Advantage of endoscopic mucosal resection with a cap for rectal neuroendocrine tumors

Endoscopic treatments for rectal neuroendocrine tumors: a systematic review and network meta-analysis

BACKGROUND

Conventional endoscopic mucosal resection (cEMR), EMR with a transparent cap, EMR using a ligation device (EMR-L), EMR after circumferential precutting (EMR-P), and endoscopic submucosal dissection (ESD) have been used for resecting rectal neuroendocrine tumors (r-NETs). However, there is no consensus regarding which is the best treatment. This study aimed to compare the outcomes of the aforementioned 5 techniques for resecting r-NETs by network meta-analysis.

METHODS

Electronic databases (PubMed, Cochrane Library, Embase, Ovid Medline, and Web of Science) were systematically searched to include relevant studies published from inception to September 1, 2023. The en bloc resection rate, histologic complete resection rate, positive lateral margin rate, positive vertical margin rate, adverse events rate, and procedure time were compared.

RESULTS

A total of 27 studies with a total of 2112 r-NETs were included, and the mean diameter of tumors was 6.24 mm. Pairwise meta-analysis showed that EMR-L and ESD had higher en bloc resection and histologic complete resection rates and lower positive vertical margin rate than those of cEMR in resecting r-NETs. Compared with ESD, EMR-L and EMR-P achieved similar resection rates and significantly shortened the procedure time without increasing adverse events. The network meta-analysis evaluated the surface under the cumulative ranking curves and revealed that EMR-L was the best modality for treating r-NETs considering the comprehensive results of the en bloc resection rate, histologic complete resection rate, positive lateral margin rate, positive vertical margin rate, adverse events rate, and procedure time.

CONCLUSION

EMR-L should be recommended as the first-line endoscopic treatment for small r-NETs.

Role of Advanced Gastrointestinal Endoscopy in the Comprehensive Management of Neuroendocrine Neoplasms

Neuroendocrine neoplasms (NENs), also called neuroendocrine tumors (NETs), are relatively uncommon, heterogenous tumors primarily originating in the gastrointestinal tract. With the improvement in technology and increasing use of cross-sectional imaging and endoscopy, they are being discovered with increasing frequency. Although traditionally considered indolent tumors with good prognoses, some NENs exhibit aggressive behavior. Timely diagnosis, risk stratification, and management can often be a challenge. In general, small NENs without local invasion or lymphovascular involvement can often be managed using minimally invasive advanced endoscopic techniques, while larger lesions and those with evidence of lymphovascular invasion require surgery, systemic therapy, or a combination thereof. Ideal management requires a comprehensive and accurate understanding of the stage and grade of the tumor. With the recent advancements, a therapeutic advanced endoscopist can play a pivotal role in diagnosing, staging, and managing this rare condition. High-definition white light imaging and digital image enhancing technologies like narrow band imaging (NBI) in the newer endoscopes have improved the diagnostic accuracy of traditional endoscopy. The refinement of endoscopic ultrasound (EUS) over the past decade has revolutionized the role of endoscopy in diagnosing and managing various pathologies, including NENs. In addition to EUS-directed diagnostic biopsies, it also offers the ability to precisely assess the depth of invasion and lymphovascular involvement and thus stage NENs accurately. EUS-directed locoregional ablative therapies are increasingly recognized as highly effective, minimally invasive treatment modalities for NENs, particularly pancreatic NENs. Advanced endoscopic resection techniques like endoscopic submucosal dissection (ESD), endoscopic submucosal resection (EMR), and endoscopic full-thickness resection (EFTR) have been increasingly used over the past decade with excellent results in achieving curative resection of various early-stage gastrointestinal luminal lesions including NENs. In this article, we aim to delineate NENs of the different segments of the gastrointestinal (GI) tract (esophagus, gastric, pancreatic, and small and large intestine) and their management with emphasis on the endoscopic management of these tumors.

Clinicopathological characteristics of rectal multiple neuroendocrine neoplasms and literature review

BACKGROUND

There are only a few epidemiological reports available for reference. The clinicopathological features are not clear, so there is no consensus on treating rectal multiple neuroendocrine neoplasms. This study aims to summarize the clinicopathological characteristics and preliminarily discuss the clinical diagnosis and treatment of rectal multiple neuroendocrine neoplasms.

METHODS

This study retrospectively analyzed rectal neuroendocrine neoplasm patients diagnosed and treated at the Fourth Hospital of Hebei Medical University from February 2007 to May 2021. The clinicopathological characteristics of rectal multiple neuroendocrine neoplasms were summarized and analyzed in combination with 14 studies on rectal multiple neuroendocrine neoplasms.

RESULTS

The incidence of RM-NENs accounted for 3.8% of all R-NENs in this study. The number of tumors varied to some extent, the size of tumors was basically no more than 10 mm, and there were more G1 grade tumors. In the analysis of 46 cases with known lymph node metastasis, the difference in lymph node metastasis rate between the number of tumors < 8 and ≥ 8 was statistically significant (p = 0.002).

CONCLUSIONS

The incidence of rectal multiple neuroendocrine neoplasms accounted for 3.8% of all rectal neuroendocrine neoplasms. For rectal multiple neuroendocrine neoplasms, the lymph node metastasis rate was higher when the number of tumors was ≥ 8. The influence of the number of tumors on lymph node metastasis should be considered in the selection of treatment.

Efficacy of Endoscopic Resection for Rectal Neuroendocrine Tumors Smaller than 15 mm

BACKGROUND

Local resection, including endoscopic resection, is recommended for rectal neuroendocrine tumors (NETs) < 15 mm in patients without risk factors for metastasis, though the short- and long-term outcomes are unclear.

AIMS

This study investigates the efficacy of endoscopic resection for rectal NETs < 15 mm.

METHODS

The short- and long-term outcomes of patients with rectal NETs < 15 mm who underwent endoscopic resection and the outcomes of each endoscopic technique were analyzed. The tumors were stratified as < 10 mm (small-size group, SSG) and 10-14 mm (intermediate-size group, IMG).

RESULTS

Overall, 139 lesions (SSG, n = 118; IMG, n = 21) were analyzed. All tumors were classified as G1 (n = 135) or G2 (n = 4) according to the 2019 World Health Organization grading criteria. The complete resection rate was not different between the groups (P = 0.151). Endoscopic submucosal dissection (ESD) and endoscopic submucosal resection with a ligation device (ESMR-L) achieved complete resection rates > 90% in the SSG. The ESMR-L procedure time (P < 0.001) and hospitalized period (P < 0.001) were significantly shorter than those of ESD. ESD achieved a complete resection rate of 80.0% in the IMG. The tumor size did not affect the overall survival or rate of lymph node/distant metastases.

