Colorectal Laterally Spreading Tumors Research Articles

The feasibility of endoscopic resection for colorectal laterally spreading tumors.

The present study aimed to investigate the feasibility and safety of endoscopic resection for colorectal laterally spreading tumors (LSTs) in different size groups. This retrospective study included 2699 patients with LSTs who underwent endoscopic treatment at the Second Xiangya Hospital of Central South University from May 2012 to February 2022. The patient baseline and procedure outcomes were compared between the < 5cm group, 5-10cm group, and ≥ 10cm group. Meanwhile, lesions larger than 5cm in diameter were longitudinally compared for endoscopic safety using ESD with surgical operation outcomes. There were 2105 patients in the < 5cm group, 547 patients in the 5-10cm group, and 47 patients in the ≥ 10cm group. En bloc resection and R0 resection rates, the incidence of adverse events, length of stay (LOS), and medical costs significantly differed between the groups (P < 0.01). Comorbidity of diabetes or hypertension, history of antithrombotic drug use, lesion size, location, gross type, endoscopic procedures selection, and circumferential extent of the mucosal defect were independent risk factors for delayed bleeding (P < 0.05). En bloc resection, R0 resection, and lesion canceration were associated with local recurrence. For lesions larger than 5cm in diameter, ESD had similar R0 resection and local recurrence rates compared with a surgical operation but a lower en bloc rate, LOS, and medical costs. Expert endoscopists can significantly increase en bloc and R0 resection rates and reduce the incidence of adverse events. Endoscopic resection results distinguish in different size groups of colorectal LSTs, yet its safety and feasibility are not inferior to a surgical operation.

Cap-assisted endoscopic mucosal resection as a salvage technique for challenging colorectal laterally spreading tumors.

Cap-assisted endoscopic mucosal resection (EMR-c) has emerged as a potential alternative to standard piecemeal wide-field EMR (WF-EMR) for the resection of laterally spreading tumors (LSTs). However, clear indications for this technique are still lacking. Our objective was to investigate the performance of salvage EMR-c after WF-EMR failure in the resection of large colorectal LSTs. The data of consecutive patients undergoing WF-EMR for large colorectal LSTs (2015-2021) were analyzed in this single-center, retrospective, observational study. In the event of a WF-EMR failure, the procedure was switched to EMR-c in the same session. The efficacy of the two techniques was evaluated in terms of complete endoscopic resection, R0 resection, and recurrence rate. Safety was also assessed. Overall,the data from 81 WF-EMRs were collected. Eighteen cases of WF-EMR failure were switched to EMR-c in the same session and complete endoscopic resection was achieved in 17/18 patients (94.4%). No statistically significant difference was observed between WF-EMR and salvage EMR-c in terms of macroscopic radicality (P = 0.40) and R0 resection (P = 0.12). However, recurrence was more common with EMR-c (44.4% vs. 23.5%; P = 0.05), as were adverse events, particularly intraprocedural bleeding (27.8% vs. 7.9%; P = 0.04). EMR-c is an effective salvage technique for challenging colorectal LSTs following WF-EMR failure. Due to the elevated risk of adverse events associated with this procedure, careful patient selection, endoscopic expertise, and close follow-up are strongly recommended.

Efficacy of endoscopic treatment oncolorectal laterally spreading tumor and risk factors of delayed bleeding after operation

