A strategy combining endoscopic hand-suturing with clips for closure of rectal defects after endoscopic submucosal dissection with or without myectomy (with video).

BACKGROUND AND AIMS: Endoscopic hand-suturing (EHS) has been preliminarily demonstrated to be effective in closing defects after endoscopic submucosal dissection (ESD), but it is not easily performed. We proposed a strategy combining EHS with clips (EHS-Clips) and explored its effectiveness in closing rectal defects after ESD or ESD with myectomy (ESD-ME). METHODS: In this observational study, data from patients with rectal defects closed using EHS-Clips were reviewed. EHS-Clips refers to a strategy where defects are sutured as much as possible by EHS first, with clips being used to close the remaining parts of defects that cannot be completely sutured. The primary endpoints included complete closure rate, delayed bleeding (DB) rate, and sustained closure rate. Logistic regression analyses were performed to identify risk factors for the sustained closure. RESULTS: All 49 (100%) defects (42 ESD defects and 7 ESD-ME defects) were completely closed through the strategy of EHS-Clips, with 35 (71.4%) through EHS alone and 14 (28.6%) through EHS and additional clips. No patients experienced DB. Thirty-six (73.5%) defects remained sustained closure on postoperative days 3 to 5 (73.8% for ESD defects vs 71.4% for ESD-ME defects). The multivariate analyses identified a stitch margin of ≥5 mm (hazard ratio, 0.313; 95% confidence interval, 0.023-0.781; P = .009) as the only independent advantage factor for the sustained closure. CONCLUSIONS: EHS-Clips can be used to effectively close the rectal defects after ESD or ESD-ME and prevent DB. Complete suture with a stitch margin of ≥5 mm may achieve more reliable sustained closure.

Perioperative chemotherapy with docetaxel plus oxaliplatin and S-1 (DOS) versus oxaliplatin plus S-1 (SOX) for the treatment of locally advanced gastric or gastro-esophageal junction adenocarcinoma (MATCH): an open-label, randomized, phase 2 clinical trial.

BACKGROUND: It remains unclear whether addition of docetaxel to the combination of a platinum and fluoropyrimidine could provide more clinical benefits than doublet chemotherapies in the perioperative treatment for locally advanced gastric/gastro-esophageal junction (LAG/GEJ) cancer in Asia. In this randomized, phase 2 study, we assessed the efficacy and safety of perioperative docetaxel plus oxaliplatin and S-1 (DOS) versus oxaliplatin plus S-1 (SOX) in LAG/GEJ adenocarcinoma patients. METHODS: Patients with cT3-4 Nany M0 G/GEJ adenocarcinoma were randomized (1:1) to receive 4 cycles of preoperative DOS or SOX followed by D2 gastrectomy and another 4 cycles of postoperative chemotherapy. The primary endpoint was major pathological response (MPR). RESULTS: From Aug, 2015 to Dec, 2019,154 patients were enrolled and 147 patients included in final analysis, with a median age of 60 (26-73) years. DOS resulted in significantly higher MPR (25.4 vs. 11.8%, P = 0.04). R0 resection rate, the 3-year PFS and 3-year OS rates were 78.9 vs. 61.8% (P = 0.02), 52.3 vs. 35% (HR 0.667, 95% CI: 0.432-1.029, Log rank P = 0.07) and 57.5 vs. 49.2% (HR 0.685, 95% CI: 0.429-1.095, Log rank P = 0.11) in the DOS and SOX groups, respectively. Patients who acquired MPR experienced significantly better survival. DOS had similar tolerance to SOX. CONCLUSIONS: Perioperative DOS improved MPR significantly and tended to produce longer PFS compared to SOX in LAG/GEJ cancer in Asia, and might be considered as a preferred option for perioperative chemotherapy and worth further investigation.

Long-term outcomes of endoscopic or surgical resection in T1 colorectal cancer patients: a retrospective cohort study.