CONCLUSIONS

Endoscopic resection is a feasible and effective treatment for patients with rectal NETs < 15 mm without the risk factors of metastasis. ESMR-L and ESD are optimal techniques for resecting tumors smaller than 10 mm and 10-14 mm, respectively.

Clinical outcomes and risk factors associated with poor prognosis after endoscopic resection of 10-20 mm rectal neuroendocrine tumors: a multicenter, retrospective study of 10-year experience

BACKGROUND

The efficacy of endoscopic resection for of 10-20 mm rectal neuroendocrine tumor (NET) remains controversial. We aimed to evaluate the clinical outcomes and risk factors associated with poor prognosis after endoscopic resection of 10-20 mm rectal NET and to determine the optimal treatment.

METHODS

Patients who underwent endoscopic resection for rectal NET in four tertiary hospitals were enrolled, and data on with the clinical outcomes and risk factors related to poor prognosis were retrospectively analyzed.

RESULTS

A total of 105 patients who underwent endoscopic submucosal resection (ESD; n = 65, 61.9%), modified endoscopic mucosal resection (mEMR; n = 31, 29.5%), and conventional EMR (cEMR; n = 9, 8.6%) were enrolled. The mean follow-up period was 41.2 ± 21.9 months. In the morphologic findings, the mean diameter was 11.6 mm (range 10-19); the shape was sessile (50.5%) and mixed type (49.5%), and surface depression was observed in 41.9% of patients. In the histologic findings, 87.6% of patients had G1 and 12.4% G2 tumor grade, and 3.8% of patients had lymphovascular invasion. The overall en bloc and histologically complete (R0) resections were 99.1% and 76.2%, respectively. cEMR was a less-frequently developed R0 resection. In the univariate and multivariate analyses for R0 resection, only surface depression was significantly associated. Regional or distant organs metastasis during follow-up developed in three patients (2.9%) and was significantly associated with female sex, redness, G2 tumor grade, and non-ESD methods.

CONCLUSION

Patients who underwent endoscopic resection of 10-20 mm rectal NET had good prognosis; therefore, endoscopic resection can be considered as the first-line treatment, particularly for 10-14 mm rectal NET. However, the risk factors, such as female sex, redness, G2 tumor grade and non-ESD methods, were associated with regional or distant metastases during follow-up. Therefore, patients with these risk factors should be carefully monitored.

Multiple ligation-assisted endoscopic submucosal resection combined with endoscopic ultrasonography: a novel method to treat rectal neuroendocrine tumors

OBJECTIVE

The first choice of treatment for rectal neuroendocrine tumors (R-NETs) 10 mm in size is endoscopic resection, there is still controversy concerning the optimal endoscopic treatment for resecting R-NETs. This study evaluated the efficacy and safety of multiple ligation-assisted endoscopic submucosal resection combined with endoscopic ultrasonography (EMR-MLUS) for R-NETs.

METHODS

We retrospectively analyzed the data of 62 patients with R-NETs ≤10 mm in size who underwent EMR-MLUS or ligation-assisted endoscopic submucosal resection combined with endoscopic ultrasonography (EMR-LUS) between May 2019 and April 2022, including tumor characteristics, endoscopic complete resection, pathological complete resection, the procedure time, adverse events, and follow-up were compared between the two groups of patients.

RESULTS

Of the 62 patients, 19 underwent EMR-MLUS and 43 underwent EMR-LUS. The endoscopic morphology of lesions was statistically different between group EMR-MLUS and group EMR-LUS ( P = 0.015), and most of them were flat and slightly raised lesions in group EMR-MLUS. Although the pathological complete resection rate was slightly higher in the EMR-MLUS group than in the EMR-LUS group (94.74% vs. 90.70%; P = 0.290), the endoscopic complete resection rate was high in both groups. Involvement of the lateral resection margin was found four cases in the ESMR-LUS group; one case of deep resection margin involvement in the EMR-MLUS group. The mean procedure time was longer in the EMR-MLUS group than in the EMR-LUS group (12.79 ± 1.01 min vs. 11.08 ± 1.89 min; P = 0.041). In group EMR-LUS, there were two cases of immediate bleeding; in group EMR-MLUS, one case of perforation, all of them were successfully treated by endoscopy. No recurrence, progression, or metastasis was found in all patients.

CONCLUSION

EMR-MLUS is a safe and effective technique that could be considered when removing small rectal NETs, especially flat and slightly raised lesions.

Modified Cap-Assisted Endoscopic Mucosal Resection Versus Endoscopic Submucosal Dissection for the Treatment of Rectal Neuroendocrine Tumors ≤10 mm: A Randomized Noninferiority Trial

INTRODUCTION

Although recent guidelines recommend endoscopic resection of rectal neuroendocrine tumors (NET) ≤10 mm, there is no consensus on which endoscopic modality should be performed. We aimed to compare the safety and efficacy of modified cap-assisted endoscopic mucosal resection (mEMR-C) and endoscopic submucosal dissection (ESD) methods for the treatment of rectal NET ≤10 mm.

METHODS

A randomized noninferiority trial comparing mEMR-C and ESD was conducted. The primary outcome was the histological complete resection rate; the secondary outcomes included en bloc resection rate, operation time, complications, and so on. Subgroup analyses and follow-up were also performed.

RESULTS

Ninety patients were enrolled, and 79 patients with pathologically confirmed rectal NET were finally analyzed, including 38 cases of mEMR-C and 41 cases of ESD. Histological complete resection rate was 97.4% in the mEMR-C group and 92.7% in the ESD group. The noninferiority of mEMR-C compared with that of ESD was confirmed because the absolute difference was 4.7% (2-sided 90% confidence interval, -3.3% to 12.2%; P = 0.616). En bloc resection and successful removal of rectal NET were achieved in all patients. Advantages of mEMR-C over ESD included shorter operation time (8.89 ± 4.58 vs 24.8 ± 9.14 minutes, P < 0.05) and lower hospitalization cost ($2,233.76 ± $717.70 vs $2,987.27 ± $871.81, P < 0.05). Postoperative complications were recorded in 4 patients who received mEMR-C and 2 patients in the ESD group (11.5% vs 4.9%, P = 0.509), which were all well managed using endoscopy. Similar findings were observed when subgroup analysis was performed.