Objective: To evaluate the endoscopic treatment efficacy of colorectal laterally spreading tumor (LST) and analyze the risk factors for delayed post-polypectomy bleeding (DPPB). Methods: Between January 2015 and December 2020, patients underwent colorectal endoscopic submucosal dissection (ESD) or hybrid ESD were recruited from the Second Affiliated Hospital of Zhejiang University. Complete resection rate, perforation rate, bleeding rate, operation time and lesion adhesion were compared between the ESD and hybrid ESD groups. Patients were divided into bleeding and non-bleeding groups based on the presence of DPPB. Multivariate logistic regression analysis was used to analyze the risk factors of DPPB. Results: A total of 665 patients with colorectal LST were enrolled, including 376 males and 289 females, with an average age of (57.4±0.4) years. There were 471 cases underwent ESD and 194 cases underwent hybridized ESD. There were no significant differences in gender, age, history of smoking and drinking, and prevalence of hypertension between the two groups (all P>0.05). Likewise, the rate of lesion adhesion (4.2% vs 7.7%, P=0.067), lesion complete resection (96.8% vs 93.8%, P=0.418), perforation (0.6% vs 1.0%, P=0.594), delayed bleeding (2.8% vs 2.1%, P=0.605) were not statistically significant between the two groups. Seventeen patients (2.6%) developed DPPB after endoscopic treatment. Multivariate logistic regression analysis showed that the lesion was in the rectum (OR=3.594, 95%CI: 1.237-10.443, P=0.019) and the diameter of the lesion>2 cm (OR=3.776, 95%CI: 1.411-10.106, P=0.008) were risk factors for DPPB. Conclusions: Both ESD and hybrid ESD are successful treatments for colorectal LST. Colorectal LST lesion site and lesion size>2 cm are risk factors of DPPB.

A diagnostic test: diagnostic value of gastrointestinal endoscopy narrow-band imaging (NBI) for colorectal laterally spreading tumor (LST) and submucosal invasion.

Endoscopic ultrasonography is an effective endoscopic examination method for determining the depth of colorectal cancer invasion. Narrow-band imaging (NBI) techniques increase the contrast of vascular structures and more clearly highlight subtle structures on mucosal surfaces, thereby improving the accuracy of endoscopic assessment. This study investigated the diagnostic efficacy of NBI in colorectal laterally spreading tumor (LST) and its submucosal invasion. A total of 224 patients with colorectal LST admitted to the Affiliated Hospital of Putian University from January 2015 to December 2021 were enrolled in this study. The patients were divided into NBI and endoscopic ultrasonography groups according to the different examination methods they received. Subsequently, the clinicopathological characteristics of the patients were collected, and the rates of submucosal invasion of the four subtypes (LST-G-H, LST-G-NM, LST-NG-F, LST-NG-PD) were compared between the two groups. Also, the accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of judging the depth of LST lesions of the two examination methods were compared, taking the results of pathological tissue examination as the gold standard. This study enrolled 224 patients with LST (mean onset age: 57.98±6.48 years), including 123 males and 101 females. In terms of tumor location, 21 cases were located in the cecum, 22 cases in the ascending colon, 38 cases in the transverse colon, 11 cases in the descending colon, 12 cases in the descending sigmoid junction, 23 cases in the sigmoid colon, and 97 cases in the rectum. The sizes of the tumors ranged from 18.81 to 52.88 mm. Moreover, there were 21 cases of lesion infiltration into the submucosa, and the infiltration rate was 9.38%. Furthermore, the accuracy of NBI in diagnosing colorectal LST was significantly higher than that of endoscopic ultrasonography (87.05% vs. 57.14%); NBI was more accurate than endoscopic ultrasonography in the preoperative diagnosis of LST lesion depth in the rectal, non-rectal, granular (LST-G), non-granular (LST-NG), <40, and ≥40 mm groups. Gastrointestinal NBI has a superior accuracy rate and value than endoscopic ultrasonography in diagnosing colorectal LST, tumor lesion depth, and submucosal invasion. Therefore, gastrointestinal NBI deserves to be promoted in clinical work.

Predictors for malignant potential and deep submucosal invasion in colorectal laterally spreading tumors.

