Genomic landscape defines peritoneal metastatic pattern and related target of peritoneal metastasis in colorectal cancer.

The primary objective of this study is to develop a prediction model for peritoneal metastasis (PM) in colorectal cancer by integrating the genomic features of primary colorectal cancer, along with clinicopathological features. Concurrently, we aim to identify potential target implicated in the peritoneal dissemination of colorectal cancer through bioinformatics exploration and experimental validation. By analyzing the genomic landscape of primary colorectal cancer and clinicopathological features from 363 metastatic colorectal cancer patients, we identified 22 differently distributed variables, which were used for subsequent LASSO regression to construct a PM prediction model. The integrated model established by LASSO regression, which incorporated two clinicopathological variables and seven genomic variables, precisely discriminated PM cases (AUC 0.899; 95% CI 0.860-0.937) with good calibration (Hosmer-Lemeshow test p = .147). Model validation yielded AUCs of 0.898 (95% CI 0.896-0.899) and 0.704 (95% CI 0.622-0.787) internally and externally, respectively. Additionally, the peritoneal metastasis-related genomic signature (PGS), which was composed of the seven genes in the integrated model, has prognostic stratification capability for colorectal cancer. The divergent genomic landscape drives the driver genes of PM. Bioinformatic analysis concerning these driver genes indicated SERINC1 may be associated with PM. Subsequent experiments indicate that knocking down of SERINC1 functionally suppresses peritoneal dissemination, emphasizing its importance in CRCPM. In summary, the genomic landscape of primary cancer in colorectal cancer defines peritoneal metastatic pattern and reveals the potential target of SERINC1 for PM in colorectal cancer.

Development and Validation of a Post-Radiotherapy Prediction Model for Bowel Dysfunction After Rectal Cancer Resection.

BACKGROUND & AIMS: The benefit of radiotherapy for rectal cancer is based largely on a balance between a decrease in local recurrence and an increase in bowel dysfunction. Predicting postoperative disability is helpful for recovery plans and early intervention. We aimed to develop and validate a risk model to improve the prediction of major bowel dysfunction after restorative rectal cancer resection with neoadjuvant radiotherapy using perioperative features. METHODS: Eligible patients more than 1 year after restorative resection following radiotherapy were invited to complete the low anterior resection syndrome (LARS) score at 3 national hospitals in China. Clinical characteristics and imaging parameters were assessed with machine learning algorithms. The post-radiotherapy LARS prediction model (PORTLARS) was constructed by means of logistic regression on the basis of key factors with proportional weighs. The accuracy of the model for major LARS prediction was internally and externally validated. RESULTS: A total of 868 patients reported a mean LARS score of 28.4 after an average time of 4.7 years since surgery. Key predictors for major LARS included the length of distal rectum, anastomotic leakage, proximal colon of neorectum, and pathologic nodal stage. PORTLARS had a favorable area under the curve for predicting major LARS in the internal dataset (0.835; 95% CI, 0.800-0.870, n = 521) and external dataset (0.884; 95% CI, 0.848-0.921, n = 347). The model achieved both sensitivity and specificity >0.83 in the external validation. In addition, PORTLARS outperformed the preoperative LARS score for prediction of major events. CONCLUSIONS: PORTLARS could predict major bowel dysfunction after rectal cancer resection following radiotherapy with high accuracy and robustness. It may serve as a useful tool to identify patients who need additional support for long-term dysfunction in the early stage. CLINICALTRIALS: gov, number NCT05129215.

CXCL16 inhibits epithelial regeneration and promotes fibrosis during the progression of radiation enteritis.

Radiation enteritis (RE) is a prevalent complication of radiotherapy for pelvic malignant tumors, characterized by severe intestinal epithelial destruction and progressive submucosal fibrosis. However, little is known about the pathogenesis of this disease, and so far, there is no specific targeted therapy. Here, we report that CXCL16 is upregulated in the injured intestinal tissues of RE patients and in a mouse model. Genetic deletion of Cxcl16 mitigates fibrosis and promotes intestinal stem cell-mediated epithelial regeneration after radiation injury in mice. Mechanistically, CXCL16 functions on myofibroblasts through its receptor CXCR6 and activates JAK3/STAT3 signaling to promote fibrosis and, at the same time, to transcriptionally modulate the levels of BMP4 and hepatocyte growth factor (HGF) in myofibroblasts. Moreover, we find that CXCL16 and CXCR6 auto- and cross-regulate themselves in positive feedback loops. Treatment with CXCL16 neutralizing monoclonal antibody attenuates fibrosis and improves the epithelial repair in RE mouse model. Our findings emphasize the important role of CXCL16 in the progression of RE and suggest that CXCL16 signaling could be a potential therapeutic target for RE. © 2022 The Pathological Society of Great Britain and Ireland.

