Waguespack, Steven G.

Abstract Disclosure: S.R. Chacko: None. C.A. Villavicencio Torres: None. K. Yu: None. S.G. Waguespack: None. L. Lu: None. Z. Belaya: None. T. Bandgar: None. A. Sada: None. O. Ragnarsson: None. B. Altieri: None. A. Newman: None. P. Vibhatavata: None. M. Tóth: None. E.V. Varlamov: None. C. Badiu: None. A. Paissan: None. M. St-Jean: None. H. Falhammar: None. N. Imamudeen: None. L. Haberbosch: None. M. Bobrowicz: None. A. Tabarin: None. R. Shah: None. M.R. Gadelha: None. A. Peersen: None. W.F. Young: None. J. Kaplan: None. J. Varghese: None. M.A. Habra: None. O. Golounina: None. G.A. Melnichenko: None. A.R. Lila: None. C. Yamichannaiah: None. I. Bancos: None. Context: Cushing syndrome (CS) due to ectopic ACTH secretion (EAS) is a rare condition, associated with severe hypercortisolism and consequent morbidity and mortality. Its varied and often emergent presentation make diagnosis and treatment challenging. Objectives: 1.Characterize clinical and biochemical presentation of EAS. 2.Describe the scope of hypercortisolism-related complications, overall and CS-specific mortality. 3.Identify factors associated with CS-specific mortality. Methods: We conducted a multicenter retrospective cohort study in patients with EAS at 37 centers. Outcomes were clinical/biochemical severity scores, complications, overall and CS-specific mortality. Results: In 1053 patients [median age at diagnosis 52 years (IQR 37-64), 57% women], metastatic disease was present at diagnosis in 585 (56%). The most common sources of EAS were bronchial neuroendocrine neoplasm (NEN) (304, 29%), pancreatic NEN (114, 11%) and small cell lung carcinoma (114, 11%), with the source of EAS being occult in 192 (18%). Clinical and biochemical severity scores were severe in 475 (45%) and 873 patients (92%) respectively. Hypokalemia was present in 819 patients (78%) in the year prior to diagnosis. Of 342 patients (32%) who had IPSS, 301 (88%) suggested an ectopic source, 7 (2%) a pituitary source, and 23 (7%) were non-diagnostic. Of 595 patients who had both functional and cross-sectional imaging, discordant findings were seen in 122 (21%), concordant lesion was seen on both in 326 (55%), and no lesion in 147 (25%). Of those with discordant results, cross-sectional imaging was accurate in 66 (54%) and functional imaging in 56 (46%).Management included medical therapy alone in 237 (23%), surgical excision of the source of EAS in 158 (15%), bilateral adrenalectomy in 77 (7%) and multimodal therapies in 498 patients (47%). Complications within 5 years after diagnosis included hospitalization related to CS or its therapy in 351 (33%), infection in 337 (32%), thromboembolic event in 102 (10%), cardiovascular event in 83 (8%) and cerebrovascular event in 27 (3%). During a median follow-up of 35 months (IQR 20-122) from CS diagnosis, death occurred in 462 patients (44%), with the cause of death related to CS in 149 (14%). CS-specific mortality was higher in metastatic compared with non-metastatic disease (19% vs. 7%, P<0.001). On multivariable analysis of age, sex, clinical and biochemical severity, older age (HR 1.03, 95% CI: 1.02-1.04) and lower clinical severity score (HR 0.97, 95% CI: 0.94-0.99), were associated with higher CS-specific mortality. Conclusion: Our interim analysis, the largest worldwide, found that most patients with EAS had severe hypercortisolism and hypokalemia. Metastatic disease was present in 56%, and the source of EAS was occult in 18%. CS-related death occurred in 14%, emphasizing the need for urgent management. Presentation: Monday, July 14, 2025