DISCUSSION

mEMR-C is noninferior to ESD with a similar complete resection rate. In addition, mEMR-C had shorter procedure duration time and lower hospitalization costs.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03982264.

Endoscopic techniques for diagnosis and treatment of gastro-entero-pancreatic neuroendocrine neoplasms: Where we are

BACKGROUND

The correct localization of the primary tumor site and a complete histological diagnosis represent the milestones for the proper management of gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs).

AIM

To analyze current evidence on the role of endoscopy in the diagnosis/treatment of GEP-NENs.

METHODS

An extensive bibliographical search was performed in PubMed to identify guidelines and primary literature (retrospective and prospective studies, systematic reviews, case series) published in the last 15 years, using both medical subject heading (MeSH) terms and free-language keywords: gastro-entero-pancreatic neuroendocrine neoplasms; endoscopy; ultrasound endoscopy; capsule endoscopy; double-balloon enteroscopy; diagnosis; therapy; staging.

RESULTS

In the diagnostic setting, endoscopic ultrasonography (EUS) represents the diagnostic gold standard for pancreatic NENs and the technique of choice for the locoregional staging of gastric, duodenal and rectal NENs. The diagnosis of small bowel NENs (sbNENs) has been improved with the advent of video capsule endoscopy and double-balloon enteroscopy, which allow for direct visualization of the entire small bowel; however, data regarding the efficacy/safety of these techniques in the detection of sbNENs are scanty and often inconclusive. From a therapeutic point of view, endoscopic removal is the treatment of choice for the majority of gastric NENs (type 1/2), for well-differentiated localized nonmetastatic duodenal NENs < 1 cm, confined to the submucosa layer and for < 10 mm, stage T1–T2, rectal NENs. EUS-guided pancreatic locoregional ablative treatments have been proposed in recent studies with promising results in order to control symptoms or reduce tumor burden in selected patients.

CONCLUSION

Standard axial endoscopy and EUS still play a pivotal role in several GEP-NENs. Advanced techniques for increasing the rate of R0 resection should be reserved for high-volume referral centers.

Endoscopic treatment for rectal neuroendocrine tumor: which method is better?

Recently, research on rectal neuroendocrine tumors (NETs) has increased during the last few decades. Rectal NETs measuring <10 mm without atypical features and confined to the submucosal layer have only 1% risk of metastasis, and the long-term survival probability of patients without metastasis at the time of diagnosis is approximately 100%. Therefore, the current guidelines suggest endoscopic resection of rectal NETs of <10 mm is regarded as a safe therapeutic option. However, there are currently no clear recommendations for technique selection for endoscopic resection. The choice of treatment modality for rectal NETs should be based on the lesion size, endoscopic characteristics, grade of differentiation, depth of vertical involvement, lymphovascular invasion, and risk of metastasis. Moreover, the complete resection rate, complications, and experience at the center should be considered. Modified endoscopic mucosal resection is the most suitable resection method for rectal NETs of <10 mm, because it is an effective and safe technique that is relatively simple and less time-consuming compared with endoscopic submucosal dissection. Endoscopic submucosal dissection should be considered when the tumor size is >10 mm, suctioning is not possible due to fibrosis in the lesion, or when the snaring for modified endoscopic mucosal resection does not work well.

Comparison between endoscopic mucosal resection with a cap and endoscopic submucosal dissection for rectal neuroendocrine tumors

Background

The aim of this study is to evaluate and compare the safety and efficacy of endoscopic mucosal resection with a cap (EMR-c) with those of endoscopic submucosal dissection (ESD) for rectal neuroendocrine tumors (R-NETs) ≤ 15 mm in diameter, and to analyze the risk factors of incomplete resection.

Methods

A total of 122 patients who underwent EMR-c or ESD for R-NETs at the Fourth Hospital of Hebei Medical University between February 2007 and December 2020 were invovled in this study. The clinical outcomes of two groups were compared and evaluated.

Results

A total of 122 patients with 128 R-NETs underwent endoscopic resection (EMR-c, 80; ESD, 48). In terms of duration of operation, EMR-c was significantly shorter than ESD (p < 0.001). Univariate analysis and multivariate analysis suggested that tumor diameter ≥ 8 mm was an independent risk factor for incomplete resection in patients with R-NETs in this study.

Conclusions

Both EMR-c and ESD were safe and effective treatments for R-NETs ≤ 15 mm in diameter. In addition, tumor diameter ≥ 8 mm was an independent risk factor for incomplete resection.

Spannungsfeld endoskopische Resektionsverfahren bei GEP-NET // Endoscopic resection for GEP-NET

Neuroendokrine Tumoren des Verdauungstraktes (GEP-NET) sind eine seltene Tumorentität, die häufig als Zufallsbefund diagnostiziert werden. Ein großer Teil dieser Zufallsdiagnosen wird im Rahmen einer endoskopischen Untersuchung gestellt. Während die vollständige Entfernung des Tumors im Sinne einer kurativen chirurgischen Resektion nach onkologischen Kriterien das Standardvorgehen für lokalisierte Tumorerkrankungen ist, kann bei kleinen Tumoren ohne Hinweis und Risiko für eine lymphogene Metastasierung eine endoskopische Abtragung in gleicher Intention erfolgen. Während dies für Magen-, Duodenum- und Rektum-NET der Standard ist, sollten NET des Jejunums und Ileums aufgrund der hohen Metastasierungsrate trotz geringer Tumorgröße regelhaft nicht endoskopisch angegangen werden. Die Grenze für eine endoskopische Resektion ergibt sich sowohl durch die technische Machbarkeit im Sinne des Erreichens einer R0-Resektion, der erwarteten Komplikationen im Sinne von Blutung und Perforationen als auch durch das vermutete Risiko für eine lymphogene Metastasierung. Generell wird eine endoskopische Resektion bei Befunden < 1 cm regelhaft empfohlen, da sowohl die gute technische Machbarkeit als auch das geringe Metastasierungsrisiko für eine endoskopische Resektion sprechen. Bei allen Befunden über 2 cm Größe sind sowohl die technischen Erfolgsaussichten so niedrig als auch das Metastasierungsrisiko so hoch, dass in dieser Situation regelhaft ein chirurgisches Vorgehen erfolgen sollte. Es bleibt somit ein Graubereich bei der Tumorgröße zwischen 1 und 2 cm, wo sowohl endoskopische, aber auch chirurgische Resektionsverfahren sinnvoll eingesetzt werden können. Zunehmend kommen auch gemeinsame Eingriffe im Sinne eines endoskopisch-laparoskopischen Rendezvous-Verfahrens zum Einsatz – insbesondere im Duodenum bieten sich diese Eingriffe an, um eine minimale Resektion mit größtmöglicher R0-Erfolgsrate und niedriger Perforationsrate zu erreichen.