BACKGROUND: The personalized treatments of T1 colorectal cancer (CRC) remains controversial. We compared the long-term outcomes of T1 CRC patients after endoscopic resection (ER) and surgery, and evaluated the risk factors for the long-term prognosis. METHODS: T1 CRCs after resection at the Cancer Hospital, Chines Academy of Medical Sciences from June 2011 to November 2021 were reviewed. High-risk factors included positive resection margin, poor differentiation, deep submucosal invasion (DSI ≥ 1000 µm), lymphovascular invasion and intermediate/high tumor budding. Comparative analyses were conducted based on three treatment methods: follow-up after ER (Group A), additional surgery after ER (Group B) and initial surgery (Group C). The primary endpoints included recurrence-free survival (RFS) and overall survival (OS). Cox proportional hazard regression models were constructed to identify risk factors for RFS and OS. RESULTS: A total of 528 patients were enrolled (173 patients in Group A, 102 patients in Group B, 253 patients in Group C). The 3-year RFS, 5-year RFS, 3-year OS, and 5-year OS rates were 96.7%, 94.7%, 99.1%, and 97.8%, respectively. In the absence of other high-risk factors, RFS (P = 0.321) and OS (P = 0.155) of patients with DSI after ER were not inferior to those after surgery. Multivariate analyses identified sex (HR 0.379; 95% CI 0.160-0.894), Charlson comorbidities index (CCI) (HR 3.330; 95% CI 1.571-7.062), margin (HR 8.212; 95% CI 2.325-29.006), and budding (HR 3.794; 95% CI 1.686-8.541) as independent predictive factors of RFS, and identified CCI (HR 10.266; 95% CI 2.856-36.899) as an independent predictive factor of OS. CONCLUSION: The long-term outcomes of ER are comparable to those of surgery in T1 CRC patients with DSI when other high-risk factors are negative. Resection margin, tumor budding, sex, and CCI may be the most important long-term prognostic factors for T1 CRC patients.

Retrospective study on endoscopic treatment of recurrent esophageal cancer patients after radiotherapy.

BACKGROUND: Esophageal cancer poses a significant health burden globally. Endoscopic treatment has emerged as a viable option for patient ineligible for surgery or experiencing disease recurrence post-radiotherapy. METHODS: Patients visiting the Department of Endoscopy at the Cancer Hospital of China Academy of Medical Sciences between March 2009 and March 2024 were retrospectively analyzed. Inclusion criteria encompassed patients with histologically confirmed esophageal cancer who had not undergone surgery, but received radiotherapy or CRT, and subsequently opted for endoscopic treatment. Data on demographics, treatment modalities, recurrence patterns, histopathological characteristics, and outcomes were collected. Statistical analysis was conducted using SPSS 27.0, employing Kolmogorov-Smirnov tests for data normality assessment. RESULTS: Out of 25 included patients, the mean age was 60.29 years, with a predominance of males (88%). Most patients (64%) received chemoradiotherapy (CRT), while the rest underwent radiotherapy alone. The median follow-up duration was 50.92 months, with a median recurrence time of 38.92 months. Majority (56%) presented with a solitary lesion and 76% had negative margins. Histopathological analysis revealed various stages of cancer, with the most common being high-grade squamous epithelial neoplasia (64%). Survival analysis indicated a 72% overall survival rate, with 16% surviving beyond 5-year post-treatment. Approximately, 20% succumbed during the study, primarily due to non-esophageal causes (16%). CONCLUSION: Endoscopic treatment shows promise as a therapeutic option for selected esophageal cancer patients, offering favorable outcomes in terms of survival and disease control. Further prospective studies are warranted to validate these findings and optimize patient selection criteria for endoscopic interventions in esophageal cancer management.

Radiotherapy Improves Survival of Patients With Lymphovascular Invasion in pT1b Esophageal Squamous Cell Cancer After Endoscopic Submucosal Dissection.

