Endoscopic resection yields reliable outcomes for small rectal neuroendocrine tumors

Comparison between Endoscopic Submucosal Dissection and Transanal Endoscopic Microsurgery in Early Rectal Neuroendocrine Tumor Patients: A Meta-Analysis

PURPOSE

To compare the effectiveness, safety and cost-effectiveness of endoscopic submucosal dissection (ESD) with transanal endoscopic microsurgery (TEM) in early rectal neuroendocrine tumor (RNET) patients. This article will provide reliable evidence for surgeons in regards to clinical decision-making.

METHODS

Systematic literature retrieval was performed in Pubmed, Embase and Cochrane database from 2013/4/30 to 2023/4/30. Methodology validation was performed by using the Newcastle-Ottawa Scale (NOS). Data-analysis was conducted by using the Review manager version 5.3 software.

RESULTS

A total of three retrospective studies were included in our meta-analysis. All eligible studies were considered to be high quality. By comparing baseline characteristics between TEM and ESD, patients in the TEM group seemed to be characterized by a larger tumor size and lower tumor level, even though no statistical significance was found. Clear statistical significance favoring TEM was identified in terms of R0 resection rate, procedure time and hospital stay. No statistical significance was found in terms of recurrence rate, adverse events rate and additional treatment rate.

CONCLUSIONS

Compared with ESD, TEM was a more effective treatment modality for early RNET patients; it was associated with a relatively higher R0 resection rate and a similar degree of safety. However, the relatively higher cost and complicated manipulation restricted the promotion of TEM. Surgeons should opt for TEM as a primary treatment in patients with a larger tumor size and deeper degree of tumorous infiltration if the financial condition and hospital facility permit.

Clinical Value of Clip-and-Snare Assisted Endoscopic Submucosal Resection in Treatment of Rectal Neuroendocrine Tumors

Introduction

The aim of the study was to introduce a new endoscopic technology, clip-and-snare assisted endoscopic submucosal resection (CS-ESMR), for treatment of rectal neuroendocrine tumors (NETs) and then to investigate the therapeutic value of CS-ESMR.

Methods

In this retrospective study, 67 patients who underwent endoscopic treatment of rectal NETs from March 2017 to December 2021 were analyzed. According to the endoscopic resection methods (endoscopic mucosal resection [EMR], CS-ESMR, and endoscopic submucosal dissection [ESD]), the cases were divided into CS-ESMR group (27 cases), ESD group (31 cases), and EMR group (9 cases). The pathological R0 resection rate and the incidence of adverse events (bleeding and perforation) were compared among the three groups.

Results

There was a significant difference about the pathological R0 resection between the CS-ESMR group and the EMR group and between the CS-ESMR group and the ESD group (both p < 0.05). Compared with ESD group, the procedure time, intraoperative bleeding, and the cost of CS-ESMR group are significantly decreased (p < 0.001, p < 0.05, p < 0.001, respectively).

Conclusion

CS-ESMR may be a safe and effective treatment for rectal NETs with a diameter of less than 10 mm, without muscularis propria invasion and metastasis.

Comparing endoscopic mucosal resection with endoscopic submucosal dissection in colorectal adenoma and tumors: Meta-analysis and system review

AIMS

This study aimed to evaluate the safety, efficacy, and long-term outcomes of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) for treating colorectal adenomas and tumors.

METHODS

A systematic literature review was conducted using databases including PubMed, Web of Science, and Embase. Parameters such as number of patients or lesions, histological diagnosis, lesion size, surgery time, en-bloc resection, R0 resection, severe postoperative complications, and local recurrence were extracted and pooled for analysis.

