Prognostic analysis for carcinoid tumours of the rectum: a single institutional analysis of 106 patients

Outcomes for a Large Cohort of Patients with Rectal Neuroendocrine Tumors: an Analysis of the National Cancer Database

BACKGROUND

Rectal neuroendocrine tumors comprise 20% of neuroendocrine tumors in the alimentary tract, but there is controversy surrounding the optimal management of this disease. The purpose of this study is to better define treatment for patients with rectal neuroendocrine tumors.

METHODS

Using the National Cancer Database, we analyzed patients with rectal neuroendocrine tumors between 2004 and 2015. Patients with metastatic disease and missing treatment data were excluded. We examined overall survival stratified by tumor size, treatment type, and presence of positive lymph nodes using Kaplan-Meier analysis with log-rank test. Cox proportional hazard regression model was performed to identify factors associated with overall survival.

RESULTS

In total, 17,448 patients with rectal neuroendocrine tumors were identified; 16,531 of these patients met inclusion criteria. The majority of patients had tumors ≤ 10 mm (9216 patients, 79.8%), and approximately 90% underwent local excision. The probability of 5-year overall survival was significantly higher for patients with smaller tumors (≤ 10 mm: 94.1% 11-20 mm: 85.7%, > 20 mm: 71.8%; p < 0.001) and those with no positive lymph nodes (91.4% versus 53.3%, p < 0.001). The probability of 5-year overall survival differed based on treatment modality (local excision: 93.6%, radical resection: 79.1%, observation alone: 77.1%; p < 0.001). On multivariable Cox regression, when compared to local excision, radical resection was not associated with a difference in overall survival but observation alone was associated with significantly worse OS (HR = 2.750, p < 0.001).

CONCLUSIONS

There is a significant difference in overall survival between patients who underwent local excision versus observation alone. Excision of the tumor should be offered to all patients with rectal neuroendocrine tumors who are appropriate surgical candidates, regardless of the tumor size.

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.

Local excision versus radical resection in patients with rectal neuroendocrine tumours: a propensity score match analysis

BACKGROUND

The rectum is a common site for neuroendocrine tumours of the gastrointestinal tract. Diagnosis of these tumours has been increasing in recent years, highlighting the need to better define treatment options for patients with rectal neuroendocrine tumours (rNETs).

METHODS

We performed a retrospective analysis using the National Cancer Database (2004-2014) to compare overall survival (OS) between local excision (LE) and radical resection (RR). To minimize bias, we performed three propensity score-matched comparisons stratified by tumour size: <10 mm, 10-20 mm, >20 mm. We compared OS by Kaplan-Meier analysis. We also examined margin status and postoperative outcomes for each comparison.

RESULTS

A total of 12 996 patients underwent surgical treatment for rNET. There was no significant difference in probability of 10-year OS between LE and RR for patients with tumours <10 mm (88.6% versus 83.8%, P = 0.631, respectively) and tumours 10-20 mm (69.5% versus 69.3%, P = 0.226, respectively). In patients with tumours >20 mm, probability of 10-year OS was significantly longer in the LE group (76.5% versus 37.0%, P < 0.001). For all tumour sizes <10 mm and >20 mm, RR had significantly higher rates of 30-day readmission and negative margins. In subset analysis, there was no difference in OS for patients with positive margins after LE versus negative margins after RR for all tumour size groups.

CONCLUSIONS

Our findings suggest that LE is a reasonable treatment option in patients with rNETs, especially for patients with high perioperative risk. Limitations to this study include its retrospective nature and inability to analyse surgeon decision-making.

A novel preoperative risk score to predict lymph node positivity for rectal neuroendocrine tumors: An NCDB analysis to guide operative technique

BACKGROUND/OBJECTIVE

Staging and type of resection for rectal neuroendocrine tumors (R-NETS) relies on preoperative identification of lymph node (LN) involvement. Study objective was to develop a Preoperative Rectal Stratification Score (PReSS) for LN-positivity and to assess the association of PReSS with overall survival (OS).

METHODS

All patients in the National Cancer Database (2004-2014) with non-metastatic/nonfunctional R-NETS were included. Tumor size was divided into three categories (<1, 1-2, and ≥2 cm).