Rectal neuroendocrine tumors: Current advances in management, treatment, and surveillance

Rectal neuroendocrine neoplasms (r-NENs) are considered among the most frequent digestive NENs, together with small bowel NENs. Their incidence has increased over the past few years, and this is probably due to the widespread use of endoscopic screening for colorectal cancer and the advanced endoscopic procedures available nowadays. According to the current European Neuroendocrine Tumor Society (ENETS) guidelines, well-differentiated r-NENs smaller than 10 mm should be endoscopically removed in view of their low risk of local and distant invasion. R-NENs larger than 20 mm are candidates for surgical resection because of their high risk of distant spreading and the involvement of the muscularis propria. There is an area of uncertainty regarding tumors between 10 and 20 mm, in which the metastatic risk is intermediate and the endoscopic treatment can be challenging. Once removed, the indications for surveillance are scarce and poorly codified by international guidelines, therefore in this paper, a possible algorithm is proposed.

Endoscopic submucosal dissection versus endoscopic mucosal resection for rectal carcinoid tumor. A meta-analysis and meta-regression with single-arm analysis

OBJECTIVE

As there has been so far no consensus on the best endoscopic resection technique, a meta-analysis was conducted to compare the efficacy and safety of endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) for treating rectal carcinoid tumors.

METHODS

MEDLINE and EMBASE databases were searched for articles on the treatment of rectal carcinoid tumors using ESD vs EMR published up to October 2020 for outcomes including en bloc and complete resection, margin involvement, procedure time, requirement for additional surgery, bleeding, perforation and recurrence. Risk ratio and weighted mean differences were used for a DerSimonian and Laird random effects pairwise meta-analysis. Single-arm meta-analyses of proportions and random effects meta-regression analysis were also conducted.

RESULTS

Twenty-two studies involving 1360 rectal carcinoid tumors were included, in which 655 and 705 rectal carcinoid tumors were resected with ESD and EMR, respectively. The resection efficacy of ESD was comparable to that of EMR for tumors <10 mm. However, there were a significantly higher complete resection rate, and lower rates of vertical margin involvement and requirement for additional surgery using ESD than using EMR for tumors ≤20 mm. ESD had a longer procedure time and an increased likelihood of bleeding than EMR.

CONCLUSIONS

ESD is more effective in providing a curative treatment for rectal carcinoid tumors ≤20 mm in size as ESD can achieve a higher complete resection rate with lower vertical margin involvement than EMR. While they are suitable for treating rectal carcinoid tumors <10 mm as both techniques provide similar efficacy.

Comparison of endoscopic therapies for rectal neuroendocrine tumors: endoscopic submucosal dissection with myectomy versus endoscopic submucosal dissection

BACKGROUND

Endoscopic submucosal dissection (ESD) has been a valuable treatment of choice for rectal neuroendocrine tumors (NETs). However, the vertical margin may remain positive after ESD because the neuroendocrine tumors develop in a submucosal tumor (SMT)-like way. Endoscopic submucosal dissection with myectomy (ESD-ME), a new method for rectal NETs, may overcome this problem.

METHODS

From August 2013 to August 2020, the medical records of 69 patients (72 rectal neuroendocrine tumors) who received endoscopic submucosal dissection (ESD) or endoscopic submucosal dissection with myectomy (ESD-ME) for rectal NETs were investigated retrospectively. The characteristics of the patients and tumors, the rate of complete resection, and the rate of complications were analyzed retrospectively.

RESULTS

The ESD-ME group contained 27 patients (12 males, 15 females; age range 29-72 years) and the ESD group contained 42 patients (21 males, 21 females; age range 29-71 years). Both groups had similar mean rectal neuroendocrine tumor diameters (ESD-ME 6.1 ± 1.8 mm, ESD 6.7 ± 2.6 mm; P = 0.219). The procedure time was not different significantly between groups (ESD-ME 21.1 ± 6.3, ESD 19.3 ± 3.1; P = 0.115). The endoscopic complete resection rate did not differ significantly between the ESD-ME and ESD groups (100% for each). The histological complete resection rate was 100% (27 of 27) in the ESD-ME group and 81.0% (34 of 42) in the ESD group (P = 0.043). Delayed bleeding occurred in 1 ESD-ME patient (3.7%) and in 2 ESD patients (4.8%) (P = 1.000). Perforation occurred in 1 ESD-ME patient (3.7%) and the patient was successfully managed by conservative measure, and there was no perforation after ESD (P = 0.391).

CONCLUSIONS

When compared with ESD, ESD-ME resulted in a higher histological complete resection rate, had a similar complication rate, and took similar time to perform. ESD-ME can be considered an effective and safe resection method for rectal NETs < 16 mm in diameter without metastasis.

An evaluation of resectability among endoscopic treatment methods for rectal neuroendocrine tumors <10 mm

BACKGROUND AND STUDY AIMS

With respect to rectal neuroendocrine tumor (NET) resection, it remains unclear which of the following methods is the most effective: conventional endoscopic mucosal resection (cEMR), EMR using a fitted cap (EMR-C), EMR with a ligation band device (EMR-L), or endoscopic submucosal dissection (ESD). Thus, in this study, we aim to retrospectively evaluate the most effective endoscopic resection for rectal NETs < 10 mm.

PATIENTS AND METHODS

In total, 61 consecutive patients with primary rectal NETs < 10 mm in diameter were included in this study; they were then divided into three groups: those with cEMR; those with modified EMR (mEMR) involving EMR-C and EMR-L; and those with ESD. The primary endpoint was to evaluate the difference in the complete en bloc resection rate. The secondary endpoint was to investigate differences in procedure time and complications.

RESULTS

Among the three groups, a significant difference was found in procedure time (cEMR vs ESD, P < .01; mEMR vs ESD, P < .01), en bloc resection rate (cEMR vs mEMR, P = .015), tumor size (mEMR vs ESD, P < .01), percentage of tumor diameter ≥ 5 mm (mEMR vs ESD, P < .01), and complete en bloc resection rate (cEMR vs mEMR, P = .014). Meanwhile, no significant difference was noted in terms of complication rate among the three groups.