BACKGROUNDColorectal laterally spreading tumors (LSTs) with malignant potential require en bloc resection by endoscopic submucosal dissection (ESD), but lesions with deep submucosal invasion (SMI) are endoscopically unresectable.AIMTo investigate the factors associated with high-grade dysplasia (HGD)/carcinoma and deep SMI in colorectal LSTs.METHODSThe endoscopic and histological results of consecutive patients who underwent ESD for colorectal LSTs in our hospital from June 2013 to March 2019 were retrospectively analyzed. The characteristics of LST subtypes were compared. Risk factors for HGD/carcinoma and deep SMI (invasion depth ≥ 1000 μm) were determined using multivariate logistic regression.RESULTSA total of 323 patients with 341 colorectal LSTs were enrolled. Among the four subtypes, non-granular pseudodepressed (NG-PD) LSTs (85.5%) had the highest rate of HGD/carcinoma, followed by the granular nodular mixed (G-NM) (77.0%), granular homogenous (29.5%), and non-granular flat elevated (24.2%) subtypes. Deep SMI occurred commonly in NG-PD LSTs (12.9%). In the adjusted multivariate analysis, NG-PD [odds ratio (OR) = 16.8, P < 0.001) and G-NM (OR = 7.8, P < 0.001) subtypes, size ≥ 2 cm (OR = 2.2, P = 0.005), and positive non-lifting sign (OR = 3.3, P = 0.024) were independently associated with HGD/carcinoma. The NG-PD subtype (OR = 13.3, P < 0.001) and rectosigmoid location (OR = 8.7, P = 0.007) were independent risk factors for deep SMI.CONCLUSIONBecause of their increased risk for malignancy, it is highly recommended that NG-PD and G-NM LSTs are removed en bloc through ESD. Given their substantial risk for deep SMI, surgery needs to be considered for NG-PD LSTs located in the rectosigmoid, especially those with positive non-lifting signs.

Cap-assisted EMR versus standard inject and cut EMR for treatment of large colonic laterally spreading tumors: a randomized multicenter study (with videos)

Piecemeal EMR of colorectal laterally spreading tumors (LSTs) >20mm is effective. Experience is limited in the use of cap-assisted EMR (EMR-C) for resection of colonic lesions. We compared the efficacy and the safety of EMR-C for the removal of colonic LSTs≥30mm with "inject-and-cut" standard EMR (EMR-S). In this randomized trial from 4 Italian centers, 138 patients were treated with EMR-C and 102 with EMR-S. The rates of residual lesions, percentage of recurrence after 12 months, and adverse events were evaluated. One hundred forty-three lesions were resected with EMR-C and 102 with EMR-S. Argon plasma coagulation (APC) was used as adjunctive treatment in 2.9% of EMR-Cs and in 22.5% of EMR-Ss (P< .001). The median time required was 20 minutes for EMR-C and 30 minutes for EMR-S (P< .001). Adverse events (AEs) occurred in 14 EMR-Cs (10.1%; 2 perforations, 11 bleeding events, and 1 stenosis) and in 22 EMR-Ss (21.6%; 1 perforation and 21 bleeding events) (P= .017). Intraprocedural AEs occurred in 3.6% of EMR-Cs and 16.7% of EMR-Ss (P= .001). Overall, residual lesions within 12 months were found to be significantly higher with EMR-S (32 patients, 31.4%) than with EMR-C (8 patients, 5.8%) (P< .001). Recurrence at follow-up colonoscopy in 12 months occurred in 7 EMR-Cs (5.1%) and 17 EMR-Ss (16.7%; P< .001). The study demonstrated the feasibility and safety of EMR-C for removing large colorectal LSTs, with higher eradication rates, shorter resection time, and less use of APC when compared with EMR-S. (Clinical trial registration number: NCT03498664.).

Endoscopic resection for colorectal laterally spreading tumors in East Asian countries: a systematic review.

BackgroundTo assess the efficacy and safety of different endoscopic resection methods for colorectal laterally spreading tumors (LSTs) in East Asian countries.MethodsA literature search was performed in PubMed, Embase, Cochrane Library and Web of Science databases. Colorectal LSTs of the included studies were resected with endoscopic mucosal resection (EMR) and/or endoscopic submucosal dissection (ESD). The main outcomes involved rates of en bloc resection, R0 resection, adverse events and recurrence.ResultsA total of 20 studies were finally included in the present study. The total number of lesions were 3,903 (EMR: 1,230, ESD: 2,673). EMR-en bloc resection was obtained in 395/591 (66.8%), with ESD-en bloc resection reported in 2,020/2,265 (89.2%) [odds ratio (OR) 0.244, P<0.0001, 95% confidence interval (CI): 0.197–0.304]. EMR-R0 resection was achieved in 409/547 (74.8%), which was lower than that of ESD (1,895/2,241, 84.6%) (OR 0.541, P<0.0001, 95% CI: 0.432–0.677). Bleedings occurred more frequently in EMR than in ESD group (10.4% vs. 3.1%, OR 3.559, P<0.0001, 95% CI: 2.618–4.836). Rates of perforations in EMR and ESD were 0.4% and 4.1% (OR 0.099, P<0.0001, 95% CI: 0.036–0.27). Recurrence of EMR was higher than ESD group (6.3% vs. 1.0%, OR 6.732, P<0.0001, 95% CI: 3.751–12.082).DiscussionEndoscopic resections of colorectal LSTs are safe and effective. ESD leads to higher rates of en bloc and R0 resection, as well as lower rates of bleeding and recurrence, but it has a high risk of perforation, compared with EMR.

