Rectal Carcinoid Tumors Research Articles

Surgical Treatment Options for Rectal Carcinoid Cancer: LocalversusLow Radical Excision

R ECTAL CARCINOIDS ARE rare and their biologic behavior and optimal surgical treatment remain poorly defined. Classically, primary tumors less than 2 cm were assumed to be indolent and were treated by transanal excision. We hypothesized that rectal carcinoids are more malignant than previously described and tumors less that 2 cm may warrant more aggressive surgery. The charts of 62 consecutive patients with rectal carcinoids seen at our institution between October 2006 and August 2011 were reviewed. The primary tumor size, extent of disease, and survival data were analyzed. The primary tumor size and the incidence of lymph node metastases were available for 60 of 62 patients and was: less than 1 cm: two of 26 (8%); 1.1 to 2 cm: nine of 13 (69%); 2.1 to 3 cm: four of five (80%), greater than 3 cm: seven of 12 (58%); and multiple primaries: two of four (50%). Small (less than 2 cm) rectal carcinoids have a higher incidence of nodal positivity than previously described. Based on our survival data, we believe that tumors larger than 1 cm should be considered for a low anterior resection with total mesorectal excision as their initial definitive treatment. For tumors less than 1 cm, treatment should be individualized. RECTAL CARCINOIDS ARE relatively rare, with a reported incidence of one in every 100,000 people.1 However, recent reports have indicated that this incidence is on the rise.2 The 5-year survival rate for all rectal carcinoid tumors has been reported to be as high as 88 per cent, and these high survival rates were attributed to the fact that most rectal carcinoids are small and present with localized disease.3, 4 The incidence of lymph node metastasis for rectal primaries less than 1 cm has been reported to be less than 3 per cent. For primaries between 1 and 2 cm, nodal positivity has generally been reported between 10 and 15 per cent,4–9 but has recently been reported as high as 31 per cent.10 In contrast, the nodal positivity rate for tumors greater than 2 cm is classically reported as 80 per cent.3, 4, 6–9 Based on this, the treatment guidelines for rectal carcinoids universally agree that tumors greater than 2 cm demand a formal oncological operation such as a low anterior resection (LAR) with total mesorectal excision (TME) or abdominal–perineal resection (APR) with TME. For local rectal carcinoids, less than 1 cm in size, without evidence of lymphatic involvement on endoscopic ultrasound, a transanal surgical or endoscopic excision has been embraced as the standard in the literature and by the major organizational guidelines: European Neuroendocrine Tumor Society, North American Neuroendocrine Tumor Society, National Cancer Institute, and National Comprehensive Cancer Network.4, 6–9 In contrast, the treatment for rectal carcinoids from 1 to 2 cm is a matter of intense debate. Some authors believe that these intermediate-sized lesions will behave in an indolent manner. These authors recommend a conservative, nonaggressive approach to their resection.4–10 However, we have observed relatively poor clinical outcomes in this intermediate rectal carcinoid population. Based on our clinical experiences in a large tertiary referral center for neuroendocrine tumors (NETs), we conducted a formal review to better define the clinical impact that tumor size has on nodal positivity and the overall survival rate for this rare malignancy. We hypothesized that the malignancy potential of rectal carcinoids has been underestimated and that smalland intermediate-sized rectal carcinoids may warrant more aggressive surgery than what has been traditionally recommended.

Endoscopic Diagnosis and Treatment of Colorectal Carcinoids

Rectal carcinoid tumors smaller than 10 mm in diameter and located within the submucosal layer have a negligible risk of lymph node involvement and distant metastasis and are suitable for endoscopic treatment. Here the authors have shown an endoscopic ultrasonography for evaluating the size and depth of carcinoid tumors and endoscopic submucosal dissection for en bloc resection. This article is part of an expert video encyclopedia.