CONCLUSION

The mEMR was the most suitable resection method for rectal NETs < 10 mm with respect to the risks and benefits from procedure-related factors, such as complete en bloc resection rate, procedure time, and complication rate.

Endoscopic mucosal resection: still a reliable therapeutic option for gastrointestinal neuroendocrine tumors

Background

Neuroendocrine tumors (NETs), as a rare and heterogeneous category of solid tumors, feature various morphologies and behaviors. In recent years, the incidence of NETs has continued to increase. Endoscopic mucosal resection (EMR) is one of the therapeutic modalities for the treatment of gastric and rectal NETs.

Methods

We evaluated patients with well-differentiated NETs of the stomach, duodenum, or rectum between 2011 and 2018. In this study, all cases with tumors confined to the mucosal or submucosal layers and smaller than 20 mm were resected using the EMR technique. We used EUS, CT scan, or MRI to exclude patients with advanced disease. All patients were actively monitored for recurrence according to the recommended protocols.

Results

A total of 36 patients with NETs entered the study; 17 (47.2%) were female and the remaining 19 (52.8%) were male, with a total age range of 20–74 years (mean: 52.47 ± 13.47 years). Among the tumors, 31 cases (86.1%) were G1 and the remaining 5 (13.9%) were G2. Based on the pathology reports, 22 tumors (61.1%) were smaller than 1 cm, while the remaining 14 (38.9%) were between 1–2 cm. Twenty-two patients (61.1%) had a margin of specimen involved with the tumor. No recurrence was observed during the mean follow-up time of 63.5 ± 19.8 months (range: 39–103 months). All 36 cases survived during the study period.

Conclusion

Conventional EMR procedure provides low chance of R0 (complete resection) achievement in gastrointestinal NETs smaller than 20 mm and limited to the mucosa or sub mucosa. However, it could be an option if patients are closely followed. Postoperative marginal involvement is not a reliable predictor of disease recurrence, which may be explained by the deleterious effect of heat coagulation and cauterization applied during tumor removal.

Diagnosis and Management of Rectal Neuroendocrine Tumors (NETs)

Rectal neuroendocrine tumors (NETs) are rare, with an incidence of 0.17%, but they represent 12% to 27% of all NETs and 20% of gastrointestinal NETs. Although rectal NETs are uncommon tumors, their incidence has increased over the past few years, and this is probably due to the improvement in detection rates made by advanced endoscopic procedures. The biological behavior of rectal NETs may be different: factors predicting the risk of metastases have been identified, such as size and grade of differentiation. The tendency for metastatic diffusion generally depends on the tumor size, muscular and lymphovascular infiltration, and histopathological differentiation. According to the current European Neuroendocrine Tumor Society (ENETS) guidelines, tumors that are smaller than 10 mm and well differentiated are thought to have a low risk of lymphovascular invasion, and they should be completely removed endoscopically. Rectal NETs larger than 20 mm have a higher risk of involvement of muscularis propria and high metastatic risk and are candidates for surgical resection. There is controversy over rectal NETs of intermediate size, 10–19 mm, where the metastatic risk is considered to be 10–15%: assessment of tumors endoscopically and by endoanal ultrasound should guide treatment in these cases towards endoscopic, transanal, or surgical resection.

Risk of lymph node metastasis after endoscopic treatment for rectal NETs 10 mm or less

PURPOSE

For rectal neuroendocrine tumors (NETs) ≤ 10 mm, endoscopic resection is a standard treatment. However, there is no consensus whether additional surgery should be performed for patients at risk of lymph node metastasis (LNM) after endoscopic resection. The purpose of this study was to analyze the results of endoscopic resection and additional surgery of rectal NETs, thereby clarify the characteristics of cases with LNM.

METHODS

This study was a multicenter retrospective cohort study conducted at 12 Japanese institutions. A total of 132 NETs ≤ 10 mm were analyzed regarding various therapeutic results. A comparative analysis was performed by dividing the cases into two groups that underwent additional surgery or not. Furthermore, the relationship between tumor size and LNM was examined.

RESULTS

The endoscopic treatments were 12 endoscopic mucosal resections (EMR), 58 endoscopic submucosal resections with ligation (ESMR-L), 29 precutting EMRs, and 33 endoscopic submucosal dissections (ESD). The R0 resection rates of EMR were 41.7%, and compared to this rate, other three treatments were 86.2% (p < 0.001), 86.2% (p = 0.005), and 97.0% (p < 0.001), respectively. There were 41 non-curative cases (31.1%), and 13 had undergone additional surgery. Then, LNM was observed in 4 of the 13 patients, with an overall rate of LNM of 3.0% (4/132). The rate of positive lymphatic invasion and the rate of LNM by tumor size ≤ 6 mm and 7-10 mm were 9.7 vs. 15.4% (p = 0.375) and 0 vs. 10.3% (p = 0.007).

CONCLUSIONS

A multicenter study revealed the priority of each endoscopic resection and the low rate of LNM for rectal NETs ≤ 6 mm.

Comparison of conventional and modified endoscopic mucosal resection methods for the treatment of rectal neuroendocrine tumors

BACKGROUND/AIM

Small rectal neuroendocrine tumors (NETs) confined to the submucosa are endoscopically resectable. Because most rectal NETs are submucosal tumors, conventional endoscopic mucosal resection (cEMR) may not result in a complete resection. This study investigated whether modified EMRs, namely endoscopic submucosal resection with ligation (ESMR-L), EMR with precutting (EMR-P), and strip biopsy are superior to cEMR for achieving histologically complete resection (HCR) of rectal NETs.

METHODS

Medical records of 215 patients who were treated with endoscopic resections for rectal NETs between January 2011 and July 2019 were retrospectively enrolled. Of the patients, 110, 33, 29, and 43 underwent cEMR, ESMR-L, EMR-P, and strip biopsy, respectively. For each method, HCR and en bloc resection rates, procedure times, and complication rates were measured.

RESULTS

HCR was achieved with cEMR, EMR-P, ESMR-L, and strip biopsies for 74.5%, 90.9%, 93.1%, and 90.7% of cases, respectively. The HCR rate for cEMR was inferior to those of the modified EMRs (p = 0.045 for cEMR vs. EMR-P; p = 0.031 for cEMR vs. ESMR-L; p = 0.027 for cEMR vs. strip biopsy). Among the three modified EMRs, there was no significant difference in achieving HCR (p = 1.000). En bloc resection (p = 0.096) and complication rates (p = 0.071) were not significantly different among the four EMR methods, although EMR-P required the longest procedure time (p = 0.000).