RESULTS

A total of 12 retrospective studies involving 1289 patients and 1850 lesions were included in the analysis. EMR was found to have a shorter operation time by 53.6 minutes (95% CI: 51.3, 55.9, P<0.001) and fewer incidences of severe postoperative complications such as perforation and delayed bleeding (OR = 0.40, 95%CI: 0.23, 0.71, P<0.001). On the other hand, ESD had higher rates of en-bloc resection (OR = 0.15, 95%CI: 0.07, 0.30, P<0.001) and R0 resection (OR = 0.32, 95%CI: 0.16, 0.65, P<0.001). Recurrence after EMR was found to be significantly higher than that after ESD surgery (OR = 5.88, 95%CI: 2.15, 16.07, P = 0.037).

CONCLUSIONS

The study suggests that the choice of surgical method may have a greater impact on recurrence compared to the pathological type, and that ESD may be more suitable for the treatment of malignant lesions despite its higher rates of severe postoperative complications and longer operation time.

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.

Diagnosis, treatment, and current concepts in the endoscopic management of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are rare tumors derived from the neuroendocrine cell system, which that have increased in incidence and prevalence in recent years. Despite improvements in radiological and metabolic imaging, endoscopy still plays a pivotal role in the number of GEP-NENs. Tumor detection, characterization, and staging are essential in management and treatment planning. Upper and lower gastrointestinal (GI) endoscopy is essential for correct localization of the primary tumor site of GI NENs. Endoscopic ultrasonography (EUS) has an important role in the imaging and tissue acquisition of pancreatic NENs and locoregional staging of GI neuroendocrine tumors. Correct staging and histological diagnosis have important prognostic implications. Endoscopic operating techniques allow the removal of small GI NENs in the early stage of mucosal or submucosal invasion of the intestinal wall. Preoperative EUS-guided techniques may help the surgeon locate small and deep tumors, thus avoiding formal pancreatic resections in favor of parenchymal-sparing surgery. Finally, locoregional ablative treatments have been proposed in recent studies with promising results in selected patients.

Long-term outcomes of transanal endoscopic microsurgery for the treatment of rectal neuroendocrine tumors

Background

Transanal endoscopic microsurgery (TEM) has been accepted worldwide for the treatment of local rectal lesions. We aimed to assess the efficacy and safety of TEM in the treatment of rectal neuroendocrine tumors (RNET).

Methods

A retrospective study of patients who had undergone TEM for RNET at our institution between December 2006 and June 2019 was performed. Demographic and tumor characteristics, operative and pathological details, complications, anal function questionnaires, and follow-up data were included.

Results

A total of 144 patients was included. TEM was performed as primary excision in 54 patients, after endoscopic forceps biopsy in 57 patients, and after incomplete resection by endoscopic excision in 33 patients. The median size of all primary tumors was 0.6 cm (range, 0.3–2.0 cm), and the negative resection margin was achieved in 142 (98.6%) patients. Postoperative complications (referring to only bleeding) occurred in 3 (2.1%) patients and was successfully managed with conservative method. After a median follow-up of 75.5 months after surgery, 3 patients died of other causes, and 2 patients suffered metastasis. An anal function questionnaire was posted 24 months after TEM. Among the results, 3 (2.1%) patients complained of major low anterior resection syndrome (LARS), including 1 (0.7%) who suffered from complete incontinence, while 6 (4.2%) patients had minor LARS.

Conclusions

TEM has satisfying long-term outcomes and relatively low anal function disturbance as for the treatment of small RNET. TEM also acts as a preferred salvage treatment for incomplete endoscopic excision.

Comparison of the efficacy of endoscopic submucosal dissection and transanal endoscopic microsurgery in the treatment of rectal neuroendocrine tumors ≤ 2 cm

INTRODUCTION

Currently, complete tumor resection is considered the most effective treatment for rectal neuroendocrine tumors (NETs). Endoscopic submucosal dissection (ESD) and transanal endoscopic microsurgery (TEM) are recommended for rectalNETs ≤2 cm, but it is not clear which method is better. Thus, we evaluated the efficacy of ESD and TEM in the treatment of rectal neuroendocrine tumors (NETs) ≤ 2 cm.

