Novel subtype of obesity influencing the outcomes of sleeve gastrectomy:Familial aggregation of obesity

BACKGROUND Differences in the preoperative characteristics and weight loss outcomes after sleeve gastrectomy(SG)between patients with familial aggregation of obesity(FAO)and patients with sporadic obesity(SO)have not been elucidated.AIM To explore the impact of SG on weight loss and the alleviation of obesity-related comorbidities in individuals with FAO.METHODS A total of 193 patients with obesity who underwent SG were selected.Patients with FAO/SO were matched 1:1 by propensity score matching and were categorized into 4 groups based on the number of first-degree relatives with obesity(1 SO vs 1FAO,2SO vs 2FAO).The baseline characteristics,weight loss outcomes,prevalence of obesity-related comorbidities and incidence of major surgeryrelated complications were compared between groups.RESULTS We defined FAO as the presence of two or more first-degree relatives with obesity.Patients with FAO did not initially show significant differences in baseline data,short-term postoperative weight loss,or obesity-related comorbidities when compared to patients with SO preoperatively.However,distinctions between the two groups became evident at the two-year mark,with statistically significant differences in both percentage of total weight loss(P=0.006)and percentage of excess weight loss(P<0.001).The FAO group exhibited weaker remission of type 2 diabetes mellitus(T2DM)(P=0.031),hyperlipidemia(P=0.012),and non-alcoholic fatty liver disease(NAFLD)(P=0.003)as well as a lower incidence of acid reflux(P=0.038).CONCLUSION FAO patients is associated with decreased mid-to-long-term weight loss outcomes;the alleviation of T2DM,hyperlipidemia and NAFLD;and decreased incidence of acid reflux postoperatively.

Khubchandani's procedure combined with stapled posterior rectal wall resection for rectocele

BACKGROUND Obstructed defecation syndrome(ODS) is a widespread disease in the world.Rectocele is the most common cause of ODS in females. Multiple procedures have been performed to treat rectocele and no procedure has been accepted as the gold-standard procedure. Stapled transanal rectal resection(STARR) has been widely used. However, there are still some disadvantages in this procedure and its effectiveness in anterior wall repair is doubtful. Therefore, new procedures are expected to further improve the treatment of rectocele.AIM To evaluate the efficacy and safety of a novel rectocele repair combining Khubchandani's procedure with stapled posterior rectal wall resection.METHODS A cohort of 93 patients were recruited in our randomized clinical trial and were divided into two different groups in a randomized manner. Forty-two patients(group A) underwent Khubchandani's procedure with stapled posterior rectal wall resection and 51 patients(group B) underwent the STARR procedure.Follow-up was performed at 1, 3, 6, and 12 mo after the operation. Preoperative and postoperative ODS scores and depth of rectocele, postoperative complications, blood loss, and hospital stay of each patient were documented. All data were analyzed statistically to evaluate the efficiency and safety of our procedure.RESULTS In group A, 42 patients underwent Khubchandani's procedure with stapled posterior rectal wall resection and 34 were followed until the final analysis. In group B, 51 patients underwent the STARR procedure and 37 were followed until the final analysis. Mean operative duration was 41.47 ± 6.43 min(group A) vs39.24 ± 6.53 min(group B). Mean hospital stay was 3.15 ± 0.70 d(group A) vs 3.14± 0.54 d(group B). Mean blood loss was 10.91 ± 2.52 mL(group A) vs 10.14 ± 1.86 m L(group B). Mean ODS score in group A declined from 16.50 ± 2.06 before operation to 5.06 ± 1.07 one year after the operation, whereas in group B it was17.11 ± 2.57 before operation and 6.03 ± 2.63 one year after the operation. Mean depth of rectocele decreased from 4.32 ± 0.96 cm(group A) vs 4.18 ± 0.95 cm(group B) preoperatively to 1.19 ± 0.43 cm(group A) vs 1.54 ± 0.82 cm(group B)one year after operation. No other serious complications, such as rectovaginal fistula, perianal sepsis, or deaths, were recorded. After 12 mo of follow-up, 30 patients'(30/34, 88.2%) final outcomes were judged as effective and 4(4/34,11.8%) as moderate in group A, whereas in group B, 30(30/37, 81.1%) patients' outcomes were judged as effective, 5(5/37, 13.5%) as moderate, and 2(2/37,5.4%) as poor.CONCLUSION Khubchandani's procedure combined with stapled posterior rectal wall resection is an effective, feasible, and safe procedure with minor trauma to rectocele.

