Bancos, Irina

Abstract Disclosure: D. Toro-Tobon: None. H. Billings: None. I. Bancos: None. Background: Mentorship is crucial for training physicians' career development, yet evidence of its impact on endocrinology trainees is lacking. We assessed the current state of mentorship in endocrine fellowship training in the United States. Methods: We conducted a cross-sectional study between June and September 2023. Endocrine fellows were invited to complete an online questionnaire describing their mentorship experience and its influence on burnout, satisfaction, and scholarly productivity. Results: Of 153 participants (mean age 34, 69% women, 47% White, 20% Hispanic/Latino), 73% had a mentor. Having a mentor was not associated with age, gender identity, race, or ethnicity. Those without mentors were more commonly in two-year fellowships (63% vs. 81%, p=0.04), had less access to formal mentorship programs (48% vs. 21%, p<0.01), cited insufficient faculty availability for mentoring (11% vs. 26%, p=0.01), and encountered more challenges finding mentors in their training programs (11% vs. 38%, p<0.001). Mentored participants exhibited increased post-fellowship interest in academic practice (69% vs. 50%, p<0.01), higher involvement in clinical research (65% vs. 49%, p=0.01), more fellowship-dedicated scholarly time (36% vs. 22%, <0.001), a greater median number of publications (4.6 vs. 1.8, p<0.01) and abstracts (7 vs. 3.7, p<0.01), were more likely to have submitted a grant (29% vs. 5%, p=0.03) and had higher satisfaction with training (92% vs. 64%, p<0.001). Mentors were mostly chosen by mentees (70%) and shared gender identity (61%) but often had a different race or ethnicity (71.8%). The majority found mentorship relationships satisfactory (87%), contributing to increased academic productivity (84%) and reduced mentee burnout and stress levels (60%). In bivariate analysis, all mentor attributes significantly influenced higher academic productivity and mentee satisfaction. The most divergent for academic productivity were improved communication, alignment with expectations, inspiration for goal attainment, and effective networking. For mentorship satisfaction, distinctions were found in communication enhancement, goal-oriented assistance, knowledge/skill enrichment, and personalized career path development. Traits like active listening and adapting communication styles were not linked to decreased burnout, but actively supporting work-life balance independently correlated with reduced burnout. Conclusion: Mentorship positively affects endocrine fellows' scholarly productivity and career development. Yet, a significant number lack mentors or access to programs. Mentor attributes, like effective communication, goal alignment, and networking support boost productivity and satisfaction. However, reducing mentee burnout hinges on actively fostering work-life balance. Presentation: 6/3/2024

Abstract Disclosure: B.M. Biller: Consulting Fee; Self; HRA Pharmaceuticals, Novartis Pharmaceuticals, Sparrow, Strongbridge Biopharma. Grant Recipient; Self; Strongbridge Biopharma. A. Gilis-Januszewska: Speaker; Self; Ipsen, Novartis Pharmaceuticals, Novo Nordisk, Recordati, Teva Pharmaceutical Industries Ltd.. M. Doknic: None. A.M. Pico: None. M. Fleseriu: Consulting Fee; Self; Ascendis, GlaxoSmithKline, Johnson &Johnson, Karyopharm, Novo Nordisk, Pfizer, Inc., Pharmacosmos. Research Investigator; Self; Ascendis. G. Raverot: None. A.M. Isidori: None. Y. Takahashi: None. J.M. Garcia: None. J.M. Silverstein: None. I. Bancos: None. E. Huang: Employee; Self; Ascendis Pharma, Inc. J. Kang: Employee; Self; Ascendis Pharma, Inc. A.S. Komirenko: Employee; Self; Ascendis Pharma, Inc. L. Domrzalski: Employee; Self; Ascendis Pharma, Inc. A. Shu: Employee; Self; Ascendis Pharma, Inc. K. Yuen: Advisory Board Member; Self; Amryt, Ascendis, Corcept, Crinetics, Novo Nordisk, Recordati, Strongbridge, Xeris. Grant Recipient; Self; Amryt, Ascendis, Corcept, Crinetics. Speaker; Self; Corcept, Novo Nordisk, Recordati. Background: Adult GHD (aGHD) is characterized by metabolic abnormalities due to insufficient growth hormone (GH) production. Lonapegsomatropin was designed to provide sustained release of unmodified somatropin, with the identical amino acid sequence as endogenous GH, and once-weekly injection reduces the burden of daily GH replacement therapy. MethodsForesiGHt was a randomized, parallel-3-arm, placebo(PL)-controlled (double-blind) and active-controlled (open-label) trial designed to establish the efficacy and safety of lonapegsomatropin in aGHD. It evaluated 259 adults with GHD across 21 countries who were GH treatment-naïve or not treated with GH in the prior year, randomized 1:1:1 to receive lonapegsomatropin, once-weekly PL, or daily somatropin (dGH). Fixed dosing was based on age and oral estrogen intake, and designed to be comparable across lonapegsomatropin and dGH arms. Following a 12-week (w) titration period to target maintenance dose, fixed doses were administered for 26w. ResultsBaseline (BL) characteristics were similar between arms. Lonapegsomatropin demonstrated superiority on the primary efficacy endpoint of change from BL in trunk percent fat at Week 38 vs PL (lonapegsomatropin -1.7% vs PL 0.4%, LS mean difference -2.0%, p < 0.0001) and on the key secondary efficacy endpoints of change from BL in total body lean mass (lonapegsomatropin 1.6 kg vs PL -0.1 kg, LS mean difference 1.7 kg, p < 0.0001) and change from BL in trunk fat mass (lonapegsomatropin -0.5 kg vs PL 0.2 kg, LS mean difference -0.7 kg, p = 0.0053). Mean total exposure and maintenance doses were similar for lonapegsomatropin and dGH arms, with larger changes from BL in average IGF-I SDS mean at Week 38 in the lonapegsomatropin arm (1.4) vs dGH arm (0.5). To assess outcomes at comparable weekly IGF-I exposure, a post-hoc analysis was performed in a subset of participants with average IGF-I SDS ≤1.75 SDS at Week 38. Mean IGF-I SDS for these subsets were similar (lonapegsomatropin -0.1, dGH -0.5), and comparable effects in fat and lean tissue compartments were demonstrated (change from BL in trunk percent fat mean -2.4% and -2.6% respectively; change from BL in total body lean mass mean 1.7 kg and 1.4 kg respectively). In the safety population, the incidence of severe AEs was low (lonapegsomatropin, 3.4%; placebo, 1.2%; dGH, 2.3%) and the incidence of treatment-related AEs was similar (lonapegsomatropin 24.7%, dGH 22.1%). Injection site reaction incidence was low and similar for lonapegsomatropin (4.5%), dGH (5.8%) and placebo (4.8%), and A1c levels remained stable in all treatment arms. ConclusionsThe results of the foresiGHt trial indicate that lonapegsomatropin is a safe, efficacious, and tolerable replacement for endogenous GH. Once-weekly dosing may be impactful for adults with GHD who typically manage multiple other medical therapies. Presentation: 6/3/2024

Abstract Disclosure: K. Yu: None. J. Saini: None. J.N. Farr: None. F. Vanessa: None. S. Khosla: None. I. Bancos: Advisory Board Member; Self; AstraZeneca, Adrenas, Neurocrine, Spruce, Recordati, Xeris, Novo Nordisk, HRA Pharmaceuticals, Sparrow, Diurnal, Corcept. Research Investigator; Self; HRA Pharmaceuticals, Recordati. Importance: Patients with both mild autonomous cortisol secretion (MACS) and overt Cushing syndrome (CS) demonstrated high prevalence of aging-related morbidity and an increased mortality. Objective: To determine whether p16INK4a in T cell, a cell cycle enzyme that associated with chronological aging and cell senescence, is associated with hypercortisolism and hypercortisolism-related comorbidities. Design, Setting, and Participants: In this single-center cross-sectional study, we prospectively recruited consecutive patients with hypercortisolism between July 1, 2020 and August 24 2022. Patients were included if they were diagnosed with Cushing syndrome (CS) or mild autonomous cortisol secretion (MACS). Age- (± 2 years) and sex-matched referent subjects without known adrenal disorders were included if abdominal imaging was available. Participants on exogenous glucocorticoids within 3 months prior were excluded. Exposure: Presence of hypercortisolism (MACS and CS). Main Outcomes and Measures: Primary outcomes included p16INK4a, advanced glycation end products (AGE) reader result, Frailty Index score, frailty (defined as frailty index>0.31), and physical performances in patients and matched referents at index date. Secondary outcomes included correlation between biological age markers, hormonal workup and the risk of comorbidities. p16INK4a expression analysis was adjusted for age, sex, smoking, and alcohol use for all analyses except for associations with CVD and frailty. Results: Of 85 patients (87% women, mean age 53 years), 51 (60%) had MACS (34 had matched referents), 34 (40%) had overt CS (16 had matched referents). Patients with CS demonstrated a median 1.9-fold higher p16INK4a expression (P<.001), and patients with MACS showed a median of 1.70-fold p16INK4a expression (P=.013), when compared to referent subjects. Age- and sex-adjusted p16INK4a expression was associated with frailty index score (r=0.23, P=.035), time-up-and-go test (r=0.28, P=.048), gait speed (r=-0.36, P=.035), but not with AGE reader result, 6-minute walk test, or hand grip measurement. The p16INK4a expression was associated with history of cardiovascular disease (age-adjusted odds ratio (aOR)=3.70, 95% confidence interval (CI), 1.20-11.43) and frailty (aOR=2.27, 95%CI, 1.04-4.98). Conclusion and relevance: We demonstrated evidence of cell senescence in both patients with CS and patients with MACS. Further studies need to determine the impact of surgical, cortisol-lowering, and senolytic medical therapies in MACS on cell senescence and associated aging-related comorbidities. Presentation: 6/1/2024

Abstract Disclosure: R. Sandooja: None. J. Saini: None. R. Gregg garcia: None. C. Zhang: None. S. Achenbach: None. E. Atkinson: None. J. Van Gompel: None. W.F. Young: None. I. Bancos: None. Hydrocortisone vs Prednisone During Recovery Following Surgical Cure for Endogenous Hypercortisolism: A Longitudinal Observational Study Introduction: Glucocorticoid withdrawal syndrome (GWS) is a constellation of symptoms that occurs after successful surgery for endogenous hypercortisolism. The objective of this study is to compare hydrocortisone versus prednisone on GWS symptoms. Methods: Study design: Single-center prospective longitudinal cohort study, 2019-2023. Participants: Adults with Cushing syndrome (CS) and mild autonomous cortisol secretion (MACS) with post-operative adrenal insufficiency treated with either hydrocortisone or prednisone for glucocorticoid replacement. Measurements: Clinical and biochemical severity scores for hypercortisolism were calculated. Quality of life (QOL) was assessed using Short Form-36 (SF-36) and Cushing QOL surveys. GWS was assessed using weekly AddiQoL surveys for the first 12 weeks after surgery. Results: Of 131 patients, 91 (69%) patients were treated with hydrocortisone and 40 (31%) with prednisone. No differences in age (median age 51 vs 53 years, P=0.62), sex (84 vs 85% women, P=0.83), etiology of hypercortisolism (ACTH-dependent: 44% vs 48%, P=0.26), clinical severity of hypercortisolism (median score 13 vs 12, P=0.97), or biochemical severity of hypercortisolism (median score of 6 in both, P=0.31) were noted between groups. When assessed at 4-, 8-, and 12-weeks post-surgery, the prevalence and trajectory of symptoms (fatigue, myalgias/arthralgias, sleep, headaches, nausea, weakness) were similar in patients treated with hydrocortisone and prednisone (P>0.05 for all). However, patients treated with prednisone were less likely to report mood changes (8.5% vs 20.9%, P= 0.004) compared to those treated with hydrocortisone. When compared to the presurgical baseline, the overall Cushing QOL score 12 weeks post-surgery improved in both groups (mean delta 8.9 vs 13.0, P=0.21). No differences in the hydrocortisone vs prednisone treatment were found in the SF-36 physical component score (mean delta of -1.7 vs 0.3, P=0.23) and SF-36 mental component score (mean delta 2.3 vs 5.0, P=0.22). Using multivariable analysis, age (estimate 0.22, P= 0.005), clinical severity score (estimate -0.73, P<0.001), female sex (estimate -5.45, P= 0.046) but not glucocorticoid type (estimate -0.06, P=0.98) were associated with the overall GWS symptom burden at 12 weeks. Conclusion: Use of prednisone after curative surgery for hypercortisolism was associated with lower mood symptoms, but did not impact the overall severity or trajectory of other symptoms associated with GWS. Baseline clinical severity of hypercortisolism, age, and female sex were associated with GWS burden. Presentation: 6/1/2024

