Evaluation of the learning curve for conformal sphincter preservation operation in the treatment of ultralow rectal cancer.

BACKGROUND: To investigate the learning curve of conformal sphincter preservation operation (CSPO) in the treatment of ultralow rectal cancer and to further explore the influencing factors of operation time. METHODS: From August 2011 to April 2020, 108 consecutive patients with ultralow rectal cancer underwent CSPO by the same surgeon in the Department of Colorectal Surgery of Changhai Hospital. The moving average and cumulative sum control chart (CUSUM) curve were used to analyze the learning curve. The preoperative clinical baseline data, postoperative pathological data, postoperative complications, and survival data were compared before and after the completion of learning curve. The influencing factors of CSPO operation time were analyzed by univariate and multivariate analysis. RESULTS: According to the results of moving average and CUSUM method, CSPO learning curve was divided into learning period (1-45 cases) and learning completion period (46-108 cases). There was no significant difference in preoperative clinical baseline data, postoperative pathological data, postoperative complications, and survival data between the two stages. Compared with the learning period, the operation time (P < 0.05), blood loss (P < 0.05), postoperative flatus and defecation time (P < 0.05), liquid diet time (P < 0.05), and postoperative hospital stay (P < 0.05) in the learning completion period were significantly reduced, and the difference was statistically significant. Univariate and multivariate analysis showed that distance of tumor from anal verge (≥ 4cm vs. < 4cm, P = 0.039) and T stage (T3 vs. T1-2, P = 0.022) was independent risk factors for prolonging the operation time of CSPO. CONCLUSIONS: For surgeons with laparoscopic surgery experience, about 45 cases of CSPO are needed to cross the learning curve. At the initial stage of CSPO, beginners are recommended to select patients with ultralow rectal cancer whose distance of tumor from anal verge is less than 4 cm and tumor stage is less than T3 for practice, which can enable beginners to reduce the operation time, accumulate experience, build self-confidence, and shorten the learning curve on the premise of safety.

LncRNA LBX2-AS1 promotes colorectal cancer progression and 5-fluorouracil resistance.

BACKGROUND: Recent reports suggest that the long non-coding RNA LBX2 antisense RNA 1 (LBX2-AS1) acts as an important regulator in cancer progression, but its significance in colorectal cancer (CRC) remains undetermined. METHODS: LBX2-AS1 expression levels in CRC were determined from the GEPIA database and CRC tissues to investigate clinical relevance. meRIP-PCR assays investigated the molecular mechanisms underlying the function of m6A in LBX2-AS1. Loss of function experiments was used to define the role of LBX2-AS1 in the progression of CRC. The ceRNA function of LBX2-AS1 was evaluated by RNA immunoprecipitation. In vitro and PDX models were used to determine if LBX2-AS1 promotes 5-fluorouracil resistance. RESULTS: Data from the TCGA and our institutional patient cohorts established that LBX2-AS1 levels were significantly upregulated in most CRC tissues relative to normal adjacent colon tissues. Moreover, LBX2-AS1 levels were positively correlated with aggressive disease characteristics, constituting an independent prognostic indicator of overall patient survival. Mechanistic investigations suggested that the increased LBX2-AS1 in CRC was mediated by METTL3-dependent m6A methylation. In vitro experiments indicated that knockdown of LBX2-AS1 inhibited CRC proliferation, migration and invasion with this phenotype linked to LBX2-AS1-mediated regulation of AKT1, acting as a ceRNA to sponge miR-422a. Ex vivo analysis of patient-derived CRC xenografts showed that low LBX2-AS1 expression cases exhibited 5-FU responsiveness and clinical investigations confirmed that low LBX2-AS1 expression was associated with improved clinical benefits from 5-FU therapy. CONCLUSIONS: Together these results suggest that LBX2-AS1 may serve as a therapeutic target and predictor of 5-FU benefit in CRC patients.

MRI-based nomogram analysis: recognition of anterior peritoneal reflection and its relationship to rectal cancers.