F-box only protein 2 exacerbates non-alcoholic fatty liver disease by targeting the hydroxyl CoA dehydrogenase alpha subunit

BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a major health burden with an increasing global incidence.Unfortunately,the unavailability of knowledge underlying NAFLD pathogenesis inhibits effective preventive and therapeutic measures.AIM To explore the molecular mechanism of NAFLD.METHODS Whole genome sequencing(WGS)analysis was performed on liver tissues from patients with NAFLD(n=6)and patients with normal metabolic conditions(n=6)to identify the target genes.A NAFLD C57BL6/J mouse model induced by 16 wk of high-fat diet feeding and a hepatocyte-specific F-box only protein 2(FBXO2)overexpression mouse model were used for in vivo studies.Plasmid transfection,co-immunoprecipitation-based mass spectrometry assays,and ubiquitination in HepG2 cells and HEK293T cells were used for in vitro studies.RESULTS A total of 30982 genes were detected in WGS analysis,with 649 up-regulated and 178 down-regulated.Expression of FBXO2,an E3 ligase,was upregulated in the liver tissues of patients with NAFLD.Hepatocyte-specific FBXO2 overexpression facilitated NAFLD-associated phenotypes in mice.Overexpression of FBXO2 aggravated odium oleate(OA)-induced lipid accumulation in HepG2 cells,resulting in an abnormal expression of genes related to lipid metabolism,such as fatty acid synthase,peroxisome proliferator-activated receptor alpha,and so on.In contrast,knocking down FBXO2 in HepG2 cells significantly alleviated the OA-induced lipid accumulation and aberrant expression of lipid metabolism genes.The hydroxyl CoA dehydrogenase alpha subunit(HADHA),a protein involved in oxidative stress,was a target of FBXO2-mediated ubiquitination.FBXO2 directly bound to HADHA and facilitated its proteasomal degradation in HepG2 and HEK293T cells.Supplementation with HADHA alleviated lipid accumulation caused by FBXO2 overexpression in HepG2 cells.CONCLUSION FBXO2 exacerbates lipid accumulation by targeting HADHA and is a potential therapeutic target for NAFLD。

Radical lymph node dissection and assessment:Impact on gallbladder cancer prognosis

AIM: To investigate the lymph node metastasis patterns of gallbladder cancer(GBC) and evaluate the optimal categorization of nodal status as a critical prognostic factor.METHODS: From May 1995 to December 2010,a total of 78 consecutive patients with GBC underwent a radical resection at Liaocheng People's Hospital.A radical resection was defined as removing both the primary tumor and the regional lymph nodes of the gallbladder.Demographic,operative and pathologic data were recorded.The lymph nodes retrieved were examined histologically for metastases routinely from each node.The positive lymph node count(PLNC) as well as the total lymph node count(TLNC) was recorded for each patient.Then the metastatic to examined lymph nodes ratio(LNR) was calculated.Disease-specific survival(DSS) and predictors of outcome were analyzed.RESULTS: With a median follow-up time of 26.50 mo(range,2-132 mo),median DSS was 29.00 ± 3.92 mo(5-year survival rate,20.51%).Nodal disease was found in 37 patients(47.44%).DSS of node-negative patients was significantly better than that of nodepositive patients(median DSS,40 mo vs 17 mo,χ2= 14.814,P < 0.001),while there was no significant difference between N1 patients and N2 patients(median DSS,18 mo vs 13 mo,χ2= 0.741,P = 0.389).Optimal TLNC was determined to be four.When node-negative patients were divided according to TLNC,there was no difference in DSS between TLNC < 4 subgroup and TLNC ≥ 4 subgroup(median DSS,37 mo vs 54 mo,χ2 = 0.715,P = 0.398).For node-positive patients,DSS of TLNC < 4 subgroup was worse than that of TLNC ≥ 4 subgroup(median DSS,13 mo vs 21 mo,χ2= 11.035,P < 0.001).Moreover,for node-positive patients,a new cut-off value of six nodes was identified for the number of TLNC that clearly stratified them into 2 separate survival groups(< 6 or ≥ 6,respectively;median DSS,15 mo vs 33 mo,χ2= 11.820,P < 0.001).DSS progressively worsened with increasing PLNC and LNR,but no definite cut-off value could be identified.Multivariate analysis revealed histological grade,tumor node metastasis staging,TNLC and LNR to be independent predictors of DSS.Neither location of positive lymph nodes nor PNLC were identified as an independent variable by multivariate analysis.CONCLUSION: Both TLNC and LNR are strong predictors of outcome after curative resection for GBC.The retrieval and examination of at least 6 nodes can influence staging quality and DSS,especially in nodepositive patients.