METHODS

We conducted a single-centre retrospective cohort study between 2010 and 2021 of rectal NETs ≤ 2 cm in 114 patients with long-term follow-up data who were divided into ESD (n=55) and TEM groups (n=59). Our study assessed differences between groups in the complete resection rate of lesions, recurrence rate, surgical complications, procedure time, and length of hospital stay.

RESULTS

The co-primary outcomes were the complete resection rate of lesions and the recurrence rate. Compared to that in the ESD group, the complete resection rate was significantly higher in the TEM group (91.5% vs. 70.9%, p=0.005). The median follow-up time was 22 months in our study, and the follow-up outcomes suggested that the rates of recurrence were 1.8% (1/55) and 6.8% (4/59) in the ESD and TEM groups, respectively, with no significant difference between the two groups. The secondary outcomes of the evaluation were surgical complications, procedural time, and length of hospital stay. The rate of complications (gastrointestinal bleeding and perforation) was low in both the ESD (7.3%, 4/55) and TEM (5.1%, 3/59) groups. No difference in hospitalization duration was observed between the two groups in our study. However, the procedure time was significantly shorter in the ESD group than in the TEM group (27.5 min vs. 56 min, p<0.001).

CONCLUSIONS

Although the rate of complete resection in the TEM group was higher than that in the ESD group, there was no difference in recurrence rates between the two modalities during long-term follow-up. Depending on the qualities of the available hospital resources in the area, one of the two approaches can be adopted.

Prognosis of rectal neuroendocrine tumors after endoscopic resection: a single-center retrospective study

BACKGROUND

The efficacy of endoscopic resection in patients with rectal neuroendocrine tumors (NETs) which are less than 20 mm in diameter remains unclear. This study aimed to investigate the efficacy and outcomes of different types of endoscopic resection in patients with NETs.

METHODS

We performed a retrospective analysis and follow-up on 98 patients who underwent endoscopic resection for rectal NETs between August 2010 and October 2019 at Guangdong Provincial People's Hospital, China. The lesions were preoperatively classified according to their endoscopic morphology and measured by endoscopic ultrasound. Patients were divided into modified endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) groups depending on the endoscopic treatment they received. The en bloc resection rate, histopathological complete resection rate, and the complication rate of the 2 groups were evaluated after the operation. The risk factors for incomplete resection were also analyzed.

RESULTS

The average diameter of the 98 NETs was 6.29±2.90 mm (range, 2-15 mm). The en bloc resection rate of the modified EMR and ESD treatment groups was 97.2% (35/36) and 100% (62/62), respectively. The histopathological complete resection rate was 86.1% (31/36) and 87.1% (54/62), respectively. No tumor recurrence or tumor-related death occurred. There were no statistically significant differences in the rate of histopathological complete resection, perforation, or delayed hemorrhage between the 2 groups (P>0.05). Multivariate analysis demonstrated that the depth of tumor invasion (P=0.007) and tumor diameter (P<0.001) were independent risk factors for histopathological complete resection.

CONCLUSIONS

Modified EMR and ESD are safe and effective endoscopic approaches for the resection of rectal NETs ≤15 mm in diameter. Endoscopic resection requires a comprehensive preoperative evaluation of risk factors including the depth of tumor invasion and tumor diameter.

Clinical Outcomes of Endoscopic Treatment for Type 1 Gastric Neuroendocrine Tumor

BACKGROUND

Although the rate of early detection and endoscopic treatment of gastric neuroendocrine tumors (NETs) is steadily increasing, there are insufficient studies on the long-term outcomes of endoscopic treatment. Therefore, we aimed to investigate the clinical features and long-term outcomes of endoscopic treatment for type 1 gastric NETs.

METHODS

Subjects who underwent endoscopic treatment for gastric NETs between March 1997 and December 2015 were included. Clinical features and endoscopic treatment outcomes were retrospectively investigated by reviewing medical records.

