Parastomal hernia (PSH) is one of the most frequent long-term complications following abdominoperineal resection (APR) for rectal cancer. The optimal colostomy route to minimize PSH remains controversial. This study aimed to compare PSH risk between extraperitoneal colostomy (EPC) and transperitoneal colostomy (TPC) after laparoscopic APR. A retrospective cohort study was conducted including patients who underwent laparoscopic APR for rectal cancer between 2014 and 2017. Patients were categorized according to colostomy route (EPC vs. TPC). The primary endpoint was PSH, and secondary endpoints included other short- and long-term stoma-related complications and perioperative outcomes. Propensity score matching (1:3) was applied to balance baseline characteristics. Risk factors for PSH were further analyzed using logistic regression. A total of 464 patients were included. After matching, 102 patients in the EPC group and 243 in the TPC group were analyzed. Perioperative outcomes and overall stoma-related complication rates were comparable between groups. However, PSH occurred less frequently in the EPC group than in the TPC group (10/102 [9.8

Background: Conventional laparoscopic-assisted surgery (CLS) for sigmoid and upper rectal cancer requires an abdominal extraction incision, linked to pain, surgical site infection and poor cosmesis. Natural orifice specimen extraction surgery (NOSES) removes tumours via the anus without abdominal wounds, yet high-quality randomised controlled trial evidence on long-term oncological safety remains scarce. This multicentre trial aimed to verify whether NOSES is non-inferior to CLS regarding 3-year disease-free survival (DFS), alongside evaluating short-term recovery and complications. Methods: This open-label, parallel-group, non-inferiority randomised trial enrolled patients with cT1-3N0-2M0 sigmoid/upper rectal adenocarcinoma across 13 Chinese tertiary centres between Aug 30, 2020, and Nov 5, 2023. Participants were 1:1 allocated via centre-stratified web randomisation; outcome assessors at discharge were masked to group assignment. The prespecified non-inferiority margin for 3-year DFS was 10%. Primary analysis used the modified intention-to-treat (mITT) population; per-protocol (PP) data served for sensitivity analysis. Trial registration: ChiCTR2000036314. Findings: 516 patients were randomised (258 per group). The mITT survival cohort included 205 CLS and 208 NOSES participants, with median follow-up of 36.9 months. 3-year DFS was 89.7% (95% CI 85.1-94.6) for CLS and 94.7% (91.1-98.4) for NOSES (absolute difference 5.0%, 95% CI -3.4 to 13.3, meeting non-inferiority; log-rank p=0.088). 3-year overall survival and local recurrence rates were similar between groups. NOSES patients had earlier first flatus (p<0.001), lower postoperative NRS pain scores, and less rescue analgesic use (17.5% vs 37.4%, p<0.001). Overall 30-day complication rate was numerically lower in NOSES (12.0% vs 18.3%, p=0.056); all incisional surgical site infections occurred only in the CLS group (6.0%). Hospital costs were higher with NOSES (mean difference 6525 CNY, p<0.001). No 30-day deaths occurred in either arm. Interpretation: For selected patients with cT1-3N0-2M0 sigmoid or upper rectal cancer, NOSES performed by experienced surgeons delivers non-inferior long-term oncological outcomes versus CLS, with meaningful improvements in postoperative pain, bowel recovery and surgical site infection risk. NOSES represents a patient-friendly minimally invasive option for suitable candidates.

AimTo evaluate the safety, feasibility, and long-term efficacy of natural orifice specimen extraction surgery (NOSES) compared with totally laparoscopic right hemicolectomy (TLRH) for right-sided colon cancer.MethodsThis single-center retrospective study included 349 patients who underwent laparoscopic curative resection for stage I-III right-sided colon cancer between January 2018 and January 2023. After 1:1 propensity score matching (PSM) for age, tumor size, BMI, neoadjuvant therapy, and T stage, 115 NOSES patients were compared with 115 TLRH patients. Outcomes included postoperative recovery, perioperative fatigue, complications, pelvic floor function, disease-free survival (DFS), and overall survival (OS).ResultsAfter PSM, baseline characteristics were balanced. Operative time and blood loss did not differ between groups. NOSES was associated with significantly less postoperative pain (P < 0.001) and lower analgesic use (25.2% vs. 47.0%, P < 0.001). Learning curves indicated proficiency after 57 transvaginal and 32 transrectal procedures. Recovery indicators, including time to first flatus, defecation, and hospital stay, were comparable. Incision-related complications occurred more frequently in TLRH (P = 0.024). NOSES patients reported lower fatigue levels on postoperative days 1 and 3 (P < 0.001), with fewer cases of postoperative fatigue syndrome. Pelvic floor and continence outcomes were similar. No local recurrences were observed, and DFS and OS did not differ significantly.ConclusionsNOSES is a safe and effective alternative for selected patients with right-sided colon cancer. It reduces postoperative pain, fatigue, and incision-related complications without compromising oncological outcomes or pelvic floor function, and demonstrates a clear learning curve supporting its broader application.