Endoscopic submucosal dissection for colorectal laterally spreading tumors: Clinical outcomes and predictors of technical difficulty.

We aimed to investigate the clinical outcomes of endoscopic submucosal dissection (ESD) for the treatment of colorectal laterally spreading tumors (LSTs) and the factors related to technical difficulty. Consecutive patients who underwent ESD for colorectal LSTs between June 2013 and January 2019 were retrospectively included. Factors associated with difficult ESD procedures (defined as conversion to piecemeal resection or discontinuation of endoscopic procedure), and dissection with a slow speed (<8 mm2 /min), were determined using the logistic regression analysis. A total of 325 patients with 342 colorectal LSTs (median size 20.0 mm) were enrolled. The proportions of granular (LST-G) and non-granular LST (LST-NG) were 62.9% and 37.1%, respectively. The overall en bloc and complete resection rates were 89.8% and 81.9%, respectively. The endoscopic procedure was discontinued in four lesions (1.2%), and 31 (9.1%) converted to piecemeal resection because of technical difficulty. Using multivariate analysis, positive non-lifting sign (odds ratio [OR] 19.9, P < 0.001), tumor size ≥20 mm (OR 10.0, P < 0.001), and less experienced endoscopists (OR 3.7, P=0.005) were independent factors for technically difficult procedure. Positive non-lifting sign (OR 3.7, P=0.004), lesion size <20 mm (OR 3.7, P < 0.001), LST-NG type (OR 1.8, P=0.034), and less colorectal ESD experience (OR 1.9, P=0.016) were independent factors of slow-speed dissection. ESD was feasible and safe for treating colorectal LSTs. Positive non-lifting sign and tumor ≥20 mm indicated difficult ESD procedures. Technical failure was more likely to occur in lesions resected by less-experienced endoscopists. Dissection speed might be improved with more experienced operators.

Pathological Analysis and Endoscopic Characteristics of Colorectal Laterally Spreading Tumors.

ObjectiveThis study aims to analyze the endoscopic and pathological characteristics of colorectal laterally spreading tumors (LSTs) to assist malignant risk stratification to inform selection of the appropriate treatment strategy.MethodsPatients with colorectal LST were selected as retrospective study objects. Characteristics, including endoscopic findings and the most common site of LSTs of different diameters and histological types, were analyzed. The risk factors for malignancy in colorectal LST were explored by multivariate logistic regression analysis.ResultsLSTs with diameters of ≥20 mm were found mainly in the rectum and mainly with granular-mixed (G-M) morphology (36% and 44.6%, respectively; p < 0.05), while LSTs with diameters of <20 mm were found mainly in the ascending colon and mainly with granular-homogenous (G-H) morphology (40.9% and 46.2%, respectively; p < 0.05). Adenoma was the main histological type in patients with tumors of all diameters. However, the cancerization rate of LSTs was 31% in patients with tumor diameter ≥20 mm, while there was no invasive cancer in patients with tumor diameter < 20 mm. In the low-grade dysphasia (adenoma) group, most of the lesions were located in the ascending colon and most had the morphology LST-G-H (35.8% and 39.2%, respectively; p < 0.05). In the cancerization group, most of the lesions were located in the rectum, with the morphology LST-G-M (51.6% and 67.2%, respectively; p < 0.05), and the diameter was larger than that of the adenoma group (33.84 ± 17.99 mm vs 21.68 ± 8.99 mm).ConclusionThe rectum was the most common site for an LST with a diameter ≥20 mm and cancerization, of which the morphology was mainly LST-G-M (endoscopic submucosal dissection is the preferred treatment for this type of LST). LST malignancy was found to be correlated with lesion diameter, location, and morphological appearance.

