Ischemic stroke (IS) remains a major cause of mortality and disability worldwide, although the causes of death after stroke have changed. Long-term mortality data from low- and middle-income countries are limited. We investigated the fatality rates and causes of death in patients with IS in Thailand within and beyond 30 days post-discharge.

We conducted a retrospective descriptive study using national hospital database records from 2004-2022. Patients with IS (ICD-10 code I63) were included without age or sex restrictions, with death status followed through 2022. The causes of death included stroke, complications, comorbidities, accidents, suicide, and unknown causes. Mortality was analyzed during hospitalization and ≤30 and >30 days post-discharge.

Among 888,003 patients with IS, the overall mortality was 47.6%: in-hospital 6.4%; ≤30 days post-discharge 8.2%; and >30 days post-discharge 33.1%. Mortality rates increased notably with age, exceeding 80% in those aged > 85 years. Stroke caused most in-hospital (58.6%) and short-term deaths (29.1%), whereas long-term mortality was primarily due to complications (30.7%) and comorbidities (30.5%). The leading comorbid causes were heart disease, dementia, and neoplasm; while pneumonia and sepsis were the primary fatal complications. Age-related debility, COVID-19 infection, and cardiovascular collapse were other major causes.

This nationwide study revealed dynamic changes in post-IS causes, with stroke predominating early deaths, while complications and comorbidities determined long-term outcomes. These findings highlight the need for integrated acute and post-discharge stroke care strategies targeting infection prevention, comorbidity management, and elder care.

Histotripsy is a novel ultrasound-guided ablation technique that has been approved by the US Food and Drug Administration as a medical device for the noninvasive destruction of liver tumors. The noninvasive, nonthermal, nonionizing mechanical mechanism by which it destroys tumor tissues makes it an appealing local therapy option in the treatment of patients with early-stage hepatocellular carcinoma (HCC). In this article, the authors review the current evidence base for histotripsy in HCC and explore its potential role in routine care based on technical, safety, and clinical considerations. They then describe the evidence gaps that remain with respect to histotripsy's treatment efficacy, comparative effectiveness, and safety relative to established local therapy options including thermal ablation, transarterial chemoembolization and radioembolization, and stereotactic body radiotherapy. Although the current body of evidence supports the technical feasibility, short-term safety, and early local tumor control of histotripsy in the treatment of patients with HCC, standardized response assessments, rigorous prospective evaluations of durable oncologic outcomes, and direct comparisons with existing therapies in well-defined patient populations are still needed before histotripsy can be fully integrated into standard HCC care.

Accurate staging and metabolic characterization of cervical cancer remains challenging despite advances in imaging. This study investigates the diagnostic utility of dual-phase [18F]FDG PET/CT in cervical carcinoma, with an emphasis on metabolic biomarkers and prognostic indicators.

A prospective study of 50 patients with histopathologically proven cervical cancer was conducted over 24 months. Patients underwent dual-phase [18F]FDG PET/CT imaging with initial whole-body acquisition at 40-60 minutes post-injection and delayed imaging at 120 minutes post-injection following intravenous furosemide administration. Standardized uptake values (SUV), lesion detection efficacy, lymph node characterization, and extra-pelvic metastatic patterns were analyzed using paired t-tests and chi-square analysis.

Mean SUV in initial images (9.074 ± 6.113) increased significantly to 12.964 ± 7.494 in delayed images (p < 0.001), representing a 42.8% increase in metabolic activity. Delayed imaging detected primary lesions in 48 cases (96%) versus 44 cases (88%) on initial imaging, demonstrating superior sensitivity (91.7%) and specificity (100%). Critically, seven patients (14%) demonstrated lymph node visualization only on delayed imaging, and 14% exhibited SUV kinetics consistent with high-grade malignancy. Parametrial involvement occurred in 66% of cases, with 81.8% demonstrating bilateral involvement. Extra-pelvic metastases including supraclavicular lymphadenopathy (10%), hepatic involvement (10%), and skeletal lesions (8%) were detected with superior specificity compared to conventional modalities. This study identified a novel metabolic phenotype: "delayed-accumulator lesions" (DAL), characterized by significant SUV escalation between initial and delayed imaging, associated with aggressive biological behavior and poor prognostic outcomes. Additionally, a mathematical model incorporating dual-phase SUV kinetics, parametrial invasion status, and bilateral lymph node involvement demonstrated superior prognostic stratification (AUC > 0.92) compared to conventional FIGO staging.

