Endoscopic mucosal resection with double band ligation versus endoscopic submucosal dissection for small rectal neuroendocrine tumors

BACKGROUND Endoscopic resection remains an effective method for the treatment of small rectal neuroendocrine tumors(NETs)(≤10 mm).Moreover,endoscopic mucosal resection(EMR)with double band ligation(EMR-dB),a simplified modification of EMR with band ligation,is an alternative strategy to remove small rectal NETs.AIM To evaluate the feasibility and safety of EMR-dB for the treatment of small rectal NETs(≤10 mm).METHODS A total of 50 patients with small rectal NETs,without regional lymph node enlargement or distant metastasis confirmed by endoscopic ultrasound,computerized tomography scan,or magnetic resonance imaging,were enrolled in the study from March 2021 to June 2022.These patients were randomly assigned into the EMR-dB(n=25)group or endoscopic submucosal dissection(ESD)group(n=25).The characteristics of the patients and tumors,procedure time,devices cost,complete resection rate,complications,and recurrence outcomes were analyzed.RESULTS There were 25 patients(13 males,12 females;age range 28-68 years old)in the EMR-dB group,and the ESD group contained 25 patients(15 males,10 females;age range 25-70 years old).Both groups had similar lesion sizes(EMR-dB 4.53±1.02 mm,ESD 5.140±1.74 mm;P=0.141)and resected lesion sizes(1.32±0.52 cm vs 1.58±0.84 cm;P=0.269).Furthermore,the histological complete resection and en bloc resection rates were achieved in all patients(100%for each).In addition,there was no significant difference in the complication rate between the two groups.However,the procedure time was significantly shorter and the devices cost was significantly lower in the EMRdB group.Besides,there was no recurrence in both groups during the follow-up period.CONCLUSION The procedure time of EMR-dB was shorter compared with ESD,and both approaches showed a similar curative effect.Taken together,EMR-dB was a feasible and safe option for the treatment of small rectal NETs.

Endoscopic submucosal dissection vs endoscopic mucosal resection for colorectal tumors: A meta-analysis

AIM: To compare the efficacy and safety of endoscopic submucosal dissection(ESD) and endoscopic mucosal resection(EMR) for the treatment of colorectal tumors.METHODS: Databases, such as PubMed, EMBASE, Cochrane Library and Science Citation Index updated to 2013 were searched to include eligible articles. In the meta-analysis, the main outcome measurements were the en bloc resection rate, the histological resection rate and the local recurrence rate. Meanwhile, we also compared the operation time and the incidence of procedure-related complications.RESULTS: Six trials were identified and a total of 1642 lesions were included. The en bloc resection rate was higher and the local recurrence rate was lower in the ESD group compared with the EMR group(OR = 7.94; 95%CI: 3.96-15.91; OR = 0.09; 95%CI: 0.04-0.19). There was no significant difference in histological resection rate(OR = 1.65; 95%CI: 0.29-9.30) and procedure-related complication rate between the two groups(OR = 1.59; 95%CI: 0.92-2.73). The meta-analysis also showed that ESD was more time consuming than EMR.CONCLUSION: Compared with EMR, ESD results in higher en bloc resection rate and lower local recurrence rate for the treatment of colorectal tumors, without increasing the procedure-related complications.

Endoscopic mucosal resection vs endoscopic submucosal dissection for superficial non-ampullary duodenal tumors

