Novel risk stratification for recurrence after endoscopic resection of advanced colorectal adenoma

New Model to Predict Recurrence After Endoscopic Mucosal Resection of Non-pedunculated Colonic Polyps ≥ 20 mm

BACKGROUND

Polyp recurrence is common after endoscopic mucosal resection (EMR) of non-pedunculated colonic polyps ≥ 20 mm. Two models haven been published for polyp recurrence prediction: Sydney EMR recurrence tool (SERT) and the size, morphology, colonic site, and access to target (SMSA) score. None of these models have been evaluated in a real-world United States (U.S.) cohort. We aimed to evaluate the external validity of these two models and develop a new model.

METHODS

Retrospective cohort study of patients with non-pedunculated polyps ≥ 20 mm that underwent EMR between 1/1/2012 and 6/30/2020. Univariate and multivariate analysis were performed to identify predictors of polyp recurrence to build a new model. Receiver Operating Characteristic (ROC) curves for the new model, SERT and a modified version of SMSA were derived and compared.

RESULTS

A total of 461 polyps from 461 unique patients were included for analysis. The average polyp size was 29.1 ± 12.4 mm. Recurrence rate at first or second surveillance colonoscopy was 29.0% at a 15.6 months median follow up (IQR 12.3-17.4). A model was created with 4 variables from index colonoscopy: size > 40 mm, tubulovillous adenoma histology, right colon location and piecemeal resection. ROC curves showed that the Area Under the ROC (AUC) for the new model was 0.618, for SERT 0.538 and for mSMSA 0.550.

CONCLUSION

SERT score and mSMSA have poor external validity to predict polyp recurrence after EMR of non-pedunculated polyps > 20 mm. Our new model is simpler and performs better in this multiethnic, non-referral cohort from the U.S.

A Comparison of Risk Classification Systems of Colorectal Adenomas: A Case-Cohort Study

BACKGROUND & AIMS

Because post-polypectomy surveillance uses a growing proportion of colonoscopy capacity, more targeted surveillance is warranted. We therefore compared surveillance burden and cancer detection using 3 different adenoma classification systems.

METHODS

In a case-cohort study among individuals who had adenomas removed between 1993 and 2007, we included 675 individuals with colorectal cancer (cases) diagnosed a median of 5.6 years after adenoma removal and 906 randomly selected individuals (subcohort). We compared colorectal cancer incidence among high- and low-risk individuals defined according to the traditional (high-risk: diameter ≥10 mm, high-grade dysplasia, villous growth pattern, or 3 or more adenomas), European Society of Gastrointestinal Endoscopy (ESGE) 2020 (high-risk: diameter ≥10 mm, high-grade dysplasia, or 5 or more adenomas), and novel (high-risk: diameter ≥20 mm or high-grade dysplasia) classification systems. For the different classification systems, we calculated the number of individuals recommended frequent surveillance colonoscopy and estimated number of delayed cancer diagnoses.

RESULTS

Four hundred and thirty individuals with adenomas (52.7%) were high risk based on the traditional classification, 369 (45.2%) were high risk based on the ESGE 2020 classification, and 220 (27.0%) were high risk based on the novel classification. Using the traditional, ESGE 2020, and novel classifications, the colorectal cancer incidences per 100,000 person-years were 479, 552, and 690 among high-risk individuals, and 123, 124, and 179 among low-risk individuals, respectively. Compared with the traditional classification, the number of individuals who needed frequent surveillance was reduced by 13.9% and 44.2%, respectively, and 1 (3.4%) and 7 (24.1%) cancer diagnoses were delayed using the ESGE 2020 and novel classifications.

CONCLUSIONS

Using the ESGE 2020 and novel risk classifications will substantially reduce resources needed for colonoscopy surveillance after adenoma removal.

Evolution of endoscopic mucosal resection (EMR) technique and the reduced recurrence of large colonic polyps from 2012 to 2020

BACKGROUND

Endoscopic mucosal resection (EMR) is an effective method for removing non-pedunculated polyps ≥ 20 mm. We aimed to examine changes in EMR techniques over a 9-year period and evaluate frequency of histologic-confirmed recurrence.

METHODS

We identified patients who underwent EMR of non-pedunculated polyps ≥ 20 mm at a safety net and the Veteran's Affairs (VA) hospital in Houston, Texas between 2012 and 2020. Odds ratios (ORs) and 95% confidence intervals (CI) for associations with recurrence risk were estimated using multivariable logistic regression.

RESULTS

461 unique patients were included. The histologic-confirmed recurrence was 29.0% at 15.6 months median follow up (IQR 12.3 - 17.4). Polyps removed between 2018 and 2020 had a 0.43 decreased odds of recurrence vs. polyps removed between 2012 and 2014. The use of viscous lifting agents increased over time (from 0 to 54%), and the use of saline was associated with increased risk of recurrence (OR 2.28 [CI 1.33 - 3.31]).

CONCLUSIONS

Histologic-confirmed recurrence after EMR for non-pedunculated polyps ≥ 20 mm decreased over the seven year-period. Saline was associated with a higher risk of recurrence and the use of more viscous agents increased over time.

Risk Factors for High-Risk Adenoma on the First Lifetime Colonoscopy Using Decision Tree Method: A Cross-Sectional Study in 6,047 Asymptomatic Koreans

Background/Aims: As risk of colorectal neoplasm is varied even in persons with “average-risk,” risk evaluation and tailored screening are needed. This study aimed to evaluate the risk factors of high-risk adenoma (HRA) in healthy individuals and determine the characteristics of advanced neoplasia (AN) among individual polyps.

Methods: Asymptomatic adults who underwent the first lifetime screening colonoscopy at the Seoul National University Hospital Healthcare System Gangnam Center (SNUH GC) were recruited from 2004 to 2007 as SNUH GC Cohort and were followed for 10 years. Demographic and clinical characteristics were compared between the subjects with and without AN (≥10 mm in size, villous component, and/or high-grade dysplasia and/or cancer) or HRA (AN and/or 3 or more adenomas). For individual polyps, correlations between clinical or endoscopic features and histologic grades were evaluated using a decision tree method.

Results: A total of 6,047 subjects were included and 5,621 polyps were found in 2,604 (43%) subjects. Advanced age, male sex, and current smoking status were statistically significant with regards to AN and HRA. A lower incidence of AN was observed in subjects taking aspirin. In the decision tree model, the location, shape, and size of the polyp, and sex of the subject were key predictors of the pathologic type. A weak but significant association was observed between the prediction of the final tree and the histological grouping (Kendall's tau-c = 0.142, p < 0001).