RESULTS

In total, 125 subjects underwent endoscopic treatment including forceps biopsy (n = 21), argon plasma coagulation (n = 1), endoscopic mucosal resection (EMR, n = 62), and endoscopic submucosal dissection (ESD, n = 41). In total, 103 patients with 114 lesions, who underwent EMR or ESD, were analyzed to evaluate endoscopic and oncologic outcomes. The rates of en bloc resection in the EMR and ESD groups were 91.5% and 97.7%, respectively. Complete resection rates were significantly higher in the ESD group than in the EMR group; it was also higher in < 1-cm small-sized lesions than in 1-2-cm large-sized lesions. Adverse events were similar between the two groups. During a median follow-up period of 63 months, local recurrence rates were 6.5% and 2.4% in the EMR and ESD groups, respectively, and the disease-free survival rate did not differ significantly between the groups.

CONCLUSION

Endoscopic treatment for type 1 gastric NETs less than 2 cm in diameter and confined to mucosal and submucosal layers could be an effective and safe treatment strategy based on the favorable long-term outcome.

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.

UNDERWATER ENDOSCOPIC MUCOSAL RESECTION FOR SMALL RECTAL NEUROENDOCRINE TUMORS

BACKGROUND

A common site of neuroendocrine tumors (NETs) is the rectum. The technique most often used is endoscopic mucosal resection with saline injection. However, deep margins are often difficult to obtain because submucosal invasion is common. Underwater endoscopic mucosal resection (UEMR) is a technique in which the bowel lumen is filled with water rather than air, precluding the need for submucosal lifting.

OBJECTIVE

This study aimed to evaluate the efficacy and safety of UEMR for removing small rectal neuroendocrine tumors (rNETs).

METHODS

Retrospective study with patients who underwent UEMR in two centers. UEMR was performed using a standard colonoscope. No submucosal injection was performed. Board-certified pathologists conducted histopathologic assessment.

RESULTS

UEMR for small rNET was performed on 11 patients (nine female) with a mean age of 55.8 years and 11 lesions (mean size 7 mm, range 3-12 mm). There were 9 (81%) patients with G1 rNET and two patients with G2, and all tumors invaded the submucosa with only one restricted to the mucosa. None case showed vascular or perineural invasion. All lesions were removed en bloc. Nine (81%) resections had free margins. Two patients had deep margin involvement; one had negative biopsies via endoscopic surveillance, and the other was lost to follow-up. No perforations or delayed bleeding occurred.

CONCLUSION

UEMR appeared to be an effective and safe alternative for treatment of small rNETs without adverse events and with high en bloc and R0 resection rates. Further prospective studies are needed to compare available endoscopic interventions and to elucidate the most appropriate endoscopic technique for resection of rNETs.

Comparison of endoscopic submucosal dissection and transanal endoscopic microsurgery for T1 rectal neuroendocrine tumors: a propensity score-matched study

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) and transanal endoscopic microsurgery (TEM) are the most effective endoscopic resection methods for T1 rectal neuroendocrine tumors (NETs). We aimed to compare the efficacy and safety of ESD and TEM for rectal NETs ≤20 mm.

METHODS

Patients with rectal NETs ≤20 mm who underwent ESD or TEM were enrolled in this retrospective observational study. ESD and TEM groups were matched for pathologic tumor size and EMR history. We evaluated between-group differences in R0 resection rate, adverse event rate, procedure time, and hospital stay.

RESULTS

We included 285 patients (ESD = 226, TEM = 59) in the final cohort, with 104 patients in the matched groups (ESD = 52, TEM = 52). The R0 resection rate was significantly higher for TEM (ESD 71.2% vs TEM 92.3%, P = .005). However, the median procedure time (ESD 22 [range, 11-65] vs TEM 35 [17-160] minutes, P < .001) and hospital stay (ESD 2.5 range 1-5] vs TEM 4 [3-8] days, P < .001) were significantly shorter for ESD. In the subgroup analysis of patients divided by tumor size <10 mm (ESD = 218, TEM = 49) and 10 to 20 mm (ESD = 8, TEM = 10)], there was no significant between-group difference in the R0 resection rate (83.5% vs 93.9%, P = .063 and 37.5% vs 80%, P = .145, respectively) or the rate of recurrence.