BACKGROUND The selection of endoscopic treatments for superficial non-ampullary duodenal epithelial tumors(SNADETs)is controversial.AIM To compare the efficacy and safety of endoscopic mucosal resection(EMR)and endoscopic submucosal dissection(ESD)for SNADETs.METHODS We retrospectively analyzed the data of patients with SNADETs from a database of endoscopic treatment for SNADETs,which included eight hospitals in Fukuoka,Japan,between April 2001 and October 2017.A total of 142 patients with SNADETs treated with EMR or ESD were analyzed.Propensity score matching was performed to adjust for the differences in the patient characteristics between the two groups.We analyzed the treatment outcomes,including the rates of en bloc/complete resection,procedure time,adverse event rate,hospital stay,and local or metastatic recurrence.RESULTS Twenty-eight pairs of patients were created.The characteristics of patients between the two groups were similar after matching.The EMR group had a significantly shorter procedure time and hospital stay than those of the ESD group[median procedure time(interquartile range):6(3-10.75)min vs 87.5(68.5-136.5)min,P<0.001,hospital stay:8(6-10.75)d vs 11(8.25-14.75)d,P=0.006].Other outcomes were not significantly different between the two groups(en bloc resection rate:82.1%vs 92.9%,P=0.42;complete resection rate:71.4%vs 89.3%,P=0.18;and adverse event rate:3.6%vs 17.9%,P=0.19,local recurrence rate:3.6%vs 0%,P=1;metastatic recurrence rate:0%in both).Only one patient in the ESD group underwent emergency surgery owing to intraoperative perforation.CONCLUSION EMR has significantly shorter procedure time and hospital stay than ESD,and provides acceptable curability and safety compared to ESD.Accordingly,EMR for SNADETs is associated with lower medical costs.

Endoscopic submucosal dissection for large laterally spreading tumors involving the ileocecal valve and terminal ileum

Endoscopic submucosal dissection is a challenging technique that enables en-bloc resection for large colorectal tumors, as laterally spreading tumors, particularly difficult, if the ileocecal valve and terminal ileum is involved. Herein, we report on one of 4 cases. The procedures, using a bipolar needle knife (B-Knife) to reduce the perforation risk and carbon dioxide instead of conventional air insufflation for patient comfort, achieved curative resections without any complications.

Early gastric cancer presenting as a typical submucosal tumor cured by endoscopic submucosal dissection:A case report

BACKGROUND Submucosal tumor(SMT)-like gastric cancer is rare,and almost all cases undergo curative surgical treatment because the submucosal layer is usually deeply invaded by tumor cells or because histopathologic types of SMT-like gastric cancer are undifferentiated or poorly differentiated.No report has been issued on an SMT-like gastric cancer cured by endoscopic resection alone or on changes in the endoscopic features of this type of tumor over several years.CASE SUMMARY We describe an exceptional case of a 53-year-old male with a 1.5 cm-sized SMTlike lesion covered by normal-appearing mucosa discovered by esophagogastroduodenoscopy(EGD)at the gastric antrum.Endoscopic ultrasound(EUS)visualized a homogeneous,well-circumscribed hypoechogenic lesion arising from the second sonographic layer with associated subtle obliteration of the third sonographic layer.Initial endoscopic biopsy was negative for neoplasm.The patient refused to undergo an invasive procedure and was subsequently lost to follow-up.Three years after initial detection,EGD revealed the lesion had become markedly erythematous,and at 4 years after initial EGD it had increased in size to 1.8 cm and developed a central ulcer and a heterogeneous EUS echo.Finally,endoscopic submucosal dissection(ESD)was performed,and histopathologic examination revealed a moderately differentiated adenocarcinoma had minutely invaded the submucosal layer(invasion depth 169μm)but without lymphovascular invasion and with negative resection margins.Fortunately,no additional surgical treatment was required.He has been followed for 4 years after ESD without any evidence of local or distant recurrence.CONCLUSION This report describes an extremely rare case of early gastric cancer presenting as SMT that was cured by ESD after a treatment delay of 4 years and the endoscopic changes that occurred during this period.The report highlights the importance of considering the possibility of gastric cancer when SMT is encountered in clinical practice.

Comparative Analysis on the Curative Effect of Endoscopic Submucosal Dissection and Mucosal Resection in the Treatment of Gastric Neuroendocrine Tumor