Abstract Disclosure: J. Saini: None. C.D. Zhang: None. V. Fell: None. E. Atkinson: None. S. Achenbach: None. I. Bancos: None. Background: Several studies employing computed tomography (CT) scans for body composition measurements have reported lower muscle mass and a higher proportion of visceral fat in patients with mild autonomous cortisol secretion (MACS) compared to referent subjects. While a CT scan assesses visceral adipose tissue (VAT) at a single slice level (L3), no studies have evaluated the overall VAT in patients with MACS using Dual-Energy X-ray absorptiometry (DXA). Objective: To determine the impact of MACS on VAT using DXA scan as compared to referent subjects. Methods: We conducted a single-center cross-sectional study of adults with 75 MACS and 75 referent subjects. MACS was defined as serum cortisol>1.8 mcg/dL after 1 mg dexamethasone suppression test in patients with adrenal adenomas and no features of overt hypercortisolism. Referent subjects were included if they had abdominal imaging and had no adrenal disorders. All the participants underwent a full body DXA scan between 04/2019 and 07/2022. We applied the CoreScan software to estimate the (1) total lean and fat mass (2) visceral fat mass and volume (3) lean android, fat android, and android mass, and compared measurements of patients and referent subjects using linear regression models adjusted for sex and BMI. Results: A total of 75 patients with MACS (median age 57.0 years, IQR 47.8-65.6, 67% women) and 75 referent subjects (median age 57.6 years, IQR 49.1-65.8, 67% women) were included. Patients had a higher BMI compared to referent subjects (median 31.7 kg/m2, IQR 27.4-37.9 vs 28.7, IQR, 25.4-33.8, P=0.004). The median post-DST cortisol in patients was 3.1 mcg/dL (IQR, 2.2-5.2). When compared to referent subjects, and after adjustment for sex and BMI, patients had a similar total body fat (estimate=846, p-value=0.28) and lean mass (estimate=-201, p-value=0.83), similar android fat mass (estimate=59, p-value=0.64) but lower gynoid fat mass (estimate=400, 0.007). Notably, sex and BMI-adjusted analysis also showed that patients had a higher VAT fat mass (estimate= -225, p-value=0.084) and a higher VAT fat mass/total mass ratio (estimate= -0.007, p-value=0.026). Conclusions: When adjusted for BMI and sex, patients with MACS do not demonstrate differences in overall fat and lean mass. However, we showed that MACS is associated with increased visceral adiposity, a known cardiovascular risk factor. Body composition assessment by DXA could be a safer and less expensive alternative in the evaluation and follow-up of patients with MACS. Presentation: 6/2/2024

Abstract Disclosure: M. Bassiony: None. P. Dogra: None. L. Šambula: None. J. Saini: None. U. Ambroziak: None. D. Kastelan: None. I. Bancos: None. Background: Frailty is characterized by a multi-system decline and increased vulnerability to adverse health outcomes. We have recently shown that patients with mild autonomous cortisol secretion (MACS) demonstrate a higher prevalence of frailty compared to patients with nonfunctioning adrenal adenomas (NFA). Objective: To determine the impact of adrenalectomy versus conservative management in patients with MACS, as compared to patients with NFA. Design: Multi-center, prospective cohort study (2019-2023). Methods: Adults with NFA and MACS were assessed for frailty at baseline and 1-year post-adrenalectomy, or conservative follow up. Frailty was assessed by frailty index (FI) that encompasses 47 health variables (comorbidities, symptoms, daily living activities). Patients with FI >0.25 were classified as frail. MACS was defined as post-dexamethasone cortisol>1.8 mcg/dL. Results: Paired frailty assessments were performed in 226 patients (MACS:117 and NFA:109). At baseline, patients’ median age was 63 years (interquartile range, IQR 55-78) and 113 (50%) were women, without differences between patients with MACS vs NFA. In conservatively treated patients with NFA (n=106) and MACS (n=61), baseline FI (median 0.15 vs 0.16, p=0.190) and frailty prevalence (18% vs 20%, p=0.846) were similar between groups. At follow up, patients with MACS demonstrated an increase in FI (mean of 0.013 vs -0.018 in patients with NFA, p=0.009). In conservatively treated patients, and after excluding outliers, post-dexamethasone cortisol positively correlated with a higher delta FI at follow up (estimate 0.015, p=0.01). Compared to conservatively treated, patients with MACS treated with adrenalectomy (n=56) were younger (median age of 58 vs 67 years, p=0.0002), had a similar post-dexamethasone cortisol (median 3.4 vs 2.8 mcg/dL, p=0.853), a higher FI (median 0.26 vs 0.15, p value <0.0001) and frailty prevalence (52% vs 20% P=0.0003) at baseline. At follow up, patients with MACS treated with adrenalectomy showed improved FI when compared to conservatively treated (mean delta FI of -0.025 vs 0.014, p=0.017). Conclusions: Patients with MACS treated conservatively demonstrate an accelerated frailty when compared to patients with NFA. In contrast, frailty improves in patients with MACS treated with adrenalectomy. Presentation: 6/2/2024

Abstract Disclosure: E.Y. Ferreira: None. J. Saini: None. J. Larson: None. E. Atkinson: None. C. Powell: None. S. Nevin: None. V. Fell: None. I. Bancos: Grant Recipient; Self; HRA Pharmaceuticals. Research Investigator; Self; HRA Pharmaceuticals. Context: Mild autonomous cortisol secretion (MACS) is the most prevalent hormonal abnormality demonstrated in 20-45% of patients with adrenal adenomas. MACS is associated with increased prevalence and incidence of cardiovascular morbidity, frailty, fragility fractures, psychiatric and sleep disorders, as well as increased mortality. Bilateral MACS due to bilateral adrenal adenomas or macronodular adrenal hyperplasia is seen in around 20% of patients with MACS. Management of patients with unilateral MACS who are not surgical candidates or do not desire adrenalectomy, and management of patients with bilateral MACS is challenging. Safe and effective medical therapy is urgently needed in these patients. Objective: 1) assess safety and tolerability of overnight metyrapone therapy in patients with MACS, 2) evaluate the impact of overnight metyrapone on steroid profiling and circadian cortisol secretion and 3) determine the efficacy of overnight metyrapone on metabolic and bone parameters, mood, sleep, cognition, quality of life, frailty and senescence biomarkers. Methods: This open-label, phase 2 interventional single-center study using overnight metyrapone opened for enrollment in December 2023 (NTC06106295) and plans to enroll 30 patients with MACS. Eligible participants include adults with adrenal adenoma or macronodular adrenal hyperplasia and MACS, and at least one comorbidity attributed to hypercortisolism. Metyrapone is administered overnight at 250 mg to 1000 mg. Duration of the study is 6 months (main study) and up to 42 months for extension study. Primary endpoint is incidence of treatment related adverse events. Key secondary endpoints include: glucocorticoid/androgen ratio, morning/evening cortisol curve, metabolic parameters (change in blood pressure, hyperglycemia, weight), frailty index and senescence biomarkers. Results: Between December 15th 2023 and April 6th, 7 patients with MACS (4, 57% women) enrolled at a median age of 62 years (IQR 56-68). Median BMI was 29 kg/m2(IQR 25-34). Post-dexamethasone cortisol was 3.1 mcg/dL (IQR 2.4-6.2), corticotropin (ACTH) was 7.3 pg/mL (IQR 5-20), and dehydroepiandrosterone-sulfate (DHEAS) was 73 mcg/dL (IQR 59-86). Median hypercortisolism clinical severity score was 9 (IQR 2-11) and biochemical severity score was 3.5 (IQR 2-5). Prevalence of hypertension (57%), dysglycemia (67%), dyslipidemia (86%), depression (57%), anxiety (43%), and bone disease (70%) was high. In 7 participants, median frailty index was 0.2 (IQR 0.2-0.4), and 3 (43%) were considered frail (frailty index >0.25). As of April 6th, 2024, no major treatment-related adverse events were reported, and no patient discontinued therapy. Conclusion: Results of this study will characterize safety and tolerability of overnight metyrapone in patients with MACS and evaluate the impact of overnight metyrapone on MACS-associated comorbidities. Presentation: 6/1/2024