Conclusions: Advanced neoplasia and HRA can be predicted using several individual characteristics and decision tree models.

Child-Pugh B or C Cirrhosis Increases the Risk for Bleeding Following Colonoscopic Polypectomy

Background/Aims

The risk for colonoscopic postpolypectomy bleeding (PPB) in patients with chronic liver disease (CLD) remains unclear. We determined the incidence and risk factors for colonoscopic PPB in patients with CLD, especially those with liver cirrhosis.

Methods

We retrospectively reviewed the medical records of patients with CLD who underwent colonoscopic polypectomy at Seoul National University Hospital between 2011 and 2014. The study endpoints were immediate and delayed PPB.

Results

A total of 1,267 consecutive patients with CLD were included in the study. Immediate PPB occurred significantly more often in the Child-Pugh (CP) B or C cirrhosis group (17.5%) than in the CP-A (6.3%) and chronic hepatitis (4.6%) groups (p<0.001). Moreover, the incidence of delayed PPB in the CP-B or C cirrhosis group (4.4%) was significantly higher than that in the CP-A (0.7%) and chronic hepatitis (0.2%) groups (p<0.001). The independent risk factors for immediate PPB were CP-B or C cirrhosis (p=0.011), a platelet count <50,000/μL (p<0.001), 3 or more polyps (p=0.017), endoscopic mucosal resection or submucosal dissection (p<0.001), and polypectomy performed by trainees (p<0.001). The independent risk factors for delayed PPB were CP-B or C cirrhosis (p=0.009), and polyps >10 mm in size (p=0.010).

Conclusions

Patients with CP-B or C cirrhosis had an increased risk for bleeding following colonoscopic polypectomy.

Incidence of microscopic residual adenoma after complete wide-field endoscopic resection of large colorectal lesions: evidence for a mechanism of recurrence

BACKGROUND AND AIMS

EMR of large (≥2 cm) nonpedunculated colorectal polyps (LNPCPs) is associated with high rates of recurrent/residual adenoma, possibly because of microadenoma left at the margin of resection. Data supporting this mechanism are required. We aimed to determine the incidence of residual microadenoma at the defect margin and base after EMR.

METHODS

We performed a retrospective observational study of patients undergoing EMR of large LNPCPs with the lateral defect margin further resected using the EndoRotor device (Interscope Medical, Inc, Worcester, Mass, USA) after confirming no visible residual adenomatous tissue. Aspects of the defect base were also resected in selected patients. Patients underwent surveillance at 3 to 6 months.

RESULTS

Resection of the normal defect margin was performed in 41 patients and of aspects of the base in 21 patients. Mean lesion size was 43.0 mm (range, 20-130). Microscopic residual lesion was detected in the margin of apparently normal mucosa in 8 cases (19%). In 7 cases this was an adenoma, and in 1 case a serrated lesion was found at the margin of a resected tubular adenoma. Microscopic residual lesion was detected at the base in 5 of 21 cases. Residual/recurrent adenoma was detected in 2 patients. Neither had residual microadenoma at the lateral margin or base detected after the primary resection.

CONCLUSIONS

Microscopic residual adenoma after wide-field EMR was detected in 19% of cases at the apparently normal defect margin and at the resection base in 5 of 21 cases. This study confirms the presence of residual microadenoma after resection of LNPCPs, providing evidence for the mechanism of recurrence.

Outcomes Of Patients with Delayed Surveillance Colonoscopy

BACKGROUND

Surveillance colonoscopy has been shown to be an effective tool for prevention of CRC in high-risk populations, if adhered to. We aimed to discover the sequelae of late surveillance in a cohort of patient's overdue for colonoscopy, in particular the development of colorectal cancer (CRC) or advanced adenoma (AA) within surveillance subgroups.

METHOD

We conducted a retrospective cohort study on all patients from the Bay of Plenty District Health Board region, New Zealand, placed on the colonoscopy surveillance waitlist from 2006 onwards who had their procedure completed between 1 November 2016 and 31 January 2018, when the total surveillance list was declared up-to-date. Patients with overdue surveillance, defined as done later than 90 days after the recommended due date were compared to patients who were done either early, or on time.

RESULTS

786 patients were recorded as overdue for surveillance colonoscopy, and 386 were completed early or on time. The median time overdue was 22 months. Three cases (0.4%) of CRC were found in overdue patients compared to 4 cases (1%) for those done on time (adjusted p=0.24). There were 86 (11%) AA in patient's overdue compared to 27 (7%) in those not overdue (odds ratio (OR) 1.6, 95% confidence interval (CI) [1.0,2.5], p=0.04). Overdue status increased the expected risk of AA by approximately 60% (adjusted; 95% CI [1%,253%], p=0.04) or 19% per year overdue (95% CI [7%,32%], p=0.002). Surveillance of 248 low-risk post-polypectomy patients demonstrated 26/211 with AA in overdue patients compared to 2/37 (12.3% vs 5.4%, unadjusted p=0.23) for those done on time. Surveillance of 180 high-risk post-polypectomy patients identified 2 CRC's and 8/43 AA in those overdue, as compared to no CRC and 9/137 AA (18.6% vs 6.6%, OR 1.79 (95% CI [1.07,2.0], unadjusted p=0.03) in those done on time.

CONCLUSION

Whilst overdue surveillance is not predictive of increased CRC, it is associated with an increase in expected number of AA, particularly in patients having surveillance for previous high-risk polypectomy. This article is protected by copyright. All rights reserved.

Cap-fitted endoscopic mucosal resection of ≥ 20 mm colon flat lesions followed by argon plasma coagulation results in a low adenoma recurrence rate

Background and study aims  Endoscopic mucosal resection (EMR) is increasingly used for the treatment of large colonic polyps (≥ 20 mm). A drawback of EMR is local adenoma recurrence. Therefore, we studied the impact of argon plasma coagulation (APC) of the EMR edge on local adenoma recurrence. Patients and methods  This was a retrospective study of patients with laterally spreading tumors (LST) ≥ 20 mm, who underwent EMR from January 2009 to August 2018 and follow-up endoscopic assessment. A cap-fitted endoscope was used to assess completeness of resection by systematically inspecting the EMR defect for any macroscopic disease. This was followed by forced APC of the resection edge followed by clip closure of the defect. Surveillance colonoscopy was performed at 6 months after resection to detect recurrence. Results  Two hundred forty-six patients met the inclusion criteria. Most were female (53 %) and white (80 %), with a Median age of 64 years. Median polyp size was 35 mm (interquartile range, 30-45 mm). Most polyps were located in the right colon (77 %) and were removed by piecemeal EMR (70 %). Eleven patients (5 %) had residual tumor at the resection site. Conclusions  We observed low adenoma recurrence after argon plasma coagulation of the EMR edge with a cap fitted colonoscope in patients with LST ≥ 20 mm of the colon, which requires further validation in a randomized controlled study.