Objective:To study the therapeutic effect of endoscopic submucosal dissection and mucosal resection on gastric neuroendocrine tumor.Methods:A hundred patients with gastric neuroendocrine tumor that were treated in the Affiliated Hospital of Chifeng University from January 2016 to May 2021 were randomly selected for this research.They were divided into two groups,which were the control group(endoscopic mucosal resection)and the study group(endoscopic submucosal dissection),by the digital table method.The curative effects of the two groups were observed and compared.Results:Before operation,there were no significant differences in serum CgA,TNF-α,and IL-6 between the two groups,p>0.05.After surgical treatment,the operation time and hospital stay of the patients in the study group were shorter than those in the control group,the amount of surgical bleeding was also less compared to the control group,and the complete tumor resection rate was higher than that in the control group(p<0.05);the levels of IL-6 and CgA of the study group were lower than those in the control group,while the levels of TNF-α were higher than those of the control group,p<0.05;the postoperative complication rate of the study group was lower than that of the reference group(p<0.05).Conclusion:Endoscopic submucosal dissection is more effective for gastric neuroendocrine tumors.The resection rate of the tumor is high,and the operation risk is low.

Endoscopic treatment and management of rectal neuroendocrine tumors less than 10 mm in diameter

Rectal neuroendocrine tumors(rNETs)measuring less than 10 mm in diameter are defined as small rNETs.Due to the low risk of distant invasion and metastasis,endoscopic treatments,including modified endoscopic mucosal resection,endoscopic submucosal dissection,and other transanal surgical procedures,are effective.This review article proposes a follow-up plan according to the size and histopathology of the tumor after operation.

Future directions of duodenal endoscopic submucosal dissection

Endoscopic therapies for lesions of the duodenum are technically more difficult than those for lesions of the other parts of the gastrointestinal tract due to the anatomical features of the duodenum, and the incidence rate of complications such as perforation and bleeding is also higher. These aforementioned trends were especially noticeable for the case of duodenal endoscopic submucosal dissection(ESD). The indication for ESD of duodenal tumors should be determined by assessment of the histopathology, macroscopic morphology, and diameter of the tumors. The three types of candidate lesions for endoscopic therapy are adenoma, carcinoma, and neuroendocrine tumors. For applying endoscopic therapies to duodenal lesions, accurate preoperative histopathological diagnosis is necessary. The most important technical issue in duodenal ESD is the submucosal dissection process. In duodenal ESD, a short needle-type knife is suitable for the mucosal incision and submucosal dissection processes, and the Small-caliber-tip Transparent hood is an important tool. After endoscopic therapies, the wound should be closed by clipping in order to prevent complications such as secondary hemorrhage and delayed perforation. At present, the criteria for selection between ESD and EMR vary among institutions. The indications for ESD should be carefully considered. Duodenal ESD should have limitations, such as the need for its being performed by experts with abundant experience in performing the procedure.

Endoscopic techniques for gastric neuroendocrine tumors:An update

Gastric neuroendocrine neoplasms(gNENs)are a rare type of gastric neoplasm,even if their frequency is increasing according to the latest epidemiologic revisions of the main registries worldwide.They are divided into three main subtypes,with different pathogeneses,biological behaviors,and clinical characteristics.GNEN heterogeneity poses challenges,therefore these neoplasms require different management strategies.Update the knowledge on the endoscopic treatment options to manage g-NENs.This manuscript is a narrative review of the literature.In recent years,many advances have been made not only in the knowledge of both the pathogenesis and the molecular profiling of gNENs but also in the endoscopic expertise towards innovative treatment options,which proved to be less aggressive without losing the capa-bility of being radical.The endoscopic approach is increasingly applied in the field of gastrointestinal(GI)luminal neoplasms,and this is true not only for adenocarcinomas but also for gNENs.In particular,different techniques have been described for the endoscopic removal of suspected lesions,ranging from classical polypectomy(cold or hot snare)to endoscopic mucosal resection(both with“en bloc”or piecemeal technique),endoscopic submucosal dissection,and endoscopic full-thickness resection.GNENs comprise different subtypes of neoplasms with distinct management and prognosis.New endoscopic techniques offer a wide variety of approaches for GI localized neoplasms,which demonstrated to be appropriate and effective also in the case of gNENs.Correct evaluation of size,site,morphology,and clinical context allows the choice of tailored therapy in order to guarantee a definitive treatment.