Abstract Disclosure: B. Vekony: None. G. Nyiro: None. Z. Herold: None. J. Fekete: None. F. Ceccato: None. S. Gruber: None. L. Kurzinger: None. M. Parasiliti-Caprino: None. B. Szeredas: None. S. Syed Mohammed Nazri: None. V. Fell: None. M. Bassiony: None. E.A. Azizan: None. I. Bancos: None. F. Beuschlein: None. P. Igaz: None. Background: The differentiation of uni- and bilateral forms of primary aldosteronism (PA) is of pivotal clinical relevance. Whereas unilateral PA warrants surgical treatment, bilateral PA is treated by aldosterone antagonists. The most reliable way to differentiate these two entities is adrenal venous sampling (AVS) that is an invasive method with limited availability and requiring great expertise. Aim: To develop a circulating blood-borne microRNA-based approach using machine learning for the differentiation of uni- and bilateral PA. Methods: Circulating microRNA profiling on an Illumina MiSeq platform was performed on total RNA samples isolated from EDTA-anticoagulated blood specimens taken by AVS from 18 pairs of right and left suprarenal veins (10 uni-, 8 bilateral PA). Significantly differentially expressed microRNAs were analyzed by a neural network (90-10% learner-tester cross-validation simulation). From the top 29 significantly differentially expressed microRNAs, 9 were selected for validation by Taqman RT-qPCR on a separate cohort of 30 AVS-confirmed samples (15-15 uni- and bilateral forms) both on plasma samples from adrenal as well as from peripheral veins. The method was finally tested on another independent cohort of peripheral blood samples from 80 patients (40 uni- and 40 bilateral PA). Results: Regarding the 9 microRNAs selected for validation, microRNA abundance was non-significantly lower in peripheral samples compared to AVS samples. By analyzing peripheral plasma samples, ten combinations of 4-8 microRNAs from the pool of 9 microRNAs turned out to have maximal sensitivity and specificity values over 85 %. The best combination included 6 microRNAs with a sensitivity of 86.3 % and a specificity of 87.91 % (AUC = 0.871). The inclusion of further parameters such as imaging, potassium and renin levels did not improve the model’s performance. Conclusion: The analysis of circulating blood-borne microRNAs represents a minimally invasive and potentially reliable way of differentiating uni- and bilateral PA. If bilateral PA is confirmed by the model, no more localization efforts would be necessary thus simplifying the management of PA patients. This would be relevant both from the patient’s and a public health perspective. Presentation: 6/3/2024

Abstract Disclosure: B. Vekony: None. G. Nyiro: None. Z. Herold: None. J. Fekete: None. F. Ceccato: None. S. Gruber: None. L. Kurzinger: None. M. Parasiliti-Caprino: None. B. Szeredas: None. S.K. Nazri: None. V. Fell: None. M. Bassiony: None. E.A. Azizan: None. I. Bancos: None. F. Beuschlein: None. P. Igaz: None. Background: The differentiation of uni- and bilateral forms of primary aldosteronism (PA) is of pivotal clinical relevance. Whereas unilateral PA warrants surgical treatment, bilateral PA is treated by aldosterone antagonists. The most reliable way to differentiate these two entities is adrenal venous sampling (AVS) that is an invasive method with limited availability and requiring great expertise. Aim: To develop a circulating blood-borne microRNA-based approach using machine learning for the differentiation of uni- and bilateral PA. Methods: Circulating microRNA profiling on an Illumina MiSeq platform was performed on total RNA samples isolated from EDTA-anticoagulated blood specimens taken by AVS from 18 pairs of right and left suprarenal veins (10 uni-, 8 bilateral PA). Significantly differentially expressed microRNAs were analyzed by a neural network (90-10% learner-tester cross-validation