mCRPC (HR = 1.36, 95% CI 1.02-1.81, p = 0.03). Conclusions: Lower circulating levels of ether lipids were associated with worse prognosis in localised and metastatic prostate cancer, suggesting that these lipids are protective against disease progression. Further research is required to understand the role of ether lipids in disease progression, and to determine if modulation of ether lipid levels through supplementation is beneficial.

Abstract Background Rifampin-resistant tuberculosis is a leading cause of morbidity worldwide; only one-third of persons start treatment, and outcomes are often inadequate. Several trials demonstrate 90% efficacy using an all-oral, 6-month regimen of bedaquiline, pretomanid, and linezolid (BPaL), but significant toxicity occurred using 1200-mg linezolid. After US Food and Drug Administration approval in 2019, some US clinicians rapidly implemented BPaL using an initial 600-mg linezolid dose adjusted by serum drug concentrations and clinical monitoring. Methods Data from US patients treated with BPaL between 14 October 2019 and 30 April 2022 were compiled and analyzed by the BPaL Implementation Group (BIG), including baseline examination and laboratory, electrocardiographic, and clinical monitoring throughout treatment and follow-up. Linezolid dosing and clinical management was provider driven, and most patients had linezolid adjusted by therapeutic drug monitoring. Results Of 70 patients starting BPaL, 2 changed to rifampin-based therapy, 68 (97.1%) completed BPaL, and 2 of the 68 (2.9%) experienced relapse after completion. Using an initial 600-mg linezolid dose daily adjusted by therapeutic drug monitoring and careful clinical and laboratory monitoring for adverse effects, supportive care, and expert consultation throughout BPaL treatment, 3 patients (4.4%) with hematologic toxicity and 4 (5.9%) with neurotoxicity required a change in linezolid dose or frequency. The median BPaL duration was 6 months. Conclusions BPaL has transformed treatment for rifampin-resistant or intolerant tuberculosis. In this cohort, effective treatment required less than half the duration recommended in 2019 US guidelines for drug-resistant tuberculosis. Use of individualized linezolid dosing and monitoring likely enhanced safety and treatment completion. The BIG cohort demonstrates that early implementation of new tuberculosis treatments in the United States is feasible.

Abstract Introduction Sleep markers can assess prodromal risk for neurodegenerative disorders (NDD). In a recent study conducted by the Mayo Clinic, most isolated REM sleep behavior disorder patients preferred knowing about their risk for parkinsonism or dementia. In their email survey, patients indicated a strong preference for disclosure of prognostic NDD risk in order to spur family discussions and plan for the future. For this pilot study, the Mayo questions were modified in order to investigate the perspectives and preferences of community-based adults about potentially being at-risk of a NDD and how it might impact their lives. Methods A brief survey was administered to Rotary Club attendees prior to a presentation on sleep and neurodegenerative disease. Each question offered five responses: strongly disagree, disagree, neutral, agree, or strongly agree. Personal identifiers were not obtained. Thirty-four surveys were completed from approximately equal numbers of older men and women with estimated ages above 50 years. Personal information were not obtained (e.g., age and sex). Results When asked whether it was important to know their NDD risk given the fact that there are no known methods to prevent or cure the disease, most (83%) strongly agreed or agreed, while only 18% preferred not to know their NDD risk. The majority felt they would be more pessimistic about their future if identified as being at risk of NDD the (62% strongly agreed/agreed). Most believed their priorities and plans for living life would change (68% strongly agreed/agreed). Further, the vast majority felt that knowing NDD risk would help them plan for the future (89% strongly agreed/agreed), including planning for health resources and support (88% strongly agreed/agreed). Conclusion Eighty-three percent of those surveyed reported they would benefit from knowing if they were at risk of NDD, even though the majority would feel more pessimistic about their future. The vast majority (89%) responded that knowing their NDD risk would help them plan for the future. These results suggest that most community adults might be receptive to future sleep screening for NDD with results. Investigations are underway to confirm these findings in a broader community-based study. Support (if any) NIA-R44AG050326