Alterations in gut microbiota during remission and recurrence of diabetes after duodenal-jejunal bypass in rats

AIM: To observe the alterations in gut microbiota in high-fat diet(HFD)-induced diabetes recurrence after duodenal-jejunal bypass(DJB) in rats. METHODS: We assigned HDF- and low-dose streptozotocin-induced diabetic rats into two major groups to receive DJB and sham operation respectively. When the DJB was completed, we used HFD to induce diabetes recurrence. Then, we grouped the DJB-operated rats by blood glucose level into the DJB-remission(DJB-RM) group and the DJB-recurrence(DJB-RC) group. At a sequence of time points after operations, we compared calorie content in the food intake(calorie intake), oral glucose tolerance test, homeostasis model assessment of insulin resistance(HOMA-IR), concentrations of glucagon-like peptide 1(GLP-1), serum insulin, total bile acids(TBAs) and lipopolysaccharide(LPS) and alterations in colonic microbiota.RESULTS: The relative abundance of Firmicutes in the control(58.06% ± 11.12%; P < 0.05 vs sham; P < 0.05 vs DJB-RC) and DJB-RM(55.58% ± 6.16%; P < 0.05 vs sham; P < 0.05 vs DJB-RC) groups was higher than that in the sham(29.04% ± 1.36%) and DJB-RC(27.44% ± 2.17%) groups; but the relative abundance of Bacteroidetes was lower(control group: 33.46% ± 10.52%, P < 0.05 vs sham 46.88% ± 2.34%, P < 0.05 vs DJB-RC 47.41% ± 5.67%. DJB-RM group: 34.63% ± 3.37%, P < 0.05 vs sham; P < 0.05 vs DJB-RC). Escherichia coli was higher in the sham(15.72% ± 1.67%, P < 0.05 vs control, P < 0.05 vs DJB-RM) and DJB-RC(16.42% ± 3.00%; P < 0.05 vs control; P < 0.05 vs DJB-RM) groups than in the control(3.58% ± 3.67%) and DJB-RM(4.15% ± 2.76%) groups. Improved HOMA-IR(2.82 ± 0.73, P < 0.05 vs DJB-RC 4.23 ± 0.72), increased TBAs(27803.17 ± 4673.42 ng/m L; P < 0.05 vs DJB-RC 18744.00 ± 3047.26 ng/m L) and decreased LPS(0.12 ± 0.04 ng/m L, P < 0.05 vs DJBRC 0.19 ± 0.03 ng/m L) were observed the in DJB-RM group; however, these improvements were reversed in the DJB-RC group, with the exception of GLP-1(DJB-RM vs DJB-RC P > 0.05). CONCLUSION: Alterations in gut microbiota may be responsible for the diabetes remission and recurrence after DJB, possibly by influencing serum LPS and TBAs.

Effects of sleeve gastrectomy with jejuno-jejunal or jejuno-ileal loop on glycolipid metabolism in diabetic rats

AIM To explore the effect of sleeve gastrectomy(SG) with jejuno-jejunal or jejuno-ileal loop on glycolipid metabolism in diabetic rats.METHODS Diabetic rats, which were induced by high-fat diet(HFD), nicotinamide and low-dose streptozotocin, underwent sham operations, SG, SG with jejuno-ileal loop(SG-JI) and SG with jejuno-jejunal loop(SG-JJ) followed by postoperative HFD. Then, at the time points of baseline and 2, 12 and 24 wk postoperatively, we determined and compared several variables, including the area under the curve for the results of oral glucose tolerance test(AUCOGTT), serum levels of triglyceride, cholesterol and ghrelin in fasting state, homeostasis model assessment of insulin resistance(HOMA-IR), body weight, calorie intake, glucagon-like peptide(GLP)-1 and insulin secretions after glucose gavage at dose of 1 g/kg.RESULTS At 2 wk postoperatively, rats that underwent SG, SGJJ and SG-JI, compared with sham-operated(SHAM)rats, demonstrated lower body weight, calorie intake and ghrelin(P < 0.05 vs SHAM), enhanced secretion of insulin and GLP-1 after glucose gavage(P < 0.05 vs SHAM), improved AUCOGTT, HOMA-IR, fasting serum triglyceride and cholesterol(AUCOGTT: 1616.9 ± 83.2, 837.4 ± 83.7, 874.9 ± 97.2 and 812.6 ± 81.9, P < 0.05 vs SHAM; HOMA-IR: 4.31 ± 0.54, 2.94 ± 0.22, 3.17 ± 0.37 and 3.41 ± 0.22, P < 0.05 vs SHAM; Triglyceride: 2.35 ± 0.17, 1.87 ± 0.23, 1.98 ± 0.30 and 2.04 ± 0.21 mmol/L, P < 0.05 vs SHAM; Cholesterol: 1.84 ± 0.21, 1.53 ± 0.20, 1.52 ± 0.20 and 1.46 ± 0.23 mmol/L). At 12 wk postoperatively, rats receiving SG-JJ and SG-JI had lower body weight, reduced levels of triglyceride and cholesterol and elevated level of GLP-1 compared to those receiving SG(P < 0.05 vs SG). At 24 wk after surgery, compared with SG, the advantage of SG-JJ and SG-JI for glucolipid metabolism was still evident(P < 0.05 vs SG). SG-JI had a better performance in lipid metabolism and GLP-1 secretion of rats than did SG-JJ.CONCLUSION SG combined with intestinal loop induces better glycolipid metabolism than simple SG, with the lipid metabolism being more improved with SG-JI compared to SG-JJ.