6008 Background: ATC patients present with advanced, often surgically unresectable disease with historically dismal prognosis. Median PFS and OS of DT without pembrolizumab were 6.7 and 13.5 months, respectively, in the ROAR trial. Neoadjuvant DTP achieved locoregional control without radical surgery in a retrospective series of BRAF m-ATC patients, providing rationale to evaluate efficacy and safety in a phase 2 prospective trial. Methods: In this single-arm multicenter phase 2 trial, patients with BRAF m-ATC stage IVB/IVC were enrolled in 5 US centers. Following a 3-6 week run-in with D (150 mg BID) and T (2 mg daily), P (200 mg Q3W) was added, with restaging every three (21-day) cycles. Post-operatively, patients continued P (or DTP) with radiotherapy or transitioned directly to adjuvant DTP (up to 26 cycles). Primary endpoints included R0/R1 resection rate (historically 5%) and overall survival (OS). Secondary endpoints included RECIST 1.1 response after DTP and progression-free survival (PFS). Results: Between 9/2021-1/2025, 42 patients were enrolled; 36 are included in the current analysis (3 not evaluable, 3 pending surgery) (Table). Patients received median 4 (range: 2-7) neoadjuvant DTP cycles, with 26 (72%) achieving radiographic PR/CR. 30 patients (83%) had surgery after neoadjuvant DTP, achieving R0/R1 resection in 29/30 (97%). Mean surgical morbidity score (0-4 scale, 4=unresectable) improved from 3.3 to 1.6 after DTP (p<0.01). Complete ATC pathologic response occurred in 20/30 patients (67%), while 10/30 (33%) had residual ATC in the surgical specimen. Postoperatively, 11/30 (37%) received adjuvant neck radiation, and 28/36 (78%) completed a median of 11 (range: 1-26) adjuvant DTP cycles. With median follow up 18 months, 15/36 (42%) patients died. Median OS was 20 months (95% CI: 12.6-NR); 1- and 2-year OS were 71% and 48%. Complete pathologic responders had better 2-year OS than those with residual ATC (69% vs. 22%, p=0.02). Median PFS was 13.9 months (95% CI, 7.5-NR); 1- and 2-year PFS were 57% and 36%. Grade 5 adverse events occurred in 8 patients (22%), including one possible (duodenal perforation), one probable (kidney injury with sepsis), and 6 unlikely/unrelated treatment-related deaths. Conclusions: Neoadjuvant DTP enables surgical resection in BRAF m-ATC compared with historical controls, and leads to improved PFS and OS. This approach should now be considered a standard of care for BRAF m-ATC. Clinical trial information: NCT04675710 . Total N=36 Age (y), median (range) 67 (46-86) Stage IVB/IVC, n (%) 15 (42%)/21 (58%) Best RECIST response neoadjuvant phase, n (%) CR 2 (6%) PR 24 (67%) SD 6 (17%) PD 4 (11%) Percent change target lesion diameter, mean (95% CI) -44% (-54%, -34%) Surgical morbidity score change, mean (95% CI) -1.7 (-2.1, -1.3)