Endoscopic mucosal resection for rectal carcinoids under micro-probe ultrasound guidance

AIM: To assess the therapeutic value of endoscopic mucosal resection (EMR) under micro-probe ultrasound guidance for rectal carcinoids less than 1 cm in diameter. METHODS: Twenty-one patients pathologically diagnosed with rectal carcinoids following colonoscopy in our hospital from January 2007 to November 2012 were included in this study. The patients consisted of 14 men and 7 women, with a mean age of 52.3 ± 12.2 years (range: 36-72 years). The patients with submucosal tumors less than 1 cm in diameter arising from the rectal and muscularis mucosa detected by micro-probe ultrasound were treated with EMR and followed up with conventional endoscopy and micro-probe ultrasound. RESULTS: All of the 21 tumors were confirmed by micro-probe ultrasound as uniform hypoechoic masses originating from the rectal and muscularis mucosa, without invasion of muscularis propria and vessels, and less than 1 cm in diameter. EMR was successfully completed without bleeding, perforation or other complications. The resected specimens were immunohistochemically confirmed to be carcinoids. Patients were followed up for one to two years, and no tumor recurrence was reported. CONCLUSION: EMR is a safe and effective treatment for rectal carcinoids less than 1 cm in diameter.

Endoscopic diagnosis and treatment of superficial nonampullary duodenal tumors

The diagnostic and treatment guidelines of superficial non-ampullary duodenal tumors have not been standardized due to their low prevalence.Previous reports suggested that a superficial adenocarcinoma(SAC) should be treated via local resection because of its low risk of lymph node metastasis,whereas a highgrade adenoma(HGA) should be resected because of its high risk of progression to adenocarcinoma.Therefore,pretreatment diagnosis of SAC or HGA is important to determine the appropriate treatment strategy.There are certain endoscopic features known to be associated with SAC or HGA,and current practice prioritizes the endoscopic and biopsy diagnosis of these conditions.Surgical treatment of these duodenal lesions is often related to high risk of morbidity,and therefore endoscopic resection has become increasingly common in recent years.Endoscopic mucosal resection(EMR) and endoscopic submucosal dissection(ESD) are the commonly performed endoscopic resection methods.EMR is preferred due to its lower risk of adverse events;however,it has a higher risk of recurrence than ESD.Recently,a new and safer endoscopic procedure that reduces adverse events from EMR or ESD has been reported.

Which endoscopic treatment is the best for small rectal carcinoid tumors?

The incidence of rectal carcinoids is rising because of the widespread use of screening colonoscopy. Rectal carcinoids detected incidentally are usually in earlier stages at diagnosis. Rectal carcinoids estimated endoscopically as < 10 mm in diameter without atypical features and confined to the submucosal layer can be removed endoscopically. Here, we review the efficacy and safety of various endoscopic treatments for small rectal carcinoid tumors, including conventional polypectomy, endoscopic mucosal resection(EMR),cap-assisted EMR(or aspiration lumpectomy),endoscopic submucosal resection with ligating device,endoscopic submucosal dissection, and transanal endoscopic microsurgery. It is necessary to carefully choose an effective and safe primary resection method for complete histological resection.

Endoscopic resection of colorectal granular cell tumors

AIM: To determine the feasibility and effectiveness of endoscopic resection for the treatment of colorectal granular cell tumors(GCTs). METHODS: This was a retrospective study performed at a single institution. From January 2008 to April 2015, we examined a total of 11 lesions in 11 patients who were treated by an endoscopic procedure for colorectal GCTs in the Endoscopy Center, Zhongshan hospital of Fudan University, Shanghai, China. Either endoscopic mucosal resection or endoscopic submucosal dissection(ESD) was performed by three surgeons with expertise in endoscopic treatment. The pre- and postoperative condition and follow-up of these patients were evaluated by colonoscopy and endoscopic ultrasonography(EUS).RESULTS: Of these 11 lesions, 2 were located in the cecum, 3 were in the ileocecal junction, 5 were in the ascending colon, and 1 was in the rectum. The median maximum diameter of the tumors was 0.81 cm(range 0.4-1.2 cm). The en bloc rate was 100%, and the complete resection rate was 90.9%(10/11). postoperative pathology in one patient showed a tumor at the cauterization margin. however, during ESD, this lesion was removed en bloc, and no tumor tissue was seen in the wound. No perforations or delayed perforations were observed and emergency surgery was not required for complications. All patients were followed up to May 2015, and none had recurrence, metastasis, or complaints of discomfort.CONCLUSION: Endoscopic treatment performed by endoscopists with sufficient experience appears to be feasible and effective for colorectal GCTs.

