Background and Objective: Enhanced Recovery After Surgery (ERAS) protocols and minimally invasive techniques may accelerate recovery following pancreatoduodenectomy (PD). We evaluated the feasibility and safety of combining minimally invasive PD with a tailored ERAS protocol on post-PD outcomes and quality of life (QoL). Methods: Patients undergoing PD from 2023 to 2025 were identified. The 2019 ERAS Society recommendations for PD were implemented. Multivariable regression was used for adjusted analyses, with performance assessed by area under the curve (AUC) and Brier scores. QoL was measured using the European Organisation for Research and Treatment of Cancer QLQ-C30 and PAN-26 modules. Results: Of 113 patients, 67.3% underwent robotic and 32.7% open PD with comparable baseline characteristics. Postoperative day (POD) 3 discharge occurred in 34.2% of robotic cases and none of the open cases ( P < 0.001). POD 3 discharge correlated with fewer cumulative 90-day hospital days (3 days vs 5 days, P < 0.001) and overall complications (42.3% vs 68.0%, P = 0.031), without differences in major complications, readmissions, or 90-day mortality. POD 1 drain fluid amylase (DFA) was lower in POD 3 discharges (40 U/L vs 808 U/L, P = 0.014), and DFA <300 U/L identified patients likely to achieve POD 3 discharge without adverse events with good discrimination and calibration (AUC = 0.843; Brier = 0.120). Early discharge was associated with improved overall QoL (+5.6 vs −15.0; P = 0.006) without differences in pain scores (+8.3 vs +12.5; P = 0.240). Conclusions: ERAS protocols with minimally invasive PD facilitated safe POD 3 discharge. POD 1 DFA <300 U/L may help identify patients safe for early discharge without compromising outcomes or QoL.
Clonal Haematopoiesis Tracks Alzheimer’s-like Cortical Atrophy in Community-Dwelling Older Adults
Summary Background Clonal haematopoiesis (CH), the age-related expansion of mutated blood stem cells, is detectable in around 10% of people in their seventies, rises steeply with age, and is associated with several diseases. Its relationship with neurodegeneration remains contentious, with conflicting evidence for both protective and detrimental effects on Alzheimer’s disease (AD). Methods Here, we applied COMET, a mutation-agnostic, methylation-based predictor of clonal haematopoiesis burden that estimates predicted VAF (pVAF), to examine longitudinal associations between clonal burden and brain structure in the Lothian Birth Cohort 1936. In addition, to capture broader clonal burden, we developed CIMS, a novel methylation-based score derived from clonal haematopoiesis of indeterminate potential (CHIP) EWAS summary statistics, which reflects the epigenetic profile of both mutant and wild-type blood immune cells. Blood DNA methylation and structural MRI data were available at three timepoints spanning ages 73–79 years. The analytic dataset comprised 1,091 participants, of whom 808 (pVAF) and 836 (CIMS) contributed clonality data and 744 had brain MRI; 479–481 had complete baseline and longitudinal imaging measures with covariates. Trajectories were modelled with latent growth curve models fitted by full information maximum likelihood. Findings Longitudinal trajectories of clonality and grey matter volume were significantly associated over 6 years (Std. est. = −0.176, p adj = 0.030), revealing a progressive, left-lateralised cortical atrophy pattern affecting medial temporal and parietal regions. This pattern showed significant spatial correspondence with established AD signatures ( r = 0.357, p = 0.003), suggesting that clonality is linked to AD-related patterns of neurodegeneration. Subcortical analyses revealed nominal relative preservation of the caudate and did not detect a statistically significant association with hippocampal volume, suggesting potential divergence from the canonical AD subcortical profile. The CIMS confirmed global atrophy but revealed divergent tissue-type and regional patterns, suggesting the two measures may capture distinct aspects of CH biology. Interpretation Together, these findings suggest that CH burden may mark biological processes associated with structural brain atrophy in cognitively healthy older adults, with clonality showing a regional pattern that resembles the one reported in AD. CH burden may therefore be a candidate marker of adverse brain ageing; whether it tracks AD pathology in particular, rather than age-related neurodegeneration more broadly, remains to be tested.