Suppressive effects of metformin on colorectal adenoma incidence and malignant progression

BACKGROUND

The linear progression from normal colonic epithelium to adenoma initiation, carcinoma transformation and metastasis is considered the classical model of colorectal cancer (CRC) development. Although metformin has been extensively reported to be negatively related to cancer incidence, the effect of metformin on CRC development remains unclear. We aimed to evaluate the role of metformin in the entire CRC linear progression.

METHODS

Systematic searches and data extraction were performed in the PubMed, Embase, and Cochrane Library databases on Jan 31, 2019. The combined relative ratios (RRs) of colorectal tumor incidence and the hazard ratios (HRs) of overall survival (OS) and cancer-specific survival (CSS) were evaluated by a random-effects model. Then, the effects of metformin were further assessed through stratified analyses by population, medication duration and dosage, dose-response analysis and comparison with other antidiabetic agents.

RESULTS

A total of 50 studies consisting of 238,540 cases of diabetes mellitus (DM) were included in this study. Metformin use was negatively associated with the incidence of colorectal adenoma (RR: 0.75, 95% CI: 0.65-0.86) and CRC (RR: 0.73, 95% CI: 0.58-0.90). Moreover, CRC patients benefited from metformin in terms of both OS (HR: 0.73, 95% Cl: 0.63-0.84) and CSS (HR: 0.60, 95% Cl: 0.50-0.73). Stratified analyses suggested that a long duration of high-dose metformin (RR: 0.52, 95% Cl: 0.36-0.83) was more effective than a short duration in Asian populations against colorectal adenoma (RR: 0.66, 95% Cl: 056-0.70) and CRC (RR: 0.45, 95% Cl: 0.29-0.70). Interestingly, metformin use decreased CRC risk in a dose-dependent manner (RR: 0.91, 95% CI: 0.87-0.95). In addition, the benefit of metformin on CRC was more significant than that of other antidiabetic agents, including insulin.

CONCLUSIONS

The use of metformin is associated with a lower incidence of adenoma and CRC and a better prognosis, especially in Asian populations.

Thermal Ablation of Mucosal Defect Margins Reduces Adenoma Recurrence After Colonic Endoscopic Mucosal Resection

BACKGROUND & AIMS

Colorectal cancer (CRC) can be prevented by colonoscopy and polypectomy. Endoscopic mucosal resection (EMR) is performed to remove large laterally spreading colonic lesions that have a high risk of progression to CRC. Endoscopically invisible micro-adenomas at the margins of the EMR site might contribute to adenoma recurrence, which occurs in 15% to 30% of patients who undergo surveillance. We aimed to determine the efficacy of adjuvant thermal ablation of the EMR mucosal defect margin in reducing polyp recurrence.

METHODS

We performed a prospective study of 390 patients with large laterally spreading colonic lesions (≥ 20 mm, n = 416) referred for EMR at 4 tertiary centers in Australia. After complete lesion excision by EMR, lesions were randomly assigned to thermal ablation of the post-EMR mucosal defect margin (n = 210) or no additional treatment (controls, n = 206). We performed surveillance colonoscopies with standardized photo documentation and biopsies of the scar after 5 to 6 months. Patient, procedure, and lesion characteristics were similar between the groups. The primary endpoint was detection of lesion recurrence at first surveillance colonoscopy.

RESULTS

A significantly lower proportion of patients who received thermal ablation of the post-EMR mucosal defect margin had evidence of recurrence at first surveillance colonoscopy (10/192, 5.2%) than controls (37/176, 21.0%) (P < .001). The relative risk of recurrence in the thermal ablation group was 0.25 compared with the control group (95% confidence interval 0.13-0.48). Rates of adverse events were similar between the groups.

CONCLUSIONS

In a multicenter randomized trial, thermal ablation of the post-EMR mucosal defect margin significantly reduced polyp recurrence at first surveillance colonoscopy, compared with no additional treatment. Routine implementation of this simple and safe technique could increase the utility of EMR, decrease surveillance burdens, and reduce morbidity and mortality from CRC. ClinicalTrials.gov no: NCT01789749.

Number of advanced adenomas on index colonoscopy: Important risk factor for metachronous advanced colorectal neoplasia

BACKGROUND/AIMS

Although the patients with multiple advanced adenomas (AA) in index colonoscopy may have an increased risk for subsequent advanced colorectal neoplasia (CRN), the current guidelines do not consider this factor. We aimed to compare the risk of metachronous advanced CRN according to the number of AAs.

METHODS

A total of 2250 patients with ≥1 adenoma at index colonoscopy were included. The patients were divided according to the number of AAs (1, 2 and ≥3 AAs). The relative and 3-year absolute risk of metachronous advanced CRN was compared between the AA groups.

RESULTS

The relative risk of metachronous advanced CRN was higher in the patients with ≥3 AAs than in the patients with one AA (16.7% vs. 6.8%, p = 0.004). The 3-year absolute risk of metachronous advanced CRN was higher in the patients with ≥3 AAs than in the patients with 1-2 AA (19.4% vs. 6.9%, p = 0.04). Having ≥3 AAs (odds ratio, 5.42; 95% confidence interval 1.75-16.83) was a significant risk factor for developing advanced CRN.

CONCLUSIONS

The risk of metachronous advanced CRN in the patients with ≥3 AAs was higher than that in the patients with one or two AAs. More intensive surveillances might be needed for these patient groups.

Long-term Outcome of Small, Incidentally Detected Rectal Neuroendocrine Tumors Removed by Simple Excisional Biopsy Compared With the Advanced Endoscopic Resection During Screening Colonoscopy

BACKGROUND

Incidental, small rectal neuroendocrine tumors during colonoscopy screening are sometimes removed using biopsy forceps. Few studies have examined the clinical course of rectal neuroendocrine tumors removed by simple excisional biopsy.

OBJECTIVE

We investigated the long-term outcome of rectal neuroendocrine tumors removed by simple excisional biopsy compared with standard endoscopic resection.