Claudin-7, a crucial tight junction protein, governs cell adhesion and permeability, yet its aberrant regulation is a common feature across numerous cancers. Despite this widespread implication, the intricate and context-dependent roles of claudin-7 in different malignancies have remained shrouded in mystery, with existing studies often confining their scope to singular tumor types. This study presents an integrated pan-cancer analysis, meticulously dissecting claudin-7 expression landscapes, prognostic signatures, immune-modulatory prowess, and interactions with therapeutic modalities. In this investigation, we uncover distinct expression profiles of claudin-7 across cancers. Claudin-7 expression is implicated in shaping the tumor immune microenvironment, with its levels correlating with the presence and abundance of various tumor-infiltrating immune cells. Downregulation of claudin-7 in colorectal cancer promotes proliferation and migration. Its downregulation promoted cell EMT and metastasis via upregulating ZEB1. Knockout of claudin-7 also modulates EGFR and several immune signaling pathways. Drug sensitivity analysis suggests that claudin-7 modulates tumor growth through drug sensitivity in colorectal cancer. Our findings underscore the multifaceted significance of claudin-7 in cancer, emphasizing its compelling potential as both a therapeutic target and a biomarker across various cancer types. Together, these revelations illuminate claudin-7's as a sentinel against tumor progression, brandishing its potential as both a linchpin therapeutic target and a potential biomarker.

Background: Currently, there is no established standard for managing resectable synchronous colorectal liver metastases (CRLM): upfront surgery or neoadjuvant therapy. This study has integrated four available clinical factors - clinicopathological characteristics, gene mutation profiles, imaging findings, and hematological indicators - to create a potentially robust tool aiding clinicians in deciding between upfront surgery and neoadjuvant therapy. Methods: This retrospective cohort study included individuals diagnosed with resectable synchronous CRLM between 2008 and 2018. The development of prediction nomograms entailed identifying independent prognostic indicators through univariate and multivariate Cox analyses. The accuracy of the predictions was evaluated through calibration curves and the C-index. Furthermore, the clinical effectiveness of the nomograms was assessed using DCA and ROC curves. To enhance accessibility, two web servers were developed to simplify the utilization of the nomograms for an improved user experience. Results: A total of 386 patients with resectable synchronous CRLM were included. The patients were categorized randomly into a training cohort (n = 270, 70%) and a testing cohort (n = 116, 30%). The nomograms incorporated nine predictors: metastatic tumor count, cN stage, KRAS and BRAF mutation status, age, primary tumor location, neutrophil and platelet counts, and D-Dimer levels. The calibration plots for resectable synchronous CRLM survival predictions showed remarkable consistency. The C-index of OS and DFS prediction models were both above 0.7. And the area under the ROC curve of 1-, 3- and 5-year OS and DFS exceeded 0.7 as well. As demonstrated by the DCA plots, both nomograms exhibit satisfactory clinical effectiveness. A web-based application was developed to demonstrate the practical application of the prediction models. Conclusion: The personalized web-based predictive models exhibited moderate predictive accuracy in resectable synchronous CRLM. These tools offer valuable assistance to physicians in deciding between upfront surgery and neoadjuvant therapy for resectable synchronous CRLM.