INTRODUCTION: Adjuvant radiotherapy is recommended for pT1b esophageal squamous cell cancer (ESCC) after endoscopic submucosal dissection (ESD). However, it is unclear whether additional radiotherapy can improve patient survival. This study aimed to evaluate the efficacy of adjuvant radiotherapy after ESD for pT1b ESCC. METHODS: This was a multicenter, cross-sectional study involving 11 hospitals in China. Between January 2010 and December 2019, patients with T1bN0M0 ESCC treated with or without adjuvant radiotherapy after ESD were included. Survival between groups was compared. RESULTS: Overall, 774 patients were screened, and 161 patients were included. Forty-seven patients (29.2%) received adjuvant radiotherapy after ESD (RT group) and 114 (70.8%) underwent ESD alone (non-RT group). There were no significant differences in overall survival (OS) and disease-free survival (DFS) between the RT and non-RT groups. Lymphovascular invasion (LVI) was the only prognostic factor. In the LVI+ group, adjuvant radiotherapy significantly improved survival (5-year OS: 91.7% vs 59.5%, P = 0.050; 5-year DFS: 92.9% vs 42.6%, P = 0.010). In the LVI- group, adjuvant radiotherapy did not improve survival (5-year OS: 83.5% vs 93.9%, P = 0.148; 5-year DFS: 84.2% vs 84.7%, P = 0.907). The standardized mortality ratios were 1.52 (95% confidence interval 0.04-8.45) in the LVI+ group with radiotherapy and 0.55 (95% confidence interval 0.15-1.42) in the LVI- group without radiotherapy. DISCUSSION: Adjuvant radiotherapy could improve survival in pT1b ESCC with LVI+ other than LVI- after ESD. Selective adjuvant radiotherapy based on LVI status achieved survival rates similar to those of the general population.

Solitary Rectal Ulcer Syndrome Is Not Always Ulcerated: A Case Report.

Solitary rectal ulcer syndrome (SRUS) is a benign and chronic disorder well known in young adults that is characterized by a series of symptoms such as rectal bleeding, copious mucus discharge, prolonged excessive straining, perineal and abdominal pain, a feeling of incomplete defecation, constipation and, rarely, rectal prolapse. The etiology of this syndrome remains obscure, and the diagnosis is easily confused with that of other diseases, contributing to difficulties in treatment. We present a case of a 37-year-old male with a nonulcerated rectal lesion grossly resembling a superficial depressed rectal cancer misdiagnosed in another hospital and describe its appearance on endoscopy and in the analysis of its pathological manifestations. The aim of this case report is to report an easily misdiagnosed case of SRUS, which needs to be distinguished from superficial rectal cancer, which should be educational for endoscopists.

Risk factors for complications after endoscopic treatment in Chinese patients with early esophageal cancer and precancerous lesions.

BACKGROUND: This study aimed to analyze the risk factors for complications after endoscopic treatment of early esophageal cancer and precancerous lesions and provides evidence for developing preventive measures against these complications. METHODS: The clinical data of patients with early esophageal cancer and precancerous lesions treated in the Department of Endoscopy, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences, and Peking Union Medical College from January 2009 to December 2015 were analyzed. The risk factors related to delayed bleeding, perforation, and stenosis were assessed. RESULTS: Of 459 patients, 15 (3.3%) had delayed bleeding, 16 (3.5%) had perforation, and 82 (17.9%) had stenosis. Conservative treatment was performed for patients with bleeding and perforation, and endoscopic dilation was performed to relieve stenosis. The independent risk factors for delayed bleeding were lesion size (OR = 1.51, P = 0.020), circumferential diameter [odds ratio (OR) = 1.24, P = 0.037]. The kind of operation method [endoscopic submucosal dissection (ESD)/cap-based endoscopic resection (EMR-Cap): OR = 15.38, P = 0.013) was the independent risk factor for perforation. The independent predictors of stenosis were circumferential diameter (OR = 1.58, P < 0.001), lesion in the neck (OR = 0.12, P = 0.003), and surgical time (OR = 1.02, P = 0.007). CONCLUSION: Few complications occur after the endoscopic treatment of early esophageal cancer and precancerous lesions which can be treated by endoscopic and conservative medical therapies. Strict operational training is required for ESD treatment.