DESIGN

This was a cohort study.

SETTINGS

This study was performed at a healthcare center in Korea.

PATIENTS

We enrolled patients with rectal neuroendocrine tumors detected during a screening colonoscopy between 2003 and 2015.

MAIN OUTCOME MEASURES

The clinical characteristics and long-term outcomes (overall survival and disease-free survival) of small neuroendocrine tumors <10 mm were compared between the simple excisional biopsy group and advanced endoscopic resection group.

RESULTS

In total, 166 patients were diagnosed with rectal neuroendocrine tumors (≤5 mm, n = 100; 6-9 mm, n = 50; 10-19 mm, n = 15; ≥20 mm, n = 1). Among the 150 patients with neuroendocrine tumors <10 mm, follow-up endoscopy was performed on 99 (59.6%). All of the tumors were confined to the mucosa or submucosa. Thirty-one and 68 patients were included in the simple excisional biopsy and advanced endoscopic resection groups. The overall follow-up duration was 6.5 years (range, 1.0-12.8 y). Neither overall nor disease-related death occurred. Two patients exhibited local recurrence (6.5%, at 8 and 11 y) in the simple excisional biopsy group and 1 patient (1.5%, at 7 y) in the advanced endoscopic resection group, resulting in no significant difference (p = 0.37). All of the recurrences were diagnosed >5 years from initial diagnosis and successfully treated endoscopically.

LIMITATIONS

More long-term data should be warranted.

CONCLUSIONS

The long-term outcome of small rectal neuroendocrine tumors <10 mm removed by simple excisional biopsy was excellent. Neither overall survival nor disease-free survival significantly differed between the simple excisional biopsy group and the advanced endoscopic resection group. Thus, simple excisional biopsy and long-term follow-up can be cautiously applied for small rectal neuroendocrine tumors in clinical practice. See Video Abstract at http://links.lww.com/DCR/A406.

Optimal colonoscopy surveillance interval period for the adenoma patients who had an adequate polypectomy at baseline colonoscopy

The role of surveillance colonoscopy has long been established: it reduces both the incidence and the mortality of colorectal cancer. We aimed to assess the optimal colonoscopy surveillance interval period for the adenoma patients who underwent an adequate polypectomy at baseline colonoscopy to avoid overuse or underuse of colonoscopy. A retrospective study was carried out on the baseline adenoma patients who had had at least two completed colonoscopy examinations during the years 2000-2013 in the Digestive Endoscopy Center of the First Affiliated Hospital of Kunming Medical University. All the patients had a complete polypectomy of adenomas at baseline. Data on the patients' demographics and colorectal findings were extracted from a specially designed colonoscopy database. The end point was the finding of adenoma during the subsequent surveillance colonoscopy; an analysis was carried out to identify recurrence factors and the optimal colonoscopy surveillance interval period. A total of 765 (463 men, 302 women, average age 56.51±11.95) eligible patients were included in the study. Three hundred and twelve patients had adenoma and 453 had no adenoma after surveillance colonoscopies (the frequency of repeat colonoscopy is 1-10, average 1.73±1.24). The diameter of adenomas found on the follow-up colonoscopy was 0.2-3.0 cm (average 0.54±0.30 cm). The number of adenomas was 1-11 (2.21±1.53) and the surveillance adenoma interval period was 0.5-13 years (2.64±2.36 years). A total of 576 patients had baseline nonadvanced adenomas. Male sex, age older than 50 years, and more than two different intestine segment adenomas were the risk factors for recurrence. The optimal colonoscopy surveillance interval period is 2.85 years (95% confidence interval: 2.53-3.17) according to the recurrence rate of 5% adenomas. One hundred and eighty-nine patients had baseline advanced adenomas. Male sex, diameter of adenomas less than 1.0 cm, and adenomas in the right colon or the whole colon were the risk factors for recurrence. The optimal colonoscopy surveillance interval period is 2.06 years (95% confidence interval: 1.71-2.45) according to the recurrence rate of 5% adenomas. The optimal colonoscopy surveillance interval period is 3 years or so for the adenoma patients who had an adequate polypectomy at baseline colonoscopy. Male sex, age older than 50 years, less than 1.0 cm adenomas diameter and the right colon, or multisegment intestine adenomas were the risk factors for recurrence. This has significance for guiding the follow-up colonoscopy interval time of the patients with intestine adenomas.

Three-year colonoscopy surveillance after polypectomy in Korea: a Korean Association for the Study of Intestinal Diseases (KASID) multicenter prospective study

Background/Aims

Colonoscopic surveillance is currently recommended after polypectomy owing to the risk of newly developed colonic neoplasia. However, few studies have investigated colonoscopy surveillance in Asia. This multicenter and prospective study was undertaken to assess the incidence of advanced adenoma based on baseline adenoma findings at 3 years after colonoscopic polypectomy.

Methods

A total of 1,323 patients undergoing colonoscopic polypectomy were prospectively assigned to 3-year colonoscopy surveillance at 11 tertiary endoscopic centers. Relative risks for advanced adenoma after 3 years were calculated according to baseline adenoma characteristics.

Results

Among 1,323 patients enrolled, 387 patients (29.3%) were followed up, and the mean follow-up interval was 31.0±9.8 months. The percentage of patients with advanced adenoma on baseline colonoscopy was higher in the surveillance group compared to the non-surveillance group (34.4% vs. 25.7%). Advanced adenoma recurrence was observed in 17 patients (4.4%) at follow-up. The risk of advanced adenoma recurrence was 2 times greater in patients with baseline advanced adenoma than in those with baseline non-advanced adenoma, though the difference was not statistically significant (6.8% [9/133] vs. 3.1% [8/254], P=0.09). Advanced adenoma recurrence was observed only in males and in subjects aged ≥50 years. In contrast, adenoma recurrence was observed in 187 patients (48.3%) at follow-up. Male sex, older age (≥50 years), and multiple adenomas (≥3) at baseline were independent risk factors for adenoma recurrence.

Conclusions

A colonoscopy surveillance interval of 3 years in patients with baseline advanced adenoma can be considered appropriate.

Local Recurrence and Its Risk Factor after Incomplete Resection of Colorectal Advanced Adenomas: A Single Center, Retrospective Study

Background/Aims

Colonoscopy can detect precancerous lesions, which can subsequently be removed and reduce incidences of and mortality from colorectal cancer (CRC). However, recently published data have highlighted a significant rate of CRC in patients who previously underwent colonoscopy. Among many reasons, incomplete resection has been considered as a significant contributor. However, to date, there have only been a few studies regarding incompletely resected polyps, especially advanced colorectal adenoma (ACA). Hence, we aimed to evaluate the prognosis of incompletely resected ACA.