CONCLUSIONS

All three modified EMRs are superior to cEMR and are equally effective for achieving HCR of rectal NETs.

Neuroendocrine neoplasia of the gastrointestinal tract revisited: towards precision medicine

Over the past 5 years, a number of notable research advances have been made in the field of neuroendocrine cancer, specifically with regard to neuroendocrine cancer of the gastrointestinal tract. The aim of this Review is to provide an update on current knowledge that has proven effective for the clinical management of patients with these tumours. For example, for the first time in the tubular gastrointestinal tract, well-differentiated high-grade (grade 3) tumours and mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are defined in the WHO classification. This novel classification enables efficient identification of the most aggressive well-differentiated neuroendocrine tumours and helps in defining the degree of aggressiveness of MiNENs. The Review also discusses updates to epidemiology, cell biology (including vesicle-specific components) and the as-yet-unresolved complex genetic background that varies according to site and differentiation status. The Review summarizes novel diagnostic instruments, including molecules associated with the secretory machinery, novel radiological approaches (including pattern recognition techniques), novel PET tracers and liquid biopsy combined with DNA or RNA assays. Surgery remains the treatment mainstay; however, peptide receptor radionuclide therapy with novel radioligands and new emerging medical therapies (including vaccination and immunotherapy) are evolving and being tested in clinical trials, which are summarized and critically reviewed here.

Comparison between cap-assisted and ligation-assisted endoscopic mucosal resection for rectal neuroendocrine tumors

Background:

Modified endoscopic mucosal resection (EMR) is considered a treatment option for rectal neuroendocrine tumors (NETs) <10 mm in diameter. In this study, we evaluated the clinical outcomes of cap-assisted EMR (EMR-C) and EMR with a ligating device (EMR-L).

Methods:

We retrospectively analyzed 158 patients with 162 rectal NETs treated endoscopically at a single Korean tertiary hospital between March 2010 and November 2017. We evaluated the rates of endoscopic en bloc resection, histologic complete resection, and procedural complications according to the treatment method.

Results:

Among 162 rectal NETs, 42 were treated with EMR-C and 120 with EMR-L. The endoscopic en bloc resection rate was higher in the EMR-L group than in the EMR-C group (100% vs. 92.9%, P=0.003). A trend was observed towards a superior histologic complete resection rate in the EMR-L group, but it was not statistically significant (92.5% vs. 83.3%, P=0.087). There were no significant differences in procedural complications (P=0.870). In a multivariate analysis, a tumor located ≥10 cm from the anal verge was related to histologic incomplete resection (P=0.039).

Conclusion:

EMR-L may be the preferable treatment method, considering both endoscopic en bloc resection rate and histologic complete resection rate.

Endoscopic mucosal resection with suction vs. endoscopic submucosal dissection for small rectal neuroendocrine tumors: a meta-analysis

OBJECTIVE

There are no guidelines or consensus on the optimal treatment measures for small rectal neuroendocrine tumors (NETs) at present. This meta-analysis was conducted to compare the efficacy and safety of endoscopic mucosal resection (EMR) with suction and endoscopic submucosal dissection (ESD) for the small rectal NETs.

METHODS

The literature searches were conducted using Pubmed and Embase databases, and then a meta-analysis was performed. The primary outcome was complete resection rate, and the secondary outcomes were complication rate, procedure time, and recurrence rate.

RESULTS

Fourteen studies with 823 patients were included in our meta-analysis. The overall complete resection rates in EMR with suction and ESD procedure were 93.65% (472/504) and 84.08% (243/289), respectively. The pooled analysis showed that EMR with suction could achieve a higher complete resection rate than ESD with significance (OR: 4.08, 95% CI: 2.42-6.88, p < .00001) when the outlier study was excluded, and procedure time was significantly shorter in the EMR with suction group than in the ESD group (SMD: -1.59, 95% CI: -2.27 to -0.90, p < .00001). Moreover, there was no significant difference in overall complication rate (OR: 0.56, 95% CI: 0.28-1.14, p = .11) and overall recurrence rate (OR: 0.76, 95% CI: 0.11-5.07, I²=48%) between EMR with suction and ESD group.

CONCLUSIONS

The present meta-analysis mostly based on retrospective studies show that EMR with suction is superior to ESD for small rectal NETs (≤10 mm) with higher complete resection rate, shorter procedure time, and similar overall complication rate and recurrence.

Comparing outcomes for endoscopic submucosal dissection between Eastern and Western countries: A systematic review and meta-analysis

AIM

To compare endoscopic submucosal dissection (ESD) outcomes between Eastern and Western countries.

METHODS

A systematic review and meta-analysis was performed using PubMed, MEDLINE, Web of Science, CINAHL and EBM reviews to identify studies published between 1990 and February 2016. The primary outcome was the efficacy of ESD based on information about either curative resection, en bloc or R0 resection rates. Secondary outcomes were complication rates, local recurrence rates and procedure times.

RESULTS

Overall, 238 publications including 84318 patients and 89512 gastrointestinal lesions resected using ESD were identified. 90% of the identified studies reporting ESD on 87296 lesions were conducted in Eastern countries and 10% of the identified studies reporting ESD outcomes in 2216 lesions were from Western countries. Meta-analyses showed higher pooled percentage of curative, en bloc, and R0 resection in the Eastern studies; 82% (CI: 81%-84%), 95% (CI: 94%-96%) and 89% (CI: 88%-91%) compared to Western studies; 71% (CI: 61%-81%), 85% (CI: 81%-89%) and 74% (CI: 67%-81%) respectively. The percentage of perforation requiring surgery was significantly greater in the Western countries (0.53%; CI: 0.10-1.16) compared to Eastern countries (0.01%; CI: 0%-0.05%). ESD procedure times were longer in Western countries (110 min vs 77 min).

CONCLUSION

Eastern countries show better ESD outcomes compared to Western countries. Availability of local ESD expertise and regional outcomes should be considered for decision making to treat gastrointestinal lesions with ESD.