BACKGROUND: This study is aimed to explore the factors influencing the visualization of the anterior peritoneal reflection (APR) and evaluated the feasibility of measuring the distance from the anal verge to APR (AV-APR), the tumor height on MRI and the accuracy of determining the tumor location with regard to APR. METHODS: We retrospectively analyzed 110 patients with rectal cancer. A univariate and multivariate logistic regression was performed to identify the independent factors (age, sex, T stage, the degree of bladder filling, pelvic effusion, intraoperative tumor location, BMI, uterine orientation, the distance from seminal vesicle/uterus to rectum) associated with the visualization of the APR on MRI. The nomogram diagram and receiver operating characteristic curve (ROC curve) were established. Intraclass correlation coefficient (ICC) was used to evaluate the consistency of the distance of AV-APR. The Pearson correlation coefficient was used to characterize the agreement between measurements of the tumor height by colonoscopy and MRI. The Kappa statistics was used to evaluate the value of MRI in the diagnosis of the tumor location with regard to the APR. RESULTS: Multivariate logistic regression showed that BMI (P = 0.031, odds ratio, OR = 1.197), pelvic effusion (P = 0.020, OR = 7.107) and the distance from seminal vesicle/uterus to the rectum (P = 0.001, OR = 3.622) were correlated with the visualization of APR. The cut-off point of BMI and the distance from seminal vesicle/uterus to the rectum is 25.845 kg/m2 and 1.15 cm. The area under curve (AUC) (95% Confidence Interval, 95% CI) of the combined model is 0.840 (0.750-0.930). The favorable calibration of the nomogram showed a non-significant Hosmer-Lemeshow test statistic (P = 0.195). The ICC value (95% CI) of the distance of AV-APR measured by two radiologists was 0.981 (0.969-0.989). The height measured by MRI and colonoscopy were correlated with each other (r = 0.699, P < 0.001). The Kappa value was 0.854. CONCLUSIONS: BMI, pelvic effusion, and the distance from seminal vesicle/uterus to rectum could affect the visualization of APR on MRI. Also, it's feasible to measure the distance of AV-APR, the tumor height, and to evaluate the tumor location with regard to APR using MRI.

Greater Peripouch Fat Area on CT Image Is Associated with Chronic Pouchitis and Pouch Failure in Inflammatory Bowel Diseases Patients.

BACKGROUND: The causes of chronic antibiotic refractory pouchitis (CARP) and pouch failure in inflammatory bowel disease (IBD) patients remain unknown. Our previous small study showed peripouch fat area measured by MRI was associated with pouchitis. AIMS: To explore the relationship between peripouch fat area on CT imaging and pouch outcomes. METHODS: This is a historical cohort study. Demographic, clinical, and radiographic data of IBD patients with abdominal CT scans after pouch surgery between 2002 and 2017 were collected. Peripouch fat areas and mesenteric peripouch fat areas were measured on CT images at the middle pouch level. RESULTS: A total of 435 IBD patients were included. Patients with higher peripouch fat areas had a higher prevalence of CARP. Univariate analyses demonstrated that long duration of the pouch, high weight or body mass index, the presence of primary sclerosing cholangitis or other autoimmune disorders, and greater peripouch fat area or mesenteric peripouch fat area were risk factors for CARP. Multivariable analyses demonstrated that the presence of primary sclerosing cholangitis or autoimmuned disorders, and greater peripouch fat area (odds ratio [OR] 1.031; 95% confidence interval [CI] 1.016-1.047, P < 0.001) or mesenteric peripouch fat area were independent risk factors for CARP. Of the 435 patients, 139 (32.0%) had two or more CT scans. Multivariable Cox proportional hazard analyses showed that "peripouch fat area increase ≥ 15%" (OR 3.808, 95%CI 1.703-8.517, P = 0.001) was an independent predictor of pouch failure. CONCLUSIONS: A great peripouch fat area measured on CT image is associated with a higher prevalence of CARP, and the accumulation of peripouch fat is a risk factor for pouch failure. The assessment of peripouch fat may be used to monitor the disease course of the ileal pouch.

Impact of high blood pressure variability on the occurrence of acute type B aortic dissection.