Dual-phase [18F]FDG PET/CT provides significantly enhanced metabolic characterization of cervical cancer, identifies novel biological markers predictive of treatment response, and enables metabolically guided precision treatment planning. The identification of delayed-accumulator lesions and dual-phase kinetic modeling represent paradigm shifts in cervical cancer stratification, with the potential to revolutionize treatment intensity selection and surveillance protocols.

Objective.A low-energy x-rays camera-based system has been introduced to image secondary electron bremsstrahlung x-rays, enabling external visualization of proton beam profiles during irradiation. To date, this approach has been demonstrated only in phantom studies and simulations, and has not yet been successfully applied in patients. To overcome this limitation, it is essential to establish the feasibility of SEB x-ray imaging in a clinical condition.Approach.We first optimized the energy window and threshold settings for range estimation by acquiring SEB x-ray images of a water phantom comparable in size to the human lower abdomen, using a cerium doped yttrium aluminum perovskite (YAP(Ce)) x-ray camera with a pinhole collimator. We then performed the firstin vivoSEB x-ray measurement by imaging proton beams during treatment of a patient of prostate cancer with two opposed fields, each delivering an RBE-weighted dose of 1.5 Gy.Main results.In the patient study, SEB x-ray distributions were observed in the measured images using the same energy window as that established in the water phantom study. From these images, the beam ranges were estimated to be within approximately 1 cm of the values calculated by the treatment planning system using the optimized profile threshold. Dynamic imaging at 1 s time intervals was achieved, enabling temporal evaluation of count rate curves.Significance.We present, for the first time, measurements of SEB x-ray images acquired in a patient during proton beam irradiation. These preliminary results indicate thatin vivoSEB x-ray imaging could be a promising approach for clinical real-time beam monitoring in proton therapy.Ethics approval.Ethics approval was obtained from the institutional review board of Kobe Proton Center: approval number: 06-10.

Elicit information from stakeholders to plan implementation of the Extension for Community Healthcare Outcomes (Project ECHO) model in Lebanon to improve cancer diagnosis and treatment in underserved and rural areas.

A qualitative descriptive study guided by the Greenhalgh diffusion of innovation framework. Semi-structured interviews explored five diffusion components: relative advantage, compatibility, low complexity, potential risks, and needed support.

Lebanon.

Twenty-six purposively sampled leaders representing governmental, non-governmental, academic, clinical, and public health sectors.

The interviews were coded and thematically analyzed to characterize the perceived facilitators, barriers, and implementation considerations related to Project ECHO adoption.

Following a standardized introduction to the ECHO model, participants generally perceived the model as acceptable and potentially beneficial for building primary care providers' (PCPs) knowledge and increasing patient access to quality care in underserved communities. Collectively, these leaders recommended careful pilot planning of infrastructure readiness, identification of clinical champions, and the use of performance indicators to monitor and evaluate implementation progress. They identified long-term sustainability, consistent financial support, workforce engagement, and medico-legal considerations as potential barriers to successful ECHO adoption. They viewed the current unstable environment in Lebanon as both a challenge and an opportunity for system transformation through strengthened collaboration, capacity building, and multi-level commitment to improve community health outcomes.

Findings suggest the need for a structured, evidence-based approach to guide the implementation of Project ECHO in Lebanon. Potential early benefits may include strengthening PCP knowledge, confidence, and capacity in underserved communities. The findings provide an evidence-informed foundation for organizations and governmental agencies to support national-level adoption of the ECHO model. Future efforts should prioritize developing a practical action plan that includes provider training, infrastructure development, and sustainable funding to improve cancer care in rural areas.

The incidence of primary central nervous system low-grade B-cell lymphoma (PCNSL-LG) is rare. We aimed to provide the first large-scale analysis of treatment modalities, survival trends, and prognostic factors for PCNSL-LG. Patient data diagnosed between 2000 and 2021 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. A total of 267 adult PCNSL-LG patients were included. The year of diagnosis was divided into the time period-1 (2000-2009) and the time period-2 (2010-2021). Radiotherapy alone usage remained stable over time (27.34% vs. 30.22%, p = 0.605). Chemotherapy alone showed a modest, non-significant increase (25.00% vs. 31.66%, p = 0.229), while combined chemoradiotherapy declined significantly from 29.69% to 15.11% (p = 0.004). The 1-, 5-, and 10-year overall survival (OS) rates for all PCNSL-LG patients were 84.3%, 73.4%, and 61.8%, respectively. Overall survival improved significantly, with median OS extending from 11.25 years in period-1 to not reached in period-2 (HR 0.46, 95% CI: 0.28-0.74; p = 0.001). Surgery was associated with improved outcomes compared with non-surgical management (HR 0.47, 95% CI: 0.31-0.72, p < 0.001). In patients with MALT lymphoma histology, no significant prognostic difference was observed across treatment modalities (p = 0.838). This study underscores a marked improvement in survival among PCNSL-LG patients over the past two decades and offers valuable insights for optimizing clinical management and improving patient outcomes.