Increased thyroid cancer risk in acromegaly

Acromegaly increases cancer risk. We aimed to determine the prevalence and the predictors of tumors in acromegalic patients treated at our department. We retrospectively evaluated 160 acromegalic patients [79 female (mean age 52.0 ± 10.4 years) and 81 male (mean age 49.1 ± 12.4 years)] between 1990 and 2012, with a mean follow up period of 7.1 ± 5.7 years. The patients were screened with colonoscopy, mammography, thyroid and prostate ultrasonography. Malignancy was found in 34 (21.3%) patients. No significant difference was observed in the distribution of malignancy among sexes (20.3% in F vs. 22.2% in M). Thyroid cancer was the most frequent (n = 17, 10.6%) followed by the breast cancer (n = 4, 2.5%) and colorectal cancer (n = 3, 1.8%). Renal cell cancer in two patients, bladder cancer in two patients, periampullary tumor, rectal carcinoid tumor, malignant melanoma, prostate cancer, lung cancer, parotid mucoepidermoid carcinoma and malignant mesenchymal tumor in brain in one patient were detected. One patient had both thyroid and renal cell cancer. Age of patients at diagnosis of acromegaly was significantly higher in patients with cancer (45.8 ± 9.9 vs. 40.9 ± 11.3 years, p < 0.05). No significant difference was found in duration of the disease, initial GH levels and IGF-1% upper limit of normal values, the prevalence of diabetes, hypertension, coronary heart disease, hyperlipidemia and treatment modalities between the patients with/without cancer. In logistic regression analysis, older age at diagnosis was associated with malignancy risk. The risk of cancer in acromegaly especially the thyroid cancer risk seems to be more increased than known in the literature. Therefore, acromegaly patients should be screened routinely for cancer, especially for thyroid cancer due to it being up to four times higher prevalence than breast and colorectal cancer.

P-0174 - Carcinoid Tumors of Gastrointestinal Tract: Outcomes According to Treatment Modality in Rectal Carcinoid Tumors

Background: With the advance of gastrointestinal diagnostic modalities, the epidemiology and clinical course of gastrointestinal neuroendocrine tumors (GI-NETs) have been changed from that of previous century. We aimed to define the characteristic of gastrointestinal carcinoid tumors in our institute for recent 5 years. Besides, this study was designed to compare the efficacy and safety of endoscopic treatments and operation in rectal carcinoid tumors.

Comparison of Endoscopic Resection Therapies for Rectal Carcinoid Tumor

Endoscopic mucosal resection (EMR) has been the endoscopic treatment of choice for rectal carcinoid tumors <10 mm in size. Endoscopic submucosal dissection (ESD) may cause more severe complications, longer operation time, and higher cost than EMR. : To compare EMR using band ligation (EMR-B) method with ESD for the endoscopic treatment of rectal carcinoid tumors. From November 2008 to September 2011, we enrolled consecutive patients with rectal carcinoid tumors <10 mm in diameter and without lymph node enlargement. Rate of complete resection rate, incidence of complications, and length of procedures were evaluated. Sixty patients were enrolled (31 ESD cases and 29 EMR-B cases). The mean age was 48.03±13.09 years. Both groups had similar mean tumor diameter (EMR-B 4.34±1.75 vs. ESD 5.22±2.09 mm; P=0.084). Resection time was longer in the ESD group than in the EMR-B group (15.09±5.73 vs. 6.37±5.52 min; P<0.001). The complete resection rate was 80.6% (25 of 31) in the ESD group and 82.8% (24 of 29) in the EMR-B group (P=0.833). In incomplete resection cases, neither local recurrence nor distant metastasis was detected during the follow-up period. Compared with ESD, EMR-B resulted in a comparable histologically complete resection rate and took less time to perform. Given the advantages of easier and shorter procedure time, EMR-B may be considered the treatment of choice for small rectal carcinoid tumors.

Tu1431 Treatment Outcomes of Endoscopic Resection for Rectal Carcinoid Tumors: an Analysis of Resectability and Long-Term Result of 37 Consecutive Cases

Most of colorectal carcinoid tumors developed in rectum in Japan, and 80% of those were especially located less than 10 cm from dentate line. The choice of treatment either endoscopic or surgical resection is very important because surgical treatment for those tumors may need to construct artificial anus. Although curative endoscopic resection (ER) is desirable from the point of maintaining of QOL, sufficient evidence of endoscopic treatment for rectal carcinoid tumors is not fully obtained. The aim of this study is to clarify the efficacy of ER for rectal carcinoid tumors and long-term consequences.