BACKGROUND: Acute type B aortic dissection is a life-threatening medical emergency, and hypertension is believed to be an important predictor of aortic dissection; the impact of blood pressure variability on the onset and development of aortic dissection has attracted increasing attention. METHODS: A total of 120 acute type B aortic dissection patients and 57 hypertensive patients without aortic dissection were consecutively enrolled and retrospectively reviewed between January 2013 and November 2015. There were 60 acute type B aortic dissection patients in both high and low blood pressure variability groups. RESULTS: Blood pressure variability showed higher diagnostic value than hypertension in aortic dissection, and the best threshold of blood pressure variability is 5.71 mmHg. By performing multivariable logistic regression, we found that the history of hypertension was likely to be a risk factor of blood pressure variability (95% CI: 1.155-6.422, P = 0.022). Nine patients from high blood pressure variability group and two from low blood pressure variability group (χ2 = 4.90, P = 0.027) received emergency surgery within 24 hours after admission. The presence of multiple tears (>2, 55.0% vs. 45.0%, P = 0.001), configuration of the false lumen (spiral false lumen) (50.0% vs. 21.7%, P = 0.001), the diameter of the false lumen (49.6 ± 15.0 mm vs. 37.6 ± 10.8 mm, P < 0.001), the false/true lumen ratio (1.53 ± 1.02 vs. 0.929 ± 0.733, P < 0.001), and the number of visceral arteries involved (1.75 ± 0.942 vs. 0.800 ± 0.927, P < 0.001) showed significant differences between high and low blood pressure variability groups. Nine (30%) patients from the high blood pressure variability group showed a maximum diameter of false lumen over 60 mm, while none was found in the low blood pressure variability group. CONCLUSIONS: High blood pressure variability, the presence of multiple tears (>2), the configuration of false lumen, the diameter of the false lumen, false/true lumen ratio, and the number of visceral arteries involved were independent risk factors for acute type B aortic dissection.

Comparison of open surgery and endovascular procedures as a therapeutic choice for visceral artery aneurysms.

Objectives Visceral arterial aneurysms may be treated using open surgery or endovascular repair, but the best approach remains controversial. This was a retrospective study aiming to compare open surgery and endovascular treatment strategies for visceral arterial aneurysms. Methods The study included all 93 patients who were admitted with visceral artery aneurysms between January 2001 and January 2011 at the Department of Vascular Surgery, Changhai Hospital, Shanghai, China. All cases underwent either open or endovascular procedures. Overall survival and adverse events were compared between the groups. Success rate, blood loss, length of surgery, and length of hospital stay were also compared. The patients were followed up at three, six, and 12 months then every year until April 2014. Results Open surgery was performed on 34 patients and endovascular procedures on 59. There were no differences in characteristics of the patients between the open surgery and endovascular groups. The perioperative complication rate was 52.9 and 13.6% in the open surgery and endovascular groups, respectively. Mean follow-up was 36.8 months (range: 11 months to 10 years). The one- and five-year survival rates were 100 and 60.6%, respectively, in the open surgery group, compared to 100 and 84.5% in the endovascular group. Multivariate analysis for factors related to overall survival showed that there was a significant relationship with the treatment approach (HR = 0.479, 95%CI: 0.278-0.825; P = 0.008) and the presence of false aneurysm (HR = 2.929, 95%CI: 1.388-6.180, P = 0.005). Conclusions Endovascular repair could be considered as an effective method for visceral artery aneurysm. Endovascular repair showed lower perioperative complication rates and better long-term survival.

Magnetic-controlled capsule endoscopy vs. gastroscopy for gastric diseases: a two-center self-controlled comparative trial.

BACKGROUND AND STUDY AIMS: We developed a novel magnetic-controlled capsule endoscopy (MCE) system for use in the human stomach. The aim of the current study was to compare the diagnostic accuracy of MCE with that of standard gastroscopy for gastric diseases. PATIENTS AND METHODS: A total of 68 patients were enrolled in this self-controlled trial. Patients were evaluated by both MCE and gastroscopy. Gastroscopy was performed 4 ­â€Š24 hours after completion of the MCE examination. RESULTS: The positive percent agreement between MCE and gastroscopy was 96.0 %, and the negative percent agreement was 77.8 %. The overall agreement was 91.2 % with a kappa value of 0.765 (P < 0.001). A total of 68 pathological findings were detected, of which 53 were identified by both methods. The MCE and standard gastroscopy missed seven and eight findings, respectively. CONCLUSIONS: MCE showed a diagnostic accuracy similar to that of standard gastroscopy. These results suggest that MCE is a promising alternative to gastroscopy for noninvasive screening of gastric diseases.Clinical trial registration number: NCT01903629.