CONCLUSIONS

Although TEM showed a better overall R0 resection rate for rectal NETs ≤20 mm, ESD could be a viable treatment modality concerning adverse events, procedure time, and hospital stay for rectal NETs <10 mm with similar R0 resection rates in comparison with TEM.

Endoscopic management versus transanal surgery for early primary or early locally recurrent rectal neoplasms-a systematic review and meta-analysis

BACKGROUND

Both endoscopic techniques and transanal surgery are viable options that allow organ preservation for early rectal neoplasms. Whilst endoscopic approaches are less invasive and carry less morbidity, it is unclear whether they are as oncologically effective.

AIM

To compare endoscopic techniques with transanal surgery in the management of early rectal neoplasms.

METHODS

A systematic literature search was performed for randomised and observational studies comparing these techniques. The pre-specified main outcomes measured were en bloc and R0 resection rates and recurrence. Pair-wise meta-analysis was performed.

RESULTS

This review included 1044 patients. Transanal surgery had increased R0 resection rates (odds ratio (OR) 2.66; 95% CI 1.64; 4.31; p < 0.001) versus endoscopic management. The latter was associated with higher rates of incomplete resection (OR 2.25; 95% CI 1.14, 4.46; p = 0.02) and further intervention (OR 1.78; 95% CI 1.09, 2.88; p = 0.02). There was no difference in the rates of late recurrence (OR 1.01; 95% CI 0.53, 1.91; p = 0.99) or further major surgery (OR 0.87; 95% CI 0.39, 1.94; p = 0.73) between the groups. Endoscopic treatment was associated with a shorter operating time (weighted mean difference (WMD) - 12.08; 95% CI - 18.97, - 5.19; p < 0.001) and LOS (WMD - 1.94; 95% CI - 2.43, - 1.44; p < 0.001), as well as lower rates of urinary retention post-operatively (OR 0.12; 95% CI 0.02, 0.63; p = 0.01).

CONCLUSION

Endoscopic techniques should be favoured in the setting of benign early rectal neoplasms given their decreased morbidity and increased cost-effectiveness. However, where malignancy is suspected transanal surgery should be the preferred option given the superior R0 resection rate.

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.

Advances in the Diagnosis and Management of Well-Differentiated Neuroendocrine Neoplasms

Neuroendocrine neoplasms constitute a diverse group of tumors that derive from the sensory and secretory neuroendocrine cells and predominantly arise within the pulmonary and gastrointestinal tracts. The majority of these neoplasms have a well-differentiated grade and are termed neuroendocrine tumors (NETs). This subgroup is characterized by limited proliferation and patients affected by these tumors carry a good to moderate prognosis. A substantial subset of patients presenting with a NET suffer from the consequences of endocrine syndromes as a result of the excessive secretion of amines or peptide hormones, which can impair their quality of life and prognosis. Over the past 15 years, critical developments in tumor grading, diagnostic biomarkers, radionuclide imaging, randomized controlled drug trials, evidence-based guidelines, and superior prognostic outcomes have substantially altered the field of NET care. Here, we review the relevant advances to clinical practice that have significantly upgraded our approach to NET patients, both in diagnostic and in therapeutic options.