RESULTS

Among 383 patients, median age was 57 years, 52% were male (n = 200), median tumor size was 1.4 cm, 43% had positive LNs (n = 163). On univariate analysis, age  > 60, poorly differentiated grade, depth of invasion past submucosa, and size >1 cm were associated with LN positivity. On multivariable analysis, depth of invasion past submucosa, and increasing tumor size >1 cm remained associated with LN positivity. As these can be determined preoperatively, incidence of LN positivity was determined for each combination of tumor size and depth of invasion. Each variable was assigned a score to create a PReSS of four groups (0-3) associated with an increasing rate of LN-positivity (PReSS group 0: 11%, 1: 38%, 2: 50%, 3: 78%, P < .01). PReSS correlated with 10-year OS (PReSS 0: 90%; 1: 81%; 2: 59%; 3: 41%).

CONCLUSION

For R-NETS, depth of invasion and tumor size predict LN positivity and both can be obtained preoperatively. PReSS incorporates both variables and stratifies tumors into four risk groups of progressively increasing LN positivity and should be used to guide surgical approach.

Endoscopic, transanal, laparoscopic, and transabdominal management of rectal neuroendocrine tumors

Rectal neuroendocrine tumors (RNET) are rare tumors but their prevalence is constantly increasing due to a prolonged survival and rising incidence related to a growing number of colonoscopies and improved knowledge. Their main prognostic determinant is tumor stage. While most RNET are localized, their management should be tailored depending on the presence or absence of the factors predictive of lymph-node metastases including tumor size, endoscopic aspect, T stage, grade and lymphovascular invasion. Endoscopic ultrasonography is the most relevant technique for locoregional assessment. Low-risk RNET can be treated using advanced endoscopic resection techniques or transanal endoscopic microsurgery, in expert centers because they require technicity and experience. Conversely, radical surgery with lymphadenectomy should be proposed in the presence of any pejorative factor. The long-term evolution of RNET remains to be specified, and prospective studies should be conducted in order to determine the relevance of the current management strategies.

Endoscopic management of 345 small rectal neuroendocrine tumours: A national study from the French group of endocrine tumours (GTE)

Introduction

Small rectal neuroendocrine tumours are good candidates for endoscopic resection provided that complete pathological resection (R0) is obtained and their risk of metastatic progression is low. We conducted a large multicentre nationwide study to evaluate the outcomes of the management of non-metastatic rectal neuroendocrine tumours ≤2 cm diagnosed endoscopically.

Patients and methods

The medical records, the endoscopic and pathological findings of patients with non-metastatic rectal neuroendocrine tumours ≤2 cm managed from January 2000-June 2018 in 16 French hospitals, were retrospectively analysed. The primary objective was to describe the proportion of R0 endoscopic resections.

Results

A total of 329 patients with 345 rectal neuroendocrine tumours were included, 330 (96%) tumours were managed by local treatments: 287 by endoscopy only and 43 by endoscopy followed by transanal endoscopic microsurgery. The final endoscopic R0 rate was 134/345 (39%), which improved from the first endoscopy (54/225, 24%), to the second (60/100, 60%) and the third endoscopy (20/26, 77%). R0 was associated with endoscopic technique (90% for advanced techniques, 40% for mucosectomy and 17% for polypectomy), but not with tumour or patient characteristics. Twenty patients had metastatic disease, which was associated with tumour size ≥10 mm (odds ratio: 9.1, 95% confidence interval (3.5-23.5)), tumour grade G2-G3 (odds ratio: 4.2, (1.5-11.7)), the presence of muscular (odds ratio: ∞, (11.9-∞)) and lymphovascular invasion (odds ratio: 57.2, (5.6-578.9)).

Conclusions

The resection of small rectal neuroendocrine tumours often requires multiple procedures. Training of endoscopists is necessary in order to better recognise these tumours and to perform the appropriate resection technique.

Endoscopic treatment of rectal neuroendocrine tumors

The rectum is one of the most frequent location where gastroenteropancreatic neuroendocrine tumors (NETs) are found. With the increasingly widespread availability of colonoscopy screening, the detection rate of rectal NETs has markedly increased, most of which are localized lesions without regional invasion or distant metastasis. Therefore, endoscopic resection is acknowledged as a leading therapeutic approach. Endoscopic mucosal resection, endoscopic submucosal dissection, and transanal endoscopic microsurgery are therapies that have been prevalently applied and technically improved in recent years, which assure increasing complete resection rate and good overall prognosis.

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.