BACKGROUND:Parastomal hernia (PSH) is a frequent complication of abdominoperineal resection (APR), yet large-scale studies characterizing its long-term incidence and tools for individualized risk stratification remain lacking. To determine the long-term incidence, independent risk factors, and develop a clinical prediction model for PSH after APR in rectal cancer patients. METHODS:We conducted a retrospective cohort study of 836 patients with rectal adenocarcinoma who underwent APR and permanent end colostomy at a high-volume tertiary center (2014-2018). PSH was diagnosed according to the European Hernia Society criteria. Independent risk factors were identified using Cox regression, and a nomogram was developed to predict 1- to 5-year PSH probabilities. Model discrimination was assessed using time-dependent AUC. RESULTS:During a median follow-up period of 85 months, 207 patients (24.8%) developed PSH, with a cumulative incidence of 26.2% at 5 years. Independent risk factors included female sex (HR = 2.28, 95% CI: 1.73-3.01), age ≥ 60 years (HR = 5.17, 95% CI: 3.72-7.18), BMI ≥ 24 kg/m2 (HR = 2.10, 95% CI: 1.57-2.80), and transperitoneal stoma route (HR = 4.11, 95% CI: 2.63-6.41; all P < 0.001). The nomogram demonstrated strong discrimination with 1-, 2-, 3-, 4-, and 5-year AUCs of 0.65, 0.70, 0.76, 0.80, and 0.83, respectively. CONCLUSION:This study provides evidence on PSH incidence and risk factors, introducing a nomogram for personalized risk stratification. The nomogram allows clinicians to identify high-risk patients and tailor preventive strategies, such as extraperitoneal stoma creation or prophylactic mesh placement, to reduce PSH burden.

BACKGROUND:While global gastric cancer incidence has declined, trends in early-onset gastric cancer (EOGC, age 15-49) remain unclear. This study evaluates EOGC's global burden (1990-2021), projects trends to 2030, and identifies epidemiological drivers. METHODS:Using Global Burden of Disease (GBD) 2021 data, we analyzed age-standardized incidence, mortality, disability-adjusted life years (DALYs), and estimated annual percentage change for EOGC globally and by sex, region, and income level. A Bayesian age-period-cohort model and decomposition analysis assessed temporal trends, epidemiological drivers (eg, aging, population growth), and projected burden through 2030. RESULTS:In 2021, EOGC caused 125 120 new cases and 78 871 deaths globally. From 1990 to 2021, age-standardized mortality, incidence, and DALYs declined worldwide. East Asia and high-middle-income regions bore the highest burden. Decomposition identified epidemiological changes as the primary driver of reduced EOGC burden. Males exhibited higher incidence, mortality, and DALYs than females. Projections suggest declining incidence and mortality rates by 2030 for both sexes, yet rising absolute case numbers due to population growth. CONCLUSIONS:Early-onset gastric cancer burden shows complex patterns: while rates have decreased over 3 decades, absolute cases and deaths increased due to demographic expansion. Disparities persist across gender, geography, and development levels. These findings highlight the need for targeted interventions in high-risk populations and regions to address inequities. Policymakers should prioritize surveillance and prevention strategies tailored to evolving epidemiological trends.

BACKGROUND:To evaluate the efficacy and toxicity of combining neoadjuvant immune checkpoint inhibitors (ICIs) with chemoradiotherapy (CRT) for patients with mismatch repair-proficient (pMMR) locally advanced rectal cancer (LARC). METHODS:PubMed, Embase, Cochrane Library, and Medline databases were searched. Phase I-III clinical trials reporting pathologic complete response (pCR) or overall CR (pCR + clinical CR) rates for neoadjuvant ICIs plus CRT in pMMR LARC were included. Studies that only enrolled patients with mismatch repair-deficient LARC were excluded. Data were analyzed at trial and arm levels and pooled using random-effects models. Primary outcomes were pCR and overall CR rates. Toxicity occurrence was also measured. RESULTS:In total, 19 trials (n = 1324) were included. At trial level, pooled odds ratios (95 % CIs) of overall CR and pCR rates for neoadjuvant ICIs plus CRT were 1.72 (1.21-2.44) and 1.68 (1.08-2.62), respectively. At arm level, compared with CRT, neoadjuvant ICIs plus CRT significantly improved overall CR (42 % vs 24 %, P < 0.001) and pCR rates (37 % vs 24 %, P = 0.008). Compared with ICIs plus long-course CRT, chemoimmunotherapy plus short-course radiotherapy significantly increased overall CR (51 % vs 36 %) and pCR (48 % vs 30 %) rates (both P < 0.001). Pooled incidence of grade 1-2 and ≥ 3 treatment-related adverse events was 63 % and 28 %, respectively-similar to CRT alone. CONCLUSION:Neoadjuvant immunotherapy plus CRT is a promising treatment strategy for pMMR LARC, with improved CR rates and manageable toxicity. Chemoimmunotherapy plus short-course radiotherapy exhibits superior efficacy. Further investigation on long-term outcomes and optimal combined regimens is warranted.

