Gastrointestinal neuroendocrine tumor is a group of heterogeneous tumors and was considered as a rare tumor.According to the data of recent years,its incidence has been increased significantly.The clinical manifestations of gastrointestinal neuroendocrine tumors are varied,and serum chromogranin-A is considered the most important biomarker of both non-functioning and functioning neuroendocrine tumors.The traditional imaging examination and somatostatin receptor scintigraphy are helpful to diagnosis.Its treatments include surgery,biological treatment,radionuclide therapy and chemical therapy.The aim of this paper is to summarize briefly the clinical symptoms,diagnostic methods and treatment options of gastrointestinal neuroendocrine tumors.

Objective To investigate the application and clinical effect of uncut Roux-en-Y (uncut RY) anastomosis in laparoscopic distal radical gastrectomy of gastric cancer.Methods The retrospective crosssectional study was adopted.The clinical data of 23 patients with gastric cancer who were admitted to the Northern Jiangsu People's Hospital from December 2014 to July 2015 were collected.All the 23 patients underwent laparoscopy-assisted distal gastrectomy (LADG) and total laparoscopic distal gastrectomy (TLDG) according to the individual situations.The indexes of observation were collected,including (1) intraoperative indexes:operation time,uncut RY anastomosis time and volume of inraoperative blood loss,(2) postoperative indexes:time to anal exsufflation,time for initial water intake,time for semi-fluid diet intake,time for out-off-bed activity,duration of hospital stay,occurrence of complications and results of pathological examination,(3) results of follow-up.The follow-up was performed by outpatient examination and telephone interview up to November 2015,including postoperative discomfort after diet intake,barium meal examination of gastrointestinal tract at postoperative month 1 (anas-tomotic stenosis,recanalization and dehiscence of occlusion),detecting situations of gastric remnant and anas-tomotic stoma at postoperative month 3 by gastroscopy and occurrence of gastrointestinal obstruction.Measurement data with normal distribution were presented as x ± s.Results (1) Intraoperative situations:all the 23 patients underwent successful uncut RY anastomosis,including 18 receiving LADG and 5 receiving TLDG.The operation time,uncut RY anastomosis time and volume of intraoperative blood loss were (165.9 ± 11.6) minutes,(18.2 ± 2.2) minutes,(48 ± 6) mL in all the 23 patients and (172.0 ± 8.5) minutes,(26.6 ± 1.5) minutes,(46 ± 4) mL in 5 patients with TLDG,respectively.Two patients received hemostatic treatment using suture and hemostatic forceps due to anastomotic bleeding.(2) Postoperative situations:time to anal exsufflation,time for initial water intake,time for semi-fluid diet intake,time for out-off-bed activity,duration of hospital stay and incidence of complications in all the 23 patients were (2.2 ± 0.4) days,(2.7 ± 0.4) days,(3.5 ± 0.4) days,(2.7 ± 0.3) days,(10.6 ± 1.4) days and 8.7％ (2/23),respectively.No patient was dead in the perioperative period.Two patients complicated with incisional infection and high fever were cured by symptomatic treatment,without occurrence of anastomotic leakage,bleeding and anastomotic-related complications.All the patients received postoperative barium meal examination of upper gastrointestinal tract,with unblocked anastomotic stoma and without leakage of barium meal.Diameter of tumor and number of lymph node dissected were (3.2 ± 1.2) cm and 30 ± 4,with negative upper and lower resection margins.Numbers of patients with tumor differentiation,T stage,N stage and TNM stage were 12 and 11 in differentiated and undifferentiated tumors,1,9 and 13 in T1,T2 and T3 stages,9,11 and 3 in N0,N1and N2 stages,1,4,9,6 and 3 in Ⅰ a,Ⅰ b,Ⅱ,Ⅲ a and Ⅲ b stages,respectively.(3) All the 23 patients were followed up by outpatient examination for 3-11 months.One patient had discomfort in upper abdomen with vomiting at postoperative week 3,and no anastomotic leakage,bleeding and anastomotic-related complications were occurred in other patients.Conclusion As a modified anastomotic method,uncut RY anastomosis is safe and feasible,and it is also an ideal method of digestive tract reconstruction after laparoscopic distal radical gastrectomy.