Influence of CXCR4/SDF-1 axis on E-cadherin/β-catenin complex expression in HT29 colon cancer cells

AIM： To study the influence of CXCR4/stromal cell- derived factor-1 （SDF-1） axis on E-cadherin/β-catenin complex expression in HT29 colon cancer ceils and its underlying mechanisms. METHODS： Effect of SDF-1 on E-cadherin/β-catenin expression was detected by immunocytochemistry. E-cadherin and/3-catenin mRNA expression levels were measured by reverse transcriptase-polymerase chain reaction. SDF-l-induced phosphorylation of phosphati- dylinositol 3-kinase （PI3K）/AKT and β-catenin was detected by Western blotting. RESULTS： The E-cadherin and β-catenin mRNA ex-pression levels in HT29 cells were lower 48 h after incubated with SDF-1 at the concentrations of 20 and 40 ng/mL （P 〈 0.05）. SDF-l-induced significant phosphorylation of PI3K/AKT and β-catenin. AMD3100 and LY294002 inhibited the phosphorylation of PI3K/AKT and β-catenin. CONCLUSION： SDF-1 down-regulates the E-cadherin/ β-catenin complex expression in HT29 cells by decreasing mRNA synthesis and increasing β-catenin phosphorylation.

Low-pressure pneumoperitoneum with abdominal wall lift in laparoscopic total mesorectal excision for rectal cancer:initial experience

AIM To evaluate the safety and feasibility of a new technology combining low-pressure pneumoperitoneum(LPP) and abdominal wall lift(AWL) in laparoscopic total mesorectal excision(TME) for rectal cancer.METHODS From November 2015 to July 2017,26 patients underwent laparoscopic TME for rectal cancer using LPP(6-8 mm Hg) with subcutaneous AWL in Qilu Hospital of Shandong University,Jinan,China.Clinical data regarding patients' demographics,intraoperative monitoring indices,operation-related indices andpathological outcomes were prospectively collected.RESULTS Laparoscopic TME was performed in 26 cases(14 anterior resection and 12 abdominoperineal resection) successfully,without conversion to open or laparoscopic surgery with standard-pressure pneumoperitoneum.Intraoperative monitoring showed stable heart rate,blood pressure and paw airway pressure.The mean operative time was 194.29 ± 41.27 min(range:125-270 min) and 200.41 ± 20.56 min(range:170-230 min) for anterior resection and abdominoperineal resection,respectively.The mean number of lymph nodes harvested was 16.71 ± 5.06(range:7-27).There was no positive circumferential or distal resection margin.No local recurrence was observed during a median follow-up period of 11.96 ± 5.55 mo(range:5-23 mo).CONCLUSION LPP combined with AWL is safe and feasible for laparoscopic TME.The technique can provide satisfactory exposure of the operative field and stable operative monitoring indices.