Novel nomogram combining depth of invasion and size can accurately predict the risk for regional nodal metastases for appendiceal neuroendocrine tumors (A-NET)

INTRODUCTION

The need for regional lymphadenectomy for treating appendiceal neuroendocrine tumors (A-NET) is determined by the risk of nodal metastasis. Current guidelines for A-NET are solely based on tumor size. Methods Patients with A-NET from 1988 to 2012 were identified from the SEER registry. The depth of invasion was defined as limited to the lamina propria (LP), invading the muscularis propria (MP), and through the serosa (TS).

RESULTS

A total of 418 patients were included; the majority were female, white, and node-negative. On univariate and multivariable, the risk of nodal metastasis was associated with age, size, depth of invasion, and extent of surgery. The model predicted the likelihood of nodal metastasis, with an area under the curve of 0.89. On survival analysis, age and tumor size predicted the survival in A-NET. In a Cox regression model, they continued to predict survival. These data were utilized to create a nomogram to predict the risk of nodal metastases.

CONCLUSION

This nomogram, accurately predicts the risk of regional nodal metastases in A-NET. In addition to providing valuable information on risk for regional nodal metastases, the depth of invasion is also predictive of survival for A-NET.

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.

Neuroendocrine Tumors of the Urinary Bladder According to the 2016 World Health Organization Classification: Molecular and Clinical Characteristics

Neuroendocrine neoplasms of the urinary bladder are a rare type of tumor that account for a small percentage of urinary bladder neoplasms. These tumors of the urinary bladder range from well-differentiated neuroendocrine neoplasms (carcinoids) to the more aggressive subtypes such as small cell carcinoma. Despite the rarity of the neuroendocrine tumors of the bladder, there has been substantial investigation into the underlying genomic, molecular, and the cellular alterations within this group of neoplasms. Accordingly, these findings are increasingly incorporated into the understanding of clinical aspects of these neoplasms. In this review, we provide an overview of recent literature related to the 2016 World Health Organization Classification of Neuroendocrine Tumors of the Urinary Bladder. Particular emphasis is placed on molecular alterations and recently described gene expression. The neuroendocrine tumors of the urinary bladder are subdivided into four subtypes. Similar to their pulmonary and other extrapulmonary site counterparts, these have different degrees of neuroendocrine differentiation and morphological features. The clinical aspects of four subtypes of neuroendocrine tumor are discussed with emphasis of the most recent developments in diagnosis, treatment, and prognosis. An understanding of molecular basis of neuroendocrine tumors will provide a base of knowledge for future investigations into this group of unusual bladder neoplasms.

Obturator Canal Lymph Node Metastasis from Rectal Carcinoid Tumors: Total Mesorectal Excision May Be Insufficient

BACKGROUND

Optimal surgical treatment for small early rectal carcinoids is controversial. Large tumors (greater than 2 cm) and those with imaging evidence of lymph node metastasis are generally treated by low anterior resection (LAR) with total mesorectal excision (TME). We first observed and reported that midgut carcinoid with extensive mesenteric lymphadenopathy often develops alternated lymphatic drainage pathways. We hypothesize that rectal carcinoids have the same potential to develop alternated lymphatic pathways outside the mesorectal envelope, which allows tumor deposits to be missed by traditional TME.

METHODS

Twenty-two consecutive rectal carcinoid surgical patient charts were reviewed to determine if alternated lymphatic drainage occurred and resulted in extra-mesorectal metastasis. We attempted to identify any risk factor(s) that may lead to developing such alternated lymphatic drainage pathways.

RESULTS

Thirteen patients underwent initial LAR with TME (13/22, 59 %) and nine underwent a staged debulking for locoregional residual disease or regional/distant metastasis after previous resection (9/22, 41 %). Fourteen (14/22, 64 %) underwent radio-guided surgery in attempt to achieve a higher level of pelvic/distant metastatic disease detection and debulking. Six patients (6/22, 27 %) had obturator canal lymph node metastases confirmed histologically.

CONCLUSIONS

Based on our study, at least 27 % of rectal carcinoid patients may have extra-mesorectal metastasis that would be missed by the traditional TME. Radio-guided surgery can identify and remove such metastasis. The effect of having such extra-mesorectal metastasis and its surgical removal on long-term survival has yet to be determined.