The application and influence of "Small Private Online Course" based on flipped classroom teaching model in the course of fundamental operations in surgery in China.

To investigate the effect of "Small Private Online Course" (SPOC) based on flipped classroom teaching model on the students in the course of fundamental operations in surgery. A prospective study. 8-year program students (juniors) majored in clinical medicine in Navy medical university. The mastery of theoretical knowledge and operational skill of the students, the comparison of final test examination score between traditional teaching method and "SPOC + flipped classroom" model and the feedback completed by students. Our study found that SPOC + flipped classroom could significantly increase the efficacy of the class and enhance the ability of the students compared with the traditional method. The new teaching model could have a positive influence for medical students on their basic knowledge and operational skill.

Impact and potential value of immunosenescence on solid gastrointestinal tumors.

Solid gastrointestinal tumors often respond poorly to immunotherapy for the complex tumor microenvironment (TME), which is exacerbated by immune system alterations. Immunosenescence is the process of increased diversification of immune genes due to aging and other factors, leading to a decrease in the recognition function of the immune system. This process involves immune organs, immune cells, and the senescence-associated secretory phenotype (SASP). The most fundamental change is DNA damage, resulting in TME remodeling. The main manifestations are worsening inflammation, increased immunosuppressive SASP production, decreased immune cell antitumor activity, and the accumulation of tumor-associated fibroblasts and myeloid-derived suppressor cells, making antitumor therapy less effective. Senotherapy strategies to remove senescent cells and block key senescence processes can have synergistic effects with other treatments. This review focuses on immunoenescence and its impact on the solid TME. We characterize the immunosenescent TME and discuss future directions for antitumor therapies targeting senescence.

WWP1 inhibition increases SHP2 inhibitor efficacy in colorectal cancer.

Protein tyrosine phosphatase SHP2 activates RAS signaling, which is a novel target for colorectal cancer (CRC) therapy. However, SHP2 inhibitor monotherapy is ineffective for metastatic CRC and a combination therapy is required. In this study, we aimed to improve the antitumor efficacy of SHP2 inhibition and try to explore the resistance mechanism of SHP2 inhibitor. Results showed that WWP1 promoted the proliferation of CRC cells. Genetic or pharmacological inhibition of WWP1 enhanced the effect of SHP2 inhibitor in suppressing tumor growth in vitro and in vivo. WWP1 may mediate feedback reactivation of AKT signaling following SHP2 inhibition. Furthermore, nomogram models constructed with IHC expression of WWP1 and SHP2 greatly improved the accuracy of prognosis prediction for patients with CRC. Our findings indicate that WWP1 inhibitor I3C can synergize with SHP2 inhibitor and is expected to be a new strategy for clinical trials in treating advanced CRC patients.

Spatial transcriptomic revealed intratumor heterogeneity and cancer stem cell enrichment in colorectal cancer metastasis.

Metastasis is the main cause of mortality in colorectal cancer (CRC) patients. Exploring the mechanisms of metastasis is of great importance in both clinical and fundamental CRC research. CRC is a highly heterogeneous disease with variable therapeutic outcomes of treatment. In this study, we applied spatial transcriptomics (ST) to generate a tissue-wide transcriptome from two primary colorectal cancer tissues and their matched liver metastatic tissues. Spatial RNA information showed intratumoral heterogeneity (ITH) of both primary and metastatic tissues. The comparison of gene expressions across tissues revealed an apparent enrichment of cancer stem cells (CSCs) in metastatic tissues and identified FOXD1 as a novel metastatic CSC marker. Trajectory and pseudo-time analyses revealed distinct evolutionary trajectories and a dedifferentiation-differentiation process during metastasis. CellphoneDB analysis suggested a dominant interaction of CD74-MIF with tumor cells in metastatic tissues. Further analysis confirmed FOXD1 as a maker of CSCs and the predictor of patient survival, especially in metastatic diseases. Our study found ITH of primary and metastatic tissues and provides novel insights into the cellular mechanisms underlying liver metastasis of CRC and foundations for therapeutic strategies for CRC metastasis.