Experimentally determined proton discrete spot scanning time structures for an improved synchrotron‐based PBS spot delivery time model
Abstract Background An accurate discrete spot scanning (DSS) beam delivery time (BDT) model is essential, particularly as 4D dynamic dose accumulation calculations rely on machine‐specific time models for reliable interplay evaluation. Purpose To derive a BDT model for a synchrotron‐based Hitachi Probeat PBS proton system from oscilloscope measurements of key BDT structures, including multi‐energy extraction (MEE) characteristics. Methods Key BDT structures were characterized using oscilloscope measurements, supplemented by delivery log files where appropriate. Spot‐to‐spot scanning trajectories were visualized using a CROSSmini 2D strip ionization chamber (Liverage Biomedical Inc, Taiwan) via the dose‐driven continuous scanning (DDCS) mode. The MEE design and MEE charge recapture efficiencies were also characterized. In addition, the impact of the number of delivered spots on both the extractable fraction of charge and MEE recapture efficiency was investigated. Results An improved synchrotron‐based BDT model was derived that incorporates dead times between radiofrequency knockout (RFK) and high‐speed steering magnet (HSST) signals. Spot‐to‐spot movement follows a “hockey‐stick”‐like behavior where the effective spot‐to‐spot move time is governed by the slower axis. An energy‐dependent variation in the number of MEE layers deliverable per spill was also observed, with fewer MEE layers per spill (1–3) was observed in low and high energy ranges compared to the mid‐energy range (4–5), deviating from the nominal vendor value of five MEE layers per spill per block. A reduction in the extractable fraction of charge was observed with an increasing number of spots per spill, while increasing the number of delivered spots in the preceding layer significantly reduced the MEE recapture efficiency. Conclusion MEE characteristics should be incorporated into synchrotron‐based time models for accurate beam delivery modeling. The methodology presented here also provides a framework for centers seeking to derive machine‐specific delivery time models for their proton systems.
De‐Escalating Surgery for 1–2 cm Appendiceal Neuroendocrine Tumors: A North American Multi‐Center Analysis
ABSTRACT Background and Objectives NCCN guidelines recommend right hemicolectomy (RHC) for appendiceal neuroendocrine tumors (aNETs) > 2 cm and observation for < 1 cm. However, optimal surgical management of 1–2 cm tumors remains controversial. This study compared long‐term survival and recurrence between patients undergoing RHC versus appendectomy (APY) for 1–2 cm aNETs. Methods Patients with pathologically confirmed 1–2 cm aNETs treated at three Mayo Clinic sites (1972–2024) were included. Primary outcomes were recurrence and all‐cause mortality after resection. Associations with lymph node (LN) metastasis were assessed in patients with lymphadenectomy. Results Sixty‐five patients were identified: 29 (45%) underwent APY, 35 (54%) RHC, and one ileocecectomy. Median age at diagnosis was 39 years; 71% were female and 94% white. LN positivity was 15.2% for tumors with nodes examined. Tumor size > 1.5 cm, stage T3/T4, and lymphovascular invasion were not associated with nodal metastasis. No survival differences were observed between APY and RHC. LN positivity did not impact survival. No recurrences occurred during a median follow‐up of 6.25 years (IQR 2.44–12.63). Conclusions Among patients with 1–2 cm aNETs, RHC conferred no survival benefit over APY. Absence of recurrence and the limited prognostic value of nodal disease suggest APY alone may suffice for this population.