Endoscopic submucosal dissection for rectal-sigmoid laterally spreading tumors ≥10 cm: an analysis of 10 cases.

BackgroundEndoscopic submucosal dissection (ESD) is a standard method for treating selected colorectal laterally spreading tumors (LSTs). However, technical difficulty occurs with the increase in tumor size, and little is known about the efficacy of ESD treatment in colorectal LSTs ≥10 cm. The present study aimed to report the feasibility, safety, and efficacy of ESD for rectal-sigmoid LSTs ≥10 cm.MethodsFrom May 2012 to December 2019, patients with rectal-sigmoid LSTs ≥10 cm and underwent colorectal ESD were enrolled retrospectively. Demographic features, procedure-related parameters (procedure time, adverse events, rate of en bloc resection and complete resection), and follow-up results were recorded and analyzed.ResultsA total of 10 patients successfully underwent ESD: nine patients received conventional ESD, while the other one underwent tunneling ESD. The median diameter of the LSTs was 11.5 cm, and the median procedure time was 210 minutes. The rates of en bloc and curative resection rates were 100% and 90%, respectively. Of the ten patients, four had developed adverse events, one had intraoperative bleeding, two patients had delayed bleeding, and the other one had postoperative fever and rectum stricture postoperatively. None of the patients experienced recurrence during a median follow-up of 62 months.ConclusionsESD can be used as a feasible, safe and effective treatment modality for the management of rectal-sigmoid LSTs ≥10 cm.

Su1070 ENDOSCOPIC SUBMUCOSAL DISSECTION FOR COLORECTAL LATERALLY SPREADING TUMORS: CLINICAL OUTCOMES AND PREDICTORS OF TECHNICAL DIFFICULTY

Endoscopic submucosal dissection (ESD) has been used for colorectal laterally spreading tumors (LSTs), yet is technically challenging. We aimed to investigate the clinical outcomes of ESD for colorectal LSTs and predictors of technical difficulty. Consecutive patients who underwent ESD for colorectal LSTs in Beijing Friendship Hospital between June 2013 and March 2019 were retrospectively involved. We evaluated the en bloc resection rate, R0 resection rate, curative resection rate and adverse events with per lesion analysis. Dissection with a slow speed (<8mm2/min), conversion to piecemeal resection or abandonment of endoscopic procedure was considered as technically difficult. Factors associated with difficult ESD procedure, including LST subtype, size, non-lifting sign, procedure duration and operator experience (scaled by prior ESD case numbers) were determined using logistic regression. Significant factors with p<0.05 were adjusted in multivariate logistic regression. A total of 322 patients (56.5% men, mean age 64.7 years old) with 335 colorectal LSTs (median size 20.0mm, range 10.0-100.0mm) were enrolled. The proportions of granular (G) subtype and the non-granular (NG) subtype LSTs were 61.9% and 38.1%, respectively (Table 1). The en bloc, R0 and curative resection rate were 90.7%, 76.1% and 73.4%, respectively. The median dissection speed was 8.2mm2/min. Endoscopic procedure was abandoned in 4 lesions (1.2%), and 27 (8.1%) converted to piecemeal resection because of technical difficulty. Four cases (1.2%) had delayed bleeding and treated under endoscopy successfully. Perforation occurred in 10 LSTs (3.0%), of which only 1 (0.3%) needed surgery. Table 2 listed the risk factors for technically difficult ESD. NG subtype (odds ratio [OR] 1.9, p=0.012), positive non-lifting sign (OR 3.2, p=0.012), and less experienced operators (≤60 colorectal ESD cases) (OR 1.8, p=0.019) associated with a slow dissection speed. After adjusted in multivariate analysis, NG subtype (OR 2.2, p=0.004), positive non-lifting sign (OR 3.4, p=0.009), and less experienced operators (OR 2.1, p=0.009) remained to be independent predictors of low speed procedure. Lesions with size ≥20mm (OR 3.6, p=0.004) and positive non-lifting sign (OR 7.5, p<0.001) had higher risk for ESD abandonment or conversion to piecemeal resection due to difficult procedure. After adjustment in multivariate analysis, larger size (OR 8.3, p<0.001) and positive non-lifting sign (OR 13.3, p<0.001) were still significant factors. Procedure with prolonged duration of ≥60min associated with perforation (OR 5.8, p=0.014). ESD is feasible and safe for treating colorectal LSTs. NG subtype, larger size and positive non-lifting sign indicate difficult ESD procedure. The dissection speed can be improved with operator experience increased.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

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

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

Comparison of the histopathological characteristics of large colorectal laterally spreading tumors according to growth pattern.