[Rectal neuroendocrine tumors: surgical therapy]

The incidence of rectal neuroendocrine tumors (NET) has increased in recent years. Most of these neoplasms are asymptomatic and are diagnosed by colonoscopy screening, which could be one of the reasons for the increasing occurrence. As less than 1 % of rectal NET produce serotonin they are practically never discovered due to a carcinoid syndrome. The current guidelines of the European (ENETS) and North American (NANETS) Neuroendocrine Tumor Societies support clinicians with useful diagnostic and treatment algorithms. The most important criteria for therapy are tumor size and histopathological risk factors for metastases. For well-differentiated rectal neuroendocrine neoplasms < 1 cm, local endoscopic or surgical excision is recommended. Due to the lack of evidence tumors sized 1-2 cm represent a grey area for prognosis and treatment. All NET > 1.5 cm must be excised by radical surgery as low anterior rectal resection or abdominoperineal extirpation with total mesorectal excision (TME). Resectable liver and lung metastases of well-differentiated NETs should be surgically treated with curative intent.

Surgical management and outcome of rectal carcinoids in a university hospital

Background

Rectal carcinoids are an uncommon entity comprising only 1%–2% of all rectal tumors. Rectal carcinoids are frequently diagnosed during colonoscopy, but management after polypectomy is still controversial. The aims of this study were to review the surgical procedures for rectal carcinoids and to compare the outcomes of patients after different treatment modalities in a university hospital in Hong Kong.

Methods

All rectal carcinoids diagnosed between January 2003 and September 2012 were reviewed retrospectively, including clinicopathological characteristics, their management, and surgical outcomes.

Results

There were 54 patients with a median age of 60 years, and 32 were males (59.3%). All patients underwent colonoscopy, and the most had rectal bleeding (53.7%). Two patients were diagnosed incidentally in the surgical specimens of rectal tissues. Eighteen patients were diagnosed to have rectal carcinoids after snaring polypectomy, and no further intervention was required. Twenty-five patients had local resection either by means of transanal resection or transanal endoscopic operation. Radical resection was performed in seven patients in which one had T3N1 disease and the others did not have any lymph node metastasis.

In the median follow-up of 30 months (10–108 months), there was no recurrence in the “incidental” or post-polypectomy group. However, two patients with transanal resection and two patients with radical resection developed hepatic metastases after 13–24 months post-treatment. The 5-year overall survival was 100% in patients having snaring polypectomy only, 83% for those with local resection, and 63% in patients who underwent radical surgery (p = 0.04).

Conclusions

Our data suggested that that local resection was an effective treatment for small rectal carcinoids and generally brought about good oncological and surgical outcomes. For larger tumors, radical resection seemed to provide acceptable oncological outcomes. Regular surveillance with colonoscopy and endorectal ultrasound is highly recommended for high-risk patients for long-term management. By sharing our experience, we hope to provide more evidence on the management on rectal carcinoids which, together with evidence from further studies, may guide us in the long-term management of these patients in the future.

Paraneoplastic brainstem encephalitis in a patient with exceptionally long course of a metastasized neuroendocrine rectum neoplasm

Background

Paraneoplastic neurological syndromes (PNS) have frequently been described in patients with lung or breast cancer. However, some reports also described a correlation to carcinoid tumors, probably triggered via the excessive release of hormones.

Case presentation

We report the case of a 40-year-old woman that was diagnosed with a neuroendocrine neoplasm (NEN) of the rectum and multiple synchronous liver metastases ten years ago. She initially responded well to transarterial chemoembolization (TACE), resulting in prolonged disease stabilization. However, ten years after initial diagnosis the patient developed unspecific neurological symptoms that could not be classified by standard neurological diagnostic work-up. Special laboratory analysis revealed a high titer of anti-Ri (ANNA-2), a well-characterized antibody that is associated with paraneoplastic neurologic syndromes. The patient’s symptoms improved markedly after a 5-day-course of high-dose glucocorticoid therapy. To our knowledge, this is the first report of a Ri-positive PNS in a patient with hormone-negative rectal NEN.

Conclusion

PNS can complicate the patient’s clinical course, response to treatment, impact prognosis and even be interpreted as metastatic spread. However, owing to their rarity, the knowledge of these syndromes is very helpful in order to be able to provide evidence-based diagnostic and therapeutic approaches.

Endoscopically identified well-differentiated rectal carcinoid tumors: impact of tumor size on the natural history and outcomes

BACKGROUND

There is a paucity of data pertaining to the natural history and outcomes of patients with well-differentiated rectal carcinoids.

OBJECTIVE

To correlate endoscopic size with the natural history and outcome.

DESIGN

Retrospective study.

SETTING

Single tertiary referral center.

PATIENTS

Eighty-seven patients with endoscopically identified well-differentiated rectal carcinoid tumors.

INTERVENTION

Colonoscopy.