Abstract 7810: Engineering macrophages as a novel therapeutic approach for high-risk neuroblastoma
Abstract Neuroblastoma (NB) accounts for 10% of pediatric cancer-related deaths. High-risk NB is frequently metastatic at diagnosis and has a poor 5-year survival rate (<50%) despite aggressive treatment. GD2, a disialoganglioside glycolipid that is expressed in nearly all NBs, has been validated as a promising immunotherapy target. Although GD2-CAR-T cells have been clinically evaluated, their efficacy has been limited by poor tumor infiltration and the immunosuppressive tumor microenvironment (TME), highlighting the need for alternative immune-based strategies. With inherent capacity of macrophages to infiltrate tumors, phagocytose cancer cells, and modulate TME, they represent a promising alternative strategy for immunotherapy in NB. In this study, we developed and evaluated GD2-CAR-macrophages (GD2-CAR-Ms) as a novel therapeutic approach for NB. GD2-specific CAR constructs were designed, validated, and introduced into multiple human and murine monocyte/macrophage cell lines via lentiviral transduction. Fluorescent microscopy and flow cytometry confirmed a significant enhancement in the phagocytosis of GD2-high NB cells by GD2-CAR-Ms containing Hu3F8 single-chain variable fragment (scFv). A strong positive correlation was observed between GD2 expression levels on the target cells and phagocytosis efficiency of GD2-CAR-Ms, indicating that the phagocytic activity of GD2-CAR-Ms is antigen-specific. Anti-tumor efficacy was further evaluated in vivo using an immunocompetent Mycn-expressing NB non-genetically engineered mouse model (MYCN-NGEMM). Mice treated with GD2-CAR-Ms exhibited significantly reduced tumor burden and prolonged survival compared to control groups. Notably, treatment of mice bearing GD2-high tumors resulted in markedly improved survival, including one complete remission among ten treated animals, underscoring the therapeutic potential of GD2-targeted macrophage therapy. Histological analysis showed increased deposition of connective tissues and decreased tumor cells density, suggesting TME remodeling. Furthermore, immunohistochemistry reveals increased immune cell infiltration, particularly of macrophages, neutrophils and T cells, indicating a favorable shift in the immune TME from “cold” to “hot” following GD2-CAR-M treatment. Additionally, inhibition of tumor growth was also observed in our zebrafish NB model after GD2-CAR-Ms treatment, further supporting their therapeutic potential. Together, our findings demonstrate that GD2-CAR-Ms exhibit potent antitumor activity and reshape the tumor immune microenvironment, supporting their translational potential as a therapeutic strategy for high-risk NB. Citation Format: Ke-En Tan, Kok Siong Yeo, Cheng Zhang, Caleb Baker, Shyang Hong Tan, Alexis M. Sosic, Yat-Yuen Lim, Choong-Yong Ung, Cristina Correia, Stephanie F. Polites, Yi Lin, William A. Weiss, Hu Li, Shizhen Zhu. Engineering macrophages as a novel therapeutic approach for high-risk neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 7810.
Longitudinal Incidence and Outcomes of Remnant Cholecystitis after Subtotal Cholecystectomy: An Analysis of 2,682 Patients
BACKGROUND: Subtotal cholecystectomy is increasingly recommended as a bailout strategy for the difficult gallbladder, yet its long-term durability and the risk profile of subsequent completion cholecystectomy remain incompletely defined. STUDY DESIGN: We performed a population-based retrospective cohort study of adults undergoing laparoscopic or open subtotal cholecystectomy for acute cholecystitis from 2012 to 2021 using Healthcare Cost and Utilization Project state databases from New York and Florida. The primary endpoint was remnant cholecystitis, defined as a postoperative emergency, inpatient, or outpatient diagnosis of cholecystitis or need for subsequent cholecystectomy. Kaplan–Meier analysis estimated cumulative incidence. Secondary outcomes included completion cholecystectomy and bile duct injury requiring surgical repair. RESULTS: Among 2,682 patients (98.7% laparoscopic), the cumulative incidence of remnant cholecystitis was 13.3% during a median follow-up of 2 years (interquartile range [IQR] 0.7 to 4.1). The median time to developing remnant cholecystitis was 28 days (IQR 13 to 91), with 79.7% occurring within 6 months. Only 70 patients (2.6%) underwent completion cholecystectomy at a median of 103 days (IQR 43 to 202). Completion cholecystectomy was performed via open surgery in 47.1% of patients and was associated with a 7.1% bile duct injury rate and median length of stay of 3 days (IQR 1 to 7), compared with a 0.9% bile duct injury rate for subtotal cholecystectomy overall. CONCLUSIONS: Although remnant cholecystitis occurred in 13.3% of patients after subtotal cholecystectomy, few required completion cholecystectomy. When necessary, completion cholecystectomy was frequently open and associated with a substantially higher bile duct injury rate, supporting referral to experienced hepatobiliary centers for reoperation.