Methods

We retrospectively reviewed the medical records of patients with ACA who had underwent endoscopic treatment with incomplete resection. The primary outcomes were (1) the incomplete resection rate of ACA, as determined by a histopathologic examination and (2) the recurrence rate of incompletely resected ACA. We also investigated the probable contributing factors that may have led to a relapse of incompletely resected ACA.

Results

A total of 7,105 patients had their colorectal polyps resected by endoscopic treatment, and 2,233 of these were considered as ACA. Of these, 354 polyps (15.8%) were resected incompletely, and only 163 patients were followed-up. Of those followed-up, 31 patients (19.0%) experienced local recurrence. The risk factors for recurrence after incomplete resection were evaluated; age, morphology of adenoma, and use of rescue therapy, such as argon plasma coagulation, were found to be associated with adenoma recurrence.

Conclusions

Incompletely resected ACA in older patients or in patients with sessile-type adenomas should be monitored strictly, and if incomplete resection is suspected, rescue therapy must be considered.

Risk factors of nonadherence to colonoscopy surveillance after polypectomy and its impact on clinical outcomes: a KASID multicenter study

BACKGROUND

An optimal surveillance program is important to prevent advanced colorectal neoplasm. In this context, we have evaluated the cumulative risk of high-risk adenoma (HRA) or colorectal cancer (CRC) according to surveillance interval time after polypectomy. In addition, we assessed risk factors for late surveillance to determine whether late surveillance can impact the risk of subsequent advanced colorectal neoplasm.

METHODS

This was a multicenter retrospective cohort study involving 3562 subjects who had undergone removal of at least one adenoma at the index colonoscopy and who subsequently underwent a surveillance colonoscopy. The subjects were classified into an early, appropriate or late group depending on the timing of the surveillance colonoscopy, performed using modified U.S.

RESULTS

With 3% of the study population with LRA and HRA at the index colonoscopy going on to develop HRA or CRC, the estimated surveillance intervals calculated would be 6.3 [95% confidence interval (CI) 5.42-7.10] years and 3.1 (95% CI 2.61-4.45) years, respectively. The predictors of late surveillance were female gender [odd ratio (OR) 1.21; 95% CI 1.04-1.40], having undergone the procedure in small-to-medium-sized cities (OR 1.92; 95% CI 1.36-2.72) and HRA at index colonoscopy (OR 1.37; 95% CI 1.19-1.59). The risk factors for subsequent HRA or CRC were late surveillance (OR 1.34; 95% CI 1.03-1.74), male gender (OR 2.13; 95% CI 1.54-2.95), having undergone the procedure in small-to-medium-sized cities (OR 1.63; 95% CI 1.11-2.40) and HRA at index colonoscopy (OR 2.60; 95% CI 2.04-3.33).

CONCLUSIONS

Women, having undergone the procedure in small-to-medium-sized cities and the presence of an HRA at the index colonoscopy were found to be independent risk factors for late surveillance colonoscopy. Late surveillance is significantly predictive of subsequent HRA or CRC.

Limited Endoscopic-Assisted Wedge Resection for Excision of Colon Polyps

BACKGROUND

Combined endoscopic laparoscopic surgical removal is used for polyps in the colon that are not suitable for endoscopic removal because of size, location, or scarring. However, the placement of a linear stapler can be challenging. Currently a wedge resection is mostly documented in the cecum or ascending colon.

OBJECTIVE

We report on our experience with limited endoscopy-assisted wedge resections in the entire colon.

DESIGN

A retrospective study was performed.

SETTINGS

This was a single-center study.

PATIENTS

Eight patients were included between March 2015 and April 2016.

INTERVENTIONS

The laparoscopic surgical technique consisted of placing a suture under endoscopic view through the base of the polyp into the lumen. Subsequently, traction was given on the suture to enable stapling of a wedge of the colon.

MAIN OUTCOME MEASURES

Medical data were collected (ie, indication for referral for surgery, location and size of the polyp, duration of surgical procedure, length of hospital stay, and perioperative and postoperative complications). Operative time was defined as the total time of general anesthesia.

RESULTS

Eight patients, with a mean age of 74.5 years (range, 68.0-82.0 years), were treated. The main indications for laparoscopic resection were the size and difficult location of the polyp. There were no complications. Mean operative time was 132 minutes. Five patients were discharged the day after surgery, and the other 3 patients were admitted for a total of 2 days.

LIMITATIONS

The study was limited by its small sample size.

CONCLUSIONS

Our study found that limited endoscopy-assisted wedge resection is a feasible and easy technique for the removal of colon polyps and residual adenomatous tissue in scars that are not accessible for endoscopic removal. Because of traction given on the suture through the base of the polyp, the linear stapler is easily used for wedge resections of polyps, even for those that are not in favorable positions.

Risk factors for metachronous colorectal cancer or polyp: A systematic review and meta-analysis

BACKGROUND AND AIM

We conducted a systematic review and meta-analysis to identify personal, lifestyle, and tumor-related risk factors for metachronous colorectal cancer (CRC) and polyp.

METHODS

Relevant studies were identified by searching MEDLINE, Web of Science and Cochrane Central Register through 15 May 2016. Estimates for associations were summarized using random effects models.

RESULTS

Fifty-five studies were included in the review. For individuals who had a CRC resection, having a synchronous polyp was a risk factor for metachronous CRC or polyp (relative risk [RR], 2.04; 95% confidence interval [CI], 1.48-2.82) and having a synchronous CRC (RR, 1.90; 95% CI, 1.25-2.91) and proximally located CRC (RR, 2.12; 95% CI, 1.24-3.64) were risk factors for metachronous CRC. For individuals who had a polypectomy, larger size (RR, 4.26; 95% CI, 2.11-8.57) or severe dysplasia of the initial polyp (RR, 5.15; 95% CI, 2.02-13.14), and having a synchronous polyp (RR, 2.52; 95% CI, 1.35-4.73) were risk factors for metachronous CRC; and a family history of CRC (RR, 1.90; 95% CI, 1.26-2.87), having a synchronous polyp (RR, 2.47; 95% CI, 1.74-3.50) and a larger size (RR, 1.49; 95% CI, 1.03-2.15) and proximal location of the initial polyp (RR, 1.20; 95% CI, 1.02-1.40) were risk factors for metachronous polyp. Meta-regression showed duration of follow-up was not a source of heterogeneity for most associations. There was no evidence that lifestyle factors were associated with metachronous CRC or polyp risk.