Long-term outcomes of endoscopic treatment for colorectal laterally spreading tumor: a large-scale multicenter retrospective study from China.

BACKGROUND: Laterally spreading tumor (LST) is a type of precancerous lesion of colorectal cancer with high malignant potential. The present study aimed to evaluate long-term outcomes of endoscopic treatment for LST in Chinese patients. METHODS: This study was a retrospective review of data collected from 653 included patients with LST from six regional representative hospitals in China between January 2007 and January 2017. Demographic characteristics, endoscopic features of LST, operation-related data, and follow-up results were collected and analyzed. RESULTS: LST-granular type (LST-G, 80.3%) was much more common than LST-non-grandular type (LST-NG, 19.7%). The overall submucosal invasion rate of all LSTs was 6.1% and the submucosal invasion rate of LST-NG was significantly higher than that of LST-G (6.79% vs. 3.87%, p = 0.000). The en bloc resection rate of ESD and EMR treatment was 96% and 93.7%, respectively, with pathologic R0 resection rate of 90.1% and 82.8%. After an average duration of follow-up about 34.52 ± 11.76 months, the recurrence rate of ESD was 3.47%, and the recurrence rate of EMR was 8.8% after an average follow-up of about 38.44 ± 4.42 months. However, the recurrence rate of ESD was much lower than piecemeal EMR for LST (3.47% vs. 8.62%, p = 0.017). Retroflexion-assisted technique applied for resection of rectal LST was associated with a significantly shortened operating time (85.40 min vs. 174.18 min, p = 0.002). CONCLUSION: Endoscopic resection is a safe and efficient modality for the treatment of colorectal LST with a relatively low recurrence rate and shortened operating time with the use of retroflexion.

Prospective study of endoscopic focal cryoballoon ablation for esophageal squamous cell neoplasia in China.

BACKGROUND AND AIMS: Esophageal squamous cell neoplasia (ESCN) has a significant risk for progression to cancer. Current treatment options, endoscopic mucosal resection (EMR) or submucosal dissection (ESD), have their limitations. The cryoballoon focal ablation system (CbFAS) is a novel endoscopic ablation therapy device. We aimed to assess the safety, tolerability, and efficacy of CbFAS for eradication of ESCN. METHODS: In this single-center prospective trial in China, patients with 1 flat unstained lesion (USL) on Lugol chromoendoscopy that contained moderate- or high-grade intraepithelial neoplasia (MGIN or HGIN, respectively) were enrolled. CbFAS was performed using side-by-side applications of 10 seconds, treatment was repeated at 3-month intervals until a complete response (CR) was established. The response at 12 months was the primary trial endpoint. Safety phone calls were performed at 2, 7, and 30 days after the initial CbFAS. RESULTS: We enrolled 80 patients (59 MGIN, 21 HGIN) with a median USL length of 3 cm (interquartile range [IQR], 3-4). Seventy-nine received treatment, with a median of 5 side-by-side applications (IQR, 4-7) per patient over a median of 8 minutes (IQR, 5-10). After a single treatment, 70 of 78 patients (90%) exhibited CR, and 1 was lost to follow-up. The other 8 with persisting USLs were retreated, and all achieved CR after this second treatment. At 12 months after the initial CbFAS, 76 of 78 patients (97%) exhibited CR and 2 (3%) had recurrent MGIN. No strictures or serious adverse events occurred. Four patients developed self-limiting mucosal lacerations on balloon inflation. The postprocedure median pain score was 1 of 10 (IQR, 0-2) at day 2 and 0 (0-0) at days 7 and 30. CONCLUSIONS: The results suggest that the CbFAS is safe, well tolerated, and effective in inducing endoscopic and histologic remission in patients with ESCN of limited size. (Clinical trial registration number: NCT02605759.).