Background/Aims: This study aimed to investigate the biological function and regulatory mechanism of TCN1 in colorectal cancer (CRC). Methods: We studied the biological function of TCN1 by performing gain-of-function and loss-offunction analyses in HCT116 cell lines; examined the effects of TCN1 on the proliferation, apoptosis, and invasion of CRC cells; and determined potential molecular mechanisms using HCT116 and SW480 CRC lines and mouse xenotransplantation models. Tumor xenograft and colonization assays were performed to detect the tumorigenicity and metastatic foci of cells in vivo. Results: TCN1 knockdown attenuated CRC cell proliferation and invasion and promoted cell apoptosis. Overexpression of TCN1 yielded the opposite effects. In addition, TCN1-knockdown HCT116 cells failed to form metastatic foci in the peritoneum after intravenous injection. Molecular mechanism analyses showed that TCN1 interacted with integrin subunit β4 (ITGB4) to positively regulate the expression of ITGB4. TCN1 knockdown promoted the degradation of ITGB4 and increased the instability of ITGB4 and filamin A. Downregulation of ITGB4 at the protein level resulted in the disassociation of the ITGB4/plectin complex, leading to cytoskeletal damage. Conclusions TCN1 might play an oncogenic role in CRC by regulating the ITGB4 signaling pathway.

Background/Aims: Colorectal cancer (CRC) patients often exhibit peritoneal metastasis, which negatively impacts their prognosis. CD31 and D2-40 have recently been suggested to be predictors of breast cancer prognosis, but their role in colorectal peritoneal metastasis (CRPM) remains unknown. Methods: The expression profiles of CD31 and D2-40 were analyzed in CRC patients with or without CRPM and in CRC cell lines with increasing metastatic potential. Overexpression and short hairpin RNA knockdown assays were performed in CRC cells, and the effects of these alterations on epithelial-mesenchymal transition (EMT) in vitro, growth of xenograft tumors in vivo, and peritoneal metastasis potential in a mouse model of CRPM were examined. Results: The expressions of CD31 and D2-40 were upregulated in CRC tumor tissues and was elevated further in tumor tissues from patients with CRPM. CD31 and D2-40 expression levels exhibited increasing trends parallel to the EMT potential of CRC cells. CD31 and D2-40 are essential for CRC cell EMT in vitro as well as for xenograft tumor growth and peritoneal metastasis in vivo. Conclusions CD31 and D2-40 contribute to CRPM by promoting EMT and may serve as prognostic markers and therapeutic targets for CRC, particularly in patients with peritoneal metastasis.

Background: Computer-aided diagnosis based on deep learning technology is a research hotspot in the field of gastroenterology, and computer-aided diagnosis of colorectal polyps has received more and more attention. Aims: To validate a model based on deep learning for the automatic identification of colorectal polyps, and to analyze its auxiliary learning function for helping novice endoscopists. Methods: A total of 1 200 colonoscopy images (600 colorectal polyp images and 600 normal images) in the endoscopy center database of Qingdao Municipal Hospital (East) from January 2019 to January 2020 were retrospectively collected. Deep learning model was used to identify the 1 200 images. The sensitivity, specificity, accuracy and diagnosis time of deep learning model and 5 novice endoscopists for diagnosis of colorectal polyps were compared. Results: The deep learning model showed a sensitivity of 93.2%, specificity of 98.7%, accuracy of 95.9% for detecting colorectal polyps, and the diagnosis time of each image was (0.20±0.03) second. The sensitivity, accuracy, and diagnosis time of the model were superior to 5 novice endoscopists, and the specificity was superior to some novice endoscopists. The accuracies of model for polyps with size ≤5 mm and 6~9 mm were 88.1% and 96.8%, respectively, and were superior to 5 novice endoscopists; the accuracy of model for polyps with size ≥10 mm was 100%, and was similar to 5 novice endoscopists. The accuracy of model for polyps with protrude type was 94.8%, and was superior to some novice endoscopists; the accuracy of model for polyps with flat type was 91.7%, and was superior to 5 novice endoscopists. Missing the polyps with flat type (38.8%), polyps at mucosal folds (32.7%), and mistaking the mucosal folds as polyps (12.2%) were the main causes of false negative or false positive results of the model. Conclusions: The deep learning model has a high accuracy, sensitivity, specificity and shorter diagnosis time for diagnosis of colorectal polyps, and can be used to assist novice endoscopists in diagnosing small polyps and flat polyps.