Abstract Introduction In a recent study, most patients diagnosed with isolated REM sleep behavior disorder (iRBD) preferred their physician discussed their risk for developing a future neurodegenerative disorder (NDD) such as parkinsonism or dementia (PD). In the Mayo Clinic email survey, 75% would lose trust in their physician if PD-risk was not discussed following an iRBD diagnosis. For this survey, questions were designed to investigate preferences for how sleep physicians might communicate to community-based adults about risk of a NDD. Methods A survey was administered to Rotary Club attendees prior to a sleep and neurodegenerative disease presentation, with options for responses being either strongly disagree, disagree, neutral, agree, or strongly agree. Thirty-four surveys were obtained from approximately equal numbers of men and women with estimated ages above 50 years. Personal information were not obtained (i.e., sex and age). Results The vast majority of respondents wanted their physician to ask their preference prior to sharing NDD risk (86% strongly agreed or agreed), while virtually all would lose trust in their physician if he/she did not discuss their NDD risk (97% strongly agreed/agreed). If identified with NDD risk, responders would seek out information about medications and adaptive therapies that could delay onset (97% strongly agreed/agreed), while only about half currently had a good understanding of lifestyle patterns that might help delay onset (47% strongly agreed/agreed and 47% disagreed/strongly disagreed). Not knowing when memory problems might begin would cause most responders to feel anxious (85% strongly agreed/agreed). Conclusion Those surveyed wanted their physician to ask their preference prior to sharing NDD risk, but virtually all would lose trust in their health care provider if the information was known but not shared. There appears to be a role for physicians in educating those who may be at NDD risk about interventions that could delay onset of NDD, given approximately half have a limited understanding of lifestyle patterns that could help delay onset. Further, routine follow-up for changes in prodromal NDD biomarker severity might help to reduce anxiety in the 85% of those concerned about when memory problems might begin. Support (if any) NIA-R44AG050326

Abstract Objectives We aimed to explore current practice and interregional differences in the treatment of idiopathic inflammatory myopathies (IIMs). We triangulated these observations considering countries' gross national income (GNI), disease subtypes, and symptoms using patient-reported information. Methods A cross-sectional ancillary analysis of the ‘COVID-19 vaccination in auto-immune disease’ (COVAD) e-survey containing demographic characteristics, IIM subtypes (DM, PM, IBM, anti-synthetase syndrome [ASSD], immune-mediated necrotizing myopathy [IMNM], overlap myopathies [OM]), current symptoms (surrogate for organ involvement) and treatments (corticosteroids [CS], immunomodulators [IM], i.e. antimalarials, immunosuppressants [IS], IVIG, biologic treatments and targeted-synthetic small molecules). Treatments were presented descriptively according to continents, GNI, IIM and organ involvement, and associated factors were analysed using multivariable binary logistic regressions. Results Of 18 851 respondents from 94 countries, 1418 with IIM were analysed (age 61 years, 62.5% females). DM (32.4%), IBM (24.5%) and OM (15.8%) were the most common subtypes. Treatment categories included IS (49.4%), CS (38.5%), IM (13.8%) and IVIG (9.4%). Notably, treatments varied across regions, GNI categories (IS mostly used in higher-middle income, IM in lower-middle income, IVIG and biologics largely limited to high-income countries), IIM subtypes (IS and CS associated with ASSD, IM with OM and DM, IVIG with IMNM, and biologic treatments with OM and ASSD) and disease manifestations (IS and CS with dyspnoea). Most inter-regional treatment disparities persisted after multivariable analysis. Conclusion We identified marked regional treatment disparities in a global cohort of IIM. These observations highlight the need for international consensus-driven management guidelines considering patient-centred care and available resources.

Abstract Background In order to compute the relative biological effectiveness (RBE) of ion radiation therapy with the Mayo Clinic Florida microdosimetric kinetic model (MCF MKM), it is necessary to process entire microdosimetric distributions. Therefore, a posteriori RBE recalculations (i.e., for a different cell line or another biological endpoint) would require whole spectral information. It is currently not practical to compute and store all this data for each clinical voxel. Purpose To develop a methodology that allows to store a limited amount of physical information without losing accuracy in the RBE calculations nor the possibility of a posteriori RBE recalculations. Methods Computer simulations for four monoenergetic 12 C ion beams and a 12 C ion spread‐out Bragg peak (SOBP) were performed to assess lineal energy distributions as a function of the depth within a water phantom. These distributions were used in combination with the MCF MKM to compute the in vitro clonogenic survival RBE for human salivary gland tumor cells (HSG cell line) and human skin fibroblasts (NB1RGB cell line). The RBE values were also calculated with a new abridged microdosimetric distribution methodology (AMDM) and compared with the reference RBE calculations using the entire distributions. Results The maximum relative deviation between the RBE values computed using the entire distributions and the AMDM was 0.61% (monoenergetic beams) and 0.49% (SOBP) for the HSG cell line, while 0.45% (monoenergetic beams) and 0.26% (SOBP) for the NB1RGB cell line. Conclusion The excellent agreement between the RBE values computed using the entire lineal energy distributions and the AMDM represents a milestone for the clinical implementation of the MCF MKM.