Analysis of Fine-Needle Biopsy vs Fine-Needle Aspiration in Diagnosis of Pancreatic and Abdominal Masses: A Prospective, Multicenter, Randomized Controlled Trial.

BACKGROUND & AIMS: Endoscopic ultrasound (EUS)-guided fine needles with side fenestrations are used to collect aspirates for cytology analysis and biopsy samples for histologic analysis. We conducted a large, multicenter study to compare the accuracy of diagnosis via specimens collected with fine-needle biopsy (FNB) versus fine-needle aspiration (FNA) for patients with pancreatic and nonpancreatic masses. METHODS: We performed a prospective single-blind study at 5 tertiary care centers in China. The study comprised 408 patients undergoing EUS for a solid mass (>1 cm) in the pancreas, abdomen, mediastinum, or pelvic cavity, from December 2014 through January 2016. Patients were randomly assigned to groups (1:1) for assessment by FNA (n = 190) or FNB (n = 187). After lesions were identified by EUS, samples were collected in a total of 4 passes by each needle. All procedures were performed by experienced endosonographers; cytologists and pathologists were blinded to the sample collection method. Patients were followed for at least 48 weeks, and final diagnoses were obtained after surgery, imaging analysis, or resolution of lesion. The primary aim was to compare diagnostic yields of EUS-FNA with EUS-FNB for all solid masses, then separately as pancreatic and nonpancreatic masses. The secondary endpoint was the quality of histologic specimen. RESULTS: Findings from FNB analysis were accurate for 91.44% of all cases, compared with 80.00% for all FNA cases, based on final patient diagnoses (P = .0015). In patients with pancreatic masses (n = 249), findings from histologic analysis of FNBs were accurate for 92.68% of the cases, compared with 81.75% for FNAs (P = .0099). In cytology analysis of pancreatic masses, samples collected by FNB accurately identified 88.62% of all pancreatic lesions, whereas samples collected by FNA accurately identified 79.37% (P = .00468). Analyses of samples of nonpancreatic masses collected by FNA versus FNB produced similar diagnostic yields. CONCLUSIONS: In a prospective study of patients with pancreatic masses, we found EUS-guided FNB samples to produce more accurate diagnoses than samples collected by EUS-guided FNA samples. No difference in diagnostic yield was seen between EUS-FNA and EUS-FNB for nonpancreatic masses. Clinical Trials.gov no: NCT02327065.

Use of sequential endorectal US to predict the tumor response of preoperative chemoradiotherapy in rectal cancer.

BACKGROUND AND AIMS: Accurate prediction of the response to preoperative chemoradiotherapy (CRT) potentially assists in the individualized selection of treatment. Endorectal US (ERUS) is widely used for the pretreatment staging of rectal cancer, but its use for preoperatively predicting the effects of CRT is not well evaluated because of the inflammation, necrosis, and fibrosis induced by CRT. This study assessed the value of sequential ERUS in predicting the efficacy of preoperative CRT for locally advanced rectal cancer. METHODS: Forty-one patients with clinical stage II/III rectal adenocarcinoma were enrolled prospectively. Radiotherapy was delivered to the pelvis with concurrent chemotherapy of capecitabine and oxaliplatin. Total mesorectal excision was performed 6 to 8 weeks later. EUS measurements of primary tumor maximum diameter were performed before (ERUS1), during (ERUS2), and 6 to 8 weeks after (ERUS3) CRT, and the ratios of these were calculated. Correlations between ERUS values, tumor regression grade (TRG), T down-staging rate, and pathologic complete response (pCR) rate were assessed, and survival was analyzed. RESULTS: There was no significant correlation between ERUS2/ERUS1 and TRG. The value of ERUS3/ERUS1 correlated with pCR rate and TRG but not T down-staging rate. An ERUS3 value of 6.3 mm and ERUS3/ERUS1 of 52% were used as the cut-off for predicting pCR, and patients were divided into good and poor prognosis groups. Although not statistically significant, 3-year recurrence and survival rates of the good prognosis group were better than those of the poor prognosis group. CONCLUSIONS: Sequential ERUS may predict therapeutic efficacy of preoperative CRT for locally advanced rectal cancer. (Clinical trial registration number: NCT01582750.).

