Endoscopic and surgical treatment of malignant colorectal polyps: a population-based comparative study

Lymphadenectomy Does Not Improve Cancer-Specific Survival for Colorectal Cancer Patients Underwent Endoscopic Therapy: A Population-Based Retrospective Study

METHODS

A total of 6626 patients with CRC who were initially referred for endoscopic polypectomy were enrolled from the Surveillance Epidemiology and End Results Database.

Results: Most enrolled patients (6557/6626, 99.0%) were at T0-T1 stage (American Joint Committee on Cancer staging system). Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were used to reduce selection bias, which resulted in balanced groups of patients with and without lymphadenectomy, with no difference in CSS (p = .99 and .074, respectively). In the subgroup analysis, insufficient lymphadenectomy (lymph node yield [LNY] < 12) was associated with poor CSS compared with no lymphadenectomy. The multivariate analysis identified adequate lymphadenectomy with an LNY ≥ 12 as an independent favorable prognostic factor. However, nearly half of the patients (59/127, 46.5%) referred for lymph node resection did not undergo adequate lymphadenectomy.

CONCLUSIONS

The prognosis of CSS cannot be improved by lymphadenectomy for most patients (T0-T1) who are referred for endoscopic therapy because of the low rate of lymph node metastasis. Nonetheless, adequate lymphadenectomy should be performed instead of diagnostic lymph node resection if lymph node involvement is suspected.

Factors affecting treatment decisions for endoscopically resected low- and high-risk malignant colorectal polyps in a screening setting

INTRODUCTION

The European Guidelines for colorectal cancer screening of 2006 state that only high-risk endoscopically resected malignant colorectal polyps (MCPs), defined as poor/no differentiation or positive resection margins or lymphovascular invasion, require colonic resection.

METHODS

A multicentre series of 954 patients with screen-detected MCP (northern Italy, 2005-2016, age 50-69) was studied to identify (1) the factors affecting the choice of colonic resection, and (2) the factors associated with deviation from the European Guidelines for low- and high-risk patients. Data analysis was based on multilevel logistic regression models.

RESULTS

Five hundred sixty-four (59.1 %) patients underwent colonic resection. The factors significantly associated with surgical referral included: distal and rectal versus proximal tumour site (inverse association); sessile and flat versus pedunculated morphology (direct association); tumour size (direct); moderate/poor versus good differentiation (direct); adenocarcinoma of not otherwise specified type versus adenocarcinoma with a residual adenoma component (direct); positive versus negative resection margins (direct); lymphovascular invasion (direct); and high-grade versus low-grade/absent tumour budding (direct). In low-risk MCPs, tumour budding encouraged strongly the decision for surgery. In high-risk MCPs, a distal/rectal tumour site encouraged the follow-up option.

CONCLUSION

The identification of factors associated with treatment choices other than those currently recommended may help prioritise the clinical questions in the development of future guidelines.

In comparison with polypectomy, colorectal resection is associated with improved survival for patients diagnosed with malignant polyps

AIM

Patients diagnosed with a malignant polyp generally have favourable overall survival (OS) and cancer-specific survival (CSS). However, it is unclear how choice in management for malignant polyps may affect survival.

METHODS

Data from the Queensland Oncology Repository was analysed to derive a population wide assessment of the impact of management strategy on OS and CSS for patients diagnosed with malignant polyps. Log-rank testing, Kaplan-Meier and Cox-regression models were performed. Patients were matched using propensity score and Mahalanobis distance matching.

RESULTS

A total of 1,646 patients were included with 240 deaths and 52 colorectal cancer related deaths until censor date. Following propensity score and Mahalanobis distance matching of patients undergoing polypectomy alone versus colorectal resection, there was no significant difference in the age groups (<60 years of age or ≥60 years of age), American Society of Anesthesiology score, comorbidity count or Association of ColoProctology of Great Britain and Ireland risk category. However, of note Log-rank testing demonstrated a significant difference in OS (p < 0.001) and CSS (p = 0.0061) between management strategies. Multivariable Cox-regression models in matched and un-matched patient cohorts demonstrated significantly lower hazards of death for OS with resection (p < 0.001). However, CSS was no longer significantly different between management groups in multivariable Cox-regression analysis (p = 0.073).