Objective: To investigate the associations of macroscopic tumor regression patterns and distal resection margin (DRM) distance with local recurrence in patients with rectal cancer after neoadjuvant chemoradiotherapy (nCRT), and to provide evidence for surgical decision-making and intraoperative assessment of the distal resection extent. Methods: This single-center retrospective cohort study used data from the prospective MONT-R registry. A total of 410 patients with mid-to-low locally advanced rectal cancer who underwent nCRT followed by radical surgery at Peking Union Medical College Hospital between December 2017 and September 2022 were included. Of these, 276 patients were male (67.3%), and the median age was 60 years (interquartile range [IQR], 51-67 years). According to the gross appearance of postoperative specimens, tumors were classified as scar-like, ulcerative, or protruding mass-type patterns. Clinicopathological characteristics, DRM distance, and the incidence of inadequate DRM, defined as DRM ≤0.5 cm, were compared among groups. Disease-free survival (DFS) and local recurrence-free survival (LRFS) were analyzed using the Kaplan-Meier method. Results: Of the 410 patients, 42 (10.2%) had scar-like tumors, 360 (87.8%) had ulcerative tumors, and 8 (2.0%) had protruding mass-type tumors. The lymph node metastasis rate differed significantly among groups (χ²=8.63, P=0.013), with no lymph node metastasis observed in the scar-like group, compared with 17.2% (62/360) in the ulcerative group and 1/8 in the protruding mass-type group. Pathological tumor diameter also differed significantly among groups (H=11.82, P=0.003) , with the mass-type showing the largest diameter [median (Q1, Q3): 2.9 (2.3, 4.0) cm], whereas no obvious difference was observed between the ulcerative type [2.0 (1.3, 2.5) cm] and the scar-like type [1.5 (1.2, 2.0) cm]. The distributions of ypT stage, perineural invasion, and lymphovascular invasion did not differ significantly among groups (all P>0.05). Only 4 patients had a positive circumferential resection margin; all of whom were in the ulcerative group. The proportions of CAP 0-1 tumor regression and pathological complete response were higher in the scar-type group than in the other groups, but the differences were not statistically significant (P=0.098 and P=0.081, respectively). The median DRM distances in the scar-type, ulcerative-type, and protruding mass-type groups were 1.15 (0.20, 2.00) cm, 1.70 (1.00, 2.75) cm, and 2.55 (1.38, 3.62) cm, respectively, with a significant difference among groups (H=9.67, P=0.008). The incidence of inadequate DRM was significantly higher in the scar-type group than in the ulcerative-type and protruding mass-type groups [38.1% (16/42) vs. 15.3% (55/360) vs. 1/8; χ²=13.67, P=0.001]. During a median follow-up of 51 months (IQR, 36-64 months), no significant differences were observed in DFS (P=0.947) or LRFS (P=0.175) among the three groups. Similarly, DFS (P=0.731) and LRFS (P=0.131) did not differ significantly between patients with inadequate and adequate distal resection margins. Conclusions: After nCRT for rectal cancer, patients with a scar-like macroscopic tumor regression pattern had a lower risk of lymph node metastasis and a shorter DRM. However, in the setting of standardized total mesorectal excision, a shorter DRM was not associated with adverse survival outcomes.

