Citations

e16323 Background: Advanced EP-NEC are typically treated with the combination of platinum plus etoposide. Despite therapy, outcomes remain poor, with reported median overall survival (OS) of 12-13 months. Early initiation of systemic therapy is commonly practiced given the aggressiveness; however, recent data from small cell lung carcinoma (SCLC) suggest that shorter TTI does not necessarily improve OS. The impact of TTI on outcomes in EP-NEC has not been well studied. Methods: We conducted a multicenter retrospective cohort study across three Mayo Clinic sites including adults with biopsy-confirmed stage IV EP-NEC diagnosed between 2005 and 2025. TTI was defined as days from pathologic diagnosis to initiation of first-line systemic therapy. A binary cutoff (≤14 vs > 14 days) was determined using receiver operating characteristic (ROC) analysis, and TTI was also analyzed as a continuous variable. OS and progression-free survival (PFS) were estimated using the Kaplan–Meier method and evaluated using Cox proportional hazards models. Multivariable analyses adjusted for age, sex, ECOG performance status, presence of liver metastases, and first-line treatment strategy (chemotherapy alone vs chemotherapy plus immunotherapy). Results: Among 248 pts, median age was 61 years. Median OS for the cohort was 13.9 months (95% CI, 11.7–16.7), and median PFS was 5.7 months (95% CI, 5.3–6.3). Pts with TTI > 14 days had longer median OS compared with those treated within ≤14 days (16.4 vs 10.1 months), with improved OS on unadjusted analysis (HR 0.69, 95% CI 0.50–0.96; p = 0.028), though this association was not statistically significant after multivariable adjustment (HR 0.74, 95% CI 0.53–1.05; p = 0.097). Pts with TTI > 14 days also had longer median PFS compared with ≤14 days (6.5 vs 4.8 months), with improved PFS on unadjusted analysis (HR 0.67, 95% CI 0.51–0.88; p = 0.0038). On multivariable analysis, TTI > 14 days remained independently associated with improved PFS (HR 0.75, 95% CI 0.56–1.00; p = 0.047). However, when analyzed as a continuous variable, TTI was not independently associated with OS (HR 0.99, 95% CI 0.98–1.00; p = 0.173) or PFS (HR 0.99, 95% CI 0.98–1.00; p = 0.089). Conclusions: In this multicenter cohort of pts with metastatic EP-NEC, earlier initiation of systemic therapy (≤14 days) was not associated with improved overall survival, and longer time-to-treatment was independently associated with improved PFS. However, when TTI was analyzed as a continuous variable, no statistically significant associations were observed, suggesting that the observed benefit with delayed treatment may reflect pt selection or clinical context rather than a direct biological effect. These findings may provide reassurance in scenarios where short delays are necessary—for biomarker testing or clinical trial enrollment—and highlight the need for further investigation in the era of precision oncology.

e15509 Background: Large language models (LLMs) are increasingly explored for oncology decision support, yet comparative evidence evaluating medical-specific versus general-purpose LLMs using expert-reviewed clinical cases is limited. We compared a medical-specific LLM (Google MedGemma 27B) with a general-purpose LLM (ChatGPT-5) using gastrointestinal (GI) and genitourinary (GU) oncology vignettes. Methods: This cross-sectional study evaluated 32 de-identified oncology vignettes (26 GI, 6 GU) created by a U.S. board-certified medical oncologist and informed by real-world cases. Vignettes included text-only information on the clinical context, description of pathology, tumor staging, biomarkers, and relevant comorbidities. Both LLMs were prompted to provide National Comprehensive Cancer Network(NCCN) guideline-based treatment recommendations, monitoring strategies, maintenance therapy considerations, and references, along with a self-reported confidence score (0–100). Board-certified U.S. medical oncologists independently reviewed outputs using a structured instrument; two disease specific expert oncologists evaluated each case. Outcomes included correctness and comprehensiveness (1–10 scales), hallucinations (factually fabricated or unsupported statements), NCCN traceability, potential patient harm, and clinician trust. Associations between accuracy and comprehensiveness were assessed using correlation coefficients. Inter-rater reliability was assessed using a two-way random-effects intraclass correlation coefficient (ICC). Results: ChatGPT-5 demonstrated higher mean correctness (8.65 vs 4.68) and comprehensiveness (8.68 vs 5.22) scores compared with MedGemma 27B. Accuracy and comprehensiveness were strongly correlated overall (Pearson r = 0.93, p < 0.001), with significant model-specific correlations (ChatGPT-5 r = 0.86, p < 0.001; MedGemma r = 0.77, p < 0.001). Hallucinations occurred less frequently with ChatGPT-5 (12.3% vs 65%), and NCCN-traceable recommendations were more common (75.4% vs 36.7%). Responses judged as potentially harmful occurred in 18.5% of ChatGPT-5 outputs versus 70% of MedGemma outputs. Clinician trust favored ChatGPT-5 (84.6% vs 15%). Inter-rater reliability improved with rater averaging (ICC(A,k): correctness 0.72; comprehensiveness 0.64). Conclusions: In expert-reviewed GI and GU oncology cases, ChatGPT-5 demonstrated higher clinical accuracy, comprehensiveness, and guideline alignment than a medical-specific LLM; however, a substantial rate of hallucinations and potentially harmful recommendations persisted across models. These findings underscore that, despite performance differences, current LLMs require rigorous clinician oversight and should not be used as standalone decision-support tools in oncology.

