Management of colorectal T1 carcinoma treated by endoscopic resection from the Western perspective

Frequency and clinicopathological correlation of gastrointestinal polyps: A six-year single center experience

Background

Most gastrointestinal polyps are asymptomatic; therefore, assessing symptoms associated with cancer and precancerous polyps is essential.

Objectives

The aim of this study was to study the histopathology, number, distribution, and degree of polyps' dysplasia in terms of age, gender, and clinical presentation.

Methods

This study was performed on patients who underwent endoscopy from July 2015 to August 2021 in Sulaimaniyah, Iraq. Surgical pathology records of patients were analyzed for age, sex, nature of the polyps, number, site, histopathology, degree of dysplasia, resection margins and patients' presented clinical data.

Results

The mean patients' age was 51.4 ± 17.1 years, and most were males (51.9%). The most common indications for endoscopy were screening (28.62%), and the least common was weight loss (4.46%). Neoplastic polyps were common among patients with hematemesis (75%), while non-neoplastic were common among those with dyspepsia (60%). Most polyps were solitary in upper (80.8%) and lower gastrointestinal tract (GIT). Most polyps in the upper GIT were non-neoplastic (87.3%), while most lower proximal/distal GIT polyps were neoplastic. Most neoplastic polyps showed low-grade dysplasia (94.4%), and most high-grade dysplasia was a villous type (24.1%).

Conclusions

Initiation of the screening program is highly recommended as a facilitating method for the early detection of multiple and high-grade gastrointestinal polyps. Thus, screening programs can reduce the rate of mortality of carcinoma in this locality.

Approaches and considerations in the endoscopic treatment of T1 colorectal cancer

The detection of early colorectal cancer (CRC) is increasing through the implementation of screening programs. This increased detection enhances the likelihood of minimally invasive surgery and significantly lowers the risk of recurrence, thereby improving patient survival and reducing mortality rates. T1 CRC, the earliest stage, is treated endoscopically in cases with a low risk of lymph node metastasis (LNM). The advantages of endoscopic treatment compared with surgery include minimal invasiveness and limited tissue disruption, which reduce morbidity and mortality, preserve bowel function to avoid colectomy, accelerate recovery, and improve cost-effectiveness. However, T1 CRC has a risk of LNM. Thus, selection of the appropriate treatment between endoscopic treatment and surgery, while avoiding overtreatment, is challenging considering the potential for complete resection, LNM, and recurrence risk.

Treatment Decision for Locally Resected T1 Colorectal Carcinoma-Verification of the Japanese Guideline Criteria for Additional Surgery Based on Long-Term Clinical Outcomes

INTRODUCTION

To verify the value of the pathological criteria for additional treatment in locally resected pT1 colorectal carcinoma (CRC) which have been used in the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines since 2009.

METHODS

We enrolled 4,667 patients with pT1 CRC treated at 27 institutions between July 2009 and December 2016 (1,257 patients with local resection alone [group A], 1,512 patients with additional surgery after local resection [group B], and 1,898 patients with surgery alone [group C]). All 5 factors of the JSCCR guidelines (submucosal resection margin, tumor histologic grade, submucosal invasion depth, lymphovascular invasion, and tumor budding) for lymph node metastasis (LNM) had been diagnosed prospectively.

RESULTS

Any of the risk factors were present in 3,751 patients. The LNM incidence was 10.4% (95% confidence interval 9.4-11.5) in group B/C patients with risk factors, whereas it was 1.8% (95% confidence interval 0.4-5.3) in those without risk factors ( P < 0.01). In group A, the incidence of recurrence was 3.6% in patients with risk factors, but it was only 0.4% in patients without risk factors ( P < 0.01). The disease-free survival rate of group A patients classified as risk positive was significantly worse than those of groups B and C patients. However, the 5-year disease-free survival rate in group A patients with no risk was 99.6%.

DISCUSSION

Our large-scale real-world multicenter study demonstrated the validity of the JSCCR criteria for pT1 CRC after local resection, especially regarding favorable outcomes in patients with low risk of LNM.