Clinicopathological features and prognosis of synchronous and metachronous colorectal cancer: a retrospective cohort study.

BACKGROUND: To investigate the clinicopathological features and prognosis of synchronous and metachronous multiple primary colorectal cancer. MATERIALS AND METHODS: Patients who underwent operation for synchronous and metachronous colorectal cancer at the colorectal surgery department of Shanghai Changhai Hospital between January 2000 and December 2021 were included. Perioperative indicators were comprehensively compared and included in the survival analyses. RESULTS: In total, 563 patients with synchronous ( n =372) and metachronous ( n =191) colorectal cancer were included. Patients with synchronous colorectal cancer were more likely to have a long onset time, positive carcinoembryonic antigen, advanced TNM stage, large tumor, perineural invasion, p53 high expression, and mismatch repair proficient. Compared with metachronous colorectal cancer, patients with synchronous colorectal cancer showed worse 5-year overall survival (68.6±3.0% vs 81.9±3.5%, P =0.018) and 5-year disease-free survival (61.2±3.1% vs 71.0±3.9%, P =0.022). In the subgroup analysis, segmental resection was an independent risk factor for the long-term outcomes of bilateral synchronous colorectal cancer. CONCLUSIONS: Clinicopathological and molecular features were different between synchronous and metachronous colorectal cancer. Patients with synchronous colorectal cancer showed a worse prognosis than those with metachronous colorectal cancer. Bilateral synchronous colorectal cancer requires extended resection to achieve improved long-term outcomes.

Integrated proteomic and phosphoproteomic data-independent acquisition data evaluate the personalized drug responses of primary and metastatic tumors in colorectal cancer.

Mass spectrometry (MS)-based proteomics and phosphoproteomics are powerful methods to study the biological mechanisms, diagnostic biomarkers, prognostic analysis, and drug therapy of tumors. Data-independent acquisition (DIA) mode is considered to perform better than data-dependent acquisition (DDA) mode in terms of quantitative reproducibility, specificity, accuracy, and identification of low-abundance proteins. Mini patient derived xenograft (MiniPDX) model is an effective model to assess the response to antineoplastic drugs in vivo and is helpful for the precise treatment of cancer patients. Kinases are favorable spots for tumor-targeted drugs, and their functional completion relies on signaling pathways through phosphorylating downstream substrates. Kinase-phosphorylation networks or edge interactions are considered more credible and permanent for characterizing complex diseases. Here, we provide a workflow for personalized drug response assessment in primary and metastatic colorectal cancer (CRC) tumors using DIA proteomic data, DIA phosphoproteomic data, and MiniPDX models. Three kinase inhibitors, afatinib, gefitinib, and regorafenib, are tested pharmacologically. The process mainly includes the following steps: clinical tissue collection, sample preparation, hybrid spectral libraries establishment, MS data acquisition, kinase-substrate network construction, in vivo drug test, and elastic regression modeling. Our protocol gives a more direct data basis for individual drug responses, and will improve the selection of treatment strategies for patients without the druggable mutation.

DSTN Hypomethylation Promotes Radiotherapy Resistance of Rectal Cancer by Activating the Wnt/ß-Catenin Signaling Pathway.