896 Well-Differentiated Rectal Carcinoids: Impact of Tumor Size on the Natural History and Outcomes

Background: There are a paucity of data pertaining to the natural history and outcomes of patients with a well-differentiated rectal carcinoid tumor. There is general consensus that a ≤10 mm, well-differentiated rectal carcinoid that does not infiltrate the muscularis propria or demonstrate nodal spread can be managed by local excision. Conversely, most favor radical resection for lesions ≥ 20mm and/or nodal metastasis. A clearer understanding of the natural history, in particular for intermediate size lesions (11-19mm), is necessary to optimize patient care. Aims: For patients with a well-differentiated rectal carcinoid who underwent endoscopic evaluation to determine the: 1.) lesion size correlating with metastasis, 2.) factors associated with disease progression, 3.) disease stage of 11-19mm lesions, and 4.) 10 year survival rates based on disease extent. Method: A histopathology database was reviewed to identify patients with a well-differentiated rectal carcinoid or neuroendocrine tumor who underwent endoscopy from 1/1/00-1/9/12. Clinical demographics, radiologic, and clinical follow-up data were analyzed. Results: Among the 87 patients diagnosed with a well-differentiated rectal carcinoid, metastatic disease (local or distant) was identified at the time of endoscopy in 2/66 (3%), 4/6 (66%) and 11/15 (73%) of patients for lesions ≤10mm, 11-19mm and ≥20mm, respectively. Metastasis was predicted with 100% sensitivity and 87% specificity using a lesion cut off size of ≥9mm, (AUC 0.948). Metastasis was subsequently discovered in 1/64 (1.6%), 1/2 (50%) and 4/4 (100%) patients with lesions measuring ≤10 mm, 11-19mm and ≥20mm, respectively. These sites included the liver (n= 4), pancreas (n=1) and liver & lung (n=1), at 34.6 (IQR 4.7-33) months from endoscopic evaluation. For patients with locally confined disease at presentation, subsequent disease progression correlated with advanced age (p=0.03), presence of initial symptoms (p=0.02), lesion size (p=0.0001) and immune-stain pattern (p=0.03). Multivariate analysis revealed one independent factor: size .20mm at the time of initial diagnosis (p,0.0001: OR 1.25, 95% CI 1.04-1.5). A lesion cut off size of .10mm, (AUC 0.957) had 83% sensitivity and 98% specificity for predicting disease progression. The ten year survival rates were 87%, 67% and 32% for patients presenting with locally confined, locally advanced and distant disease, respectively. Conclusions: Our data support the contention that small ( ≤10 mm) well differentiated lesions have a generally benign disease course. However, our findings indicate that the clinical behavior of intermediate sized tumors (11-19 mm) mimics that of large (≥20 mm) tumors and, thus, need for a more aggressive management strategy. Examination of other staging and clinical parameters may be key, particularly for patients with intermediate size lesions.

897 Prognostic Heterogeneity Among Patients With Bone Metastases From Well-Differentiated Digestive Neuroendocrine Tumors

Background: There are a paucity of data pertaining to the natural history and outcomes of patients with a well-differentiated rectal carcinoid tumor. There is general consensus that a ≤10 mm, well-differentiated rectal carcinoid that does not infiltrate the muscularis propria or demonstrate nodal spread can be managed by local excision. Conversely, most favor radical resection for lesions ≥ 20mm and/or nodal metastasis. A clearer understanding of the natural history, in particular for intermediate size lesions (11-19mm), is necessary to optimize patient care. Aims: For patients with a well-differentiated rectal carcinoid who underwent endoscopic evaluation to determine the: 1.) lesion size correlating with metastasis, 2.) factors associated with disease progression, 3.) disease stage of 11-19mm lesions, and 4.) 10 year survival rates based on disease extent. Method: A histopathology database was reviewed to identify patients with a well-differentiated rectal carcinoid or neuroendocrine tumor who underwent endoscopy from 1/1/00-1/9/12. Clinical demographics, radiologic, and clinical follow-up data were analyzed. Results: Among the 87 patients diagnosed with a well-differentiated rectal carcinoid, metastatic disease (local or distant) was identified at the time of endoscopy in 2/66 (3%), 4/6 (66%) and 11/15 (73%) of patients for lesions ≤10mm, 11-19mm and ≥20mm, respectively. Metastasis was predicted with 100% sensitivity and 87% specificity using a lesion cut off size of ≥9mm, (AUC 0.948). Metastasis was subsequently discovered in 1/64 (1.6%), 1/2 (50%) and 4/4 (100%) patients with lesions measuring ≤10 mm, 11-19mm and ≥20mm, respectively. These sites included the liver (n= 4), pancreas (n=1) and liver & lung (n=1), at 34.6 (IQR 4.7-33) months from endoscopic evaluation. For patients with locally confined disease at presentation, subsequent disease progression correlated with advanced age (p=0.03), presence of initial symptoms (p=0.02), lesion size (p=0.0001) and immune-stain pattern (p=0.03). Multivariate analysis revealed one independent factor: size .20mm at the time of initial diagnosis (p,0.0001: OR 1.25, 95% CI 1.04-1.5). A lesion cut off size of .10mm, (AUC 0.957) had 83% sensitivity and 98% specificity for predicting disease progression. The ten year survival rates were 87%, 67% and 32% for patients presenting with locally confined, locally advanced and distant disease, respectively. Conclusions: Our data support the contention that small ( ≤10 mm) well differentiated lesions have a generally benign disease course. However, our findings indicate that the clinical behavior of intermediate sized tumors (11-19 mm) mimics that of large (≥20 mm) tumors and, thus, need for a more aggressive management strategy. Examination of other staging and clinical parameters may be key, particularly for patients with intermediate size lesions.