Potential Molecular Markers Related to Lymph Node Metastasis and Stalk Resection Margins in Pedunculated T1 Colorectal Cancers Using Digital Spatial Profiling: A Pilot Study with a Small Case Series

There is a debate regarding the prediction of lymph node metastasis (LNM) in pedunculated T1 colorectal cancer (CRC). In this study with four cases of pedunculated T1 CRCs, we aimed to investigate gene expression variations based on the distance from the Haggitt line (HL) and identify potential molecular risk factors for LNM. By leveraging the Cancer Transcriptome Atlas and digital spatial profiling technology, we meticulously analyzed discrete regions, including the head, HL, proximal stalk region (300-1000 μm from HL), and distal stalk region (1500-2000 μm from HL) to identify spatially sequential molecular changes. Our findings showed significant overall gene expression variations among the head, proximal stalk, and distal stalk regions of pedunculated T1 CRCs compared to the control adenoma. Compared to LNM-negative T1 CRCs, LNM-positive T1 CRC showed that the expression of genes involved in immune-related pathways such as B2M, HLA-B, and HLA-E were significantly downregulated in the distal stalk region compared to the proximal stalk region. In summary, our results may tentatively suggest considering endoscopic resection of the stalk with a minimum 2000 μm margin from the HL, taking into account the gene expression alterations related to immune-related pathways. However, we acknowledge the limitations of this pilot study, notably the small case series, which may restrict the depth of interpretation. Further validation is imperative to substantiate these findings.

Differences in Factors Predicting Lymph Node Metastasis Between pT1 Rectal Cancer and pT1 Colon Cancer: A Retrospective Study

BACKGROUND

Studies have demonstrated conflicting results regarding factors that predict lymph node metastasis (LNM) in pT1 colorectal cancers. We hypothesized that these discrepancies could be related to different factors predicting LNM between rectal and colon cancer. This study aimed to compare predicting factors for LNM between pT1 rectal and colon cancer.

METHODS

This retrospective study evaluated a prospectively maintained database that included 380 patients with pT1 colorectal cancer from January 2010 to December 2020. Patients were grouped according to whether they had rectal or colon cancer, with or without LNM, and factors predicting LNM were analyzed.

RESULTS

In pT1 rectal cancer, LNM was associated with deeper submucosal (SM) invasion (P = .024) and a higher proportion of poorly differentiated tumors (P = .006). In pT1 colon cancer, LNM was associated with a higher proportion of moderately/poorly differentiated tumors (P = .002) and lymphatic invasion (P = .004). In the multivariate analysis for rectal cancer, depth of SM invasion (≥3000 μm) was an independent predictive factor for LNM (95% confidence interval [CI], 1.48-27.94; P = .013), whereas for colon cancer, moderately/poorly differentiated tumors (95% CI, 1.38-8.13; P = .008) and lymphatic invasion (95% CI, 1.44-11.78; P = .008) were independent predictive factors for LNM.

DISCUSSION

There were distinct differences in the factors predicting LNM between pT1 rectal cancer and colon cancer. These results suggest the necessity in differentiating between rectal and colon cancer when performing studies on LNM in pT1 colorectal cancer.

Weighing the benefits of lymphadenectomy in early-stage colorectal cancer

Recent advancements in endoscopic procedures have resulted in a growing diagnosis of early colorectal cancer (CRC) cases, where classical en bloc lymph node (LN) dissection is not performed and treatment is terminated with the removal of the main cancer lesion by endoscopy without pathologic LN staging. Although many studies report noninferior outcomes of endoscopic resection in comparison to surgical resection, a cautious approach to completing treatment with endoscopic resection alone is recommended because LN metastases may be present even in early-stage CRC. In most countries, including the United States, Europe, and South Korea, the guidelines for additional surgery after endoscopic resection are very similar. If LN metastasis is suspected, even in T1 stage or lower lesions, further surgery is an essential treatment modality, but confirmation of the presence of LN metastasis is perhaps the most difficult part of this process. Another paradoxical recent trend is the expansion of more extensive and complete surgical lymphadenectomy for CRC. The success rate of surgery has improved dramatically over the past decade with the introduction of surgical devices and minimally invasive surgery, and the associated risks have been significantly reduced. While the burden of surgery on patients is understandable, the indications for surgery in early colon cancer need to be carefully reviewed to improve cure rates. In this process, we believe that an integrated decision-making process with surgeons, radiologists, and pathologists, in addition to the opinions of endoscopists, will be an important process to improve the cure rate.