CT-based deep learning model for the prediction of DNA mismatch repair deficient colorectal cancer: a diagnostic study.

BACKGROUND: Stratification of DNA mismatch repair (MMR) status in patients with colorectal cancer (CRC) enables individual clinical treatment decision making. The present study aimed to develop and validate a deep learning (DL) model based on the pre-treatment CT images for predicting MMR status in CRC. METHODS: 1812 eligible participants (training cohort: n = 1124; internal validation cohort: n = 482; external validation cohort: n = 206) with CRC were enrolled from two institutions. All pretherapeutic CT images from three dimensions were trained by the ResNet101, then integrated by Gaussian process regression (GPR) to develop a full-automatic DL model for MMR status prediction. The predictive performance of the DL model was evaluated using the area under the receiver operating characteristic curve (AUC) and then tested in the internal and external validation cohorts. Additionally, the participants from institution 1 were sub-grouped by various clinical factors for subgroup analysis, then the predictive performance of the DL model for identifying MMR status between participants in different groups were compared. RESULTS: The full-automatic DL model was established in the training cohort to stratify the MMR status, which presented promising discriminative ability with the AUCs of 0.986 (95% CI 0.971-1.000) in the internal validation cohort and 0.915 (95% CI 0.870-0.960) in the external validation cohort. In addition, the subgroup analysis based on the thickness of CT images, clinical T and N stages, gender, the longest diameter, and the location of tumors revealed that the DL model showed similar satisfying prediction performance. CONCLUSIONS: The DL model may potentially serve as a noninvasive tool to facilitate the pre-treatment individualized prediction of MMR status in patients with CRC, which could promote the personalized clinical-making decision.

Medical Management of Inoperable Malignant Bowel Obstruction.

OBJECTIVE: To review medical management of inoperable malignant bowel obstruction. DATA SOURCES: A literature review using PubMed and MEDLINE databases searching malignant bowel obstruction, etiology, types, pathophysiology, medical, antisecretory, anti-inflammatory, antiemetic drugs, analgesics, promotion of emptying, prevention of infection, anticholinergics, somatostatin analogs, gastric antisecretory drugs, prokinetic agents, glucocorticoid, opioid analgesics, antibiotics, enema, and adverse effects. STUDY SELECTION AND DATA EXTRACTION: Randomized or observational studies, cohorts, case reports, or reviews written in English between 1983 and November 2020 were evaluated. DATA SYNTHESIS: Malignant bowel obstruction (MBO) commonly occurs in patients with advanced or recurrent malignancies and severely affects the quality of life and survival of patients. Its management remains complex and variable. Medical management is the cornerstone of MBO treatment, with the goal of reducing distressing symptoms and optimizing quality of life. Until now, there has been neither a standard clinical approach nor registered medications to treat patients with inoperable MBO. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: This review provides information on the etiology, type and pathophysiology, and medical treatment of MBO and related adverse reactions of the drugs commonly used, which can greatly assist clinicians in making clinical decisions when treating MBO. CONCLUSIONS: Published research shows that medical management of MBO mainly consists of antisecretory, anti-inflammatory strategies, controlling vomiting and pain, promoting emptying, preventing infection, and combination therapy. Being knowledgeable about the most current treatment options, the related adverse effects, and the evidence supporting different practices is critical for clinicians to provide individualized medical therapy for MBO patients.

Diverting colostomy is an effective procedure for ulcerative chronic radiation proctitis patients after pelvic malignancy radiation.

BACKGROUND: Chronic radiation proctitis (CRP) with rectal ulcer is a common complication after pelvic malignancy radiation, and gradually deteriorating ulcers will result in severe complications such as fistula. The aim of this study was to evaluate effect of colostomy on ulcerative CRP and to identify associated influence factors with effectiveness of colostomy. METHODS: Between November 2011 to February 2019, 811 hospitalized patients were diagnosed with radiation-induced enteritis (RE) in Sun Yat-sen University Sixth Affiliated Hospital, among which 284 patients presented with rectal ulcer, and 61 ulcerative CRP patients were retrospectively collected and analyzed. RESULTS: The overall effective rate of colostomy on ulcerative CRP was 49.2%, with a highest effective rate of 88.2% within 12 to 24 months after colostomy. 9 (31.1%) CRP patients with ulcers were cured after colostomy and 12 (19.67%) patients restored intestinal continuity, among which including 2 (3.3%) patients ever with rectovaginal fistula. 100% (55/55) patients with rectal bleeding and 91.4% (32/35) patients with anal pain were remarkably alleviated. Additionally, multivariable analysis showed the duration of stoma [OR 1.211, 95% CI (1.060-1.382), P = 0.005] and albumin (ALB) level post-colostomy [OR 1.437, 95% CI (1.102-1.875), P = 0.007] were two independent influence factors for the effectiveness of colostomy on the rectal ulcer of CRP patients. CONCLUSIONS: Colostomy was an effective and safe procedure for treating rectal ulcer of CRP patients, and also a potential strategy for preventing and treating fistula. Duration of stoma for 12-24 months and higher ALB level could significantly improve the effectiveness of colostomy on ulcerative CRP patients.