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Idiopathic ventricular fibrillation (IVF) is responsible for 5-7% of sudden cardiac arrests in the absence of substrate for ventricular arrhythmia, structural diseases, or primary arrhythmic syndromes. The characteristics, management, and prognosis of these patients are unclear. Purpose To investigate the clinical features, management, and prognosis of IVF in our hospital healthcare system Methods Mayo Database Explorer software was used to identify IVF patients from our hospital electronic medical records between 1990 to 2022 in 5 states. The medical records were manually reviewed. Results A total of 132 patients were initially diagnosed with IVF. During the 9.2±6.8 years mean follow-up, 36 [27.3%] patients were later diagnosed with structural diseases or primary arrhythmic syndromes (dilated cardiomyopathy [41.7%], Long QT syndrome [27.8%], catecholaminergic polymorphic ventricular tachycardia [8.3%], Brugada syndrome [5.6%], mitral valve-related arrhythmia [5.6%], and short QT syndrome [2.8%]). Among the rest of the 96 patients with true IVF (mean age 38.4±15.7 years, male 59.4%, Caucasian 80.2%, hypertension 28.1%, diabetes 8.3%), 91 (94.8%) patients presented with out-of-hospital cardiac arrest and 88 (91.7%) patients had a history of syncope. Early repolarization and fragmented QRS were noted in 32 (33.3%) and 28 (29.1%) patients, respectively. Defibrillators were implanted in 92 (95.8%) patients. Genetic testing was performed in 35 (36.5%) patients, and possible associated mutations were found in 13 (37.1%) patients. An Electrophysiology study was conducted in 55 (57.3%) patients, and ventricular fibrillation was induced in 17 (30.9%) patients. The medical management with antiarrhythmic drugs was selected in 60 (62.5%) patients, and the catheter ablation ± anti-arrhythmic drugs was selected in 36 (37.5%) patients. The recurrence of ventricular fibrillation during 9.2±6.8 years of mean follow-up was significantly higher in the ablation strategy group (p=0.0003) (Figure 1). Conclusions We reported the largest cohort of IVF patients from a single healthcare system. Early repolarization and fragmented QRS were common in IVF. The possible associated mutations were found in one-third of IVF who underwent genetic testing. The ventricular fibrillation recurrences were significantly higher in the catheter ablation strategy group.

Brugada syndrome (BrS), early repolarization syndrome (ERS), and idiopathic ventricular fibrillation (iVF) have long been considered primary electrical disorders associated with malignant ventricular arrhythmia and sudden cardiac death. However, recent studies have revealed the presence of subtle microstructural abnormalities of the extracellular matrix in some cases of BrS, ERS, and iVF, particularly within right ventricular subepicardial myocardium. Substrate-based ablation within this region has been shown to ameliorate the electrocardiographic phenotype and to reduce arrhythmia frequency in BrS. Patients with ERS and iVF may also exhibit low-voltage and fractionated electrograms in the ventricular subepicardial myocardium, which can be treated with ablation. A significant proportion of patients with BrS and ERS, as well as some iVF survivors, harbor pathogenic variants in the voltage-gated sodium channel gene, SCN5A , but the majority of genetic susceptibility of these disorders is likely to be polygenic. Here, we postulate that BrS, ERS, and iVF may form part of a spectrum of subtle subepicardial cardiomyopathy. We propose that impaired sodium current, along with genetic and environmental susceptibility, precipitates a reduction in epicardial conduction reserve, facilitating current-to-load mismatch at sites of structural discontinuity, giving rise to electrocardiographic changes and the arrhythmogenic substrate.