Randomized controlled trials have revealed that abdominoperineal resection leads to inferior oncological outcomes compared with low anterior resection, especially regarding local recurrence rates (LRRs). While neoadjuvant chemoradiotherapy can lower LRRs, it is linked to potential short- and long-term radiation-induced adverse effects. Consequently, meticulous patient selection for neoadjuvant chemoradiotherapy is imperative to balance benefits and risks. This research encompassed individuals with rectal cancer (RC) who underwent abdominoperineal resection (APR) from January 2006 to December 2017. The cohort was categorized into two cohorts on the basis of tumor location: the anterior cohort and the nonanterior cohort. Propensity score matching (PSM) was employed to mitigate selection bias, and this resulted in 767 patients in both cohorts. The primary endpoint assessed was survival without local recurrence (LR). Of the 2025 cases examined, 1806 were deemed eligible for inclusion. In the entire cohort, the incidence of LR was 9.9

In the context of surgical treatment for rectal cancer, the dentate line is acknowledged as a critical anatomical landmark. However, the prognostic implications of dentate line invasion (DLI) remain elusive and warrant further investigation. This study aims to evaluate and compare the outcomes of patients with rectal cancer who underwent abdominoperineal resection (APR), distinguishing between those with and without DLI. Between January 2006 and December 2017, this study enrolled 1854 patients with rectal cancer who underwent APR. The cohort was divided into two groups, namely the DLI group (n = 340) and the non-DLI group (n = 1514). The primary endpoints were distant relapse-free survival (DRFS) and local recurrence-free survival (LRFS). Univariate and multivariate analyses were conducted to assess the impact of DLI on DRFS, LRFS, overall survival (OS), and disease-free survival (DFS). The median follow-up duration for the patients was 92.9 months, with a 5-year OS rate of 92.0

Background Randomized studies have demonstrated that laparoscopic abdominoperineal resection is not inferior to open abdominoperineal resection for rectal cancer. Aims Evaluate the immediate and extended results of laparoscopic abdominoperineal resection versus open abdominoperineal resection for rectal cancer. Methods From January 2006 to December 2017, a total of 1852 patients with rectal cancer who had undergone abdominoperineal resection were enrolled in this investigation. The groups were matched in a 1:1 ratio using propensity score matching. The primary endpoints were overall survival and disease-free survival. The secondary endpoints were pathology and short-term postoperative outcomes. Results Compared to the open abdominoperineal resection group, the laparoscopic abdominoperineal resection group exhibited a higher rate of positive circumferential resection margins (P < 0.001) and fewer postoperative complications (P < 0.001). 5-year disease-free survival (P = 0.449) and overall survival rates (P = 0.664) were comparable. Age (P < 0.001), comorbidity (P = 0.040), (y)pT (P = 0.024), (y)pN (P < 0.001), lymphovascular invasion (P = 0.003) and positive circumferential resection margins (P = 0.014) were independent prognostic risks for overall survival. Conclusion The pathological outcomes of laparoscopic abdominoperineal resection are inferior compared to open abdominoperineal resection. However, they demonstrate comparable long-term oncological outcomes, and laparoscopic abdominoperineal resection offers certain short-term advantages over the open approach.

Aim: To investigate the safety and efficacy of radical surgery in colon cancer patients over 80 years old. Methods: Data from colon cancer patients aged ≥80 years who underwent radical surgery at the Cancer Hospital of the Chinese Academy of Medical Sciences and affiliated Heji Hospital of Changzhi Medical College from January 2011 to December 2022 were retrospectively analysed. Data on clinical characteristics, pathological features, perioperative data, and long-term prognosis were collected. Severe complications were classified as grade III-V. Logistic regression models were used to identify the risk factors for severe postoperative complications, and a Cox regression model was used to determine prognostic variables. Results: A total of 403 eligible patients were included in the study. A total of 118 (29.3%) patients developed postoperative complications, of which 51 (12.7%) experienced grade 3-5 severe complications. Two (0.5%) patients died of pulmonary embolism and myocardial infarction during the perioperative period. The multivariate logistic regression analysis showed that preoperative albumin levels <35 g/L and right colon cancer were independent risk factors for grade 3-5 postoperative complications. In terms of prognosis, multivariate analysis revealed that overall survival was significantly affected by TNM stage III and grade 3-4 postoperative complications. In addition, TNM stage III and perineural invasion were the independent prognostic factors for disease-free survival. Conclusion: Radical surgery can be performed safely in elderly colon cancer patients aged over 80 years, with an acceptable morbidity and mortality. Patients with preoperative albumin levels <35 g/L or tumors in the right colon should be alerted to the development of severe postoperative complications. In addition, the occurrence of severe complications can significantly affect the prognosis of elderly colon cancer patients.