Clinical Anastomotic Leakage After Rectal Cancer Resection Can Be Predicted by Pelvic Anatomic Features on Preoperative MRI Scans: A Secondary Analysis of a Randomized Controlled Trial.

BACKGROUND: We demonstrated previously that radiation proctitis induced by preoperative radiotherapy is a predisposing factor for clinical anastomotic leakage in patients undergoing rectal cancer resection. Quantitative measurement of radiation proctitis is needed. OBJECTIVE: This study aimed to quantitate the changes of anatomic features caused by preoperative radiotherapy for rectal cancer and evaluate its ability to predict leakage. DESIGN: It was a secondary analysis of a randomized controlled trial (NCT01211210). MRI variables were retrospectively assessed. SETTINGS: The study was conducted in the leading center of the trial, which is a tertiary GI hospital. PATIENTS: Patients undergoing preoperative chemoradiation with sphincter-preserving surgery were included. MAIN OUTCOME MEASURES: Anatomic features were measured by preradiotherapy and postradiotherapy MRI. Univariate analyses were used to identify prognostic factors. Receiver operating characteristic curves were constructed to determine the cutoff value of the changes of MRI variables in predicting leakage. RESULTS: Eighteen (14.4%) of the 125 included patients developed clinical anastomotic leakage. Baseline characteristics were comparable between leakage group and nonleakage group. Relative increments of width of presacral space, thickness of rectal wall, and distal end of sigmoid colon discriminate between the 2 groups better than random chance. Relative increments of width of presacral space was the best performing predictor, with area under the curve of 0.722, sensitivity of 66.7%, specificity of 72.0%, and positive and negative predictive value of 28.6% and 92.8%. LIMITATIONS: The study was limited by its small sample size and retrospective design. CONCLUSIONS: Increments of the width of the presacral space, thickness of rectal wall, and distal part of the sigmoid colon helps to identify individuals not at risk for clinical anastomotic leakage after rectal cancer resection. The first variable is the strongest predictor. Changes of these variables should be taken into consideration when evaluating the application of defunctioning stoma. See Video Abstract at http://links.lww.com/DCR/B23. CLINICAL TRIALS IDENTIFIER: NCT1211210. LAS FUGAS ANASTOMÓTICAS CLÍNICAS DESPUÉS DE LA RESECCIÓN DEL CÁNCER DEL RECTO PUEDEN PREDECIRSE POR LAS CARACTERÍSTICAS ANATÓMICAS PÉLVICAS EN LAS IMAGENES DE RESONANCIA MAGNÉTICA PREOPERATORIA: UN ANÁLISIS SECUNDARIO DE UN ESTUDIO CONTROLADO ALEATORIZADO:: Anteriormente demostramos que la proctitis inducida por la radiación de radioterapia preoperatoria es un factor predisponente para la fuga anastomótica clínica en pacientes sometidos a resección de cáncer rectal. Es necesaria la medición cuantitativa de la proctitis por radiación.Este estudio tuvo como objetivo cuantificar los cambios en las características anatómicas causados por la radioterapia preoperatoria para el cáncer de recto y evaluar su capacidad para predecir las fugas anastomoticas.Fue un análisis secundario de un estudio controlado aleatorio (NCT01211210). Los variables de imagines de resonancia magnetica se evaluaron retrospectivamente.Se llevó a cabo en el centro principal del estudio, que es un hospital gastrointestinal terciario.Se incluyeron pacientes sometidos a quimiorradiación preoperatoria con cirugía conservadora del esfínter.Las características anatómicas se midieron mediante imagines de resonancia magnetica previa y posterior a la radioterapia. Se utilizaron análisis univariados para identificar los factores pronósticos. Las curvas de características operativas del receptor se construyeron para determinar el valor de corte de los cambios de los variables de resonancia magnetica en la predicción de fugas.Dieciocho (14.4%) de los 125 pacientes incluidos desarrollaron fugas anastomóticas clínicas. Las características basales fueron comparables entre el grupo de fugas y el grupo de no fugas. Los incrementos relativos del ancho del espacio presacro, el grosor de la pared rectal y distal del colon sigmoide discriminan entre los dos grupos mejor que la posibilidad aleatoria. Los incrementos relativos del ancho del espacio presacro fueron el mejor pronóstico con un AUC de 0.722, sensibilidad del 66.7%, especificidad del 72.0%, valor predictivo positivo y negativo del 28.6% y 92.8%.Estaba limitado por el tamaño de muestra pequeño y el diseño retrospectivo.Los incrementos en el ancho del espacio presacro, el grosor de la pared rectal y la parte distal del colon sigmoide ayudan a identificar a las personas que no tienen riesgo de fuga anastomótica clínica después de la resección del cáncer rectal. La primera variable es el predictor más fuerte. Los cambios de estos variables deben tenerse en cuenta al evaluar la aplicación del estoma para desvio. Vea el Resumen del Video en http://links.lww.com/DCR/B23.