Selection of appropriate endoscopic therapies for duodenal tumors: An open-label study, single-center experience

AIM:To determine an appropriate compartmentalization of endoscopic submucosal dissection(ESD)or endoscopic mucosal resection(EMR)for duodenal tumors.METHODS:Forty-six duodenal lesions(excluding papillary lesions)from 44 patients with duodenal tumors treated endoscopically between 2005 and 2013 were divided into the ESD and EMR groups for retrospective comparison and analysis.RESULTS:The mean age was 65±9 years(35-79years).There were 24 lesions from men and 22 from women.The lesions consisted of 6 early cancers,31adenomas and 9 neuroendocrine tumors.Lesion location was the duodenal bulb in 15 cases and the descending part of the duodenum in 31 cases.The most common macroscopic morphology was elevated type in 21 cases(45.6%).Mean tumor diameter was 11.9±9.7 mm(3-60 mm).Treatment procedure was ESD(15 cases)vs EMR(31 cases).The examined parameters in the ESD vs EMR groups were as follows:mean tumor diameter,12.9±14.3 mm(3-60 mm)vs 11.4 ±6.7 mm(4-25 mm);en bloc resection rate,86.7%vs 83.9%;complete resection rate,86.7%vs 74.2%;procedure time,86.5±63.1 min(15-217 min)vs 13.2±17.0 min(2-89 min)(P<0.0001);intraprocedural perforation,3 cases vs none(P=0.0300);delayed perforation,none in either group;postprocedural bleeding,1 case vs none;mean postoperative length of hospitalization,8.2±2.9 d(5-16 d)vs 6.1±2.0 d(2-12 d)(P=0.0067);recurrence,none vs 1 case(occurring at 7 mo postoperatively).CONCLUSION:ESD was associated with a longer procedure time and a higher incidence of intraprocedural perforation;EMR was associated with a lower rate of complete resection.

Mucosal-incision assisted biopsy for suspected gastric gastrointestinal stromal tumors

To evaluate the diagnostic yield of the procedure, mucosal-incision assisted biopsy (MIAB), for the histological diagnosis of gastric gastrointestinal stromal tumor (GIST), we performed a retrospective review of the 27 patients with suspected gastric GIST who underwent MIAB in our hospitals. Tissue samples obtained by MIAB were sufficient to make a histological diagnosis (diagnostic MIAB) in 23 out of the 27 patients, where the lesions had intraluminal growth patterns. Alternatively, the samples were insufficient (non-diagnosticMIAB) in remaining 4 patients, three of whom had gastric submucosal tumor with extraluminal growth patterns. Although endoscopic ultrasound and fine needle aspiration is the gold standard for obtaining tissue specimens for histological and cytological analysis of suspected gastric GISTs, MIAB can be used as an alternative method for obtaining biopsy specimens of lesions with an intraluminal growth pattern.

Recent advances in endoscopic management of gastric neoplasms

The development and clinical application of new diagnostic endoscopic technologies such as endoscopic ultrasonography with biopsy,magnification endoscopy,and narrow-band imaging,more recently supplemented by artificial intelligence,have enabled wider recognition and detection of various gastric neoplasms including early gastric cancer(EGC)and subepithelial tumors,such as gastrointestinal stromal tumors and neuroendocrine tumors.Over the last decade,the evolution of novel advanced therapeutic endoscopic techniques,such as endoscopic mucosal resection,endoscopic submucosal dissection,endoscopic fullthickness resection,and submucosal tunneling endoscopic resection,along with the advent of a broad array of endoscopic accessories,has provided a promising and yet less invasive strategy for treating gastric neoplasms with the advantage of a reduced need for gastric surgery.Thus,the management algorithms of various gastric tumors in a defined subset of the patient population at low risk of lymph node metastasis and amenable to endoscopic resection,may require revision considering upcoming data given the high success rate of en bloc resection by experienced endoscopists.Moreover,endoscopic surveillance protocols for precancerous gastric lesions will continue to be refined by systematic reviews and meta-analyses of further research.However,the lack of familiarity with subtle endoscopic changes associated with EGC,as well as longer procedural time,evolving resection techniques and tools,a steep learning curve of such high-risk procedures,and lack of coding are issues that do not appeal to many gastroenterologists in the field.This review summarizes recent advances in the endoscopic management of gastric neoplasms,with special emphasis on diagnostic and therapeutic methods and their future prospects.