A randomized trial comparing multiband mucosectomy and cap-assisted endoscopic resection for endoscopic piecemeal resection of early squamous neoplasia of the esophagus.

BACKGROUND AND AIM: Piecemeal endoscopic resection for esophageal high grade intraepithelial neoplasia (HGIN) or early squamous cell carcinoma (ESCC) is usually performed by cap-assisted endoscopic resection. This requires submucosal lifting and multiple snares. Multiband mucosectomy (MBM) uses a modified variceal band ligator without submucosal lifting. In high-risk areas where ESCC is common and endoscopic expertise is limited, MBM may be a better technique. We aimed to compare MBM to the cap-assisted technique for piecemeal endoscopic resection of esophageal ESCCs. METHODS: Patients with mucosal HGIN/ESCC (2 - 6 cm, maximum two-thirds of esophageal circumference) were included. Lesions, delineated by 1.25 % Lugol staining, were randomized to MBM or cap-assisted piecemeal resection. Endpoints were procedure time and costs, complete endoscopic resection, adverse events, and absence of HGIN/ESCC at 3-month and 12-month follow-up.  RESULTS: Endoscopic resection was performed in 84 patients (59 men, mean age 60) using MBM (n = 42) or the endoscopic resection cap (n = 42). There were no differences in baseline characteristics. Endoscopic complete resection was achieved in all lesions. Procedure time was significantly shorter with MBM (11 vs. 22 minutes, P < 0.0001). One perforation, seen after using the endoscopic resection cap, was treated conservatively. Total costs of disposables were lower for MBM (€200 vs. €251, P = 0.04). At 3-month and 12-month follow-ups none of the patients had HGIN/ESCC at the resection site. CONCLUSION: Piecemeal endoscopic resection of esophageal ESCC with MBM is faster and cheaper than with the endoscopic resection cap. Both techniques are highly effective and safe. MBM may have significant advantages over the endoscopic resection cap technique, especially in countries where ESCC is extremely common but limited endoscopic expertise and resources exist. (Netherlands trial register: NTR 3246.).

Endoscopic radiofrequency ablation for early esophageal squamous cell neoplasia: report of safety and effectiveness from a large prospective trial.

BACKGROUND AND STUDY AIMS: Endoscopic radiofrequency ablation (RFA) is an established therapy for Barrett's esophagus. Preliminary reports, limited by low patient numbers, also suggest a possible role for RFA in early esophageal squamous cell neoplasia (ESCN). The aim of this study was to evaluate the safety and effectiveness of RFA for early ESCN (moderate/high grade intraepithelial neoplasia [MGIN/HGIN] and early flat-type esophageal squamous cell carcinoma [ESCC]). PATIENTS AND METHODS: This prospective cohort study included patients with at least one flat (type 0-IIb) unstained lesion (USL) on Lugol's chromoendoscopy and a consensus diagnosis of MGIN, HGIN, or early ESCC. RFA was used at baseline to treat all USLs, and then biopsy (and focal RFA if USL persisted) was performed every 3 months until all biopsies were negative for MGIN, HGIN, and ESCC. The main outcome measurements were complete response at 3 and 12 months (absence of MGIN, HGIN, and ESCC), neoplastic progression, and adverse events. RESULTS: A total of 96 patients participated (MGIN 45, HGIN 42, early ESCC 9). At 3 and 12 months, 73 % (70/96) and 84 % (81/96), respectively, showed a complete response. Two patients (2 %) progressed (MGIN to HGIN; HGIN to T1m2 ESCC); both were treated endoscopically and achieved complete response. Stricture occurred in 20 patients (21 %), all after circumferential RFA. Lugol's + RFA 12 J/cm(2) (single application, no cleaning) was the favored baseline circumferential RFA technique (82 % 12-month complete response [14/17], 6 % stricture [6/17]). CONCLUSION: In patients with early ESCN, RFA was associated with a high complete response rate and an acceptable safety profile.