CONCLUSION

Patients who underwent colorectal resection had significantly improved OS and CSS compared with polypectomy alone. Improved OS was furthermore seen on multivariable analysis, and in matched cohorts. Future research should investigate why this unexpected finding may be the case and whether updates to guidelines should be considered.

Impact of Salvage Surgery following Colonic Endoscopic Polypectomy for Patients with Invasive Neoplasia

BACKGROUND

Invasive neoplasia (Tis-T1) are increasingly being encountered in the daily routine of endoscopic polypectomy. However, the need for salvage surgery following endoscopic therapy for invasive neoplasia is controversially discussed.

PATIENTS AND METHODS

Patients with endoscopic removal of invasive neoplasia were identified from the national Surveillance Epidemiology and End Results (SEER) Database 2005 to 2015. Survival analysis and Cox proportional hazard regression analysis in cancer-specific mortality and overall survival rate was used, which were stratified by T stage and polyp size.

RESULTS

A total of 5805 patients with endoscopic removal of invasive neoplasia were included in the analysis, of whom 1214 (20.9%) underwent endoscopic treatment alone and 4591 (79.1%) underwent endoscopic resection plus surgery. The survival analysis revealed that patients undergoing salvage surgery had a significantly better cancer-specific survival (97.4% vs. 95.8%, p-value = 0.017). In patients with T1 stage, additional salvage surgery led to a significantly higher cancer-specific survival (92.1% vs. 95.0%, p value = 0.047).

CONCLUSION

Salvage surgery following endoscopic polypectomy may improve the oncological survival of patients with invasive neoplasia, especially in patients with T1 stage. Furthermore, the T stage, size, and localization of polyps, as well as the level of CEA, could be identified as significant predictors for lymphonodal and distant metastases.

Colon Polypectomy with Endoscopic Submucosal Dissection and Endoscopic Full-Thickness Resection

Endoscopic resection has become the gold standard for the management of most of the large colorectal polyps. Various endoscopic resection techniques include endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and endoscopic full-thickness resection (EFTR). ESD is a minimally invasive method for the resection of advanced lesions in the gastrointestinal (GI) tract to achieve en-bloc resection. While, EFTR is more commonly used in lesions with suspected deeper submucosal invasion, lesions originating from muscularis propria, or those with advanced fibrosis. This article reviews the indications, technique, and adverse events for use of ESD and EFTR in the colon.

Colorectal Endoscopic Submucosal Dissection: An Update on Best Practice

Endoscopic submucosal dissection (ESD) is a method of en-bloc resection of neoplastic colorectal lesions which is less invasive compared to surgical resection. Lesion stratification, architecture recognition and estimation of depth of invasion are crucial for patient selection. Expert endoscopists have integrated a variety of classification systems including Paris, lateral spreading tumor (LST), narrow band imaging (NBI), international colorectal endoscopic (NICE) and Japanese NBI expert team (JNET) in their day-to-day practice to enhance lesion detection accuracy. Major societies recommend ESD for LST-non granular (NG), Kudo-VI type, large depressed and protruded colonic lesions with shallow submucosal invasion. Chance of submucosal invasion enhances with increased depth as well as tumor location and size. In comparison to endoscopic mucosal resection (EMR), ESD has a lowerl recurrence rate and higher curative resection rate, making it superior for larger colonic lesions management. Major complications such as bleeding and perforation could be seen in up to 11% and 16% of patients, respectively. In major Western countries, performing ESD is challenging due to limited number of expert providers, lack of insurance coverage, and unique patient characteristics such as higher BMI and higher percentage of previously manipulated lesions.

[Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer]

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Clinical practice guideline for endoscopic resection of early gastrointestinal cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Reappraisal of the characteristics, management, and prognosis of intramucosal colorectal cancers and their comparison with T1 carcinomas

BACKGROUND AND AIMS

The recent description of "invasive" forms of intramucosal carcinoma (IMC) has rekindled interest in studying the characteristics, management, and prognosis of IMCs and comparing them with T1 colorectal cancers (CRCs).

METHODS

This population-based study included 282 cases of IMC and 207 cases of T1 CRC diagnosed by colonoscopy after a positive fecal blood test through a screening program.