Tn as a potential predictor for regional lymph node metastasis in T1 colorectal cancer

BACKGROUND

Approximately 10 percent of T1 colorectal cancer (CRC) has lymph node metastasis. In this study, we aimed to determine possible predictors for nodal involvement in order to aid selection of appropriate patients for organ-preserving strategies.

METHODS

We retrospectively reviewed CRC patients underwent radical surgery from January 2009 to December 2016, with final pathology report disclosed as T1 lesion. The paraffin-embedded samples were achieved for glycosylated proteins expression analysis by immunohistochemistry.

RESULTS

Totally, 111 CRC patients with T1 lesion were enrolled in this study. Of these patients, seventeen patients had nodal metastases, with the lymph node positive rate of 15.3%. Semiquantitative analysis of immunohistochemical results indicated that mean value of Tn protein expression in T1 CRC specimens was significantly different between patients with and without lymph node metastasis (63.6 vs. 27.4; p = 0.018).

CONCLUSIONS

Our data shown that Tn expression may be applied as a molecular predictor for regional lymph node metastasis in T1 CRC. Moreover, the organ-preserving strategy could be improved by proper classification of patients. The mechanism involved in expression of Tn glycosylation protein and CRC metastasis need further investigation.

Demystifying Supervised Learning in Healthcare 4.0: A New Reality of Transforming Diagnostic Medicine

The global healthcare sector continues to grow rapidly and is reflected as one of the fastest-growing sectors in the fourth industrial revolution (4.0). The majority of the healthcare industry still uses labor-intensive, time-consuming, and error-prone traditional, manual, and manpower-based methods. This review addresses the current paradigm, the potential for new scientific discoveries, the technological state of preparation, the potential for supervised machine learning (SML) prospects in various healthcare sectors, and ethical issues. The effectiveness and potential for innovation of disease diagnosis, personalized medicine, clinical trials, non-invasive image analysis, drug discovery, patient care services, remote patient monitoring, hospital data, and nanotechnology in various learning-based automation in healthcare along with the requirement for explainable artificial intelligence (AI) in healthcare are evaluated. In order to understand the potential architecture of non-invasive treatment, a thorough study of medical imaging analysis from a technical point of view is presented. This study also represents new thinking and developments that will push the boundaries and increase the opportunity for healthcare through AI and SML in the near future. Nowadays, SML-based applications require a lot of data quality awareness as healthcare is data-heavy, and knowledge management is paramount. Nowadays, SML in biomedical and healthcare developments needs skills, quality data consciousness for data-intensive study, and a knowledge-centric health management system. As a result, the merits, demerits, and precautions need to take ethics and the other effects of AI and SML into consideration. The overall insight in this paper will help researchers in academia and industry to understand and address the future research that needs to be discussed on SML in the healthcare and biomedical sectors.

Long-term prognosis of curative endoscopic submucosal dissection for early colorectal cancer according to submucosal invasion: a multicenter cohort study

Background

Endoscopic submucosal dissection (ESD) can provide a high en bloc resection rate and has been widely applied as curative treatment for early colorectal cancer (ECC). However, surgical treatment is occasionally required, and reports on the long-term prognosis of ESD are insufficient. This study aimed to investigate the long-term outcomes of ECC removal by ESD, including local recurrence and metastasis.

Methods

This multicenter study was conducted retrospectively on 450 consecutive patients with ECC who were treated with ESD between November 2003 and December 2013. Clinical, pathological, and endoscopic data were collected to determine tumor depth, resection margin, lymphovascular invasion, and recurrence.