Tu1088 Prediction of Tumor Recurrence in Patients With Gastrointestinal Stromal Tumors Following Resection by the Modified NIH Criteria

Background: Endoscopic ultrasound (EUS) is often performed to evaluate patients with rectal carcinoid tumor to evaluate tumor size, depth of invasion and lymph node status. A recently proposed surveillance protocol calls for an EUS examination at 3 months following local therapy and then every 6 months for 3 years. The need and utility for surveillance programs in this setting have not been validated. Aims: In patients who have undergone resection of a rectal carcinoid to determine the potential utility of endoscopic surveillance for identifying disease recurrence. Method: A histopathology database was reviewed to identify patients with an endoscopic diagnosis of a well-differentiated rectal carcinoid tumor from 1/1/00-1/9/12. Clinical, radiologic, endoscopic, EUS, and follow-up outcome data were analyzed. Results: Among 87 patients who met inclusion criteria, local excision was performed in 75 (86%) to include: hot snare polypectomy n=56, transanal excision (TAE) n=13, endoscopic mucosal resection (EMR) n=5 and endoscopic submucosal dissection (ESD) n=1. Of 70 patients with local disease management, 55 (79%) underwent post intervention surveillance, 20 (36%) of whom included EUS [1 (IQR 1-2.5)]. Colonoscopy alone was performed in n=23, colonoscopy and non-invasive imaging n=7, non-invasive imaging alone n= 5, colonoscopy and EUS n=4, colonoscopy and EUS and non-invasive imaging n=1. Fifteen (21%) patients had no specific rectal carcinoid surveillance on site but had ongoing on site separate clinical evaluations. Disease progression was identified in 6 (8.6%) patients at 1.4 (IQR 0.38-2.7) years from initial diagnosis. All 6 cases reflected distant metastatic locations (n=4 liver, n=1 pancreas, n=1 lung and liver) rather than that of local recurrence or a combination of local and distant disease. All were identified by non-invasive imaging at 35 (IQR 4.7-33) months following initial therapy. At no point during their course was local recurrence identified. Disease specific mortality (n=3) occurred at 13 (IQR 9-69) months following initial therapy. Conclusions: Our data suggest the lack of local recurrence of rectal carcinoid following local disease management. These data call into question the utility of any endoscopic surveillance program. Additional study is needed to more firmly establish the natural course of disease in such patients to help devise a more accurate and tailored approach to disease surveillance.