RESULTS

IMC presented mainly in the form of pedunculated polyps (68.4%) located in the distal colon (69.9%) ≥20 mm in size (60.6%). IMCs were resected endoscopically in 227 (80.5%) patients and surgically resected in 55 (19.5%) patients. Surgical patients had more right-sided, more sessile, and larger lesions. There was no sign of lymphovascular invasion. Compared with T1 CRCs, IMCs demonstrated lower rates of sessile polyps (31.6% vs 49.8%, P < .0001), primary and ultimate surgical treatment (19.5% vs 39.1% and 19.9% vs 78.7%, P < .0001, respectively), lymph node metastasis in surgical patients (0% vs 9.5%, P = .041), cancer recurrence and cancer-related mortality (0% vs 5.6% and 0% vs 2.5%, respectively), and bleeding after endoscopic resection (1.8% vs 8.7%, P = .001). By multivariate analysis of the pooled cohort (IMC + T1 CRC, n = 489), the factors significantly associated with first-line surgery were shown to be polyp characteristics and the gastroenterologist who performed the colonoscopy.

CONCLUSIONS

IMCs account for a quarter of all screening-detected CRCs. They have an excellent prognosis regardless of whether endoscopic or surgical treatment is performed. IMCs differ significantly from T1 carcinomas in terms of management and prognosis.

Long-term Outcomes of Primary Endoscopic Resection vs Surgery for T1 Colorectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

There is controversy over the best therapeutic approach for T1 colorectal cancer. We performed a systematic review and meta-analysis of long-term outcomes of endoscopic resection (ER) vs those of primary or additional surgery.

METHODS

We performed a systematic review of the PubMed, Embase, and Cochrane databases through October 2019 for studies that reported outcomes (overall survival, disease-specific survival, recurrence-free survival at 5 years, recurrence, and metastasis) of ER vs surgery in patients with colorectal neoplasms. Hazard ratios (HR) were calculated based on time to events.

RESULTS

In total, 17 published studies with 19,979 patients were included. The median follow-up time among the studies was 36 months. The meta-analysis found no significant differences between primary ER and primary surgery in overall survival (79.6% vs 82.1%, HR, 1.10; 95% CI, 0.84-1.45), recurrence-free survival (96.0% vs 96.7%, HR, 1.28; 95% CI, 0.87-1.88), or disease-specific survival (94.8% vs 96.5%; HR, 1.09; 95% CI, 0.67-1.78). Additional surgery and primary surgery did not produce significant differences in recurrence-free survival (HR, 1.27; 95% CI, 0.85-1.89). A significantly lower proportion of patients who underwent primary ER had procedure-related adverse events (2.3%) than patients who underwent primary surgery (10.9%) (P < .001). Lymphovascular invasion and rectal cancer, but not depth of submucosal invasion, were independently associated with recurrence for all T1 colorectal cancers.

CONCLUSIONS

In a systematic review and meta-analysis, we found that ER should be considered as the first-line treatment for endoscopically resectable T1 colorectal cancers. In cases of noncurative resection, additional surgery can have comparable outcomes to primary surgery.

Recurrence, death risk, and related factors in patients with stage 0 colorectal cancer: A nationwide population-based study

In this study, the National Health Insurance Research Database of Taiwan was used to examine the recurrence and death risk for stage 0 colorectal cancer patients. We examined stage 0 colorectal cancer patients to identify factors causing recurrence and death.This is a retrospective study, and stage 0 colorectal cancer patients that are registered in the Taiwan Cancer Registry of the Health Promotion Administration in 2007 to 2012 were included. The database was linked to the National Health Insurance Research Database, and subjects were followed up until the end of 2016. The mean follow-up period was 69 months. Bivariate analysis methods (log-rank test) and Cox proportional hazards model were used to evaluate the risk of recurrence and death and demographic characteristics, economic factors, environmental factors, health factors, treatment and hospitals, and absence/presence of postoperative tests were used to examine related risk factors.Our study showed that the 5-year recurrence rate and 5-year mortality rate for stage 0 colorectal cancer are 1.68% and 0.6%, respectively. For stage 0 colorectal cancer, age (61-74 years) is the only factor affecting recurrence in patients (hazard ratio (HR) = 2.44; 95% CI: 1.41-4.22), while age >75 years (HR = 4.35; 95% CI: 1.14-16.68) and Charlson Comorbidity Index >4 points (HR = 7.20, 95% CI: 2.60-19.94) can increase the risk of death. In contrast, patients who underwent one (HR = 0.27, 95% CI: 0.10-0.71) and two or more colonoscopies (HR = 0.26, 95% CI: 0.10-0.70) within 2 years after surgery can reduce the risk of death from stage 0 colorectal cancer. In addition, the risk of recurrence is higher in patients who underwent colonoscopic polypectomy (HR = 2.07, 95% CI: 0.98-4.33) and patients with rectal cancer (HR = 2.74, 95% CI: 0.96-7.83), but these differences are not statistically significant (P > .05).From this study, we can see that age and comorbidity index increase the risk of recurrence and death for stage 0 colorectal cancer, while postoperative colonoscopy can decrease the risk of death.