Objective: To analyze the characteristics of recurrence and metastasis as well as survival outcomes in patients with No.253 lymph node metastasis from sigmoid colon or rectal cancer, and patients with M1 colorectal cancer who underwent radical resection of metastatic lesions in the same period. Methods: A retrospective cohort study was conducted. Inclusion criteria: (1) Preoperative clinical staging indicated non-metastatic colorectal cancer; (2) Patients underwent standard radical surgery with D3 lymphadenectomy; (3) Postoperative pathology confirmed sigmoid colon adenocarcinoma or rectal adenocarcinoma, with definite status of No.253 lymph node metastasis; (4) No concurrent or prior other malignant tumors; (5) Complete clinical and follow-up data. Exclusion criteria: Patients who received preoperative neoadjuvant chemoradiotherapy, or underwent emergency surgery due to complications such as intestinal obstruction or perforation. Clinical and pathological data of 41 patients with sigmoid colon and rectal cancer who received radical resection with pathologically verified No.253 lymph node metastasis postoperatively between February 2016 and February 2018 were retrieved from the colorectal cancer database of the Department of General Surgery, Nanfang Hospital, Southern Medical University (No.253-positive group). Additionally, 71 patients with stage M1 colorectal cancer who had distant metastasis underwent radical resection of both primary and metastatic lesions and achieved postoperative no evidence of disease were enrolled as the stage M1 group. A 1∶1 propensity score matching (PSM) was performed between the No.253-positive group and the stage M1 group based on gender, age, tumor location, tumor diameter, pT stage, preoperative carcinoembryonic antigen level and postoperative adjuvant therapy. After PSM, 25 patients were included in each group. The 5-year disease-free survival (DFS) rate, 5-year overall survival (OS) rate, and characteristics of recurrence and metastasis were compared between the two groups. Results: After propensity score matching (PSM), there were no statistically significant differences in baseline characteristics between the No.253-positive group and the stage M1 group (all P>0.05, SMD<0.2). The overall 5-year DFS rate was 24.0% in the No.253-positive group versus 8.0% in the stage M1 group, with no significant difference (P=0.094). The overall 5-year OS rate was 32.0% and 16.0% for the two groups, respectively, and the difference was also not statistically significant (P=0.108). Stratified analysis by tumor location revealed no significant between-group differences in 5-year DFS and OS among patients with lower rectal cancer and upper rectal cancer (all P>0.05). For patients with sigmoid colon cancer, the No.253-positive group had a higher 5-year DFS rate than the stage M1 group (P=0.017), while no significant difference was observed in 5-year OS (P=0.581). Following PSM, recurrence or metastasis occurred in 76.0% (19/25) of patients in the No.253-positive group and 96.0% (24/25) in the stage M1 group. There were no significant differences in the patterns and anatomical distribution of recurrence and metastasis between the two groups (all P>0.05). However, the rate of multiple-site recurrence or metastasis was markedly higher in the stage M1 group (50.0%) than in the No.253-positive group (10.5%), and the difference reached statistical significance (P=0.009). The median time to recurrence or metastasis was 19 (2-58) months in the No.253-positive group and 17 (2-64) months in the stage M1 group, without a significant difference (U=215.5, P=0.767). Conclusions: Patients with No.253-positive sigmoid colon or rectal cancer showed overall survival outcomes similar to those of patients with synchronous M1 colorectal cancer who underwent curative-intent resection of metastatic lesions, but their recurrence and metastasis were relatively more limited in extent. No.253 lymph node metastasis may represent a high-risk state in the transition from regional lymphatic progression to systemic dissemination in sigmoid colon and rectal cancer, and its clinical significance may differ according to tumor location.