PURPOSE: Although surgical resection combined with neoadjuvant radiation therapy can reduce the local recurrence rate of rectal cancer, not all patients benefit from neoadjuvant radiation therapy. Therefore, screening for patients with rectal cancer who are sensitive or resistant to radiation therapy has great clinical significance. METHODS AND MATERIALS: Patients with rectal cancer were selected according to postoperative tumor regression grade, and tumor samples were taken for detection. Differential genes between radiation-resistant and radiation-sensitive tissues were screened and validated by Illumina Infinium MethylationEPIC BeadChip, proteomics, Agena MassARRAY methylation, reverse transcription quantitative real-time polymerase chain reaction, and immunohistochemistry. In vitro and in vivo functional experiments verified the role of DSTN. Protein coimmunoprecipitation, western blot, and immunofluorescence were used to investigate the mechanisms of DSTN-related radiation resistance. RESULTS: DSTN was found to be highly expressed (P < .05) and hypomethylated (P < .01) in rectal cancer tissues resistant to neoadjuvant radiation therapy. Follow-up data confirmed that patients with high expression of DSTN in neoadjuvant radiation therapy-resistant rectal cancer tissues had shorter disease-free survival (P < .05). DSTN expression increased after methyltransferase inhibitor inhibition of DNA methylation in colorectal cancer cells (P < .05). In vitro and in vivo experiments showed that knockdown of DSTN promoted the sensitivity of colorectal cancer cells to radiation therapy, and overexpression of DSTN promoted the resistance of colorectal cancer cells to radiation (P < .05). The Wnt/ß-catenin signaling pathway was activated in colorectal cancer cells overexpressing DSTN. ß-catenin was highly expressed in radiation therapy-resistant tissues, and there was a linear correlation between the expression of DSTN and ß-catenin (P < .0001). Further studies showed that DSTN can bind to ß-catenin and increase its stability. CONCLUSIONS: The degree of DNA methylation and the expression level of DSTN can be used as biomarkers to predict the sensitivity of neoadjuvant radiation therapy for rectal cancer. DSTN and ß-catenin are also expected to become a reference for the selection of neoadjuvant radiation therapy.

Single-cell sequencing technology in colorectal cancer: a new technology to disclose the tumor heterogeneity and target precise treatment.

Colorectal Cancer (CRC) is one of the most common gastrointestinal tumors, and its high tumor heterogeneity makes traditional sequencing methods incapable of obtaining information about the heterogeneity of individual cancer cells in CRC. Therefore, single-cell sequencing technology can be applied to better analyze the differences in genetic and protein information between cells, to obtain genomic sequence information of single cells, and to more thoroughly analyze the cellular characteristics and interactions in the CRC microenvironment. This will provide a more comprehensive understanding of colorectal cancer development and metastasis and indicate the treatment plan and prognosis. In this study, we review the application of single-cell sequencing to analyze the tumor microenvironment of CRC, explore the mechanisms involved in CRC metastasis and progression, and provide a reference for potential treatment options.

Neoadjuvant chemoradiation therapy combined with immunotherapy for microsatellite stable ultra-low rectal cancer (CHOICE II): study protocol of a multicentre prospective randomised clinical trial.

INTRODUCTION: Neoadjuvant chemoradiotherapy (nCRT) could bring tumour shrinking and downstaging and increase the probability of organ preservation for patients with low rectal cancer. But for ultra-low rectal cancer, there is little possibility for organ preservation. Immunotherapy has been shown to have significant survival benefits in microsatellite instability-high patients but poor response in microsatellite stable (MSS) patients. Studies have demonstrated that radiotherapy and immunotherapy have synergistic effects in cancer treatment. There is no existing evidence about the clinical efficacy of immunotherapy combined with nCRT for patients with MSS ultra-low rectal cancer. METHOD AND ANALYSIS: This trial is an open-labelled multicentre prospective randomised controlled trial (NCT05215379) with two parallel groups and allocation ratio 1:1 (nCRT+immunotherapy vs nCRT group). Eligible participants will be aged 18-75 years, with a desire for anus preservation, confirmed cT1-3aN0-1M0 rectal adenocarcinoma, confirmed MSS type, inferior margin of ≤5 cm from the anal verge. The primary endpoint of this trial is complete clinical response (cCR) rate. Immunotherapy is added after 1 week of chemoradiotherapy for two cycles, and then the patients will be administered two cycles of immunotherapy and CAPOX. The evaluations will be carried out after the completion of the whole neoadjuvant therapy. We expect the programme to improve the cCR rate and the quality of life for patients with ultra-low rectal cancer. ETHICS AND DISSEMINATION: This trial was approved by the Ethics committee of Changhai Hospital and other medical centres (Grant number:CHEC2022-118). The results of this study will provide further insight into the clinical efficacy of immunotherapy in combination with nCRT in patients with MSS ultra-low rectal cancer. TRIAL REGISTRATION NUMBER: NCT05215379.