Background: The incidence of pediatric thyroid cancer has been increasing, and care varies due to socioeconomic disparities or differing practice patterns. Clinical guidelines call for care in multidisciplinary teams to minimize variance and provide protocols. Based on expert opinion, we hope to describe the form and function of such multidisciplinary teams for pediatric thyroid programs. Methods: A modified Delphi method to reach consensus statements over two rounds. Twenty-one experts with varying backgrounds responded to each statement on a 9-point Likert scale. Upon completion of the survey, the panel reviewed and shared the results and comments from participants and modified the statements accordingly. This process was repeated such that statements reached consensus, were deemed no consensus, or had no change in the mean. Results: There was an 88% and 83% completion rate for Rounds 1 and 2, respectively. A consensus was observed that there is a distinct definable model of care for pediatric thyroid patients. No consensus was reached for the age range of patients, but programs should care for children with medullary thyroid cancer, differentiated thyroid cancer, and patients with genetic predisposition syndromes. A comprehensive team includes, but is not limited to, a thyroid surgeon, a pediatric endocrinologist, a high-volume fine-needle aspiration (FNA) proceduralist, an oncologist, a nuclear medicine physician, a pediatric pathologist, a pediatric radiologist, and a nurse coordinator. Necessary support services involve care coordination, access to a multidisciplinary tumor board, ability to perform ultrasound-guided FNA, and access to molecular testing. The panel emphasized cross-institutional collaborative research prioritizing guidelines development, disease-specific outcomes, treatment toxicity, and the molecular landscape of thyroid cancer. Conclusions: These consensus statements can be beneficial in improving multidisciplinary care, by describing which elements of pediatric thyroid programs should be consistent across institutions. Overall, the panel agreed that pediatric thyroid centers should provide integrated care with defined team members, services, resources, and research priorities. This model has the potential to standardize various aspects of clinical care and enhance our ability to study patient outcomes, improve health care delivery, and increase scholarly collaboration.

Background Pituitary carcinoma (PC) is an aggressive neuroendocrine tumor diagnosed when a pituitary adenoma (PA) becomes metastatic. PCs are typically resistant to therapy and develop multiple recurrences despite surgery, radiotherapy and chemotherapy. Recently, treatment with temozolomide (TMZ) has shown promising results, although the lack of prospective trials limits assessment of benefit. Methods We describe a single-center multidisciplinary experience in managing PC patients over a 22-year period and review previously published PC series. Results Seventeen patients were identified. Median age at PC diagnosis was 44 years (range 16–82 years), and the median time from PA to PC transformation was 5 years (range 1–29 years). Median follow-up time was 28 months. Most PCs were hormone-positive (n = 12): ACTH (n = 5), PRL (n = 4), LH/FSH (n = 2) and GH (n = 1). All patients underwent at least one resection and at least one course of radiation after PC diagnosis. Immunohistochemistry showed high Ki-67 labeling index (>3%) in 10/15 cases. Eight patients (47%) had only central nervous system (CNS) metastases; six (35%) had combined CNS and systemic metastases. The most commonly used chemotherapy was TMZ, and TMZ-based therapy was associated with the longest PFS in 12 (71%) cases, as well as the longest period from PC diagnosis to first progression (median 30 months). The 2, 3 and 5-year survival rate of the entire cohort was 71, 59 and 35%, respectively. All patients surviving >5 years had been treated with TMZ-based therapy. Conclusions PC management benefits from multidisciplinary care and multimodality therapy. TMZ-based regimens were associated with high survival rates and long disease control.

Abstract Objectives Localization of ectopic ACTH‐secreting tumours causing Cushing syndrome (ECS) is essential for clinical management, yet often difficult. [ 68 Ga]‐DOTATATE PET/CT ([ 68 Ga]‐DOTA‐(Tyr 3 )‐octreotate)] is an FDA‐approved high‐resolution diagnostic tool for imaging neuroendocrine tumours. Data on the clinical utility of [ 68 Ga]‐DOTATATE in patients with ECS, however, are scarce. The objectives of this study were to determine the efficacy for ECS localization and the clinical benefit of [ 68 Ga]‐DOTATATE imaging. Method We conducted a retrospective review of all cases with ECS evaluated with [ 68 Ga]‐DOTATATE from November 2016 through October 2018 at three referral centres. The clinical benefit of [ 68 Ga]‐DOTATATE was based on detection of new tumours and resultant changes in management. Results Over the study period, 28 patients with ECS underwent [ 68 Ga]‐DOTATATE: 17 for identification of the primary tumour and 11 during follow‐up. [ 68 Ga]‐DOTATATE identified the suspected primary ECS in 11/17 patients (65%). Of these, nine patients underwent surgery: eight with confirmed ECS (5 bronchial, 1 thymic, 1 pancreatic and 1 metastatic neuroendocrine tumour of unknown primary origin) and one patient with a false‐positive scan (adrenal gland). Of the 11 patients with ECS who underwent [ 68 Ga]‐DOTATATE evaluation during follow‐up, the study led to changes in clinical management in 7/11 (64%) patients. Conclusions [ 68 Ga]‐DOTATATE is sensitive in detecting primary and metastatic ECS, often identifies occult tumours after conventional imaging, and impacts clinical care in the majority of patients.