Objective: To analyze the application and clinical efficacy of the "three-step posterior approach" for preserving the vagus nerve in laparoscopic radical distal gastrectomy for gastric cancer. Methods: This was a retrospective cohort study. Clinical data of patients who underwent laparoscopic radical distal gastrectomy at the Department of Gastric Surgery, The First Affiliated Hospital of Nanjing Medical University from March 2020 to June 2023 were collected. Inclusion criteria included: age 18-75 years; pathological diagnosis of gastric adenocarcinoma; clinical stage cT1~2N0~1M0; and no history of gallstones. Patients with preoperative neoadjuvant chemotherapy, combined organ resection, or missing data were excluded. Patients were divided into a conventional laparoscopic radical distal gastrectomy (LDG) group and a laparoscopic vagus nerve-preserving distal gastrectomy (LVNPDG) group based on the surgical procedure. The preservation of the celiac branch of the vagus nerve was performed using the "three-step posterior approach". Step 1: First, lymph node dissection at No.11p was performed along the proximal splenic artery at the upper border of the pancreas. The left Toldt space was entered, Gerota fascia was exposed, and dissection was extended rightward along its surface to the left diaphragmatic crus. Step 2: Lymph nodes No.8 and No.12a were dissected, then retracted leftward to dissect No.9 lymph nodes. The adhesion between the right diaphragmatic crus and the left gastric mesentery was divided and connected to the left Toldt space, thereby completely mobilizing the left gastric mesentery from the posterior abdominal wall. Step 3: From the root of the left gastric artery, the left gastric mesentery was opened dorsally toward the diaphragm and incised distally to expose the left gastric artery. Using dissecting forceps, the left gastric mesentery was dissected toward the posterior trunk of the vagus nerve to identify, expose, and preserve the celiac branch running within it. Subsequently, dissection was extended along the celiac branch toward the cardia, and the posterior gastric branches of the vagus nerve to the posterior gastric wall were divided. Below the emergence of the hepatic branch from the anterior trunk of the vagus nerve, the hepatogastric ligament was incised to expose the right diaphragmatic crus, and a fixing suspension suture was placed while sparing the hepatic branch of the vagus nerve. A maximum ratio of 1∶3 propensity score matching (PSM) (caliper value 0.02) was performed using sex, age, body mass index (BMI), American Society of Anesthesiologists (ASA) score, tumor size, differentiation, depth of invasion, lymph node metastasis, TNM stage, and anastomosis method as covariates. Perioperative indicators (operation time, blood loss, lymph node count, time to first flatus and diet, hospital stay), early postoperative complications, quality of life at 1 year postoperatively (constipation, diarrhea, flatulence, appetite, dumping syndrome), and nutritional status. Results: After PSM, 76 patients were included in the LVNPDG group, and 204 patients in the LDG group. There were no statistically significant differences in baseline characteristics between the two groups (all P> 0.05). The operation time in the LVNPDG group was longer than that in the LDG group [(183.2±35.8) minutes vs. (168.4±34.9) minutes, t=-3.136, P=0.002], but the time to first flatus was shorter in the LVNPDG group [(2.6±0.8) days vs. (2.9±0.7) days, t=2.748, P=0.007]. No statistically significant differences were observed between the two groups regarding intraoperative blood loss, the number of retrieved lymph nodes (total and per station), time to first liquid diet, or postoperative hospital stay (all P> 0.05). The incidence of early postoperative complications was 5.9% (12/204) in the LDG group and 7.9% (6/76) in the LVNPDG group, with no significant difference (χ²=0.113, P=0.736). Regarding quality of life and long-term complications at 1 year postoperatively, the incidence of diarrhea in the LVNPDG group was lower than in the LDG group [3.9% (3/76) vs. 13.2% (27/204), χ²=4.993, P=0.025], and the incidence of increased flatulence was also significantly lower [17.1% (13/76) vs. 33.3% (68/204), χ²=7.092, P=0.008]. Additionally, the incidence of gallstones in the LVNPDG group was 1.3% (1/76), which was significantly lower than the 8.8% (18/204) observed in the LDG group (χ²=4.934, P=0.026). There were no statistically significant differences between the two groups in terms of constipation, appetite loss, dumping syndrome, or changes in postoperative albumin levels (all P >0.05). Conclusions: The "three-step posterior approach" for preserving the vagus nerve in laparoscopic radical distal gastrectomy is technically safe and feasible, without increasing the risk of postoperative complications. Compared with traditional laparoscopic distal gastrectomy, this procedure effectively improves patients' postoperative quality of life.