Bowel Dysfunction After Low Anterior Resection With Neoadjuvant Chemoradiotherapy or Chemotherapy Alone for Rectal Cancer: A Cross-Sectional Study from China.

BACKGROUND: Neoadjuvant therapy plays a vital role in the treatment of locally advanced rectal cancer but impairs bowel function after restorative surgery. Optimal decision making requires adequate information of functional outcomes. OBJECTIVE: This study aimed to assess postoperative bowel function and to identify predictors for severe dysfunction. DESIGN: The study included a cross-sectional cohort and retrospective assessments of pelvic anatomic features. SETTINGS: The study was conducted at a tertiary GI hospital in China. PATIENTS: Included patients underwent neoadjuvant chemoradiotherapy or chemotherapy without radiation and curative low anterior resection for rectal cancer between 2012 and 2014. MAIN OUTCOME MEASURES: Bowel function was assessed using the validated low anterior resection syndrome score. The thicknesses of the rectal wall, obturator internus, and levator ani were measured by preoperative MRI. RESULTS: A total of 151 eligible patients were identified, and 142 patients (94.0%) participated after a median of 19 months from surgery. Bowel dysfunction was observed in 71.1% (101/142) of patients, with 44.4% (63/142) reporting severe dysfunction. Symptoms of urgency and clustering were found to be major disturbances. Regression analysis identified preoperative long-course radiotherapy (p < 0.001) and a lower-third tumor (p = 0.002) independently associated with severe bowel dysfunction. Irradiated patients with a lower-third tumor (OR = 14.06; p < 0.001) or thickening of the rectal wall (OR = 11.09; p < 0.001) had a markedly increased risk of developing severe dysfunction. LIMITATIONS: The study was based on a limited cohort of patients and moderate follow-up after the primary surgery. CONCLUSIONS: Bowel function deteriorates frequently after low anterior resection for rectal cancer. Severe bowel dysfunction is significantly associated with preoperative long-course radiotherapy and a lower-third tumor, and the thickening of rectal wall after radiation is a strong predictor. Treatment decisions and patient consent should be implemented with raising awareness of bowel symptom burdens. See Video Abstract at http://links.lww.com/DCR/A317.

Restorative resection of radiation rectovaginal fistula can better relieve anorectal symptoms than colostomy only.

BACKGROUND: Radiation-induced rectovaginal fistula (RVF) is a severe and difficult complication after pelvic malignancy radiation. This study was to retrospectively compare the outcomes of restorative resection and colostomy only in remission of anorectal symptoms. METHODS: We enrolled a cohort of 26 consecutive cases who developed RVF after pelvic radiation. Two main procedures for these patients in our institution were used: one was restorative resection and pull-through coloanal anastomosis with a prophylactic colostomy, and another was a simple colostomy without resection. Thus, we divided these patients into these two groups. Anorectal symptoms including rectal pain, bleeding, tenesmus, and perineal mucous discharge were recorded and scored prior to surgery and at postoperative multiple time points. RESULTS: The baseline was similar among the two groups. All patients acquired good efficacy with improved symptoms at postoperative 6, 12, and 24 months, when compared to baseline. In addition, the resection group showed a better remission of tenesmus (6 months 33.3 vs 0%; 12 months 66.7 vs 16.7%) and perineal mucous discharge (6 months 88.9 vs 6.7%; 12 months 77.8 vs 15.4%; 24 months 85.7 vs 25.0%). Furthermore, three (30%) patients in the resection group successfully reversed stomas while no stoma was closed in the simple colostomy group. CONCLUSIONS: Both restorative resection procedure and colostomy only can improve anorectal symptoms of radiation-induced RVF, but restorative resection can completely relieve anorectal symptoms in selected cases.