Objectives: Colorectal laterally spreading tumors (LSTs) are widely recognized owing to their structural characteristics. This study aims to clarify the histopathological characteristics of large colorectal LSTs according to growth pattern. Methods: We studied 297 colorectal LSTs measuring ≥20 mm in diameter. The LSTs were classified into four types: granular homogenous type (LST-G-H), granular nodular mixed type (LST-G-M), non-granular flat elevated type (LST-NG-F), and non-granular pseudo-depressed type (LST-NG-PD). Retrospectively collected data were examined to compare the histopathological characteristics of LSTs according to the growth pattern. Results: LST-G-M lesions (142 lesions) were most common, followed by LST-NG-F (74 lesions), LST-G-H (61 lesions), and LST-NG-PD (20 lesions). The mean tumor diameter of LST-G lesions (38.5 ± 17.2 mm) was significantly greater than that of LST-NG lesions (26.3 ± 7.0 mm, P < 0.001). In particular, 45% of LST-G-M lesions were ≥40 mm in diameter. Adenomas accounted for 54% of LST-G-H lesions compared with only 10% of LST-NG-PD lesions. Pathological T1 carcinomas accounted for 55% of LST-NG-PD lesions and were not found among LST-G-H lesions. Conclusions: The biological malignancy of colorectal LSTs differs considerably depending on the growth pattern even among large lesions and therefore should be considered when selecting treatment regimens.

INCREASED RISK OF SYNCHRONOUS COLORECTAL LESIONS IN PATIENTS REFERRED FOR ENDOSCOPIC MUCOSAL RESECTION OF LATERAL SPREADING TUMORS.

Endoscopic mucosal resection is one of the most frequent therapeutic alternatives for large colorectal lateral spreading tumors. There are few data on the prevalence of synchronous lesions on these patients. To describe the prevalence of synchronous colorectal lesions in patients referred for endoscopic mucosal resection of lateral spreading tumors >20 mm. We reviewed the endoscopic database of our Department and identified adult patients who were referred for the resection of a colorectal lateral spreading tumor >20 mm and had a diagnostic colonoscopy performed up to six months before. The proportion of patients with at least one synchronous lesion was estimated. The following features were compared between patients with and without synchronous lesions: age, gender, bowel preparation quality and cecal intubation on index colonoscopy and therapeutic colonoscopy, serrated adenoma as index lesion. From December 2016 to November 2017, we identified 70 patients who fulfilled inclusion criteria. Median size of lesions was 25 mm (20-45). Eighty percent were located in the right colon and 35.71% were serrated adenomas. Synchronous lesion rate was 38.57%. Bowel preparation quality was similar in both groups when comparing both index and therapeutic colonoscopies. Patients with synchronous lesions had a higher proportion of serrated adenoma as index lesion than patients without synchronous lesions [51.85% vs 25.58%, OR 3.13 (1.13-8.68), P=0.03]. We found a high prevalence of synchronous lesions among patients with a large colorectal lateral spreading tumor. This risk seems to be increased if index lesions are serrated adenomas.

A clinical study of preoperative endoscopic assessment of the invasion depth of colorectal laterally spreading tumor