Long-term outcomes according to additional treatments after endoscopic resection for rectal small neuroendocrine tumors

The present study aimed to investigate treatment strategies determining additional treatment after endoscopic resection (ER) of rectal neuroendocrine tumor (NET)s and long-term outcomes of endoscopically resected rectal NETs. We analyzed a total of 322 patients medical records of patients who underwent ER for rectal NETs. Rectal NETs initially resected as polyps and treated with conventional endoscopic mucosal resection (EMR) were observed more frequently in the non-curative group (P = 0.041 and P = 0.012, respectively). After ER, only 44 of the 142 patients (31.0%) who did not meet the criteria for curative resection received additional salvage treatment. In multivariate analysis, lesions diagnosed via biopsies (OR, 0.096; P = 0.002) or suspected as NETs initially (OR, 0.04; P = 0.001) were less likely to undergo additional treatment. Positive lymphovascular invasion (OR 61.971; P < 0.001), positive (OR 75.993; P < 0.001), or indeterminate (OR 13.203; P = 0.001) resection margins were more likely to undergo additional treatment. Although lymph node metastasis was found in 6 patients, none experienced local or metastatic tumor recurrence during the median follow-up of 40.49 months. Long-term outcomes after ER for rectal NETs were excellent. The prognosis showed favorable outcomes regardless of whether patients receive additional salvage treatments.

Colorectal Neuroendocrine Neoplasms: Areas of Unmet Need

The subject of colorectal neuroendocrine neoplasms (NENs), subdivided into well-differentiated NENs, termed neuroendocrine tumours (NETs; grade (G) 1 and 2), and poorly differentiated NENs, termed neuroendocrine carcinomas (NECs; G3) according to the 2010 World Health Organisation (WHO) classification, has arguably not had as much attention or study as NENs occurring in other sites. Colorectal NETs and NECs are however easier to study than many others since they are usually not difficult to remove and are increasingly detected because of intensified colorectal cancer screening and surveillance programmes. Colorectal NETs and NECs show site-specific heterogeneity with variable behaviour and different therapeutic options; these various aspects provide unique challenges. Because of bowel cancer screening programmes, colorectal NENs, like conventional adenocarcinomas, may be diagnosed at a stage that is associated with improved survival. In this article we intend to describe and define areas of unmet needs relating to the epidemiology, classification, pathology, diagnosis and therapy of colorectal NETs (including NETs G3), colorectal NECs, and finally, mixed adeno-neuroendocrine carcinomas (MANECs) by reviewing and discussing the relevant literature.

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.

Prognostic Factors for Locoregional Recurrence in Neuroendocrine Tumors of the Rectum

BACKGROUND

Optimal management of rectal neuroendocrine tumors is not yet well defined. Various pathologic factors, particularly tumor size, have been proposed as prognostic markers.

OBJECTIVE

We characterized sequential patients diagnosed with rectal neuroendocrine tumors in a population-based setting to determine whether tumor size and other pathologic markers could be useful in guiding locoregional management.

DESIGN

This study is a retrospective analysis of data from the British Columbia provincial cancer registry.

SETTINGS

The study was conducted at a tertiary care center.

PATIENTS

Sequential patients diagnosed with rectal neuroendocrine tumors between 1999 and 2011 were identified. Neuroendocrine tumors were classified as G1 and G2 tumors with a Ki-67 ≤20% and/or mitotic count ≤20 per high-power field.

MAIN OUTCOME MEASURES

Baseline clinicopathologic data including TNM staging, depth of invasion, tumor size, treatment modalities, and outcomes including survival data were measured.

RESULTS

Of 91 rectal neuroendocrine tumors, the median patient age was 58 years, and 35 were men. Median tumor size was 6 mm. Median length of follow-up was 58.1 months, with 3 patients presenting with stage IV disease. Treatment included local ablation (n = 5), local excision (n = 79), surgical resection (n = 4), and pelvic radiation (n = 1; T3N1 tumor). Final margin status was positive in 17 cases. Local relapse occurred in 8 cases and 1 relapse to bone 13 months after T3N1 tumor resection. Univariate analysis demonstrated an association between local relapse and Ki-67, mitotic count, grade, and lymphovascular invasion (p < 0.01). Larger tumor size was associated with decreased disease-free survival.

LIMITATIONS

Sample size was 91 patients in the whole provincial population over a 13-year time period because of the low incidence of rectal neuroendocrine tumors.