Duodenal neuroendocrine tumor-tertiary care centre experience:A case report

BACKGROUND Neuroendocrine neoplasms(NENs)are a heterogeneous group of neoplasms arising from neuroendocrine cells,which contribute a small fraction of gastrointestinal malignancies.Duodenal neuroendocrine tumors(dNETs)represent 2%of all gastroenteropancreatic NENs.NENs are heterogeneous in terms of clinical symptoms,location,and prognosis.Non-functional NETs are mostly asymptomatic and need a high degree of clinical suspicion.Diagnosis of NETs is by endoscopic,endosonographic biopsy,and histopathological examination with immunohistochemistry staining for synaptophysin and chromogranin A.CASE SUMMARY We present case reports of 5 patients obtained over a period of 10 years in our center with dNETs.One patient had moderately differentiated NET and the remaining four had well-differentiated NET.Surveillance endoscopy was recommended in all the patients and is kept under regular follow-up after performing endoscopic therapy using endoscopic mucosal resection in 4 of them and one patient was advised to undergo a Whipple procedure.CONCLUSION Recently,the number of reported cases of NETs has increased due to advancements in diagnostic modalities and prevalence because of longer survival duration.The management differs based on the site,size,proliferation grade,and locally invasive pattern.They are slow-growing tumors with a good overall prognosis.The prognosis correlates with local lymph node status and metastasis.

超声内镜及ESD对直肠神经内分泌肿瘤的诊治意义

目的 回顾性分析超声内镜(endoscopic ultrasonography,EUS)及内镜下黏膜剥离术(endoscopic mucosal dissection,ESD)对直肠神经内分泌肿瘤(rectal neuroendocrine tumors,R-NET)的诊治意义。方法 选取2019年8月—2023年7月于莆田学院附属医院就诊的33例经电子结肠镜和EUS检查且经ESD治疗的R-NET患者进行临床特征和治疗效果分析。结果 33例患者中位于低位和中位的R-NET病灶分别占45.5%(15/33)和39.4%(13/33),66.7%(22/33)病灶最大直径<5 mm,54.5%(18/33)位于黏膜下层,经ESD术后病灶完全切除率达81.8%(27/33),余紧邻切缘占18.2%(6/33)。所有患者术后病理分级均为G1,术后3个月和6个月行电子结肠镜复查未见复发。免疫组化结果显示,突触素(synaptophysin,Syn)、CD56和细胞角蛋白(cytokeratin,CK)阳性率较高,嗜铬粒蛋白A(chromograninA,CgA)反而较低。结论 R-NET病灶小且隐匿,EUS可助其全面评估;ESD对R-NET患者的诊治效果好、安全性高。