Diabetes recurrence after metabolic surgeries correlates with re-impaired insulin sensitivity rather than beta-cell function

AIM To investigate factors causing diabetes recurrence after sleeve gastrectomy(SG)and duodenal-jejunal bypass(DJB).METHODS SG and DJB were performed on rats with diabetes induced by high-fat diet(HFD)and streptozotocin(STZ).HFD was used to induce diabetes recurrence at 4 wk postoperatively.Body weight,oral glucose tolerance test,homeostatic model assessment of insulin resistance(HOMA-IR),insulin signaling[IR,insulin receptor substrate(IRS 1,IRS2,phosphatidylinositol3-kinase and AKT in liver and skeletal muscle],oral glucose stimulated insulin secretion,beta-cell morphology(mass,apoptosis and insulin secretion),glucagon-like peptide(GLP)-1,PYY and ghrelin were compared among SG rats with common low-fat diet(SG-LFD),SG with HFD(SG-HFD),DJB rats with LFD(DJB-LFD),DJB with HFD(DJB-HFD)and shamoperation with LFD(Sham)at targeted postoperative times.RESULTS SG and DJB resulted in significant improvement in glucose tolerance,lower HOMA-IR,up-regulated hepatic and muscular insulin signaling,higher levels of oral glucose-stimulated insulin secretion,bigger betacell mass,higher immunofluorescence intensity of insulin,fewer transferase-mediated d UTP-biotin 3’nick end-labeling(TUNEL)-positive beta cells and higher postprandial GLP-1 and PYY levels than in the Sham group.The improvement in glucose tolerance was reversed at 12 wk postoperatively.Compared with the SG-LFD and DJB-LFD groups,the SG-HFD and DJB-HFD groups showed higher HOMA-IR,down-regulated hepatic and muscular insulin signaling,and more TUNEL-positive beta cells.No significant difference was detected between HFD and LFD groups for body weight,glucose-stimulated insulin secretion,betacell mass,immunofluorescence intensity of insulin,and postprandial GLP-1 and PYY levels.Fasting serum ghrelin decreased in SG groups,and there was no difference between HFD-SG and LFD-SG groups.CONCLUSION HFD reverses the improvement in glucose homeostasis after SG and DJB.Diabetes recurrence may correlate with re-impaired insulin sensitivity,but not with alterations of beta-cell function and body weight.

Effects of sleeve gastrectomy plus trunk vagotomy compared with sleeve gastrectomy on glucose metabolism in diabetic rats

AIM To investigate the effects of sleeve gastrectomy plus trunk vagotomy(SGTV) compared with sleeve gastrectomy(SG) in a diabetic rat model.METHODS SGTV, SG, TV and Sham operations were performed on rats with diabetes induced by high-fat diet and streptozotocin. Body weight, food intake, oral glucose tolerance test, homeostasis model assessment of insulin resistance(HOMA-IR), hepatic insulin signaling(IR, IRS1, IRS2, PI3 K and AKT), oral glucose stimulatedinsulin secretion, GLP-1 and ghrelin were compared at various postoperative times.RESULTS Both SG and SGTV resulted in better glucose tolerance, lower HOMA-IR, up-regulated hepatic insulin signaling, higher levels of oral glucose-stimulated insulin secretion, higher postprandial GLP-1 and lower fasting ghrelin levels than the TV and Sham groups. No significant differences were observed between the SG and SGTV groups. In addition, no significant differences were found between the TV and Sham groups in terms of glucose tolerance, HOMA-IR, hepatic insulin signaling, oral glucose-stimulated insulin secretion, postprandial GLP-1 and fasting ghrelin levels. No differences in body weight and food intake were noted between the four groups.CONCLUSION SGTV is feasible for diabetes control and is independent of weight loss. However, SGTV did not result in a better improvement in diabetes than SG alone.

Sleeve gastrectomy ameliorates endothelial function and prevents lung cancer by normalizing endothelin-1 axis in obese and diabetic rats

BACKGROUND Previous evidence has implied that obesity is an independent risk factor for developing cancer.Being closely related to obesity,type 2 diabetes mellitus provides a suitable environment for the formation and metastasis of tumors through multiple pathways.Although bariatric surgeries are effective in preventing and lowering the risk of various types of cancer,the underlying mechanisms of this effect are not clearly elucidated.AIM To uncover the role and effect of sleeve gastrectomy(SG)in preventing lung cancer in obese and diabetic rats.METHODS SG was performed on obese and diabetic Wistar rats,and the postoperative transcriptional and translational alterations of the endothelin-1(ET-1)axis in the lungs were compared to sham-operated obese and diabetic rats and age-matched healthy controls to assess the improvements in endothelial function and risk of developing lung cancer at the postoperative 4 th,8 th,and 12 th weeks.The risk wasalso evaluated using nuclear phosphorylation of H2 A histone family member X as a marker of DNA damage(double-strand break).RESULTS Compared to obese and diabetic sham-operated rats,SG brought a significant reduction to body weight,food intake,and fasting blood glucose while improving oral glucose tolerance and insulin sensitivity.In addition,ameliorated levels of gene and protein expression in the ET-1 axis as well as reduced DNA damage indicated improved endothelial function and a lower risk of developing lung cancer after the surgery.CONCLUSION Apart from eliminating metabolic disorders,SG improves endothelial function and plays a protective role in preventing lung cancer via normalized ET-1 axis and reduced DNA damage.