Abstract Background Thyroid carcinoma, which is rare in pediatric patients (age 0–18 years) but more common in adolescent and young adult (AYA) patients (age 15–39 years), carries the potential for morbidity and mortality. Methods Hybrid-capture-based comprehensive genomic profiling (CGP) was performed prospectively on 512 consecutively submitted thyroid carcinomas, including 58 from pediatric and AYA (PAYA) patients, to identify genomic alterations (GAs), including base substitutions, insertions/deletions, copy number alterations, and rearrangements. This PAYA data series includes 41 patients with papillary thyroid carcinoma (PTC), 3 with anaplastic thyroid carcinoma (ATC), and 14 with medullary thyroid carcinoma (MTC). Results GAs were detected in 93% (54/58) of PAYA cases, with a mean of 1.4 GAs per case. In addition to BRAF V600E mutations, detected in 46% (19/41) of PAYA PTC cases and in 1 of 3 AYA ATC cases, oncogenic fusions involving RET, NTRK1, NTRK3, and ALK were detected in 37% (15/41) of PAYA PTC and 33% (1/3) of AYA ATC cases. Ninety-three percent (13/14) of MTC patients harbored RET alterations, including 3 novel insertions/deletions in exons 6 and 11. Two of these MTC patients with novel alterations in RET experienced clinical benefit from vandetanib treatment. Conclusion CGP identified diverse clinically relevant GAs in PAYA patients with thyroid carcinoma, including 83% (34/41) of PTC cases harboring activating kinase mutations or activating kinase rearrangements. These genomic observations and index cases exhibiting clinical benefit from targeted therapy suggest that young patients with advanced thyroid carcinoma can benefit from CGP and rationally matched targeted therapy.

Background: Previous guidelines for the management of thyroid nodules and cancers were geared toward adults. Compared with thyroid neoplasms in adults, however, those in the pediatric population exhibit differences in pathophysiology, clinical presentation, and long-term outcomes. Furthermore, therapy that may be recommended for an adult may not be appropriate for a child who is at low risk for death but at higher risk for long-term harm from overly aggressive treatment. For these reasons, unique guidelines for children and adolescents with thyroid tumors are needed. Methods: A task force commissioned by the American Thyroid Association (ATA) developed a series of clinically relevant questions pertaining to the management of children with thyroid nodules and differentiated thyroid cancer (DTC). Using an extensive literature search, primarily focused on studies that included subjects ≤18 years of age, the task force identified and reviewed relevant articles through April 2014. Recommendations were made based upon scientific evidence and expert opinion and were graded using a modified schema from the United States Preventive Services Task Force. Results: These inaugural guidelines provide recommendations for the evaluation and management of thyroid nodules in children and adolescents, including the role and interpretation of ultrasound, fine-needle aspiration cytology, and the management of benign nodules. Recommendations for the evaluation, treatment, and follow-up of children and adolescents with DTC are outlined and include preoperative staging, surgical management, postoperative staging, the role of radioactive iodine therapy, and goals for thyrotropin suppression. Management algorithms are proposed and separate recommendations for papillary and follicular thyroid cancers are provided. Conclusions: In response to our charge as an independent task force appointed by the ATA, we developed recommendations based on scientific evidence and expert opinion for the management of thyroid nodules and DTC in children and adolescents. In our opinion, these represent the current optimal care for children and adolescents with these conditions.