内镜黏膜下剥离术治疗胃肠神经内分泌肿瘤的疗效

目的探讨内镜黏膜下剥离术治疗胃肠神经内分泌肿瘤(NET)的疗效。方法将80例胃肠NET患者按手术方法的不同分为切除组(45例)和剥离组(35例),切除组患者行内镜下黏膜切除术,剥离组患者行内镜黏膜下剥离术。比较两组患者围手术期相关指标(手术时间、术中出血量、术后住院时间)、血清肿瘤标志物[糖类抗原125(CA125)、糖类抗原19-9(CA19-9)、癌胚抗原(CEA)]、炎症指标[白细胞介素-6(IL-6)、中性粒细胞与淋巴细胞比值(NLR)、血小板与淋巴细胞比值(PLR)]、病灶切除情况及并发症发生情况。结果剥离组患者手术时间明显长于切除组,术后住院时间明显短于切除组,差异均有统计学意义(P﹤0.01)。术后,两组患者CA125、CA19-9、CEA、IL-6水平和NLR、PLR均较术前降低,且剥离组患者CA125、CA19-9、CEA、IL-6水平和NLR、PLR均低于切除组,差异均有统计学意义(P﹤0.05)。剥离组患者治愈性切除率、整块切除率均高于切除组,差异均有统计学意义(P﹤0.05)。两组患者术后并发症总发生率比较,差异无统计学意义(P﹥0.05)。结论胃肠NET患者采用内镜黏膜下剥离术能够缩短术后住院时间,降低血清肿瘤标志物以及炎症指标水平,有效清除病灶,疗效更好。

Endoscopic and surgical resection of T1a/T1b esophageal neoplasms: A systematic review

AIM: To investigate potential therapeutic recommendations for endoscopic and surgical resection of T1a/ T1b esophageal neoplasms. METHODS: A thorough search of electronic databases MEDLINE, Embase, Pubmed and Cochrane Library, from 1997 up to January 2011 was performed. An analysis was carried out, pooling the effects of outcomes of 4241 patients enrolled in 80 retrospective studies. For comparisons across studies, each reporting on only one endoscopic method, we used a random effects meta-regression of the log-odds of the outcome of treatment in each study. "Neural networks" as a data mining technique was employed in order to establish a prediction model of lymph node status in superficial submucosal esophageal carcinoma. Another data mining technique, the "feature selection and root cause analysis", was used to identify the most impor-tant predictors of local recurrence and metachronous cancer development in endoscopically resected patients, and lymph node positivity in squamous carcinoma (SCC) and adenocarcinoma (ADC) separately in surgically resected patients. RESULTS: Endoscopically resected patients: Low grade dysplasia was observed in 4% of patients, high grade dysplasia in 14.6%, carcinoma in situ in 19%, mucosal cancer in 54%, and submucosal cancer in 16% of patients. There were no significant differences between endoscopic mucosal resection and endoscopic submucosal dissection (ESD) for the following parameters: complications, patients submitted to surgery, positive margins, lymph node positivity, local recurrence and metachronous cancer. With regard to piecemeal resection, ESD performed better since the number of cases was significantly less [coefficient: -7.709438, 95%CI: (-11.03803, -4.380844), P < 0.001]; hence local recurrence rates were significantly lower [coefficient: -4.033528, 95%CI: (-6.151498, -1.915559),P < 0.01]. A higher rate of esophageal stenosis was observed following ESD [coefficient: 7.322266, 95%CI: (3.810146, 10.83439), P < 0.001]. A significantly greater number of SCC patients were submitted to surgery (log-odds, ADC: -2.1206 ± 0.6249 vs SCC: 4.1356 ± 0.4038, P < 0.05). The odds for re-classification of tumor stage after endoscopic resection were 53% and 39% for ADC and SCC, respectively. Local tumor recurrence was best predicted by grade 3 differentiation and piecemeal resection, metachronous cancer development by the carcinoma in situ component, and lymph node positivity by lymphovascular invasion. With regard to surgically resected patients: Significant differences in patients with positive lymph nodes were observed between ADC and SCC [coefficient: 1.889569, 95%CI: (0.3945146, 3.384624), P<0.01). In contrast, lymphovascular and microvascular invasion and grade 3 patients between histologic types were comparable, the respective rank order of the predictors of lymph node positivity was: Grade 3, lymphovascular invasion (L+), microvascular invasion (V+), submucosal (Sm) 3 invasion, Sm2 invasion and Sm1 invasion. Histologic type (ADC/SCC) was not included in the model. The best predictors for SCC lymph node positivity were Sm3 invasion and (V+). For ADC, the most important predictor was (L+). CONCLUSION: Local tumor recurrence is predicted by grade 3, metachronous cancer by the carcinoma insitu component, and lymph node positivity by L+. T1b cancer should be treated with surgical resection.