Impact of Preoperative Radiotherapy on Anastomotic Leakage and Stenosis After Rectal Cancer Resection: Post Hoc Analysis of a Randomized Controlled Trial.

BACKGROUND: Evidence regarding the effect of preoperative radiotherapy on anastomotic integrity remains conflicting in rectal cancer surgery. Prospective comparisons with appropriate controls are needed. OBJECTIVE: This study aimed to assess the impact of preoperative radiotherapy on anastomotic leakage and stenosis after rectal cancer resection. DESIGN: This was a post hoc analysis of a randomized controlled trial (NCT01211210). SETTINGS: Data were retrieved from the leading center of the trial, which is a tertiary hospital. PATIENTS: The full analysis population of 318 patients was included. INTERVENTIONS: Patients were randomly assigned to receive preoperative radiation (50 Gy per 25 fractions) and 5-fluorouracil infusion, alone (arm A) or combined with oxaliplatin (arm B), or preoperative chemotherapy with 5-fluorouracil and oxaliplatin without radiation (arm C). MAIN OUTCOME MEASURES: The rates of anastomotic leakage and stenosis were calculated for each treatment arm. Multivariate analysis was used to verify the effect of preoperative radiotherapy. RESULTS: The treatment arms were comparable in terms of most baseline characteristics, but more diversions were used in the chemoradiotherapy arms. Anastomotic leakage occurred in 20.2% of patients in arm A, 23.6% of patients in arm B, and 8.5% of patients in arm C (p = 0.007). The corresponding rates of stenosis were 17.0%, 18.9%, and 6.8% (p = 0.02). Multivariate analysis confirmed the correlation between preoperative radiotherapy and clinical leakage (p = 0.02), which was associated with delayed stenosis (p < 0.001). For patients undergoing chemoradiotherapy, radiation proctitis was identified as an independent risk factor for clinical leakage (p = 0.01) and stenosis (p < 0.001). LIMITATIONS: The main limitations were discrepancies in stoma creation and chemotherapy regimen among the treatment arms. CONCLUSIONS: Preoperative radiotherapy increases the risk of anastomotic leakage and stenosis after rectal cancer resection. Clinical leakage independently contributes to the development of stenosis.

Molecular mechanism of acute radiation enteritis revealed using proteomics and biological signaling network analysis in rats.

BACKGROUND AND AIMS: Radiation enteritis (RE) has emerged as a significant complication that can progress to severe gastrointestinal disease and the mechanisms underlying its genesis remain poorly understood. The aim of this study was to identify temporal changes in protein expression potentially associated with acute inflammation and to elucidate the mechanism underlying radiation enteritis genesis. METHODS: Male Sprague-Dawley rats were irradiated in the abdomen with a single dose of 10 Gy to establish an in vivo model of acute radiation enteritis. Two-dimensional fluorescence difference gel electrophoresis, matrix-assisted laser desorption/ionization time-of-flight spectrometer (MALDI-TOF) tandem mass spectrometry, and peptide mass fingerprinting were used to determine differentially expressed proteins between normal and inflamed intestinal mucosa. Additionally, differentially expressed proteins were evaluated by KO Based Annotation System to find the biological functions associated with acute radiation enteritis. RESULTS: Intensity changes of 86 spots were detected with statistical significance (ratio ≥ 1.5 or ≤ 1.5, P < 0.05). Sixty one of the 86 spots were identified by MALDI-TOF/TOF tandem mass spectrometry. These radiation-induced proteins with biological functions showed that the FAS pathway and glycolysis signaling pathways were significantly altered using the KOBAS tool. CONCLUSIONS: Our results reveal an underlying mechanism of radiation-induced acute enteritis, which may help clarify the pathogenesis of RE and point to potential targets for therapeutic interventions.

Evaluation of transrectal ultrasound-guided tru-cut biopsy as a complementary method for predicting pathological complete response in rectal cancer after neoadjuvant treatment: a phase II prospective and diagnostic trial.