CONCLUSIONS

In this population-based cohort, rectal neuroendocrine tumors generally presented with small, early tumors and were treated with local excision or surgical resection without pelvic radiation. Pathologic markers play a role in risk stratification and prognostication. See Video Abstract at http://links.lww.com/DCR/A514.

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.

Role of endoscopic submucosal dissection in treatment of rectal gastroenteropancreatic neuroendocrine neoplasms

INTRODUCTION

A significant rise in incidence of rectal gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) has been observed in the last decade. Most detected gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are well differentiated and less than 2 cm in diameter. Endoscopic submucosal dissection (ESD) is a new method for endoscopic treatment of such tumors, difficult to resect by conventional endoscopic techniques and thus subject to surgical treatment.

AIM

To present the results of the endoscopic treatment of GEP NET tumors in the rectum using ESD in single academic center.

MATERIAL AND METHODS

From June 2013 to April 2014, 4 cases of GEP-NET in the rectum were treated by ESD in our center. Effectiveness of dissection, complications and tumor recurrence after 3 months of treatment were then retrospectively investigated.

RESULTS

The group contained 2 patients with primary rectal GEP-NET (1 male, 1 female; age range: 48-60 years) and 2 with scars after incomplete polypectomy of rectal GEP-NET (1 male, 1 female; 61-65 years). Primary rectal GEP-NET diameters were 0.6 cm and 1.5 cm. Scar resection specimen diameters were 0.7 cm and 1 cm. Mean resection time was 28 min. The en bloc resection rate was 100% (2 of 2) and the histologically complete resection was confirmed in both cases. No foci of neuroendocrine neoplasia were reported in dissected scars. No complications were observed. After 3 months, 3 patients underwent follow-up colonoscopy - no local recurrence was reported.

CONCLUSIONS

Endoscopic submucosal dissection of rectal GEP-NET should be recommended as a treatment of choice when dealing with lesions over 1 cm in diameter without invasion of the muscle layer. Due to technical difficulties, performing this procedure should be reserved for centers with appropriately trained endoscopic staff.

Transanal endoscopic microsurgery as optimal option in treatment of rare rectal lesions: A single centre experience

AIM

To analyze the outcomes of transanal endoscopic microsurgery (TEM) in the treatment of rare rectal condition like mesenchymal tumors, condylomas, endometriosis and melanoma.

METHODS

We retrospectively reviewed a twenty-three years database. Fifty-two patients were enrolled in this study. The lesions were considered suitable for TEM if they were within 20 cm from the anus. All of them underwent an accurate preoperative workup consisting in clinical examination, total colonoscopy with biopsies, endoscopic ultrasonography, and pelvic computerized tomography or pelvic magnetic resonance imaging. Operative time, intraoperative complications, rate of conversion, tumor size, postoperative morbidity, mortality, the length of hospital stay, local and distant recurrence were analyzed.

RESULTS

Among the 1328 patients treated by TEM in our department, the 52 patients with rectal abnormalities other than adenoma or adenocarcinoma represented 4.4%. There were 30 males (57.7%) and 22 females (42.3%). Mean age was 55 years (median = 60, range = 24-78). This series included 14 (26.9%) gastrointestinal stromal tumors, 21 neuroendocrine tumors (40.4%), 1 ganglioneuroma (1.9%), 2 solitary ulcers in the rectum (3.8%), 6 cases of rectal endometriosis (11.5%), 6 cases of rectal condylomatosis (11.5%) and 2 rectal melanomas (3.8%). Mean lesion diameter was 2.7 cm (median: 4, range: 0.4-8). Mean distance from the anal verge was 9.5 cm (median: 10, range: 4-15). One patient operated for rectal melanoma developed distant metastases and died two years after the operation. We experienced 2 local recurrences (3.8%) with an overall survival equal to 97.6% (95%CI: 95%-99%) at the end of follow-up and a disease free survival of 98% (95%CI: 96%-99%).