simulation). From the top 29 significantly differentially expressed microRNAs, 9 were selected for validation by Taqman RT-qPCR on a separate cohort of 30 AVS-confirmed samples (15-15 uni- and bilateral forms) both on plasma samples from adrenal as well as from peripheral veins. The method was finally tested on another independent cohort of peripheral blood samples from 80 patients (40 uni- and 40 bilateral PA). Results: Regarding the 9 microRNAs selected for validation, microRNA abundance was non-significantly lower in peripheral samples compared to AVS samples. By analyzing peripheral plasma samples, ten combinations of 4-8 microRNAs from the pool of 9 microRNAs turned out to have maximal sensitivity and specificity values over 85 %. The best combination included 6 microRNAs with a sensitivity of 86.3 % and a specificity of 87.91 % (AUC = 0.871). The inclusion of further parameters such as imaging, potassium and renin levels did not improve the model’s performance. Conclusion: The analysis of circulating blood-borne microRNAs represents a minimally invasive and potentially reliable way of differentiating uni- and bilateral PA. If bilateral PA is confirmed by the model, no more localization efforts would be necessary thus simplifying the management of PA patients. This would be relevant both from the patient’s and a public health perspective. Presentation: 6/3/2024

Abstract Disclosure: K. Yu: None. S. Athimulam: None. J. Saini: None. R. Kaur: None. R.J. Singh: None. S.K. Grebe: None. Q. Xue: None. I. Bancos: Advisory Board Member; Self; AstraZeneca, Corcept, Novo Nordisk, HRA Pharmaceuticals, Neurocrine, Diurnal, Recordati, Sparrow, Xeris, Spruce, Adrenas. Research Investigator; Self; HRA Pharmaceuticals, Recordati. Context: Early diagnosis is essential to assure a better prognosis in patients with adrenocortical carcinoma (ACC). Guidelines suggested performing urine steroid profiling in patients with indeterminate adrenal tumors to make a noninvasive diagnosis of ACC. However, urine steroid profiling is not widely available. Accuracy of clinically available serum steroids in diagnosing ACC has not been established. Objective: To determine the accuracy of 11-deoxycortisol, 17OH-progesterone, and 17OH-pregnenolone in diagnosing ACC. Design: Prospective single-center cohort study. Participants: Between 2015 and 2023, consecutive patients with adrenal mass were prospectively enrolled in the prospective registry and biobank study. Patients who agreed to contribute a fasting serum sample were included in the study. Exclusion criteria were congenital adrenal hyperplasia, exogenous glucocorticoid use, absence of unenhanced Hounsfield unit measurements (HU), and lack of established reference standard (histopathology, imaging characteristics, 2-year imaging follow up, or 5-year clinical follow up). Measures and Outcomes: measurements included 11-deoxycortisol, 17OH-progesterone, and 17OH-pregnenolone by liquid chromatography–mass spectrometry. Localized Generalized Matrix Learning Vector Quantization (LGMLVQ) analysis was used to develop serum steroid score and assessed with area under receiver operating curve (AUROC). Results: Of 263 patients with adrenal masses, 44 (17%) were diagnosed with ACC, 161 (61%) with adrenocortical adenomas (ACAs), 27 (10%) with other adrenal malignancies, and 31 (12%) with other. HU ≥ 20 were demonstrated in all ACCs, in all but one other adrenal malignancy, and only in 58 (31%) ACAs. All 3 steroids were higher in patients with ACCs vs nonACCs, including when comparing ACCs with functioning ACAs, and with ACAs with HU ≥ 20 (P<0.0001 for all). LGMLVQ analysis yielded a serum steroid score that discriminated between ACC and non-ACC groups with a mean threshold fixed AUROC of 0.823. Serum steroid score of 0.29 demonstrated a mean false negative rate of 0% and a score of 0.61 demonstrated a mean false positive rate of 0%. Conclusions: We showed that measurements of 11-deoxycortisol, 17OH-progesterone, and 17OH-pregnenolone could be valuable in diagnosing ACC. After appropriate validation, serum steroid score could be integrated in clinical practice. Presentation: 6/2/2024