Neuroendocrine neoplasms of rectum: A management update

The estimated annual incidence of R-NENs is 1.04 per 100,000 persons although the real incidence may be underestimated, as not all R-NEN are systematically reported in registers. Also the prevalence has increased substantially, reflecting the rising incidence and indolent nature of R-NENs, showing the highest prevalence increase among all site of origin of NENs. The size of the tumor reveals the behavior of R-NENs where the risk for metastatic spread increases for lesions > 10 mm. Applying the WHO 2010 grading system to whole NENs originating in the gastroenteropancreatic system, R-NENs are classified as Well-Differentiated Neuroendocrine Tumors (WD-NET), which contain NET G1 and NET G2, and Poorly-Differentiated Carcinomas (PD-NEC) enclosing only G3 neoplasms for which the term carcinoma is applied. The treatment is endoscopic resection in most cases: conventional polypectomy or endoscopic mucosal resection (EMR) for smaller lesions or endoscopic submucosal resection with a ligation device (ESMR-L), cap-assisted EMR (EMR-C) and endoscopic submucosal dissection (ESD). However it is important to know when the endoscopic treatment is not enough, and surgical treatment is indicated, or when the latter could be unnecessary. For PD-NECs, it has recently been demonstrated that chemoradiotherapy is associated with a similar long-term survival to that obtained with surgery. As well, new targeted-agents chemotherapy may be indicated for metastatic WD-NETs.

Comparison of endoscopic therapies for rectal carcinoid tumors: Endoscopic mucosal resection with circumferential incision versus endoscopic submucosal dissection

BACKGROUND AND OBJECTIVE

Although various endoscopic resection techniques have been established for rectal carcinoid tumors, there remains controversy regarding the best endoscopic treatment modality for these tumors. This study aimed to evaluate and compare the therapeutic efficacy and safety of EMR with circumferential incision (EMR-CI) and endoscopic submucosal dissection (ESD) for endoscopic resection of rectal carcinoid tumors.

METHODS

From March 2012 to June 2016, 66 rectal carcinoid tumors in 66 patients were resected by using EMR-CI (n=30) or ESD (n=36). The rates of both en bloc resection and complete resection, procedure time, procedure-related complications, and local or metastatic recurrence were analyzed retrospectively.

RESULTS

The en bloc resection rate was 96.7% (29/30) and 100% (36/36) for EMR-CI and ESD groups, respectively, and the difference was not statistically significant (P=0.455). The complete resection rate of the ESD group was 97.2% (35/36) and significantly higher than 76.7% (23/30) of the EMR-CI group (P=0.030). The mean procedure time of the ESD group was 20.44±6.64minutes, which was significantly longer than that of the EMR-CI group at 8.47±3.40minutes (P<0.001). The complication rates for ESD and EMR-CI did not differ significantly (0% for EMR-CI vs. 2.8% for ESD, P=1.000). No local or metastatic recurrence was found in either group during the follow-up period.

CONCLUSION

This study suggested that ESD may be a safe, effective, and feasible endoscopic technique for removing rectal carcinoid tumors. ESD showed a similar safety profile and superior efficacy to EMR-CI.

Diagnosis and Management of Rectal Neuroendocrine Tumors

The incidence of rectal neuroendocrine tumors (NETs) has increased by almost ten-fold over the past 30 years. There has been a heightened awareness of the malignant potential of rectal NETs. Fortunately, many rectal NETs are discovered at earlier stages due to colon cancer screening programs. Endoscopic ultrasound is useful in assessing both residual tumor burden after retrospective diagnosis and tumor characteristics to help guide subsequent management. Current guidelines suggest endoscopic resection of rectal NETs ≤10 mm as a safe therapeutic option given their low risk of metastasis. Although a number of endoscopic interventions exist, the best technique for resection has not been identified. Endoscopic submucosal dissection (ESD) has high complete and en-bloc resection rates, but also an increased risk of complications including perforation. In addition, ESD is only performed at tertiary centers by experienced advanced endoscopists. Endoscopic mucosal resection has been shown to have variable complete resection rates, but modifications to the technique such as the addition of band ligation have improved outcomes. Prospective studies are needed to further compare the available endoscopic interventions, and to elucidate the most appropriate course of management of rectal NETs.

Local surgical excision versus endoscopic resection for rectal carcinoid: A meta-analysis

Purpose: To date, there is not enough evidence concerning the optimal treatment strategy for early rectal carcinoids, we conducted a meta-analysis in order to determine the feasible local treatment for these selected patients. Methods: We searched the studies from the PubMed, Cochrane database, Medline, Ovid, SpringerLink, PMC and Embase between January 2007 and April 2017. Studies of local surgical excision compared with endoscopic resection for rectal carcinoids less than 20mm without adverse features were included. Data were analyzed by using Stata SE 12.0. Results: Seven studies were included in this meta-analysis, with a total of 1056 patients. The data showed that local surgical excision was associated with higher complete resection rate than that of endoscopic resection (OR 5.837, 95%CI 2.048 to 16.632, P=0.001) but consuming longer procedural time (SMD 1.757, 95% CI 1.263 to 2.251, P=0.000). Additionally, incidences of recurrence and en bloc resection rate were comparable between two kinds of resections. The difference of post-operative complications remained unclear. Conclusions: For rectal carcinoids sized 20mm or smaller without adverse features, endoscopic resection might be an efficient treatment, which achieved a comparable oncological safety as local surgical excision.

The clinical outcomes and risk factors associated with incomplete endoscopic resection of rectal carcinoid tumor

BACKGROUND AND AIM

The risk of lymph node metastasis of a small rectal carcinoid tumor (<10 mm) is known to be lower than that of tumors at other gastrointestinal sites. Although rectal carcinoid tumors can be treated by endoscopic resection, the resected specimen may be incomplete. The consequences of an incomplete resection are not well known.

METHOD

From December 2008 to November 2015, cases of rectal carcinoid tumors resected by endoscopic resection techniques such as endoscopic submucosal dissection (ESD), or endoscopic mucosal resection using band ligation device (EMR-L), or cap aspiration (EMR-C) were enrolled. The factors associated with incomplete endoscopic resection and clinical outcomes were retrospectively analyzed.