BackgroundGastric signet ring cell carcinoma (GSRCC) is a rare and highly malignant disease with a poor prognosis. To assess the overall survival (OS) and cancer-specific survival (CSS) of patients with GSRCC, prognostic nomograms were developed and validated using common clinical factors.MethodsThis retrospective cohort study included patients diagnosed with GSRCC between 2011 and 2018 from the National Cancer Center (n = 1453) and SEER databases (n = 2745). Prognostic nomograms were established by identifying independent prognostic factors using univariate and multivariate Cox regression analyses. The calibration curve and C-index were used to assess the predictions. The clinical usefulness of the survival prediction model was further evaluated using the DCA and ROC curves. The models were internally validated in the training cohort and externally validated in the validation cohort. Two web servers were created to make the nomogram easier to use.ResultsPatients with GSRCC were divided into training (n = 2938) and validation (n = 1260) cohorts. The nomograms incorporated six predictors: age, race, tumor site, tumor size, N stage, T stage, and AJCC stage. Excellent agreement was observed between the internal and exterior calibration plots for the GSRCC survival estimates. The C-index and area under the ROC curve were roughly greater than 0.7. Both nomograms had adequate clinical efficacy, as demonstrated by the DCA plots. Furthermore, we developed a dynamic web application utilizing the constructed nomograms available at https://jiangyujuan.shinyapps.io/OS-nomogram/ and https://jiangyujuan.shinyapps.io/DynNomapp-DFS/.ConclusionWe developed web-based dynamic nomograms utilizing six independent prognostic variables that assist physicians in estimating the OS and CSS of patients with GSRCC.

Background: Chemoradiotherapy (CRT) is the main treatment for elderly patients with non-metastatic rectal cancer who are ineligible for or decline surgery, but the optimal modality remains unclear. Objectives: This study was to validate the safety and efficacy of comprehensive geriatric assessment (CGA) guided radiotherapy in older patients. Design: An exploratory analysis of a single-arm, multicenter, Phase II trial. Methods: Patients aged over 70 and diagnosed with rectal cancer were enrolled and evaluated by CGA. CGA-guided radiotherapy was individually conducted in a multidisciplinary setting. Patients in fit, intermediate, and frail groups were scheduled to receive CRT, long-course radiotherapy, and short-course radiotherapy (SCRT) alone respectively. Patients who were unfit for or refused surgery were analyzed for acute toxicities and survival outcomes. Results: In a total of 109 enrolled patients, 47 individuals who did not undergo surgery were included, with 26, 9, and 12 categorized into fit, intermediate, and frail groups. Only 11 (23.4%) grade 3 or above toxicities were observed overall. Within a median follow-up of 69.0 months, the 3-year overall survival (OS), progression-free survival (PFS), and cancer-specific survival (CSS) rates were 44.3% (95% CI: 32.1%–61.2%), 25.5% (95% CI: 15.7%–41.6%) and 61.0% (95% CI: 47.8%–77.6%) in total. The 5-year OS, PFS, and CSS reached 15.0% (95% CI: 7.4%–30.3%), 14.6% (95% CI: 7.3%–29.4%), and 36.2% (95% CI: 22.0%–59.4%), with no significant difference among the three subgroups. SCRT ( p < 0.001) and dose boost ( p = 0.045) contributed to lower tumor-related death rates in multiple competing risk regressions. Conclusion: Radiotherapy guided by CGA was effective and well-tolerated in non-surgical elderly patients. SCRT alone seemed to achieve similar clinical outcomes as CRT in corresponding subgroups. However, given the limited size of this study, further investigation in a larger population is still needed for this strategy.