An easy-to-use artificial intelligence preoperative lymph node metastasis predictor (LN-MASTER) in rectal cancer based on a privacy-preserving computing platform: multicenter retrospective cohort study.

BACKGROUND: Although the surgical treatment strategy for rectal cancer (RC) is usually based on the preoperative diagnosis of lymph node metastasis (LNM), the accurate diagnosis of LNM has been a clinical challenge. In this study, we developed machine learning (ML) models to predict the LNM status before surgery based on a privacy-preserving computing platform (PPCP) and created a web tool to help clinicians with treatment-based decision-making in RC patients. PATIENTS AND METHODS: A total of 6578 RC patients were enrolled in this study. ML models, including logistic regression, support vector machine, extreme gradient boosting (XGB), and random forest, were used to establish the prediction models. The areas under the receiver operating characteristic curves (AUCs) were calculated to compare the accuracy of the ML models with the US guidelines and clinical diagnosis of LNM. Last, model establishment and validation were performed in the PPCP without the exchange of raw data among different institutions. RESULTS: LNM was detected in 1006 (35.3%), 252 (35.3%), 581 (32.9%), and 342 (27.4%) RC patients in the training, test, and external validation sets 1 and 2, respectively. The XGB model identified the optimal model with an AUC of 0.84 [95% confidence interval (CI), 0.83-0.86] compared with the logistic regression model (AUC, 0.76; 95% CI, 0.74-0.78), random forest model (AUC, 0.82; 95% CI, 0.81-0.84), and support vector machine model (AUC, 0.79; 95% CI, 0.78-0.81). Furthermore, the XGB model showed higher accuracy than the predictive factors of the US guidelines and clinical diagnosis. The predictive XGB model was embedded in a web tool (named LN-MASTER) to predict the LNM status for RC. CONCLUSION: The proposed easy-to-use model showed good performance for LNM prediction, and the web tool can help clinicians make treatment-based decisions for patients with RC. Furthermore, PPCP enables state-of-the-art model development despite the limited local data availability.

Optimal examined lymph node number for accurate staging and long-term survival in rectal cancer: a population-based study.

BACKGROUND: Although the recommended minimal examined lymph node (ELN) number in rectal cancer (RC) is 12, this standard remains controversial because of insufficient evidence. We aimed to refine this definition by quantifying the relationship between ELN number, stage migration and long-term survival in RC. METHODS: Data from a Chinese multi-institutional registry (2009-2018) and the Surveillance, Epidemiology, and End Results (SEER) database (2008-2017) on stages I-III resected RC were analysed to determine the relationship between ELN count, stage migration, and overall survival (OS) using multivariable models. The series of odds ratios (ORs) for negative-to-positive node stage migration and hazard ratios (HRs) for survival with more ELNs were fitted using a Locally Weighted Scatterplot Smoothing (LOWESS) smoother, and structural breakpoints were determined using the Chow test. The relationship between ELN and survival was evaluated on a continuous scale using restricted cubic splines (RCS). RESULTS: The distribution of ELN count between the Chinese registry ( n =7694) and SEER database ( n =21 332) was similar. With increasing ELN count, both cohorts exhibited significant proportional increases from node-negative to node-positive disease (SEER, OR, 1.012, P <0.001; Chinese registry, OR, 1.016, P =0.014) and serial improvements in OS (SEER: HR, 0.982; Chinese registry: HR, 0.975; both P <0.001) after controlling for confounders. Cut-point analysis showed an optimal threshold ELN count of 15, which was validated in the two cohorts, with the ability to properly discriminate probabilities of survival. CONCLUSIONS: A higher ELN count is associated with more precise nodal staging and better survival. Our results robustly conclude that 15 ELNs are the optimal cut-off point for evaluating the quality of lymph node examination and stratification of prognosis.