CONCLUSION

A comprehensive list of risk factors identified for metachronous CRC or polyp may have important clinical implications.

Determining the optimal surveillance interval after a colonoscopic polypectomy for the Korean population?

Background/Aims

Western surveillance strategies cannot be directly adapted to the Korean population. The aim of this study was to estimate the risk of metachronous neoplasia and the optimal surveillance interval in the Korean population.

Methods

Clinical and pathological data from index colonoscopy performed between June 2006 and July 2008 and who had surveillance colonoscopies up to May 2015 were compared between low- and high-risk adenoma (LRA and HRA) groups. The 3- and 5-year cumulative risk of metachronous colorectal neoplasia in both groups were compared.

Results

Among 895 eligible patients, surveillance colonoscopy was performed in 399 (44.6%). Most (83.3%) patients with LRA had a surveillance colonoscopy within 5 years and 70.2% of patients with HRA had a surveillance colonoscopy within 3 years. The cumulative risk of metachronous advanced adenoma was 3.2% within 5 years in the LRA group and only 1.7% within 3 years in the HRA group. The risk of metachronous neoplasia was similar between the surveillance interval of <5 and ≥5 years in the LRA group; however, it was slightly higher at surveillance interval of ≥3 than <3 years in the HRA group (9.4% vs. 2.4%). In multivariate analysis, age and the ≥3-year surveillance interval were significant independent risk factors for metachronous advanced adenoma (P=0.024 and P=0.030, respectively).

Conclusions

Patients had a surveillance colonoscopy before the recommended guidelines despite a low risk of metachronous neoplasia. However, the risk of metachronous advanced adenoma was increased in elderly patients and those with a ≥3-year surveillance interval.

Expert opinions and scientific evidence for colonoscopy key performance indicators

Colonoscopy is a widely performed procedure with procedural volumes increasing annually throughout the world. Many procedures are now performed as part of colorectal cancer screening programmes. Colonoscopy should be of high quality and measures of this quality should be evidence based. New UK key performance indicators and quality assurance standards have been developed by a working group with consensus agreement on each standard reached. This paper reviews the scientific basis for each of the quality measures published in the UK standards.

A prognostic model for advanced colorectal neoplasia recurrence

PURPOSE

Following colonoscopic polypectomy, US Multisociety Task Force (USMSTF) guidelines stratify patients based on risk of subsequent advanced neoplasia (AN) using number, size, and histology of resected polyps, but have only moderate sensitivity and specificity. We hypothesized that a state-of-the-art statistical prediction model might improve identification of patients at high risk of future AN and address these challenges.

METHODS

Data were pooled from seven prospective studies which had follow-up ascertainment of metachronous AN within 3-5 years of baseline polypectomy (combined n = 8,228). Pooled data were randomly split into training (n = 5,483) and validation (n = 2,745) sets. A prognostic model was developed using best practices. Two risk cut-points were identified in the training data which achieved a 10 percentage point improvement in sensitivity and specificity, respectively, over current USMSTF guidelines. Clinical benefit of USMSTF versus model-based risk stratification was then estimated using validation data.

RESULTS

The final model included polyp location, prior polyp history, patient age, and number, size and histology of resected polyps. The first risk cut-point improved sensitivity but with loss of specificity. The second risk cut-point improved specificity without loss of sensitivity (specificity 46.2 % model vs. 42.1 % guidelines, p < 0.001; sensitivity 75.8 % model vs. 74.0 % guidelines, p = 0.64). Estimated AUC was 65 % (95 % CI: 62-69 %).

CONCLUSION

This model-based approach allows flexibility in trading sensitivity and specificity, which can optimize colonoscopy over- versus underuse rates. Only modest improvements in prognostic power are possible using currently available clinical data. Research considering additional factors such as adenoma detection rate for risk prediction appears warranted.

Factors Associated With Recurrence of Advanced Colorectal Adenoma After Endoscopic Resection

BACKGROUND & AIMS

Studies have identified risk factors for recurrence of advanced colorectal adenoma (ACA) after polypectomy, but the relative importance and interaction of these risk factors, and their potential impact on surveillance recommendations, are unclear. We aimed to develop a model to identify ACA features associated with risk of recurrence after polypectomy.

METHODS

In a retrospective study, we collected data from 3360 patients who underwent colonoscopy with polypectomy at University of Foggia from 2004 through 2008 and identified 746 patients with 1017 ACAs. We performed recursive partitioning analysis to identify factors associated with recurrence of ACA within 3 years after polypectomy.

RESULTS

Median ACA size was 16 mm (range, 8-34 mm) and median number was 1.5 (range, 1-2). Pedunculated, sessile, and nonpolypoid lesions accounted for 41.3%, 39.4%, and 19.3% of ACAs detected, respectively. Factors independently associated with local recurrence of ACA and metachronous distant polyps within 3 years after polypectomy included size and number of ACAs and grade of dysplasia. The recurrence rate was 4.2% in patients with a single ACA ≤15 mm without high-grade dysplasia (HGD), 21.3% in patients with HGD ≤15 mm, ACA without HGD >15 mm, or multiple ACAs without HGD ≤15 mm, and 57.9% in patients with HGD >15 mm.

CONCLUSIONS

In this retrospective analysis of 746 patients with ACA who underwent polypectomy and surveillance colonoscopy within 3 years, the recurrence rate was highest in those with HGD ≥15 mm. These patients might benefit from more intensive surveillance, whereas patients with a single ACA without HGD ≤15 mm are at lower risk for and could be considered for longer follow-up intervals.

Development and validation of a risk score for advanced colorectal adenoma recurrence after endoscopic resection

AIM: To develop and validate a risk score for advanced colorectal adenoma (ACA) recurrence after endoscopic polypectomy.

METHODS: Out of 3360 patients who underwent colon polypectomy at University of Foggia between 2004 and 2008, data of 843 patients with 1155 ACAs was retrospectively reviewed. Surveillance intervals were scheduled by guidelines at 3 years and primary endpoint was considered 3-year ACA recurrence. Baseline clinical parameters and the main features of ACAs were entered into a Cox regression analysis and variables with P < 0.05 in the univariate analysis were then tested as candidate variables into a stepwise Cox regression model (conditional backward selection). The regression coefficients of the Cox regression model were multiplied by 2 and rounded in order to obtain easy to use point numbers facilitating the calculation of the score. To avoid overoptimistic results due to model fitting and evaluation in the same dataset, we performed an internal 10-fold cross-validation by means of bootstrap sampling.