Background The purpose of this study was to evaluate the safety and efficacy of preoperative concurrent chemoradiotherapy (preCRT) for locally advanced rectal cancer in older people who were classified as "fit" by comprehensive geriatric assessment (CGA).Methods A single-arm, multicenter, phase II trial was designed. Patients were eligible for this study if they were aged 70 years or above and met the standards of "fit" (SIOG1) as evaluated by CGA and of the locally advanced risk category. The primary endpoint was 2-year disease-free survival (DFS). Patients were scheduled to receive preCRT (50 Gy) with raltitrexed (3 mg/m2 on days 1 and 22).Results One hundred and nine patients were evaluated by CGA, of whom eighty-six, eleven and twelve were classified into the fit, intermediate and frail category. Sixty-eight fit patients with a median age of 74 years were enrolled. Sixty-four patients (94.1%) finished radiotherapy without dose reduction. Fifty-four (79.3%) patients finished the prescribed raltitrexed therapy as planned. Serious toxicity (grade 3 or above) was observed in twenty-four patients (35.3%), and fourteen patients (20.6%) experienced non-hematological side effects. Within a median follow-up time of 36.0 months (range: 5.9-63.1 months), the 2-year overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) rates were 89.6% (95% CI: 82.3-96.9), 92.4% (95% CI: 85.9-98.9) and 75.6% (95% CI: 65.2-86.0), respectively. Forty-eight patients (70.6%) underwent surgery (R0 resection 95.8%, R1 resection 4.2%), the corresponding R0 resection rate among the patients with positive mesorectal fascia status was 76.6% (36/47).Conclusion This phase II trial suggests that preCRT is efficient with tolerable toxicities in older rectal cancer patients who were evaluated as fit based on CGA.Trial registration The registration number on ClinicalTrials.gov was NCT02992886 (14/12/2016).

To investigate the impact of preoperative cardiovascular disease on the perioperative period of rectal cancer patients over 75 years old. The clinicopathological data of 625 elderly patients aged ≥ 75 years who underwent radical rectal cancer surgery in the Cancer Hospital of the Chinese Academy of Medical Sciences and affiliated Heji Hospital of Changzhi Medical College from January 2011 to December 2022 were retrospectively collected and analyzed. According to preoperative comorbidities, all patients were divided into cardiovascular disease group (n = 361) and non-cardiovascular disease group (n = 264). One hundred and ninety-two pairs were selected from each group through Propensity score-matched to further analysis. Perioperative indexes and postoperative complications were compared between the two groups. There were no significant differences in clinicopathological data between the two groups (P > 0.05). The proportion of elderly patients with cardiovascular disease who went to ICU after radical surgery was significantly higher than those without cardiovascular disease (19.3

BackgroundNatural orifice specimen extraction surgery (NOSES) has been widely applied to the treatment of colorectal cancer. This study aim to investigate the short-term and survival outcomes of transrectal specimen extraction after laparoscopic right hemicolectomy.MethodsFrom January 2016 to December 2021, a total of 166 consecutive patients with right colon cancer who underwent laparoscopic right hemicolectomy in Cancer Hospital of Chinese Academy of Medical Sciences and Beijing Hospital were identified. Baseline data, perioperative parameters, anal function, inflammatory indicators and survival outcomes were collected and compared.ResultsTotally, 24 patients who underwent transrectal NOSE were matched with 24 patients who received conventional laparoscopic surgery (LAP). Patients in NOSES group had a significantly lower incidence of incision infection (0 vs 20.8%, P=0.048), faster recovery of gastrointestinal function (2.1 vs 3,1 days, P=0.032) compared with those in LAP group. In addition, patients in the NOSE group experienced significantly less postoperative pain on POD1 (2.3 vs 4.4, P<0.001), POD3 (2.1 vs 3.9, P<0.001), and POD5 (1.7 vs 2.8, P=0.011). Regarding to anal function 6 months after surgery, no significant difference was observed in Wexner incontinence scale (9.8 vs 9.5, P=0.559) between the two groups. In terms of indicators of the inflammatory response, there were no significant differences in body temperature, neutrophils, and PCT levels between the two groups. However, CRP levels in the NOSES group on POD 3 (6.9 vs 5.1 mg/L, P=0.016) and POD 5 (3.8 vs 2.6 mg/L, P=0.027) were significantly higher than in the LAP group. With regarded to survival outcomes, patients in the NOSES group were similar to those in the LAP group for 3-year OS (100% vs 91.2%, P=0.949), 3-year DFS (86.2% vs 84.8%, P=0.949), and 3-year LRFS (94.2% vs 88.7%, P=0.549).ConclusionFor total laparoscopic right hemicolectomy, transrectal NOSE is effective and safe, and associated with lower incidence of wound infection, less pain, faster recovery, and similar survival outcomes compared to conventional laparoscopic surgery.