Results

The median follow-up period was 53.8 (12–138 months). The en bloc resection rate was 85.3% (384) and in intramucosal cancer being 84.1% and in superficial submucosal invasion (SM1) cancer being 89.8% (p = 0.158). The curative resection rate was 76.0% (n = 342), and there was no statistical difference between the two groups (77.3% vs. 71.4%, p = 0.231). The overall recurrence free survival rate (RFS) was 98.7% (444/450). In patients with curative resection, there was no statistically significant difference in RFS according to invasion depth (intramucosal: 99.3% vs. SM1: 97.1%, p = 0.248).

Conclusions

Patients with curatively resected ECC treated with ESD showed favorable long-term outcomes. Curatively resected SM1 cancer has a RFS similar to that of intramucosal cancer.

Endoscopic Management of Complex Colorectal Polyps: Current Insights and Future Trends

Most colorectal cancers arise from adenomatous polyps and sessile serrated lesions. Screening colonoscopy and therapeutic polypectomy can potentially reduce colorectal cancer burden by early detection and removal of these polyps, thus decreasing colorectal cancer incidence and mortality. Most endoscopists are skilled in detecting and removing the vast majority of polyps endoscopically during a routine colonoscopy. Polyps can be considered “complex” based on size, location, morphology, underlying scar tissue, which are not amenable to removal by conventional endoscopic polypectomy techniques. They are technically more challenging to resect and carry an increased risk of complications. Most of these polyps were used to be managed by surgical intervention in the past. Rapid advancement in endoscopic resection techniques has led to a decreasing role of surgery in managing these complex polyps. These endoscopic resection techniques do require an expert in the field and advanced equipment to perform the procedure. In this review, we discuss various advanced endoscopic techniques for the management of complex polyps.

Colorectal malignant polyps: a modern approach

Colorectal malignant polyps (MP) are polyps with invasive cancer into the submucosa harboring a variable risk of lymph node involvement, which can be estimated through evaluation of morphological, endoscopic, and histologic features. The recent advances in imaging endoscopic techniques have led to the possibility of performing an optical diagnosis of T1 colorectal cancer, allowing the selection of the best therapeutic modality to optimize outcomes for the patient. When MP are diagnosed after endoscopic removal, their management can be challenging. Differentiating low- and high-risk histologic features that influence the possibility of residual tumor, the risk of recurrence and the risk of lymph node metastasis, is crucial to further optimize treatment and surveillance plans. While the presence of high-risk features indicates a need for surgery in the majority of cases, location, comorbidities and the patient’s preference should be taken in account when making the final decision. This is a particularly important issue in the management of low rectal MP presenting with high-risk features, where chemoradiotherapy followed by a watch-and-wait strategy has demonstrated promising results. In this review we discuss the important prognostic features of MP and the most modern approaches regarding their management.

Artificial intelligence-assisted colonoscopy: A review of current state of practice and research

Colonoscopy is an effective screening procedure in colorectal cancer prevention programs; however, colonoscopy practice can vary in terms of lesion detection, classification, and removal. Artificial intelligence (AI)-assisted decision support systems for endoscopy is an area of rapid research and development. The systems promise improved detection, classification, screening, and surveillance for colorectal polyps and cancer. Several recently developed applications for AI-assisted colonoscopy have shown promising results for the detection and classification of colorectal polyps and adenomas. However, their value for real-time application in clinical practice has yet to be determined owing to limitations in the design, validation, and testing of AI models under real-life clinical conditions. Despite these current limitations, ambitious attempts to expand the technology further by developing more complex systems capable of assisting and supporting the endoscopist throughout the entire colonoscopy examination, including polypectomy procedures, are at the concept stage. However, further work is required to address the barriers and challenges of AI integration into broader colonoscopy practice, to navigate the approval process from regulatory organizations and societies, and to support physicians and patients on their journey to accepting the technology by providing strong evidence of its accuracy and safety. This article takes a closer look at the current state of AI integration into the field of colonoscopy and offers suggestions for future research.