RESULTS: Median lesion size was 16 mm (12-23) while median number of adenomas was 2.5 (1-3), whereof the number of ACAs was 1.5 (1-2). At 3 years after polypectomy, recurrence was observed in 229 ACAs (19.8%), of which 157 (13.5%) were metachronous neoplasms and 72 (6.2%) local recurrences. Multivariate analysis, after exclusion of the variable “type of resection” due to its collinearity with other predictive factors, confirmed lesion size, number of ACAs and grade of dysplasia as significantly associated to the primary outcome. The score was then built by multiplying the regression coefficients times 2 and the cut-off point 5 was selected by means of a Receiver Operating Characteristic curve analysis. In particular, 248 patients with 365 ACAs fell in the higher-risk group (score ≥ 5) where 3-year recurrence was detected in 174 ACAs (47.6%) whereas the remaining 595 patients with 690 ACAs were included in the low-risk group (score < 5) where 3-year recurrence rate was 7.9% (55/690 ACAs). Area under the curve of the model was 0.81 (0.72-0.86) with an overall classification error rate of 0.09. The model was finally validated by means of 10-fold cross validation.

CONCLUSION: Our study provides support for the use of a novel risk score as a clinical predictor of ACA recurrence after colon polypectomy.

Characteristics and outcomes of endoscopically resected colorectal cancers that arose from sessile serrated adenomas and traditional serrated adenomas

Background/Aims

The efficacy and safety of endoscopic resection of colorectal cancer derived from sessile serrated adenomas or traditional serrated adenomas are still unknown. The aims of this study were to verify the characteristics and outcomes of endoscopically resected early colorectal cancers developed from serrated polyps.

Methods

Among patients who received endoscopic resection of early colorectal cancers from 2008 to 2011, cancers with documented pre-existing lesions were included. They were classified as adenoma, sessile serrated adenoma, or traditional serrated adenoma according to the baseline lesions. Clinical characteristics, pathologic diagnosis, and outcomes were reviewed.

Results

Overall, 208 colorectal cancers detected from 198 patients were included: 198 with adenoma, five with sessile serrated adenoma, and five with traditional serrated adenoma. The sessile serrated adenoma group had a higher prevalence of high-grade dysplasia (40.0% vs. 25.8%, P<0.001) than the adenoma group. During follow-up, local recurrence did not occur after endoscopic resection of early colorectal cancers developed from serrated polyps. In contrast, two cases of metachronous recurrence were detected within a short follow-up period.

Conclusions

Cautious observation and early endoscopic resection are recommended when colorectal cancer from serrated polyp is suspected. Colorectal cancers from serrated polyp can be treated successfully with endoscopy.

Risk of Advanced Colorectal Neoplasia According to the Number of High-Risk Findings at Index Colonoscopy: A Korean Association for the Study of Intestinal Disease (KASID) Study

BACKGROUND

Data regarding outcomes for patients with multiple findings for high-risk adenomas are scarce.

AIM

To compare the risk for colorectal neoplasm (CRN) recurrence according to the number of high-risk findings.

METHODS

This was a retrospective and multicenter study. Patients who had one or more high-risk adenomas at the index colonoscopy and underwent follow-up colonoscopy 2.5 or more years after the index colonoscopy were included. The number of high-risk findings was defined as follows: number of adenomas larger than 1 cm + number of adenomas with HGD + number of adenomas with a villous component + existence (counted as 1) or nonexistence (counted as 0) of three or more adenomas.

RESULTS

A total of 1646 patients were included, and the mean duration between index and follow-up colonoscopy was approximately 4 years. The cumulative incidence rate of recurrent advanced CRN in patients with three or more high-risk findings was higher than that in patients with one or two high-risk findings (p < 0.001). However, the difference in 3-year cumulative incidence rates of recurrent advanced CRN between the two groups was not great, although it was statistically significant (4.8 vs. 2.3 %, p = 0.039).

CONCLUSIONS

A 3-year surveillance interval for patients with multiple high-risk findings, regardless of the number of high-risk findings, appears reasonable.

Complication and local recurrence rate after endoscopic resection of large high-risk colorectal adenomas of ≥3 cm in size

PURPOSE

Endoscopic resection is a widely used technique for treatment of large colorectal adenomas, but few data are available including only lesions larger than ≥2 cm. The aim of this study is to evaluate the complication and recurrence rate after endoscopic resection of high-risk colorectal adenomas ≥3 cm in size.

METHODS

Retrospective analysis of a prospectively maintained database of patients undergoing polypectomy of large colorectal polyps of ≥3 cm.

RESULTS

In 341 patients, 360 colorectal adenomas with a mean size of 3.9 cm were resected endoscopically. In 25 patients, a complication including 22 delayed bleedings (6.5%) and three perforations (0.9%) occurred. Single-variate analysis showed an increasing risk of complications for larger adenomas (3.9 vs. 4.6 cm; p ≤ 0.05). Two hundred twelve patients with 224 adenomas had undergone at least one documented follow-up endoscopy with a medium follow-up period of 16 months. In 95 resected lesions (42.4%), a residual adenoma occurred in the first follow-up colonoscopy (n = 88, 92.6%) or a recurrent adenoma occurred after at least one negative follow-up colonoscopy (n = 7, 7.4%). In multivariate analysis, risk factors were lesion size, sessile growth pattern, and the performing endoscopist. The complication and recurrence rate correlated inversely between endoscopists.

CONCLUSIONS

The present study is the largest study showing complication and recurrence rates after colorectal polypectomy of advanced colorectal adenomas of ≥3 cm in size. Polyp size was identified as the most important risk factor for complications. For the first time, this study shows that the complication rate after colorectal polypectomy of large adenomas is correlated inversely with the residual and/or recurrence rate.

A novel method for screening colorectal cancer by infrared spectroscopy of peripheral blood mononuclear cells and plasma

BACKGROUND

Early detection of colorectal cancer (CRC) can reduce mortality and morbidity. Current screening methods include colonoscopy and stool tests, but a simple low-cost blood test would increase compliance. This preliminary study assessed the utility of analyzing the entire bio-molecular profile of peripheral blood mononuclear cells (PBMCs) and plasma using Fourier transform infrared (FTIR) spectroscopy for early detection of CRC.