Objective: To investigate the incidence of immune-related adverse events (irAEs) and corresponding perioperative outcomes among patients with colorectal cancer who received neoadjuvant immunotherapy and underwent curative radical resection. Methods: This was a retrospective, multicenter, real-world cohort study. A total of 452 patients with pathologically confirmed colorectal adenocarcinoma who completed neoadjuvant immunotherapy and curative radical surgery were enrolled from five tertiary hospitals between January 1, 2020 and December 31, 2024. The participating institutions included Beijing Friendship Hospital, Capital Medical University; Union Hospital, Tongji Medical College, Huazhong University of Science and Technology; The Sixth Affiliated Hospital, Sun Yat-sen University; The First Affiliated Hospital of Nanchang University; and The Second Affiliated Hospital, Zhejiang University. The median age of the overall cohort was 58.5 years. In terms of clinical TNM staging, 86 patients (19.0%) were at stage Ⅱ and 366 (81.0%) were at stage Ⅲ. Based on MMR/MSI status, 116 patients (25.7%) were identified as deficient mismatch repair/high microsatellite instability (dMMR/MSI-H), and the remaining 336 (74.3%) as proficient mismatch repair/microsatellite stable (pMMR/MSS). Regarding treatment modalities, 92 patients (20.4%) received single-agent immune checkpoint inhibitor (ICI) therapy, 22 (4.9%) dual ICI combination therapy, 30 (6.6%) immunotherapy combined with chemotherapy, and 308 (68.1%) immunotherapy combined with chemoradiotherapy. All irAEs were graded in accordance with the Common Terminology Criteria for Adverse Events Version 5.0 (CTCAE v5.0), and grade ≥3 irAEs were defined as severe irAEs. The primary outcomes were the overall incidence and organ-specific distribution of irAEs. Secondary outcomes covered irAE risks stratified by treatment regimens and MMR/MSI status, overall pathological complete response (pCR) rate, as well as perioperative clinical outcomes. Temporal trend analysis was conducted after logical validation of the initial onset time of irAEs. Results: The overall incidence of all-grade irAEs reached 24.6% (111/452), including 73 cases (16.2%) of grade 1, 24 (5.3%) of grade 2, 7 (1.5%) of grade 3, 5(1.1%) of grade 4 and 2 (0.4%) of grade 5. Severe irAEs (grade ≥3) occurred in 14 patients, accounting for 3.1% of the total cohort. A total of 157 irAE episodes were documented, among which single-organ involvement was observed in 65 patients (58.6%) and multi-organ involvement in 46 patients (41.4%). The most frequently affected organ systems were skin and mucous membranes (40 episodes, 25.5%), endocrine and thyroid system (36 episodes, 22.9%), hematopoietic system (34 episodes, 21.7%), hepatobiliary system (21 episodes, 13.4%), and gastrointestinal tract (9 episodes, 5.7%). Other involved systems comprised musculoskeletal system (6 episodes, 3.8%), urinary and renal system (6 episodes, 3.8%), cardiovascular system (4 episodes, 2.5%), and general systemic reactions (1 episode, 0.6%). One fatal grade 5 event consisting of fulminant myocarditis complicated with malignant arrhythmia and liver failure was recorded. Stratified by treatment strategy, the incidence of all-grade irAEs was 23.9% (22/92) for single-agent ICI, 27.3% (6/22) for dual ICI combination, 23.3% (7/30) for immunochemotherapy and 24.7% (76/308) for immunochemoradiotherapy; the corresponding incidence of severe irAEs was 3.3%, 4.5%, 3.3%, and 2.9%, respectively. Univariate and multivariate regression analyses confirmed that MMR/MSI status was the only independent risk factor for irAE occurrence (OR=2.626,95%CI:1.566-4.402,P<0.001). Validated complete onset time data were available for 85 patients, who were included in the temporal analysis, with 110 irAE episodes including 14 severe events identified. Approximately 58.8% (50/85) of irAEs emerged within 84 days after the first ICI administration, and 52.9% (45/85) developed one month after treatment cessation, including two grade 5 fatal events: severe myelosuppression/overlap syndrome following immunochemoradiotherapy, and fulminant myocarditis accompanied by malignant arrhythmia and liver failure after immunochemotherapy. The median time to first irAE onset was 61 (35-100) days. Among 14 severe irAEs, 9 events occurred after immunochemoradiotherapy, 3 after single-agent ICI therapy, 1 after dual ICI combination, and 1 after immuneochemotherapy. Apart from the 2 fatal cases, the other 11 severe irAEs were effectively alleviated via drug discontinuation, glucocorticoid intervention and/or supportive treatment, whereas one case of immune-related enteritis progressed into a chronic condition. No surgical delay of 14 days or longer attributed to irAEs was noted in the entire cohort. The median length of hospital stay was 14 (12-18) days in patients with irAEs versus 13 (11-16) days in those without irAEs, with no significant intergroup difference (Z=1.80, P=0.072). The postoperative complication rates were 18.9% (21/111) and 18.5% (63/341) in the irAEs and non-irAEs groups, respectively, showing no statistical discrepancy (χ²=0.01, P>0.999). The overall pCR rate of all enrolled patients was 49.8% (225/452). Conclusions: IrAEs, which are mostly mild-to-moderate and manifest as multi-organ involvement, are not rare during neoadjuvant immunotherapy for colorectal cancer. Skin, endocrine and hematopoietic systems are the predominantly affected sites, and the majority of irAEs are clinically manageable. Although severe irAEs remain uncommon, they are featured with delayed onset and life-threatening potential; in particular, cardiovascular toxicities such as fulminant myocarditis warrant close clinical vigilance. The onset of irAEs is not confined to the conventional neoadjuvant treatment period, hence sustained safety monitoring is required throughout the perioperative phase and even after treatment completion.