Objective To compare the diagnostic accuracy of magnifying chromoendoscopy (MCE) and endoscopic ultrasonography (EUS) for preoperative endoscopic assessment of the invasion depth of colorectal laterally spreading tumour(LST). Methods Data of 104 cases of colorectal LST were included. With the final pathological diagnosis as the golden standard, the accuracies of MCE and EUS for preoperative assessment of the invasion depth of colorectal LST were compared. Results The diagnostic accuracies of MCE and EUS for evaluating the invasion depth of LST were 89.4%(93/104) and 73.1%(76/104), respectively(P<0.05). The lesion size and the endoscopist could affect the accuracy of the EUS evaluation(P=0.017, OR=3.561; P=0.035, OR=1.399). The accuracy of EUS seemed to show a downward trend for colorectal LST of larger diameters. Conclusion Both MCE and EUS are effective for evaluating the invasion depth of colorectal LST, but the accuracy of MCE may be higher than that of EUS. Large diameter of the lesion and the doctor's experience inadequacy may be the risk factors for the accuracy of EUS. Key words: Colorectal neoplasms; Endosonography; Program evaluation; Laterally spreading tumor; Magnifying chromoendoscopy

Predictors of invasive cancer of large laterally spreading colorectal tumors: A multicenter study in Japan.

Background and AimAlthough colorectal laterally spreading tumors (LSTs) can be classified into four subtypes, the histopathological characteristics are known to differ among these subtypes. We therefore performed a logistic regression analysis to determine whether the risk of pathological T1 cancer of large colorectal LSTs can be predicted based on factors such as endoscopic findings in a large group of patients enrolled in a multicenter study in Japan.MethodsIn the main study, we assessed 1236 colorectal adenomas or early cancers that were classified as LSTs measuring 20 mm or more in diameter and treated endoscopically. Logistic regression analysis was performed to determine whether factors such as the subtype of LST could be used to predict the risk of pathological T1 cancer. A validation study of 356 large colorectal LSTs was conducted to confirm the validity of the results obtained in the main study.ResultsThe locations and tumor diameter of the LSTs in the main study were found to differ significantly according to the LST subclassification (P < 0.001). The frequency of pathological T1 cancers was the highest at 36% of LST nongranular pseudodepressed type, followed by 14% of LST nongranular flat‐elevated type, 11% of LST granular nodular mixed type, and 3% of LST granular homogenous type lesions. The risk of pathological T1 cancer was significantly associated with LST subclassification and tumor diameter. The area under the curve (AUC) was high (0.743). In the validation study, the AUC was 0.573.ConclusionsIn patients with large colorectal LSTs resected endoscopically, the risk of pathological T1 cancer can be predicted on the basis of the LST subclassification and tumor diameter.

Effect of Preceding Biopsy on the Results of Endoscopic Submucosal Dissection for Colorectal Laterally Spreading Tumor.

Forceps biopsies are usually performed before endoscopic submucosal dissection (ESD) for colonic laterally spreading tumors (LSTs). However, preceding biopsy is commonly believed to possibly inhibit complete tumor resection by causing blurring of tumor borders and tissue fibrosis. The aims were to investigate whether the preceding biopsy of colorectal LST affects the complete endoscopic tumor resection and increases the risk of complications. We retrospectively reviewed the medical records of patients with colorectal LSTs who underwent ESD at our center during an 8-year period. Patients were divided into two groups according to whether they underwent biopsy of the tumor before ESD. In addition, the characteristics of patients and tumors, including the completeness of tumor resection, were investigated. Of 288 patients (174 men) enrolled in this study, 194 (67.4%, preceding biopsy group) underwent biopsies before ESD, whereas 94 (32.6%, no biopsy group) did not. There were no significant differences in age, sex, comorbidity, medication history, tumor location, and final pathologic result between both groups. Tumor size was larger (p = 0.002) and LST-G tumor was more common (p = 0.003) in the preceding biopsy group than in the no biopsy group. No significant difference was seen in ESD outcomes, including procedure time, hospitalization period, incidence of complications, en bloc resection rate, resection margin status, and incidence of surgical operation, between both groups. Biopsy of LST is commonly performed before endoscopic resection. Contrary to popular belief, it does not increase the incomplete tumor resection rate and incidence of complications. KCT0002321.

Endoscopic submucosal dissection for colorectal laterally spreading tumors with the Dual knife only.