Effect of oligofructose on resistance to postoperative high-fat diet-induced damage of metabolism in diabetic rats after sleeve gastrectomy

BACKGROUND Sleeve gastrectomy(SG) can induce prominent remission of type 2 diabetes mellitus.However,the long-term remission rate of diabetes usually decreases over time.Oligofructose has been verified to modulate host metabolism.The aim of this study was to explore the protective effect of oligofructose on high-fat diet(HFD)-induced metabolic dysfunction after SG.AIM To study the effect and mechanism of oligofructose on diabetic remission in diabetic rats after SG.METHODS SG and SHAM operation were performed on diabetes rats induced with an HFD,nicotinamide,and low-dose streptozotocin.Then the rats in the SHAM and SG groups were continuously provided with the HFD,and the rats in sleeve gastrectomy-oligofructose group were provided with a specific HFD containing10% oligofructose.Body weight,calorie intake,oral glucose tolerance test,homeostasis model assessment of insulin resistance,lipid profile,serum insulin,glucagon-like peptide 1(GLP-1),total bile acids,lipopolysaccharide(LPS),and colonic microbiota levels were determined and compared at the designated time points.All statistical analyses were performed using Statistic Package for Social Science version 19.0(IBM,United States),and the statistically significant difference was considered at P <0.05.RESULTS At 2 wk after surgery,rats that underwent SG exhibited improved indexes of glucose and lipid metabolism.Compared with the SG group,the rats from SGoligofructose group exhibited better parameters of glucose and lipid metabolism,lower body weight(526.86±21.51 vs 469.25±21.84,P <0.001),calorie intake(152.14±9.48 vs 129.63±8.99,P <0.001),homeostasis model assessment of insulin resistance(4.32±0.57 vs 3.46±0.52,P <0.05),and LPS levels(0.19±0.01 vs 0.16±0.01,P <0.05),and higher levels of insulin(1.17±0.17 vs 1.58±0.16,P <0.001) and GLP-1(12.39±1.67 vs 14.94±1.86,P <0.001),and relative abundances of Bifidobacterium(0.0034±0.0014 vs 0.0343±0.0064,P <0.001),Lactobacillus(0.0161±0.0037 vs 0.0357±0.0047,P <0.001),and Akkermansia muciniphila(0.0050±0.0024 vs 0.0507±0.0100,P <0.001) at the end of the study.However,no difference in total bile acids levels was observed between the two groups.CONCLUSION Oligofructose partially prevents HFD-induced glucose and lipid metabolism damage after SG,which may be due to the changes of calorie intake,insulin,GLP-1,LPS,and the gut microbiota in rats.

Can aspirin use reduce the risk of pancreatic cancer:an updated systematic review and meta-analysis

Background:Chemoprevention effect of aspirin for pancreatic cancer(PC)remains unclear.Here we performed an updated systematic review and meta-analysis to investigate the real association between aspirin consumption and risk of PC.Methods:PubMed,Web of Science,EMBASE and the Cochrane Database were systematic searched to identify the potential studies.Odds ratio(ORs)with 95%confidence intervals(CIs)were applied to assess the strength of associations.Results:Thirteen studies and approximately 28,440 participants were included.Aspirin significantly reduced the incidence of PC(OR,0.82;95%CI,0.73-0.93)in case-control studies.However,the overall results did not reveal an obvious association(OR,0.92;95%CI,0.74-1.16).Both low-dose(OR=0.86)and high-dose(OR=0.80)aspirin intake showed prevention effect.In addition,low frequency(OR,0.87;95%CI,0.73-1.05)and high frequency(OR,0.84;95%CI,0.69-1.03)seemed to be equally associated with decreased risk for PC.Aspirin consumption longer than 10 years use seems to have better effect(OR,0.73;95%CI,0.51-1.04)than shorter aspirin use(OR,0.94;95%CI,0.77-1.15).Conclusions:Our study indicated that aspirin use might be associated with decreased risk of PC,especially at high doses.But we still need to be cautious when interpreting the results.