Predictors of lymph-node metastasis in surgically resected T1 colorectal cancer in Western populations

Background

The risk of lymph-node metastasis (LNM) in T1 colorectal cancer (CRC) has not been well documented in heterogeneous Western populations. This study investigated the predictors of LNM and the long-term outcomes of patients by analysing T1 CRC surgical specimens and patients’ demographic data.

Methods

Patients with surgically resected T1 CRC between 2004 and 2014 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Patients with multiple primary cancers, with neoadjuvant therapy, or without a confirmed histopathological diagnosis were excluded. Multivariate logistic-regression analysis was used to identify the predictors of LNM.

Results

Of the 22,319 patients, 10.6% had a positive lymph-node status based on the final pathology (nodal category: N1 9.6%, N2 1.0%). Younger age, female sex, Asian or African-American ethnicity, poor differentiation, and tumor site outside the rectum were significantly associated with LNM. Subgroup analyses for patients stratified by tumor site suggested that the rate of positive lymph-node status was the lowest in the rectum (hazard ratio: 0.74; 95% confidence interval: 0.63–0.86).

Conclusion

The risk of LNM was potentially lower in Caucasian patients than in API or African-American patients with surgically resected T1 CRC. Regarding the T1 CRC site, the rectum was associated with a lower risk of LNM.

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.

A Focused Review on Advances in Risk Stratification of Malignant Polyps

Colorectal cancer is the third most common cancer in both men and women in the United States, with most cases arising from precursor adenomatous polyps. Colorectal malignant polyps are defined as cancerous polyps that consist of tumor cells invading through the muscularis mucosae into the underlying submucosa (pT1 tumor). It has been reported that approximately 0.5-8.3% of colorectal polyps are malignant polyps, and the potential for lymph node metastasis in these polyps ranges from 8.5% to 16.1%. Due to their clinical significance, recognition of malignant polyps is critical for clinical teams to make treatment decisions and establish appropriate surveillance schedules after local excision of the polyps. There is a rapidly developing interest in malignant polyps within the literature as a result of an increasing number of identifiable adverse histologic features and recent advancements in endoscopic treatment techniques. The purpose of this paper is to have a focused review of the recent histopathologic literature of malignant polyps.

Pathological assessment of endoscopic resections of the gastrointestinal tract: a comprehensive clinicopathologic review

Endoscopic resection (ER) allows optimal staging with potential cure of early-stage luminal malignancies while maintaining organ preservation. ER and surgery are non-competing but complementary therapeutic options. In addition, histological examination of ER specimens can either confirm or refine the pre-procedure diagnosis. ER is used for the treatment of Barrett's related early carcinomas and dysplasias, early-esophageal squamous cell carcinomas and dysplasias, early gastric carcinomas and dysplasia, as well as low-risk submucosal invasive carcinomas (LR-SMIC) and, large laterally spreading adenomas of the colon. For invasive lesions, histological risk factors predict risk of lymph node metastasis and residual disease at the ER site. Important pathological risk factors predictive of lymph node metastasis are depth of tumor invasion, poor differentiation, and lymphovascular invasion. Complete resection with negative margins is critical to avoid local recurrences. For non-invasive lesions, complete resection is curative. Therefore, a systematic approach for handling and assessing ER specimens is recommended to evaluate all above key prognostic features appropriately. Correct handling starts with pinning the specimen before fixation, meticulous macroscopic assessment with orientation of appropriate margins, systematic sectioning, and microscopic assessment of the entire specimen. Microscopic examination should be thorough for accurate assessment of all pathological risk factors and margin assessment. Site-specific issues such as duplication of muscularis mucosa of the esophagus, challenges of assessing ampullectomy specimens and site-specific differences of staging of early carcinomas throughout the gastrointestinal tract (GI) tract should be given special consideration. Finally, a standard, comprehensive pathology report that allows optimal staging with potential cure of early-stage malignancies or better stratification and guidance for additional treatment should be provided.