IMPORTANCE: Patients with pathological complete response (pCR) of rectal cancer following neoadjuvant treatment had better oncological outcomes. However, reliable methods for accurately predicting pCR remain limited. OBJECTIVE: To evaluate whether transrectal ultrasound-guided tru-cut biopsy (TRUS-TCB) adds diagnostic value to conventional modalities for predicting pathological complete response in patients with rectal cancer after neoadjuvant treatment. DESIGN, SETTING, AND PARTICIPANTS: This study evaluated data of patients with rectal cancer who were treated with neoadjuvant treatment and reassessed using TRUS-TCB and conventional modalities before surgery. This study is registered with ClinicalTrials.gov. MAIN OUTCOMES AND MEASURES: The primary outcome was accuracy, along with secondary outcomes including sensitivity, specificity, negative predictive value, and positive predictive value in predicting tumour residues. Final surgical pathology was used as reference standard. RESULTS: Between June 2021 and June 2022, a total of 74 patients were enroled, with 63 patients ultimately evaluated. Among them, 17 patients (28%) exhibited a complete pathological response. TRUS-TCB demonstrated an accuracy of 0.71 (95% CI, 0.58-0.82) in predicting tumour residues. The combined use of TRUS-TCB and conventional modalities significantly improved diagnostic accuracy compared to conventional modalities alone (0.75 vs. 0.59, P =0.02). Furthermore, TRUS-TCB correctly reclassified 52% of patients erroneously classified as having a complete clinical response by conventional methods. The occurrence of only one mild adverse event was observed. CONCLUSIONS AND RELEVANCE: TRUS-TCB proves to be a safe and accessible tool for reevaluation with minimal complications. The incorporation of TRUS-TCB alongside conventional methods leads to enhanced diagnostic performance.

Unsupervised Learning Composite Network to Reduce Training Cost of Deep Learning Model for Colorectal Cancer Diagnosis.

Deep learning facilitates complex medical data analysis and is increasingly being explored in colorectal cancer diagnostics. However, the training cost of the deep learning model limits its real-world medical utility. In this study, we present a composite network that combines deep learning and unsupervised K-means clustering algorithm (RK-net) for automatic processing of medical images. RK-net was more efficient in image refinement compared with manual screening and annotation. The training of a deep learning model for colorectal cancer diagnosis was accelerated by two times with utilization of RK-net-processed images. Better performance was observed in training loss and accuracy achievement as well. RK-net could be useful to refine medical images of the ever-expanding quantity and assist in subsequent construction of the artificial intelligence model.

Peritoneal cell-free DNA as a sensitive biomarker for detection of peritoneal metastasis in colorectal cancer: a prospective diagnostic study: A prospective diagnostic study.

BACKGROUND: The detection of peritoneal metastasis (PM) is limited by current imaging tools. In this prospective study, we aimed to evaluate the sensitivity and specificity of peritoneal cell-free DNA (cfDNA) for diagnosis of PM. METHODS: Colorectal cancer (CRC) patients with/without PM were enrolled. The cfDNA experimental personnel and statists were blinded to the diagnosis of PM. Ultradeep sequencing covering large genomic regions (35000X, Next-generation sequencing) of cfDNA in peritoneal lavage fluid (FLD) and matched tumor tissues was performed. RESULTS: A total of 64 cases were recruited prospectively and 51 were enrolled into final analysis. In training cohort, 100% (17/17) PM patients obtained positive FLD cfDNA, comparing to 5/23 (21.7%) in patients without PM. Peritoneal cfDNA had a high sensitivity of 100% and specificity of 77.3% for diagnosis of PM (AUC: 0.95). In validation group of 11, 5/6 (83%) patients with PM obtained positive FLD cfDNA, comparing to 0/5 in non-PM (P = 0.031) with a sensitivity of 83.3% and specificity of 100%. Positive FLD cfDNA was associated with poor recurrence-free survival (P = 0.013) and was preceding radiographic evidence of recurrence. CONCLUSIONS: Peritoneal cfDNA is a promising sensitive biomarker for earlier detection of PM in CRC than current radiological tools. It can potentially guide selection for targeted therapies and serve as a surrogate instead of laparoscopic explore in the future. Trial Registration Chinese Clinical Trial Registry at chictr.org.cn (ChiCTR2000035400). URL: http://www.chictr.org.cn/showproj.aspx?proj=57626.

Identification of immune cell function in breast cancer by integrating multiple single-cell data.