1557 Background: Immunotherapy is now a standard-of-care treatment for lung cancer across most stages. Access to immunotherapy and molecular diagnostic tests in conflict-affected countries such as Syria remains poorly described. As the principal cancer center in Syria, Al-Bairouni University Hospital (ABUH) provides care for nearly three-quarters of all cancer cases nationally. We conducted this study to evaluate access to immunotherapy and molecular diagnostic services at ABUH. Methods: A mixed-methods study was performed between 2022 and 2024 at ABUH. This study included a retrospective cohort of all patients diagnosed with lung adenocarcinoma. Quantitative data included disease stage at diagnosis, molecular testing rates, and immunotherapy utilization. In addition, a qualitative patient survey was thematically analyzed to explore barriers to treatment access in a separate cohort of patients with mixed tumor types. Results: Among 2,920 patients diagnosed with lung cancer, 1,393 (47.7%) had lung adenocarcinoma. The median age at diagnosis was 61 years; 79.7% of patients were male. Smoking history was as follows: Current 792 (56.9%), Former 268 (19.2%), never smoked 318 (22.8%) At presentation, 3 patients (0.2%) had stage I disease, 40 (2.9%) stage II, 174 (12.5%) stage III, and 778 (55.8%) stage IV disease, staging was unknown for the rest of the patients. EGFR mutation testing was performed by ABUH for 226/1393 patients (16.2%) only, with positive results identified in 124 cases (8.9%). PD-L1 testing was conducted by ABUH in only 32/1393 patients (2.3%) and was positive in 23 (1.65%). Of all patients with lung adenocarcinoma, only 5 patients (0.6%) with stage IV disease received immunotherapy. All were treated with nivolumab. Thematic analysis of qualitative data (35 patients) revealed that high treatment costs and limited drug availability are the primary barriers to accessing immunotherapy. Conclusions: This study represents the first evaluation of access to immunotherapy for patients with lung cancer in Syria. Even at ABUH, the country's main cancer center, access to immunotherapy and molecular testing remains markedly limited. International collaboration is necessary to expand diagnostic infrastructure, standardize data reporting, and enhance financial protection mechanisms. These are critical steps toward achieving better cancer care in Syria.