RESULTS

During the study period, a total of 134 rectal carcinoid tumors were resected by endoscopic techniques; ESD (n = 53), EMR-C (n = 65), and EMR-L (n = 16). The mean tumor size was 5.5 ± 2.4 mm. The mean follow-up period was 835 ± 501 days. The en bloc resection and complete resection rates were 100 and 85.8%, respectively. Procedure time was longer and the size of the resected tumor was larger in the ESD group than in the EMR-C or EMR-L (p < 0.001) group by the univariate analysis. A factor related to incomplete resection was central depression on the surface (OR 11.529, 95% CI 2.377-55.922, p = 0.002), as revealed by the multivariate analysis. Nineteen patients had an incomplete resection status and did not undergo additional resection treatment; none of these patients had recurrence during the study period.

CONCLUSIONS

A rectal carcinoid tumor with a central depression on the surface was associated with a higher incomplete resection rate. After an incomplete resection of small rectal carcinoid tumors, without evidence of lymphovascular invasion, a periodic follow-up examination without additional resection may be recommended.

Lymphovascular invasion in more than one-quarter of small rectal neuroendocrine tumors

AIM

To identify the frequency, clinicopathological risk factors, and prognostic significance of lymphovascular invasion (LVI) in endoscopically resected small rectal neuroendocrine tumors (NETs).

METHODS

Between June 2005 and December 2015, 104 cases of endoscopically resected small (≤ 1 cm) rectal NET specimens at Hallym University Sacred Heart Hospital in Korea were retrospectively evaluated. We compared the detected rate of LVI in small rectal NET specimens by two methods: hematoxylin and eosin (H&E) and ancillary immunohistochemical staining (D2-40 and Elastica van Gieson); in addition, LVI detection rate difference between endoscopic procedures were also evaluated. Patient characteristics, prognosis and endoscopic resection results were reviewed by medical charts.

RESULTS

We observed LVI rates of 25.0% and 27.9% through H&E and ancillary immunohistochemical staining. The concordance rate between H&E and ancillary studies was 81.7% for detection of LVI, which showed statistically strong agreement between two methods (κ = 0.531, P < 0.001). Two endoscopic methods were studied, including endoscopic submucosal resection with a ligation device and endoscopic submucosal dissection, and no statistically significant difference in the LVI detection rate was detected between the two (26.3% and 26.8%, P = 0.955). LVI was associated with large tumor size (> 5 mm, P = 0.007), tumor grade 2 (P = 0.006). Among those factors, tumor grade 2 was the only independent predictive factor for the presence of LVI (HR = 4.195, 95%CI: 1.321-12.692, P = 0.015). No recurrence was observed over 28.8 mo regardless of the presence of LVI.

CONCLUSION

LVI may be present in a high percentage of small rectal NETs, which may not be associated with short-term prognosis.

Endoscopic treatments for rectal neuroendocrine tumors smaller than 16 mm: a meta-analysis

OBJECTIVE

Endoscopic mucosal resection (EMR), including conventional EMR (c-EMR) and modified EMR (m-EMR), was applied to remove small rectal neuroendocrine tumors (NETs). We aim to evaluate treatment outcomes of endoscopic submucosal dissection (ESD), m-EMR and c-EMR for rectal NETs <16 mm.

METHODS

The PubMed, Cochrane Library and Elsevier Science Direct were searched to identify eligible articles. After quality assessment and data extraction, meta-analysis was performed. The main outcomes were complete resection rate, overall complication rate, procedure time and local recurrence rate.

RESULTS

Compared with c-EMR, ESD could achieve higher complete resection rate (OR = 4.38, 95%CI: 2.43-7.91, p < 0.00001) without increasing overall complication rates (OR = 2.21, 95%CI: 0.56-8.70, p = 0.25). However, ESD was more time-consuming than c-EMR (MD = 6.72, 95%CI: 5.84-7.60, p < 0.00001). Compared with m-EMR, ESD did not differ from m-EMR in complete resection and overall complication rates (OR = 0.80, 95%CI: 0.51-1.27, p = 0.34; OR = 1.91, 95%CI: 0.75-4.86, p = 0.18, respectively). However, ESD was more time-consuming than m-EMR (MD = 12.21, 95%CI: 7.78-16.64, p < 0.00001). Compared with c-EMR, m-EMR could achieve higher complete resection rate (OR = 4.23, 95%CI: 2.39-7.50, p < 0.00001) without increasing overall complication rate (OR = 1.07, 95%CI: 0.35-3.32, p = 0.90). Moreover, m-EMR was not time-consuming than c-EMR (MD = 2.01, 95%CI: -0.37-4.40, p= 0.10). The local recurrence rate was 0.84% (9/1067) during follow-up.

CONCLUSIONS

Both ESD and m-EMR have great advantages over c-EMR in complete resection rate without increasing safety concern while m-EMR shares similar outcomes with ESD for rectal NETs <16 mm. The results should be confirmed by well-designed, multicenter, randomized controlled trials with large samples and long-term follow-ups from more countries.

Comparing endoscopic mucosal resection with endoscopic submucosal dissection: the different endoscopic techniques for colorectal tumors

BACKGROUND

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are used for the removal of colorectal tumors. There are no current guidelines or consensus on the optimal treatment strategy for these lesions. A meta-analysis was conducted to compare the effectiveness and safety of ESD and EMR for colorectal tumors.

METHODS

For the years 1966 until October 2014, Medline, PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were searched for articles comparing the effectiveness and safety of ESD and EMR. STATA 11.0 and RevMan 5.0 were used for meta-analysis and publication bias.

RESULTS

Seventeen articles were included in this meta-analysis. ESD was more effective than EMR in endoscopic complete resection rate (odds ratio [OR] = 2.81; 95% confidence interval [CI], 1.39-5.70; Z = 2.86; P = 0.004) and pathologic complete resection rate (OR = 2.81; 95% CI, 1.39-5.70; Z = 2.86; P = 0.004). ESD resulted in a higher perforation rate (OR = 5.27; 95% CI, 2.75-10.08; Z = 5.01; P < 0.00001) and a lower recurrence rate (OR = 0.14; 95% CI, 0.06-0.30; Z = 5.04; P < 0.00001). The tumor size was larger in the ESD group (OR = 3.09; 95% CI, 1.54-4.63; Z = 3.92; P < 0.0001), and the procedure time was longer in the ESD group (OR = 21.39; 95% CI, 10.33-32.46; Z = 3.79; P = 0.0002). But bleeding rate did not differ significantly (OR = 1.34; 95% CI, 0.81-2.20; Z = 1.14; P = 0.25). There was no publication bias analyzed by Begg test and Egger test.

CONCLUSIONS

The study indicates that ESD is the better treatment for colorectal tumors for its higher complete resection rate despite the longer procedure time and higher perforation rate.