Management of T1 colorectal cancers detected at screening colonoscopy: A study from the French national screening programme

AIM

The main aim of this study was to examine the management strategies that were used and to determine the outcomes (survival and recurrence rate) of screen-detected T1-CRC.

METHODS

Medical records from 207 patients with T1-CRC diagnosed through the French national screening programme in one district from 2003 to 2015 were analysed. The 5-year overall, CRC-specific and CRC-free survival were calculated for the whole cohort and for the 3 groups treated by endoscopic resection (ER) alone, ER followed by subsequent surgery (ERSS), and primary surgery (PS).

RESULTS

Of the 207 patients, 81 (39%) underwent PS, and 126 (61%) underwent primary ER, of whom 82 (64%) underwent subsequent surgery. The 5-year overall and cancer-specific survival rates were 95.5% (95% CI, 90.8; 97.9) and 98.8% (95% CI, 95.4; 99.7%), respectively. Long-term cancer-specific mortality and recurrence crude rates were 2.4% and 5.6%, respectively. The 5-year CRC-free survival rate was 96.1% (95% CI, 91.8; 98.1%) and did not differ amongst the 3 groups (ER alone, ERSS and PS).

CONCLUSION

This study demonstrates the good prognosis of screen-detected T1-CRC, regardless of the treatment strategy used. But, there is a room to improve the screening programme quality with regard to the management of screen-detected CRC.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by <i>en bloc</i> fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Outcomes following polypectomy for malignant colorectal polyps are similar to those following surgery in the general population

OBJECTIVE

Population-based studies on colorectal malignant polyps (MPs) are scarce. The aim of this study was to describe time trends in the incidence of colorectal MPs before and after the introduction of a colorectal mass-screening programmein 2003 and to assess outcomes (survival and recurrence) after endoscopic or surgical resection in patients with MPs.

DESIGN

We included 411 patients with MPs diagnosed between 1982 and 2011 in a well-defined population. Age-standardised incidence rates were calculated. Univariate and multivariate 5-year recurrence and net survival analyses were performed according to gross morphology.

RESULTS

Age-standardised incidence of MPs in patients aged 50-74 years doubled from 5.4 in 1982-2002 to 10.9 per 100 000 in 2003-2011. Pedunculated MPs were more frequently resected endoscopically (38.2%) than were sessile MPs (19.1%; p<0.001). For patients with pedunculated MPs and a pathological margin ≥1 mm, the 5 -year cumulative recurrence rate did not differ significantly between surgical and endoscopic resection (8.2% and 2.4%, respectively). For patients with sessile MPs, it was 3.0% after first-line or second-line surgical resection, 8.6% after endoscopic resection and 17.9% after transanal resection (p=0.016). The recurrence rate decreased dramatically for patients with sessile MPs from 11.3% (1982-2002) to 1.2% (2003-2009) (p=0.010) and remained stable for pedunculated MPs at 4.6% and 6.7%, respectively. Five-year net survival was 81.0% when pathological margins were <1 mm and 95.6% when ≥1 mm (p=0.024).

CONCLUSION

Outcomes following polypectomy in patients with a pathological margin ≥1 mm are similar to those following surgery in the general population. Endoscopic resection needs to be completed by surgery if pathological margins are less than 1 mm.

Polypectomy versus surgery in early colon cancer: size and location of colon cancer affect long-term survival

BACKGROUND AND AIMS

The colon cancer survival rate is significantly affected by location, stage, and size of the cancer. Polypectomy was shown be as equally effective as surgery in early-stage colon cancer, but there have been no established clinical guidelines in the management of colon cancer based on the size of the polyp or the tumor location. The aim of our study was to assess the early-stage colon cancer-specific survival rate in patients who underwent endoscopic polypectomy versus surgery, based on size and location of tumor in early-stage colon cancer.