Breast cancer has now become the most commonly diagnosed cancer worldwide. It is a highly complex and heterogeneous disease that comprises distinct histological features and treatment response. With the development of molecular biology and immunology, immunotherapy has become a new field of breast cancer treatment. Identifying cell-type-specific genes critical to the immune microenvironment contributes to breast cancer treatment. Single-cell RNA sequencing (scRNA-seq) technology could serve as a powerful tool to analyze cellular genetic information at single-cell resolution and to uncover the gene expression status of each cell, thus allowing comprehensive assessment of intercellular heterogeneity. Because of the influence of sample size and sequencing depth, the specificity of genes in different cell types for breast cancer cannot be fully revealed. Therefore, the present study integrated two public breast cancer scRNA-seq datasets aiming to investigate the functions of different type of immune cells in tumor microenvironment. We identified total five significant differential expressed genes of B cells, T cells and macrophage and explored their functions and immune mechanisms in breast cancer. Finally, we performed functional annotation analyses using the top fifteen differentially expressed genes in each immune cell type to discover the immune-related pathways and gene ontology (GO) terms.

Serial Circulating Tumor DNA in Monitoring the Effect of Neoadjuvant and Adjuvant Immunotherapy in Patients With Colon Cancer: Case Series and Review of the Literature.

Although programmed death 1 blockade has significantly improved the survival of advanced colorectal cancer patients with DNA mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H), clinical data in neoadjuvant and adjuvant setting are limited. The role of circulating tumor DNA (ctDNA) in precision oncology is promising, but its clinical significance in immunotherapy needs to be validated. We report a case series of 3 colon patients who received neoadjuvant and adjuvant immunotherapy and serial ctDNA analysis. This report summarizes clinical and molecular details for 3 patients with locally advanced or recurrent dMMR/MSI-H/polymerase epsilon ( POLE ) mutation-positive tumors treated with neoadjuvant/adjuvant immunotherapy. One stage IV recurrent colon cancer patient diagnosed with Lynch syndrome received adjuvant sintilimab monotherapy and had a progression-free survival (PFS) over 16 months, one stage Ⅲc colon cancer patient with MSI-H/high tumor mutation burden received neoadjuvant toripalimab monotherapy, was assessed as clinical complete response before surgery, continued with adjuvant sintilimab monotherapy and had a PFS over 17 months, one stage Ⅱ colon cancer patient with POLE P286R also received adjuvant sintilimab monotherapy and had a PFS over 17 months. All patients had detectable ctDNA after radical surgery and clearance of ctDNA during adjuvant immunotherapy. All 3 patients are free of tumor disease at the time of this report. Further studies are warranted to evaluate the long-term efficacy of neoadjuvant and adjuvant programmed death 1 blockade in locally advanced and metastasis in dMMR/MSI-H/ POLE mutated colorectal cancer and the role of ctDNA monitoring.

Laparoscopic Proximally Extended Colorectal Resection With Two-Stage Turnbull-Cutait Pull-Through Coloanal Anastomosis for Late Complications of Chronic Radiation Proctopathy.

Background: Chronic radiation proctopathy (CRP) is a common complication after radiation therapy for pelvic malignancies. Compared with diversion surgery, resection surgery removes the damaged tissue completely to avoid the risks of recurrence and improve patients' outcome. Hence, resection surgery could be an optimal surgical approach when CRP is complicated by late complications. This study aimed to describe a modified surgical procedure of resection surgery and report its preliminary efficacy and safety in treating patients with CRP with late complications. Methods: We retrospectively reviewed the patients who were diagnosed with CRP with late complications and underwent the modified surgical procedure of laparoscopic proximally extended colorectal resection with two-Stage Turnbull-Cutait pull-through coloanal anastomosis (PE-Bacon) between November 2019 and October 2020 in the Sixth Affiliated Hospital of Sun Yat-sen University. Results: A total of 15 patients were performed the modified laparoscopic procedure of PE-Bacon, of which 1 patient underwent conversion from laparoscopic to open operation for intraoperative massive hemorrhage. Overall, the major (Clavien-Dindo III-V) postoperative complications occurred in 1 patient, anastomotic leakage was observed in 2 (13.3%) patients, and anastomotic stricture was observed in 4 (26.7%) patients. No patient had to be reoperated and died. Up to now, at the average follow-up of (524.40 ± 108.39) days, the preoperative symptoms of 93.3% (14/15) patients were relieved, with nine patients achieved complete remission, five patients only suffered minor symptoms. Because of the progression of radiation uropathy, one patient still had a vesicovaginal fistula as pre-operative complication. Colostomy reversal has been performed on 8 (53.3%) patients at an average postoperative duration of 299.5 ± 92.68 days, among whom only 2 patients suffered from major Low Anterior Resection Syndrome (LARS) until now. Conclusions: Laparoscopic PE-Bacon surgery is a safe and feasible surgical procedure for late complications of CRP with low morbidity and high symptom remission rate.

Expression Pattern and Prognostic Value of CTLA-4, CD86, and Tumor-Infiltrating Lymphocytes in Rectal Cancer after Neoadjuvant Chemo(radio)therapy.