A control study of endoscopic mucosal resection and endoscopic submucosal dissection in treating rectal carcinoid tumors

Objective To evaluate the efficacy and safety of endoscopic submucosal dissection （ESD） for rectal carcinoid tumors by comparing with endoscopic mucosal resection （EMR）. Methods Da ta of patients with rectal eareinoid tumors between May 2010 to May 2012, who received EMR （n = 24） or ESD （n = 19 ） were reviewed to compare the diameter measured by EUS, operation time, en bloc resection rate, complication, R0 resection rate, and recurrence rate between two methods. Results Diameter measured by EUS in ESD group （ 7.4 ± 5.3 mm ） was significantly higher than that in EMR group （ 5.6 ± 2. lmm, P 〈0. 05）. Mean operation time of ESD group （32. 6 ± 10. 5 min） was significantly longer than that of EMR group （8. 9 ±6. 3 min, P 〈0.05）. En bloc resection and R0 resection rates were similar between EMR （ 100. 0%, 100.0% , respectively） and ESD group （ 100. 0% , 95.0% , respectively）. Complications including perforation and delayed bleeding in EMR group （ 15. 3% ） was significantly higher than those in ESD groups （ 5.0% , P 〈 0. 05 ）. No local recurrence had been detected in either the EMR or ESD group. Conclusion For rectal earcinoid tumor with diameter less than 7mm, EMR can effectively achieve complete resection of the lesions and shorten the operation time. For lesions with diameter greater than 7mm, after muhiple biopsies or partial resection, which results in endoscopic injection flattering intrinsic-negativesigns, ESD might be a better choice. Key words: Rectal; Carcinoid; Endoscopic mucosal resection; Endoscopic submucosal dissection

Increased thyroid cancer risk in acromegaly

Acromegaly increases cancer risk. We aimed to determine the prevalence and the predictors of tumors in acromegalic patients treated at our department. We retrospectively evaluated 160 acromegalic patients [79 female (mean age 52.0 ± 10.4 years) and 81 male (mean age 49.1 ± 12.4 years)] between 1990 and 2012, with a mean follow up period of 7.1 ± 5.7 years. The patients were screened with colonoscopy, mammography, thyroid and prostate ultrasonography. Malignancy was found in 34 (21.3 %) patients. No significant difference was observed in the distribution of malignancy among sexes (20.3 % in F vs. 22.2 % in M). Thyroid cancer was the most frequent (n = 17, 10.6 %) followed by the breast cancer (n = 4, 2.5 %) and colorectal cancer (n = 3, 1.8 %). Renal cell cancer in two patients, bladder cancer in two patients, periampullary tumor, rectal carcinoid tumor, malignant melanoma, prostate cancer, lung cancer, parotid mucoepidermoid carcinoma and malignant mesenchymal tumor in brain in one patient were detected. One patient had both thyroid and renal cell cancer. Age of patients at diagnosis of acromegaly was significantly higher in patients with cancer (45.8 ± 9.9 vs. 40.9 ± 11.3 years, p < 0.05). No significant difference was found in duration of the disease, initial GH levels and IGF-1 % upper limit of normal values, the prevalence of diabetes, hypertension, coronary heart disease, hyperlipidemia and treatment modalities between the patients with/without cancer. In logistic regression analysis, older age at diagnosis was associated with malignancy risk. The risk of cancer in acromegaly especially the thyroid cancer risk seems to be more increased than known in the literature. Therefore, acromegaly patients should be screened routinely for cancer, especially for thyroid cancer due to it being up to four times higher prevalence than breast and colorectal cancer.

Well‐differentiated papillary mesothelioma, possibly giving rise to diffuse malignant mesothelioma: A case report

Well-differentiated papillary mesothelioma (WDPM) is a distinct subtype of mesothelial tumor from diffuse malignant mesothelioma (DMM), with an uncertain malignant potential. The relationship between WDPM and DMM, with regard to the ability of the former to develop into the latter, is also unknown. A 58-year-old woman, diagnosed with a rectal carcinoid tumor, underwent removal of the lymph nodes via the abdomen in 2004. A large number of white miliary nodules were identified on the mesentery and peritoneum, which were histologically diagnosed as WDPM. No further therapy was administered, but the patient was followed-up using imaging methods. Seven years later, an abdominal wall mass was discovered using positron emission tomography-computed tomography, and a laparotomy biopsy was performed. DMM was diagnosed, because mesothelioma with extended invasion had been histologically identified. Mesothelioma similar to papillary proliferation was present on the outer layer of the peritoneum, and an infiltrating lesion with continuous restiform or solid-like structures was noted. WDPM was believed to have undergone malignant transformation. Compared to DMM, WDPM has a good prognosis and is considered a benign or borderline neoplasm. Our findings suggest that WDPM does have malignant potential, however, because histological findings indicated a malignant transformation of WDPM to DMM.