METHODS

This is a population-based nationwide study in the USA.

RESULTS

Of 13,157 patients, 15.5% underwent endoscopic treatment and 84.5% underwent surgical therapy. For early cancer tumors located in the left colon, polypectomy yielded comparable 5-year survivals to surgery irrespective of size of the tumors. Five-year early cancer-specific survivals were similar for tumors located in the right colon that were < 20 mm in size (94.5 vs 94.3%, p value = 0.94). However, tumors > 20 mm in size that were located in the right colon had better survivals when treated surgically compared to those treated with polypectomy (20-39 mm: 91.8 vs 74.2%; ≥ 40 mm: 92.4 vs 60%, both p values < 0.01). Similar results were obtained on propensity score analysis.

CONCLUSIONS

Polypectomy was as effective as surgical therapy for small tumors. For larger tumors, surgical therapy is better than polypectomy for right-sided tumors, but both are equally effective for left-sided tumors.

Colorectal endoscopic mucosal resection (EMR)

Colonoscopy has the benefit of detecting and treating precancerous adenomatous polyps and thus reduces mortality associated with CRC. Screening colonoscopy is the keystone for prevention of colorectal cancer. Over the last 20 years there has been increased in the management of large colorectal polyps from surgery to endoscopic removal techniques which is less invasive. Traditionally surgical resection was the treatment of choice for many years for larger polyps but colectomy poses significant morbidity of 14-46% and mortality of up to 7%. There are several advantages of endoscopic resection technique over surgery; it is less invasive, less expensive, has rapid recovery, and preserves the normal gut functions. In addition patient satisfaction and efficacy of EMR is higher with minor complications. Thus, this has facilitated the development of advanced resection technique for the treatment of large colorectal polyps called as endoscopic mucosal resection (EMR).

Recent Advances in Endoscopy

In this narrative review, invited by the Editors of Gastroenterology, we summarize recent advances in the field of gastrointestinal endoscopy. We have chosen articles published primarily in the past 2-3 years. Although a thorough literature review was performed for each topic, the nature of the article is subjective and systematic and is based on the authors' experience and expertise regarding articles we believed were most likely to be of high clinical and scientific importance.

Efficacy and safety of endoscopic submucosal dissection for superficial colorectal tumors more than 50 mm in diameter

BACKGROUND AND AIMS

The feasibility of endoscopic submucosal dissection (ESD) for large superficial colorectal tumors is undefined. The aim of this study was to assess the outcomes for patients undergoing ESD of superficial colorectal tumors larger than 50 mm.

METHODS

A total of 472 patients who underwent ESD for superficial colorectal tumors from 2010 to 2014 were enrolled. We retrospectively reviewed their records.

RESULTS

We compared patients with 20-mm to 50-mm lesions and those with lesions >50 mm regarding demographics, the ESD procedure, and histopathology. Among patients with lesions >50 mm, laterally spreading tumors nongranular and protruded types were uncommon. Histopathologically, deeply invasive (≥1000 μm) submucosal carcinomas were more frequent in lesions >50 mm (14% [10/70] vs 5% [20/402], P < .01). Technically, en bloc resection was successfully accomplished in 99% of patients (69/70). Although the total dissection time for lesions >50 mm was significantly longer than for lesions 20 mm to 50 mm (mean ± SD, 157 ± 114 minutes vs 68 ± 50 min; P < .01), dissection speed for lesions >50 mm was significantly faster than for lesions 20 mm to 50 mm (P < .01). There were no significant differences in en bloc R0 resection rate comparing both groups (>50 mm, 83% vs 20 mm to 50 mm, 87%; P = .31). No perforations or postoperative bleeding occurred in patients with lesions >50 mm. Post-ESD colorectal strictures requiring intervention did not develop in any patient.

CONCLUSIONS

ESD for superficial colorectal tumors >50 mm is feasible. ESD of these lesions had a high R0 resection rate and a low adverse event rate. En bloc resection by ESD provides adequate pathological specimens and may limit the need for surgical intervention.