SRS391 - Global outcomes after robotic left pancreatectomy: learning curve, morbidity, and oncological quality
Abstract Background Robotic left pancreatectomy (RLP) is increasingly adopted worldwide. Current guidelines suggest a learning curve of 21 cases, yet its impact on major morbidity and oncological quality remains uncertain. Methods A retrospective multicentre international study was undertaken across 10 centres in the UK, Spain, Germany, the USA, and Australia (2014–2025). Consecutive patients undergoing RLP were categorised into competency (first 21 cases per centre) or proficiency phase (>21). The primary outcome was major morbidity (Clavien–Dindo grade ≥ IIIa), and secondary outcome was the R1-margin rate. Mixed-effects logistic regression and risk-adjusted cumulative sum (RA-CUSUM) analyses were performed. Results 521 patients underwent RLP, including 200 (38.4%) in the competency phase and 321 (61.6%) in the proficiency phase. Median age was 63 years (IQR 54–73), and 56.4% were female. Rates of major morbidity were similar between phases (14.5% versus 14.0%, P = 0.981), as were R1 margin rates (21.6% versus 19.7%, P = 0.092). Independent predictors of major morbidity included male sex (OR 1.76, P = 0.037), preoperative pancreatitis (OR 2.23, P = 0.031), and multivisceral resection (OR 2.29, P = 0.034). Among patients with adenocarcinoma (n = 110), prolonged operative time (OR 1.39 per hour, P = 0.004) and nodal positivity (OR 2.62, P = 0.047) predicted R1 resection, while learning phase was not associated with margin status. RA-CUSUM demonstrated no excess morbidity over time in any centre. Conclusions In this first multicentre international analysis, the learning phase of RLP did not increase the risk of major morbidity or compromise oncological quality. These findings support the safe global adoption of RLP with appropriate training and case selection.
The Association of Extended Venous Thromboembolism Prophylaxis and Venous Thromboembolism After Cancer Surgery
Background: ASCO recommends extended venous thromboembolism (VTE) prophylaxis with low-molecular-weight heparin (LMWH) or direct oral anticoagulants (DOACs) following cancer surgery. However, these recommendations were based on trials using routine venography, which detects asymptomatic VTEs, and real-life efficacy is not well studied. We aimed to assess the association of extended VTE prophylaxis with the incidence of clinically significant VTE after elective cancer surgery. Patients and Methods: In this retrospective, population-based cohort study, we identified patients who underwent surgical resection for lung, breast, esophageal, gastric, pancreas, and colon cancer from 2010 to 2017 using the SEER–Medicare linked dataset. Patients were divided into 1 of 2 main groups for comparative analyses: those who received extended VTE prophylaxis after cancer surgery and those who did not. Patients who received extended VTE prophylaxis after cancer surgery were identified as those prescribed prophylactic doses of LMWH or a DOAC within 7 days of discharge, as captured in Medicare Part D files. Results: A total of 113,739 Medicare beneficiaries were identified, of whom 1,570 (1.4%) received extended VTE prophylaxis. There was a year-over-year increase in the use of extended VTE prophylaxis during the study period, rising from 0.6% in 2010 to 3.3% in 2017. The overall incidence of VTE was 1.6% at 1 month, 4.3% at 6 months, 5.7% at 12 months, with significant differences observed across cancer types ( P <.001). However, patients who received extended VTE prophylaxis had a higher 1-year cumulative incidence of postoperative VTE compared with those who did not (11.4% vs 5.3%; P <.001), an association that was consistent across cancer sites. In adjusted analyses, extended VTE prophylaxis was independently associated with an increased risk of VTE (hazard ratio, 1.6; 95% CI, 1.3–2.0; P <.001). Extended prophylaxis was also associated with a higher 1-year incidence of bleeding events compared with patients who did not receive prophylaxis (12.0% vs 8.5%; P <.001). Conclusions: The utilization of extended VTE prophylaxis after cancer surgery remains low, although it has increased every year. Paradoxically, patients who received extended VTE prophylaxis had higher incidences of clinically significant VTE and bleeding compared with those who did not, likely reflecting patient selection and surveillance bias after surgery. In light of these findings, national guidelines recommending postoperative extended VTE prophylaxis, and its use as a surrogate for quality of care, should continue to be re-examined.