MAIN OUTCOME MEASUREMENTS

Prevalence of metastasis at diagnosis, disease progression, and survival.

RESULTS

Metastasis was present at diagnosis in 3%, 66%, and 73% of tumors measuring ≤10 mm, 11 to 19 mm, and ≥20 mm, respectively. Metastasis was predicted with 100% sensitivity and 87% specificity using an endoscopic lesion size ≥9 mm. In patients without identified metastasis, 64% were identified during screening colonoscopy. Within this select cohort, subsequent metastasis was discovered only at distant extra pelvic sites, in 1.6%, 50%, and 100% of patients with tumors initially measuring ≤10 mm, 11 to 19 mm, and ≥20 mm, respectively. The carcinoid related 5- and 10-year survival rates for locally confined disease were 96%. The corresponding survival rates for local and advanced metastatic disease were 60% and 35%, respectively.

LIMITATIONS

Subjective estimation of tumor size, mitotic index or Ki-67 labeling index not reported, and lack of formal and standardized baseline staging algorithm and surveillance program.

CONCLUSIONS

The clinical behavior of 11- to 19-mm tumors appears to mimic that of larger (>20 mm) lesions with respect to the presence of metastasis at diagnosis and disease progression. Therefore, if local therapy is contemplated, we propose to make a distinction between ≤10-mm and 11- to 19-mm tumors, favoring an aggressive staging and management protocol for 11- to 19-mm carcinoid tumors.

Rectal carcinoids: a systematic review. Surg Endosc. 2014;28:2020-2026. [PMID: 24584484 DOI: 10.1007/s00464-014-3430-0]

BACKGROUND

Rectal carcinoids are increasing in incidence worldwide. Frequently thought of as a relatively benign condition, there are limited data regarding optimal treatment strategies for both localized and more advanced disease. The aim of this study was to summarize published experiences with rectal carcinoids and to present the most current data.

METHODS

Following PRISMA guidelines, an electronic literature search performed of PubMed, Medline, Embase, and the Cochrane Library using the terms "rectum" or "rectal" AND "carcinoid" over a 20-year study period from January 1993 to May 2013. Non-English-language studies, animal studies, and studies of fewer than 100 patients were excluded. Study end points included demographic information, tumor features, intervention and outcomes. All included articles were quality assessed.

RESULTS

Using the search parameters and exclusions as outlined above, a total of 14 articles were identified for detailed analysis. The quality of articles was low/moderate for all included scoring 9 to 17 of 27. The articles included 4,575 patients diagnosed with a rectal carcinoid. Approximately 80% of tumors were <10 mm, 15% 11-20 mm, and 5% >20 mm. Eight percent of patients presented with regional lymph node metastases, and 4% presented with distant metastases. Tumor size >10 mm, and muscular and lymphovascular invasion are independently associated with an increased risk of metastases. The 5-year survival was 93% in patients presenting with localized disease and 86% overall.

CONCLUSIONS

Small tumors up to 10 mm without any adverse features can be treated with endoscopic or local excision. The treatment of carcinoids between 10 and 20 mm is still contentious, but those up to 16 mm without adverse feature are suitable for local/endoscopic excision followed by careful histopathological assessment. Those >20 mm or with adverse features require radical surgery with mesorectal clearance in suitable patients.

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

AIM: To assess the therapeutic value of endoscopic mucosal resection (EMR) under micro-probe ultrasound guidance for rectal carcinoids less than 1 cm in diameter.

METHODS: Twenty-one patients pathologically diagnosed with rectal carcinoids following colonoscopy in our hospital from January 2007 to November 2012 were included in this study. The patients consisted of 14 men and 7 women, with a mean age of 52.3 ± 12.2 years (range: 36-72 years). The patients with submucosal tumors less than 1 cm in diameter arising from the rectal and muscularis mucosa detected by micro-probe ultrasound were treated with EMR and followed up with conventional endoscopy and micro-probe ultrasound.

RESULTS: All of the 21 tumors were confirmed by micro-probe ultrasound as uniform hypoechoic masses originating from the rectal and muscularis mucosa, without invasion of muscularis propria and vessels, and less than 1 cm in diameter. EMR was successfully completed without bleeding, perforation or other complications. The resected specimens were immunohistochemically confirmed to be carcinoids. Patients were followed up for one to two years, and no tumor recurrence was reported.

CONCLUSION: EMR is a safe and effective treatment for rectal carcinoids less than 1 cm in diameter.