CONCLUSION

We could conclude that TEM is an important therapeutical option for rectal rare conditions.

Esophageal insufflation computed tomography for the diagnosis and management of esophageal submucosal tumors

BACKGROUND

The selection of therapy for benign esophageal lesions depends in part on whether the lesion extends to or through the esophageal muscle wall. The advent of endoscopic dissection of deep lesions has made this distinction important in the choice between different forms of advanced endoscopic therapy. The goal of this study was to evaluate esophageal insufflation computed tomography (EICT) for the diagnosis and management of esophageal submucosal tumors (SMTs).

METHODS

Between April 2011 and May 2013 at the Second Affiliated Hospital of Harbin Medical University, 27 patients with esophageal SMTs diagnosed by gastroscopy were studied observationally. Entry criteria included tumors larger than 0.5 cm. We compared endoscopic ultrasound (EUS) and EICT to assess lesion depth and the relationship between the submucosal lesion and the esophageal wall using the resected lesion as the gold standard.

RESULTS

Twenty-seven esophageal SMTs were evaluated. EUS and EICT accurately identified nine as superficial to the muscularis propria. EICT correctly identified the relation of the tumor extension and the outer esophageal wall in all 18 lesions that originated from the muscularis propria; only nine were correctly assessed by EUS (P < 0.001).

CONCLUSIONS

EICT enables improved judgment of the relation of esophageal lesions and the esophageal-mediastinal border. We propose EICT as a new, safe, effective, useful, simple and high-tolerance method for assessing the depth and relationships of esophageal submucosal lesions.

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.

Transanal Endoscopic Microsurgery

Transanal endoscopic microsurgery (TEM) was developed by Professor Gerhard Buess 30 years ago at the dawn of minimally invasive surgery. TEM utilizes a closed proctoscopic system whereby endoluminal surgery is accomplished with high-definition magnification, constant CO2 insufflation, and long-shafted instruments. The end result is a more precise excision and closure compared to conventional instrumentation. Virtually any benign lesion can be addressed with this technology; however, proper patient selection is paramount when using it for cancer.

Characteristics and long-term prognosis of patients with rectal neuroendocrine tumors

AIM: To analyze the clinicopathologic characteristics and prognostic factors of rectal neuroendocrine tumors.

METHODS: The records of 48 patients with rectal neuroendocrine tumors who were treated at the Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, from March 2004 to September 2009 were retrospectively reviewed. The clinicopathological data were extracted and analyzed, and patients were followed-up by telephone or follow-up letter to determine their survival status. Follow-up data were available for all 48 patients. Uni- and multivariate Cox regression analyses were performed to determine the prognostic factors significantly associated with overall survival.

RESULTS: The tumors occurred mostly in the middle and lower rectum, and the most prominent symptoms experienced by patients were hematochezia and diarrhea. The median distance between the tumors and the anal edges was 5.0 ± 2.257 cm, and the median diameter of the tumors was 0.8 ± 1.413 cm. The major pathological type was a typical carcinoid tumor, which accounted for 93.8% (45/48) of patients. Tumor-node-metastasis (TNM) stages I, II, III and IV tumors accounted for 78.8%, 3.9%, 9.6% and 7.7% of patients, respectively. The main treatment method, in 72.9% (35/48) of patients, was transanal extended excision. The 1-, 3- and 5-year survival rates of the whole group of patients were 100%, 93.7%, and 91.3%, respectively. Univariate analysis showed that age (P = 0.032), tumor diameter (P < 0.001), histological type (P < 0.001), TNM stage (P < 0.001), and surgical approach (P = 0.002) were all prognostic factors. On multivariate analysis, only the pathological type was shown to be an independent prognostic factor (HR = 2.797, 95%CI: 1.676-4.668, P = 0.004).

CONCLUSION: In patients with rectal neuroendocrine tumors, TNM stage I is the most common stage found, and lymph node or distant metastases are rarely seen. The pathological type of the tumor is an independent prognostic factor.