METHODS

Blood samples were prospectively collected from 62 candidates for CRC screening/diagnostic colonoscopy or surgery for colonic neoplasia. PBMCs and plasma were separated by Ficoll gradient, dried on zinc selenide slides, and placed under a FTIR microscope. FTIR spectra were analyzed for biomarkers and classified by principal component and discriminant analyses. Findings were compared among diagnostic groups.

RESULTS

Significant changes in multiple bands that can serve as CRC biomarkers were observed in PBMCs (p = ~0.01) and plasma (p = ~0.0001) spectra. There were minor but statistically significant differences in both blood components between healthy individuals and patients with benign polyps. Following multivariate analysis, the healthy individuals could be well distinguished from patients with CRC, and the patients with benign polyps were mostly distributed as a distinct subgroup within the overlap region. Leave-one-out cross-validation for evaluating method performance yielded an area under the receiver operating characteristics curve of 0.77, with sensitivity 81.5% and specificity 71.4%.

CONCLUSIONS

Joint analysis of the biochemical profile of two blood components rather than a single biomarker is a promising strategy for early detection of CRC. Additional studies are required to validate our preliminary clinical results.

Dynamic Article: Full-Thickness Excision for Benign Colon Polyps Using Combined Endoscopic Laparoscopic Surgery

BACKGROUND

Benign colon polyps are commonly encountered but may not always be amenable to endoscopic excision because of their size, shape, location, or scarring from previous attempts. The addition of laparoscopy allows a greater degree of bowel manipulation, but the current technique is still limited when encountering a polyp with inadequate lifting attributed to polyp morphology or scarring. We describe an extension to the existing combined endoscopic laparoscopic surgery technique using a full-thickness approach to increase polyp maneuverability and local excision of difficult but benign polyps.

OBJECTIVE

The purpose of this study was to report the technical details and preliminary results of a new approach for full-thickness excision of difficult colon polyps, combined endoscopic laparoscopic surgery full-thickness excision.

DESIGN

This study is a retrospective review of our experience from December 2013 to May 2015.

SETTINGS

The study was conducted at a single academic institution.

PATIENTS

All of the patients had previous incomplete colonoscopic polypectomy performed at other institutions. Patients were selected for our technique if the polyp had a benign appearance but was unable to be resected by traditional endoscopic or combined endoscopic laparoscopic surgery methods because of polyp morphology or scarring from previous biopsies.

MAIN OUTCOME MEASURES

The safety and feasibility of this procedure were measured.

RESULTS

Three patients underwent combined endoscopic laparoscopic surgery-full-thickness excision for difficult colon polyps. There were no intraoperative or postoperative complications. The length of stay was 1 day for all of the patients. All 3 of the patients had benign final pathology.

LIMITATIONS

This study was limited by the small number of patients in a single institution.

CONCLUSIONS

Full-thickness excision for benign colon polyps using combined endoscopic laparoscopic surgery is safe and feasible. Using this technique, difficult polyps not amenable to traditional endoscopic approaches can be removed and colectomy may be avoided.

Endoscopic resection of tumors in the lower digestive tract

As endoscopic technology has developed and matured, the endoscopic resection of gastrointestinal tract polyps has become a widely used treatment. Colorectal polyps are the most common type of polyp, which are best managed by early resection before the polyp undergoes malignant transformation. Methods for treating colorectal tumors are numerous, including argon plasma coagulation, endoscopic mucosal resection, endoscopic submucosal dissection, and laparoscopic-endoscopic cooperative surgery. In this review, we will highlight several currently used clinical endoscopic resection methods and how they are selected based on the characteristics of the targeted tumor. Specifically, we will focus on laparoscopic-endoscopic cooperative surgery.

Progress in research of colorectal intraepithelial neoplasia and adenoma

Colorectal cancer is a common malignant tumor in the digestive system, and the early diagnosis of colorectal cancer has been the focus of its prevention and control. Colorectal intraepithelial neoplasia and adenoma are considered to be the most important precancerous lesions of colorectal cancer. In recent years, with the development of biological medicine, genetics,

and other disciplines, many studies have explored the relationship between intraepithelial neoplasia and adenoma and colorectal cancer, and some new research progress has been achieved to provide some guidance for the future clinical screening, regular follow-up and chemical prevention. However, it remains to be studied how colorectal intraepithelial neoplasia and adenoma form and evolve to colorectal cancer.

Non-polypoid colorectal neoplasms: Classification, therapy and follow-up

In the last years, an increasing interest has been raised on non-polypoid colorectal tumors (NPT) and in particular on large flat neoplastic lesions beyond 10 mm tending to grow laterally, called laterally spreading tumors (LST). LSTs and large sessile polyps have a greater frequency of high-grade dysplasia and local invasiveness as compared to pedunculated lesions of the same size and usually represent a technical challenge for the endoscopist in terms of either diagnosis and resection. According to the Paris classification, NPTs are distinguished in slightly elevated (0-IIa, less than 2.5 mm), flat (0-IIb) or slightly depressed (0-IIc). NPTs are usually flat or slightly elevated and tend to spread laterally while in case of depressed lesions, cell proliferation growth progresses in depth in the colonic wall, thus leading to an increased risk of submucosal invasion (SMI) even for smaller neoplasms. NPTs may be frequently missed by inexperienced endoscopists, thus a careful training and precise assessment of all suspected mucosal areas should be performed. Chromoendoscopy or, if possible, narrow-band imaging technique should be considered for the estimation of SMI risk of NPTs, and the characterization of pit pattern and vascular pattern may be useful to predict the risk of SMI and, therefore, to guide the therapeutic decision. Lesions suitable to endoscopic resection are those confined to the mucosa (or superficial layer of submucosa in selected cases) whereas deeper invasion makes endoscopic therapy infeasible. Endoscopic mucosal resection (EMR, piecemeal for LSTs > 20 mm, en bloc for smaller neoplasms) remains the first-line therapy for NPTs, whereas endoscopic submucosal dissection in high-volume centers or surgery should be considered for large LSTs for which en bloc resection is mandatory and cannot be achieved by means of EMR. After piecemeal EMR, follow-up colonoscopy should be performed at 3 mo to assess resection completeness. In case of en bloc resection, surveillance colonoscopy should be scheduled at 3 years for adenomatous lesions ≥ 1 cm, or in presence of villous features or high-grade dysplasia patients (regardless of the size), while less intensive surveillance (colonoscopy at 5-10 years) is needed in case of single (or two) NPT < 1 cm presenting tubular features or low-grade dysplasia at histology.