[Clinical characteristics of multiple primary cancer associated with esophageal squamous carcinoma].

OBJECTIVE: To examine the characteristics of esophageal squamous cancers with multiple primary cancers in another organ. METHODS: Between January 2012 and December 2014, 3 104 patients with esophageal squamous cell carcinoma treated in Cancer Institute and Hospital, Chinese Academy of Medical Sciences, were reviewed for the presence of an additional primary cancer retrospectively. The patients were divided into two groups according to whether they had multiple primary cancer. RESULTS: Totally 369 (11.9%) patients were found multiple primary cancer in the other organs. Among these patients, 72.4% was found synchronously, another primary cancer was found in the head and neck region in 211 (6.8%), in the stomach in 140 (4.2%), and in the lung, colon, breast, and other locations in the remaining patients. Of the 211 patients with another primary cancer in the head and neck region, 156 (73.2%) had hypopharyngeal cancer. Furthermore, the incidence of intraesophageal multiple cancerous lesion in the patients with primary cancer in the head and neck region was significantly higher than that in those whose other primary cancers were gastric cancer or in those with non-multiple primary cancer (P<0.01). CONCLUSION: There is a high incidence of multiple primary cancers in patients with esophageal squamous carcinoma, mostly found synchronously. The leading multiple primary cancers were head and neck cancer and stomach cancer. Intraesophageal multiple cancerous lesion is an indicator for a second primary cancer in head and neck. A better knowledge of the relationships between esophageal carcinoma and cancers in other organs may lead to earlier detection of other primary cancers and improved therapeutic results.

Treatment outcomes of endoscopic resection for nonampullary duodenal neuroendocrine tumors.

Background: The incidence rate of duodenal neuroendocrine tumors has been increasing in recent years. Endoscopic resection [ER; endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD)] is recommended for nonampullary duodenal neuroendocrine tumors (NAD-NETs) ≤10 mm in diameter that are confined to the submucosal layer and without lymph node or distant metastasis. However, the efficacy and safety of and indications for EMR/ESD remain unclear. Methods: Between November 2011 and April 2021, 12 NAD-NETs in 12 patients who underwent either EMR or ESD were analyzed retrospectively. The rates of en bloc resection, complete resection, pathologic complete resection, margin involvement, lymphovascular invasion, perineural invasion, complications and prognosis were determined during follow-up (median observation period 53.0 months). Results: EMR was performed for two tumors, and ESD was performed for ten tumors. En bloc resection was performed for both tumors (100%) in the EMR group, and complete resection was achieved in one case (50%). Pathological complete resection was achieved in one case (50%), while in the ESD group, these three rates were 90% (9/10), 80% (8/10), and 80% (8/10), respectively. Intraoperative perforation occurred in one patient (10%) during ESD treatment, with no intraoperative or delayed bleeding in either group. Recurrence and distant metastasis were not observed during the mean follow-up period of 53.0 months (range, 18-131 months). Conclusions: For NAD-NETs that measure ≤10 mm in size, are confined to the submucosal layer and have neither suspicious lymph nodes nor distant metastasis, ER (EMR and ESD) may be a safe, effective, and feasible endoscopic technique for removing them.