IntroductionThe knives for endoscopic submucosal dissection (ESD) have their strengths as well as shortcomings. They need to be used in combination in most cases. The Dual knife is a relatively novel type of ESD knife produced in 2009, which can be used for completing the whole procedure of ESD.AimColorectal laterally spreading tumors (LSTs) are a special subtype of colorectal neoplasms. We aimed to evaluate the clinical features and outcomes of ESD for colorectal LSTs only using the Dual knife from our experience.Material and methodsThis retrospective study included 162 patients (each patient had 1 lesion) with colorectal LSTs treated by ESD with the Dual knife by a single endoscopist at our hospital between June 2015 and January 2018. We analyzed the clinical features and outcomes after resection.ResultsWe obtained the en bloc ESD of the colorectal LSTs and the complete histological assessment in all patients. The mean age of the patients was 53.9 years. The mean diameter of lesions was 46 mm. The most common location of LSTs was the rectum. The most common histological type was tubular adenoma with 63 cases. The mean operating time was 56 min. Perforation and bleeding rates were 0.6% and 0.6%, respectively. No cases of local persistence or recurrence were observed at a follow-up endoscopy 6 to 31 months after the en bloc resection.ConclusionsThe ESD using the Dual knife only for colorectal LSTs has the advantages of safety, efficiency, and minimally invasiveness. It is worthy of widespread clinical application.

Clinicopathological feature and treatment outcome of patients with colorectal laterally spreading tumors treated by endoscopic submucosal dissection

Background/AimsEndoscopic submucosal dissection (ESD) is an advanced technique that can be used to treat precancerous and early colorectal neoplasms by facilitating en bloc resection regardless of tumor size. In our study, we investigated the clinicopathological feature and the treatment outcome of patients with colorectal laterally spreading tumors (LSTs) that were treated by ESD. MethodsThe study enrolled all of 210 patients with colorectal LSTs who underwent ESD. Clinical outcomes were analyzed by retrospectively reviewing medical records. ResultsA cancerous pit pattern (Vi/Vn) was more common in pseudo-depressed (PD) subtype than in flat elevated (FE) subtype. The incidence of adenocarcinoma in the PD subtype and nodular mixed (NM) subtypes was significantly higher than in the homogenous (HG) subtype and FE subtype. The en bloc and R0 resection rates were 89.0% and 85.7%, respectively. The bleeding and perforation rates were 5.2% and 1.9%, respectively. The mean procedure time was much longer in the PD subtype than in the FE subtype. The en bloc resection rate was significantly higher in the NM subtype than in the HG subtype. However, there were no statistically significant differences in mean procedure time, en bloc resection rate, R0 resection rate, bleeding rate, or perforation rate between LST-granular and LST-nongranular types. ConclusionsThese results indicate that ESD is acceptable for treating colorectal LSTs concerning en bloc resection, curative resection, and risk of complications. Careful consideration is required for complete resection of the PD subtype and NM subtype because of their higher malignant potential.

Risk factors for procedure-related complications after endoscopic resection of colorectal laterally spreading tumors.

Colorectal laterally spreading tumors (LSTs) are large and flat elevated neoplasms with diameters of at least 10 mm. Endoscopic resection of LSTs, with their large size and broad base, is difficult and dangerous compared with the resection of polypoid neoplasms. This study aimed to determine the risk factors for procedure-related complications including bleeding and perforation after endoscopic resection of LSTs.Patients with colorectal LST undergoing endoscopic resection at 5 university hospitals in Honam Province of South Korea were enrolled, and their records about patients, lesions, and procedure parameters associated with the occurrence of complications were reviewed retrospectively. Logistic regression analysis was performed to identify risk factors for complications.The frequency of comorbidities in bleeding group was significantly higher than in the no bleeding group. The frequency of bleeding was significantly higher in lesions with adenocarcinoma than in lesions with low or high-grade dysplasia. The frequency of bleeding was significantly higher in piecemeal resection than in en bloc resection. The frequency of perforation was significantly higher in endoscopic mucosal resection-precutting (EMR-P) than in endoscopic mucosal resection (EMR) or endoscopic submucosal dissection. The mean procedure duration was significantly longer in the perforation group than in the no perforation group. On multivariate analysis, patient comorbidity and histologic grade of the lesion were significant independent risk factors for bleeding, whereas EMR-P was a significant independent risk factor for perforation after endoscopic resection.This study demonstrated that patient comorbidity and histologic grade of lesion were significant independent risk factors for bleeding, and EMR-P was a significant independent risk factor for perforation after endoscopic resection of colorectal LSTs.