e15511 Background: As one of the most concerning world public health issue, cancer accounted for 21% of all deaths. Early cancer detection methods help reduce the chance of dying from cancer. The fragmentation patterns of plasma circulating cell-free DNA (cfDNA) in tumor patients and healthy people are different, which reflects aberrant gene-regulation in cancer patients. Measure cfDNA fragmentomics not only identify the biomarkers to detect cancer early, but also contribute to revealing the biological regulatory mechanism of cancer. In this study, a novel method, i.e. multi-fragmentomics early tumor detection method (METD) was developed, which combined multiple cfDNA fragmentation features and effectively predicted early stage cancer patients. Methods: Adapter sequences were removed from raw data which are then aligned to hg19 reference genome. Duplicated reads, low quality reads and reads aligned to sex chromosomes were removed. Fragment length were normalized through z-score and GC content were regressed out from each bin using GBM (Gradient Boosting Machine) regression tree. Using data from 100 healthy samples, the baseline were calculated. Six fragmentation features including FSD (fragment size distribution) that is a ratio of short/long fragment numbers, EM (end motif) which represent the frequency of 5’end 2-6bp sequence patterns, BPM (break-point motifs) that is the frequency of 5’ end break-point sequences, TFAS (transcription factor accessibility score) that is the rank of coverage at transcription factor binding sites, CFS (co-fragmentation score) which calculate the first principle component of the free-C correlation matrix, GES (gene expression score) that measures the predicted gene expression from cfDNA lp-WGS data were calculated for each sample. Then these 6 fragmentation features were fitted in a penalized logistic regression for cancer prediction. Data of each sample was also downsampled to 0.1x, 0.5x, 1x, 3x and 5x to test the minimum amount of data needed for this prediction model. Results: In training data set, 208 samples from gastrointestinal cancer patients and 100 samples from healthy individuals, our method METD detect tumor patients with a AUC of 0.98. The AUC is 0.95 when the training data were downsampled to 0.1x. This method was then tested in a validation data set containing 32 cancer patients and 32 healthy individuals, which showed a specificity of 0.9 and sensitivity of 0.88. Conclusions: In this study, we develop a new method for early cancer detection integrating different fragmentomics features and demonstrated that lp-WGS data even with 0.1x data can be used to distinguish cancer and healthy groups. Studies with larger cohorts is warranted to verify the performance of this method in future.

Background: Lateral lymph node (LLN) metastases (LLNM) are often associated with poor prognosis. This study aimed to investigate the prognostic significance and postoperative recurrence pattern in rectal cancer patients with LLNM after LLN dissection (LLND). Materials and Methods: This is a multicenter retrospective case-control study where propensity score-matched (PSM) analysis was introduced. From January 2012 to December 2019, 259 patients with clinical suspicion of LLNM who underwent LLND without neoadjuvant therapy were included in the study. They were divided into the negative (n = 197) and positive (n = 62) LLN groups. Primary endpoints were 3-year recurrence-free survival (RFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS). Results: After PSM, the DMFS rate in the positive LLN group was significantly worse (67.9 vs. 52.5%, P = 0.012). Pathological LLNM (HR, 3.07; 95% CI, 1.55-6.05; P = 0.001) were independent prognostic factors for DMFS. Patients in the positive LLN group had a higher proportion of distant metastases in all recurrence patterns (92.3% vs 82.6%). Among patients with LLN metastasis, metastases to the common iliac and external iliac arteries were the independent prognostic factor for DMFS (HR: 2.85; 95% CI, 1.31-4.67; P = 0.042). No significant different was observed for prognosis between patients with metastases to the obturator or internal iliac vessels and patients with a N2b stage. Conclusion: Distant metastasis is the main cause of treatment failure after LLND in patients with LLNM. Because of the low completion rate of adjuvant chemotherapy, preoperative chemotherapy or total neoadjuvant therapy may be considered before LLND. In addition, patients with metastasis to external iliac and common iliac vessels have an extremely poor prognosis, and systemic chemotherapy instead of LLND should be recommended.