Background. Solid organ transplant recipients (SOTRs) are at heightened risk for cardiovascular implantable electronic device-related complications, particularly infection, because of chronic immunosuppression and comorbidities. Although leadless pacemakers (LPs) reduce infection risk by eliminating transvenous leads and generator pockets, adoption in SOTRs has remained limited, largely because earlier systems were restricted to single-chamber ventricular pacing and lacked physiologic atrioventricular synchrony. The helix-fixation Aveir LP platform enables atrial, ventricular, and dual-chamber leadless pacing, but clinical experience in transplant recipients remains limited. Methods. We conducted a retrospective, multisite analysis across an integrated health system, identifying all adult SOTRs who underwent Aveir LP implantation between January 2022 and October 2025. Clinical characteristics, transplant details, pacing indications, device configuration, procedural outcomes, and follow-up data were collected. Primary outcomes included procedural success, complications, and device-related infection. Secondary outcomes included pacing performance, need for system revision or upgrade, and early device durability. Results. Thirteen SOTRs (mean age 64 ± 15 y; 15% female) underwent Aveir LP implantation, including atrial (n = 4), ventricular (n = 5), and dual-chamber (n = 4) systems. Transplanted organs included heart (46%), lung (31%), kidney (38%), and liver (15%), with 31% having multiple organ transplants. Over half of patients were critically ill at implantation, and 46% were dialysis-dependent, representing a high-risk cohort. All procedures were acutely successful with no intraprocedural complications. During a median follow-up of 258 d (interquartile range, 216–641 d), no device-related infections occurred. Electrical performance remained stable, with 1 atrial device replacement at 2.5 y for elevated capture thresholds. Conclusions. In a high-risk population of SOTRs, atrial and atrioventricular synchronous leadless pacing using the Aveir platform was feasible, achieved high acute procedural success, and demonstrated favorable early safety signals, including absence of device-related infection over available follow-up. Larger studies with longer-term follow-up are needed to define durability and long-term outcomes.

Abstract Transcriptional condensates (TCs) are dynamic, membrane-less assemblies of proteins and nucleic acids that form at specific genomic loci to control gene expression. The primary drivers of TC formation and function are long stretches of polypeptide chains that lack well-defined tertiary structure, known as the intrinsically disordered regions (IDRs) of Transcription Factors (TFs). However, the role of well-structured domains such as the DNA-binding domain (DBD) in condensate formation and downstream regulation remains poorly understood. Here, we investigated whether the DBD of the Progesterone Receptor (PR), a model TF regulated by hormone binding, contributes to the formation of PR TCs. By combining Single Particle Tracking (SPT) with deep-learning-based single-trajectory analysis, we demonstrated that both the IDR and the DBD are required for the formation of PR condensates. Furthermore, transcriptomic analysis showed that mutations of either of the two domains result in the expression of a distinct set of genes, with functional assays corroborating these findings and linking domain-specific transcription to differential effects on cell proliferation and migration. Together, our results show that domains beyond IDRs also play a role in TC formation and function and uncover domain-specific regulation of transcriptional and oncogenic programs.

Objective Immunohistochemically (IHC) measured transactive response DNA‐binding protein 43 (TDP‐43) inclusions are observed in Alzheimer's disease (AD) and are associated with medial temporal lobe atrophy. Accumulation of cryptic exons occurs in AD in response to TDP‐43 pathology. We aimed to assess relationships between IHC and biochemically measured insoluble TDP‐43 and cryptic exons and assess associations with hippocampal and amygdala volume loss and atrophy rates on magnetic resonance imaging (MRI). Methods Eighty‐one neuropathologically diagnosed AD cases were analyzed. For biochemistry, insoluble TDP‐43 was quantified using a Meso‐scale discovery (MSD) immunoassay. IHC‐TDP burden was quantified with digital histopathology. Cryptic RNAs were assessed via quantitative real‐time polymerase chain reaction (qRT‐PCR). Thirty‐eight cases had serial brain MRI. Hippocampal and amygdala volumes were calculated using FreeSurfer. Regression models were used to investigate associations among IHC‐TDP‐43 status/burden, MSD‐TDP status/levels, cryptic RNAs, and hippocampal and amygdala volumes and atrophy rates. Results IHC‐TDP(+) cases exhibited elevated levels of MSD‐TDP and cryptic RNAs ( KCNQ2 , STMN2 , and UNC13A ) and increased MSD‐TDP levels were associated with increased cryptic RNA levels, in the hippocampus and amygdala. IHC‐TDP(+) cases had smaller hippocampal and amygdala volumes compared to IHC‐TDP(−) cases. MSD‐TDP(+) cases had smaller hippocampal volumes and faster amygdala rates of atrophy compared with MSD‐TDP(−) cases. Higher KCNQ2 and UNC13A levels were associated with smaller amygdala volumes. Interpretation MSD‐TDP level is a reliable surrogate for IHC‐based TDP‐43 status. Both TDP‐43 and cryptic RNA levels are associated with reduced medial temporal volumes, suggesting cryptic exons may be playing a role in brain volume loss in AD. ANN NEUROL 2026;100:193–205