Clinical outcomes for rectal carcinoid tumors according to a new (AJCC 7th edition) TNM staging system: A single institutional analysis of 122 patients

This study aimed to describe clinical outcomes of rectal carcinoids according to the 7th American Joint Council on Cancer (AJCC) TNM staging system. We retrospectively reviewed 122 patients who were treated for rectal carcinoids between 1995 and 2010. Among 122 patients, 81.2% (n = 99) were classified as stage I, 4.9% (n = 6) as stage II, 11.5% (n = 14) as stage III, and 2.5% (n = 3) as stage IV. Lymph node (LN) metastasis rates for pT1a, 1b, 2, and 3 stages were 1.2% (1/85), 16.7% (3/18), 0% (0/4) and 84.6% (11/13), respectively. The 5-year overall survival (OS) rate was 88.4%. The 5-year OS rates were estimated to be 100%, 80%, 51.4% and 0% for stage I, II, III, and IV, respectively (P < 0.001). The 5-year disease-free survival (DFS) rate was 82.3%. The 5-year DFS rates were estimated to be 97.7%, 62.5%, 17.1%, and 0% for stages I, II, III, and IV, respectively (P < 0.001). Using the new TNM stage, we confirmed a prognostic difference in LN metastasis rates, OS, and DFS for rectal carcinoids. In clinical practice, the new TNM stage can be very useful for predicting prognosis.

Endoscopic mucosal resection vs endoscopic submucosal dissection for rectal carcinoid tumours: a systematic review and meta‐analysis

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are used for the removal of rectal carcinoid tumours. There are no current guidelines or consensus on the optimal treatment strategy for these lesions. A systematic review was conducted to compare the efficacy and safety of ESD and EMR. The generation of inclusion criteria and analysis of data were based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. A systematic literature review was conducted using the following databases: Medline, Embase, SpringerLink, Elsevier ScienceDirect, Science Citation Index and the Cochrane Library. Only papers comparing treatment of rectal carcinoid tumours by EMR and by ESD were selected. The data collected included the patients' demographic information, interventions made, observed outcome and sources of bias. Four papers were included in this systematic review and meta-analysis. ESD was more effective than EMR in complete resection (OR 0.29; 95% CI 0.14-0.58; P = 0.000). ESD was as safe as EMR [rate difference (RD) -0.01; 95% CI -0.07 to 0.05; P = 0.675]. Recurrence rates did not differ significantly between the EMR and ESD groups (RD 0.04; 95% CI -0.01 to 0.09; P = 0.150). The duration of ESD was longer than EMR (standardized mean difference -1.73; 95% CI -2.73 to -0.74; P = 0.001). The study indicates that ESD is the better treatment for rectal carcinoid tumours.

Evaluation of colonoscopy in the diagnosis and treatment of rectal carcinoid tumors with diameter less than 1 cm in 21 patients

The aim of this study was to evaluate colonoscopy in the diagnosis and treatment of rectal carcinoid tumors with diameter <1 cm. Elevated lesions with normal mucosal appearance under colonoscopy were identified. Endoscopic ultrasound (EUS) was performed in 16 patients. Lesions diagnosed as rectal carcinoid tumors were resected by endoscopic mucosal resection (EMR). The diagnosis of specimens by EMR was confirmed by pathological examination. Immunohistochemical staining was undertaken and follow-up data were collected. Twenty-two lesions were found among the 21 cases. The majority of these were located within 10 cm of the anal opening. Twenty two cases with rectal carcinoids were diagnosed by EUS under colonoscopy and all cases were verified by pathological examination. The resection rate was 95.5% (21/22). Of the lesions, six were mucosal and 10 were submucosal. Immunohistochemistry was undertaken for carcinoid tumors. Histological patterns of rectal carcinoids revealed solid nests or trabecular patterns. Eleven cases were synaptophysin (SYN)-positive, 8 cases were neurone-specific enolase (NSE)-positive and 5 cases were chromogranin A (CgA)-positive. Colonoscopy combined with EUS is effective in the diagnosis and determination of small rectal carcinoids. Endoscopic treatment is effective for small-sized tumors. Pathology and immunohistochemistry remain the diagnostic gold standard.