The synergistic effect of combining immune checkpoint inhibitors (ICIs) with neoadjuvant chemo(radio)therapy (nCRT) in colorectal cancer is still limited. We aimed to understand the impact of nCRT on the tumor microenvironment and to explore favorable immune markers of this combination. Herein, we investigated the expression of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), CD86, CD4, and CD8 after nCRT and its association with clinicopathological characteristics. Immunostaining of immune-related molecules was performed in 255 surgically resected specimens from rectal cancer patients treated with nCRT. CD4 and CD8 expression on the tumor (tCD4/CD8), stroma (sCD4/CD8), and invasive front (iCD4/CD8) was evaluated. The expression levels of immune-related molecules were significantly lower in the nCRT-treated group, except for CTLA-4 and sCD8. However, patients with higher sCD8+ cell density and CTLA-4 expression had better progression-free survival (PFS) and distant metastasis-free survival (DMFS). In addition, higher CD86 expression was associated with poorer overall survival (OS). Higher CTLA-4 expression was associated with higher tCD8+ cell density, whereas CD86 expression was correlated with the cell density of t/sCD8. Prognostic analysis confirmed that the relationships between CTLA-4 and DMFS as well as CD86 and OS were significantly correlated in low rather than high CD8+ cell density. Further the combination of CD8+ cell density and CD86 expression was shown to be an independent prognostic factor of OS, whereas the combination of CTLA-4 was not for DMFS. Together, these results demonstrate significant correlations between CD86 expression and t/sCD8+ cell density in rectal cancer after nCRT and could potentially have clinical implications for combining ICIs and nCRT.

Risk Factors of Delayed Recovery of Gastrointestinal Function After Ileostomy Reversal for Rectal Cancer Patients.

PURPOSE: The aim of this study was to identify the risk factors associated with delayed recovery of gastrointestinal function after ileostomy reversal for rectal cancer patients. METHODS: In this retrospective study, the data of rectal cancer patients who underwent ileostomy reversal from January 2018 to December 2019 at the Sixth Affiliated Hospital of Sun Yat-sen University were assessed to investigate potential risk factors of delayed flatus after ileostomy reversal. RESULTS: A total of 282 patients were eligible for this study. Postoperative first flatus time ranged from 1 to 9 days, of which 58.8% patients presented with delayed flatus that was longer than 3 days. Univariate analysis showed that delayed postoperative flatus was significantly associated with the length of postoperative hospital stay (P<0.001) and postoperative complications (P=0.037). Multivariate analysis showed that intravenous fluid infusion at postoperative day 1 (POD1) (OR=1.001, 95% CI: 1.001-1.002, P=0.001) and duration of stoma ≥6 months (OR=2.005, 95% CI:1.155-3.657, P=0.014) were independent risk factors for delayed flatus. CONCLUSION: Increased intravenous fluid infusion at POD1 and duration of stoma ≥6 months were related to delayed recovery of gastrointestinal function after ileostomy reversal for rectal cancer patients.

ROS/JNK/C-Jun Pathway is Involved in Chaetocin Induced Colorectal Cancer Cells Apoptosis and Macrophage Phagocytosis Enhancement.

There is an urgent need for novel agents for colorectal cancer (CRC) due to the increasing number of cases and drug-resistance related to current treatments. In this study, we aim to uncover the potential of chaetocin, a natural product, as a chemotherapeutic for CRC treatment. We showed that, regardless of 5-FU-resistance, chaetocin induced proliferation inhibition by causing G2/M phase arrest and caspase-dependent apoptosis in CRC cells. Mechanically, our results indicated that chaetocin could induce reactive oxygen species (ROS) accumulation and activate c-Jun N-terminal kinase (JNK)/c-Jun pathway in CRC cells. This was confirmed by which the JNK inhibitor SP600125 partially rescued CRC cells from chaetocin induced apoptosis and the ROS scavenger N-acetyl-L-cysteine (NAC) reversed both the chaetocin induced apoptosis and the JNK/c-Jun pathway activation. Additionally, this study indicated that chaetocin could down-regulate the expression of CD47 at both mRNA and protein levels, and enhance macrophages phagocytosis of CRC cells. Chaetocin also inhibited tumor growth in CRC xenograft models. In all, our study reveals that chaetocin induces CRC cell apoptosis, irrelevant to 5-FU sensitivity, by causing ROS accumulation and activating JNK/c-Jun, and enhances macrophages phagocytosis, which suggests chaetocin as a candidate for CRC chemotherapy.