Redefining Upfront Resectable Pancreatic Ductal Adenocarcinoma: Should Vein Abutment Matter?
Background: Upfront resectable pancreatic ductal adenocarcinoma (PDAC) is defined by the NCCN as disease with ≤180° portomesenteric vein (PMV) abutment. However, the clinical significance of PMV abutment in this cohort remains unexplored, and we sought to investigate its impact. Methods: This multi-institutional study included patients who underwent pancreatoduodenectomy (PD) for upfront resectable PDAC from 2002 to 2023. Patients with PDAC with ≤180° PMV abutment were compared with those without. Overall survival (OS) was compared and stratified based on whether patients underwent upfront surgery or neoadjuvant therapy (NAT). Results: Among 1,446 patients included, 521 (36.0%) had PMV abutment. Median OS for patients with PMV abutment was 28.8 months compared with 31.2 months for those without ( P =.17). In a stratified analysis of patients who underwent upfront surgery, patients with PMV abutment had worse OS (19.2 vs 27.6 months; P <.05) and lower R0 resection rates (63.1% vs 87.2%; P <.05) compared with those without. However, in patients who underwent NAT, this difference in R0 resection rate was not observed (91.4% vs 94.0%, respectively; P =.27). Furthermore, there was no significant difference in median OS with NAT (42.5 vs 51.6 months, respectively; P =.48). Conclusions: In this largest cohort to date of patients with upfront resectable PDAC, PMV abutment was associated with worse OS compared with no PMV abutment when an upfront resection strategy was used. The use of NAT in patients with PMV abutment mitigated this survival difference with increased R0 resection rates. These findings suggest that patients with upfront resectable PDAC with PMV abutment benefit from a NAT approach for optimal survival outcomes, and that the current criteria guidelines need to be redefined.
Objective: To establish international benchmark values for relevant outcome parameters in robotic Whipple. Summary Background Data: For safe adoption of surgical innovation, robust quality control is essential. Benchmarking is a validated tool for assessing surgical performance. Recent international consensus identified establishing benchmark values for robotic Whipple as top priority. Methods: We analyzed consecutive patients undergoing robotic Whipple between 2020-2023 with a minimum one-year follow-up. Reference centers were required to perform ≥15 cases/year, be scientifically active in the field, and maintain a prospective database. Benchmark criteria included benign or resectable malignant disease without neoadjuvant therapy, arterial resection, major co-morbidities, or significant previous abdominal surgery. Benchmarks were established for 13 outcome parameters. Result: The benchmark cohort comprised 418 patients from 12 centers across four continents. Benchmark values were: conversion rate ≤4.3%, transfusion rate ≤2.1%, 6-month mortality ≤2.2%, major complications ≤23.2%, and CCI® ≤20.9. Clinically relevant pancreatic fistula (grade B/C) and hemorrhage (grade B/C) rates were ≤23.6% and ≤12.7%, respectively. For pancreatic ductal adenocarcinoma (n=123), the benchmark for lymph node yield was ≥20. Higher surgical difficulty was associated with increased overall postoperative morbidity (R 2 =0.38, P =0.019), higher center caseload with reduced pancreas-specific complications (R 2 =0.28, P =0.044). Independent POPF predictors included duct diameter ≤4 mm (OR 1.37, 95% CI: 1.03, 1.82), anticoagulation (OR 2.45, 95% CI: 1.47, 3.99), and indication other than PDAC (OR 2.33, 95% CI: 1.68, 3.27). Conclusions: This study establishes the first international benchmarks for robotic Whipple, demonstrating oncologic outcomes and morbidity comparable to open surgery with the benefits of minimally invasive surgery.