Indications for and Technical Aspects of Colorectal Endoscopic Submucosal Dissection

Due to the widespread acceptance of gastric and esophageal endoscopic submucosal dissections (ESDs), the number of medical facilities that perform colorectal ESDs has grown and the effectiveness of colorectal ESD has been increasingly reported in recent years. The clinical indications for colorectal ESD at the National Cancer Center Hospital, Tokyo, Japan include laterally spreading tumor (LST) nongranular type lesions >20 mm and LST granular type lesions >30 mm. In addition, 0-IIc lesions >20 mm, intramucosal tumors with nonlifting signs and large sessile lesions, all of which are difficult to resect en bloc by conventional endoscopic mucosal resection (EMR), represent potential candidates for colorectal ESD. Rectal carcinoid tumors less than 1 cm in diameter can be treated simply, safely, and effectively by endoscopic submucosal resection using a ligation device and are therefore not indications for ESD. The en bloc resection rate was 90%, and the curative resection rate was 87% for 806 ESDs. The median procedure time was 60 minutes, and the mean size for resected specimens was 40 mm (range, 15 to 150 mm). Perforations occurred in 23 (2.8%) cases, and postoperative bleeding occurred in 15 (1.9%) cases, but only two perforation cases required emergency surgery (0.25%). ESD was an effective procedure for treating colorectal tumors that are difficult to resect en bloc by conventional EMR. ESD resulted in a higher en bloc resection rate as well as decreased invasiveness in comparison to surgery. Based on the excellent clinical results of colorectal ESDs in Japan, the Japanese healthcare insurance system has approved colorectal ESD for coverage.

Prognostic Significance of Ki-67 Expression in Rectal Carcinoid Tumors

Rectal carcinoid tumors can be resected with endoscopy, and it is important to assess their prognostic factors. We evaluated the potential of Ki-67 expression as a prognostic factor in rectal carcinoid tumors. We retrospectively reviewed the medical records of 37 patients with rectal carcinoid tumors who got endoscopic resection from January 2001 to January 2011 at Inje University Seoul Paik Hospital. We analyzed their endoscopic and histologic findings, Ki-67 expression, clinical outcome, and prognosis. The mean age (±SD) of the patients was 56.3±10.7 years, and the male : female ratio was 3.6 : 1. The mean tumor size was 0.5±0.4 cm, 33 patients showed grade 1 tumors (89.2%) and the average Ki-67 expression was 0.7±1.2%. Thirty five patients underwent endoscopic mucosal resection, and two required endoscopic submucosal dissection. Eight patients had positive margins after resection, but no cases of lymphovascular invasion were identified. The median follow-up duration was 21.4±25.4 months, and no recurrences were observed. In low grade rectal carcinoid tumors which are lack of central depression on colonoscopy, the expression of a molecular marker of malignant potential, Ki-67, was low. Therefore, endoscopic resection seemed to be a safe and effective treatment for these tumors.

Tips and Tricks for Better Endoscopic Treatment of Colorectal Tumors: Usefulness of Cap and Band in Colorectal Endoscopic Mucosal Resection

Endoscopic mucosal resection (EMR) is an endoscopic alternative to surgical resection of mucosal and submucosal neoplastic lesions. Prior to the development of knives, EMR could be performed with accessories to elevate the lesion. After the development of various knives, en bloc resection was possible without other accessories. So, recently, simple snaring without suction or endoscopic submucosal dissection using knife in the epithelial lesions such as adenoma or early mucosal cancer has been performed. However, for easy and complete resection of subepithelial lesions such as carcinoid tumor, a few accessories are needed. Complete resection of rectal carcinoid tumors is difficult to achieve with conventional endoscopic resection techniques because these tumors often extend into the submucosa. The rate of positive resection margin for tumor is lower in the group of EMR using a cap (EMR-C) or EMR with a ligation device (EMR-L) than conventional EMR group. EMR-C and EMR-L (or endoscopic submucosal resection with a ligation device) may be a superior method to conventional EMR for removing small rectal carcinoid tumors.

Can Ki-67 Expression Predict the Prognosis in Low Grade Rectal Carcinoid Tumor?

Can Ki-67 Expression Predict the Prognosis in Low Grade Rectal Carcinoid Tumor?

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

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