Recurrence with malignancy after endoscopic resection of large colon polyps with high-grade dysplasia: incidence and risk factors

BACKGROUND

In the West, piecemeal endoscopic resection remains the primary treatment for large colon polyps (LCP), as most recurrences are believed to be benign and resectable with follow-up endoscopy. However, invasive malignancy at the site of prior piecemeal endoscopic mucosal resection has been reported in the Asian literature. This study aims to identify the incidence of and the risk factors for local recurrence with malignancy after endoscopic resection of LCP with high-grade dysplasia (HGD).

METHODS

In this retrospective cohort study, we identified patients undergoing complete endoscopic resection of LCPs (≥ 20 mm) with HGD at the Cleveland Clinic between January 2000 and December 2016. Demographic, endoscopic, and pathologic data were collected. All subsequent endoscopic and pathology reports were reviewed to identify recurrence. The cumulative incidence of malignancy at the polypectomy site was determined and univariate analysis was performed to assess risk factors.

RESULTS

A total of 254 LCPs with HGD were resected in 229 patients. Mean polyp size was 29.2 mm. There were 138 lesions resected in piecemeal fashion and 116 en-bloc. After a median follow-up of 28.7 months for the entire cohort, local recurrence with malignancy was diagnosed in six cases. Median time to malignancy diagnosis was 28.5 months. All malignant cases occurred after piecemeal resection and none after en-bloc resection (HR 11.4; 95% CI 0.48-273).

CONCLUSION

Malignancy after endoscopic resection of LCPs with HGD is uncommon and may be associated with piecemeal resection. When possible, en-bloc resection should be the goal for the management of LCPs.

Long-term follow-up after endoscopic submucosal dissection of colorectal lesions in a Spanish cohort

INTRODUCTION

ESD in the colon is an increasingly important technique in Western countries. There are few studies that include long term follow-up.

AIM

to analyze the long term recurrence free survival rate after ESD and to compare recurrence rates according to different variables.

METHODS

this was a prospective observational study of patients with a planned ESD from September 2008 to December 2015. When it was not possible to achieve an ESD, hybrid ESD was performed, either en bloc or piecemeal. Kaplan-Meier survival curves were used to assess the five year local recurrence free survival rate and the recurrence rate. The results were compared according to different factors.

RESULTS

of the 89 patients scheduled for ESD who were initially enrolled in the study, 69 were finally included for follow-up. ESD was performed in 31 (45%) patients, KAR in eleven (16%) and pKAR in 27 (39%). The median follow-up was 27 months (range 6-60). The five year disease free survival rate was 81%. The average number of endoscopies needed to eliminate recurrence was two (range 2-7) and no patient required surgery for this reason. The recurrence rate was significantly higher in piecemeal resections vs en bloc resections (27% vs 15%, p = 0.036) and R1 resections vs R0 resections (26% vs 0%, p = 0.034). The presence of affected or unknown lateral margins in en bloc resections without other poor prognosis factors had higher recurrence rates but the difference was not statistically significant (28% vs 0%, p = 0.09).

CONCLUSIONS

in our study, the five year disease free survival rate was 81% and no patient required surgery during follow-up. Piecemeal and R1 resections had significantly higher recurrence rates, as well as LM involvement, although this was not statistically significant.

Endoscopic diagnosis and treatment planning for colorectal polyps using a deep-learning model

We aimed to develop a computer-aided diagnostic system (CAD) for predicting colorectal polyp histology using deep-learning technology and to validate its performance. Near-focus narrow-band imaging (NBI) pictures of colorectal polyps were retrieved from the database of our institution. Of these, 12480 image patches of 624 polyps were used as a training set to develop the CAD. The CAD performance was validated with two test datasets of 545 polyps. Polyps were classified into three histological groups: serrated polyp (SP), benign adenoma (BA)/mucosal or superficial submucosal cancer (MSMC), and deep submucosal cancer (DSMC). The overall kappa value measuring the agreement between the true polyp histology and the expected histology by the CAD was 0.614-0.642, which was higher than that of trainees (n = 6, endoscopists with experience of 100 NBI colonoscopies in <6 months; 0.368-0.401) and almost comparable with that of the experts (n = 3, endoscopists with experience of 2,500 NBI colonoscopies in ≥5 years) (0.649-0.735). The areas under the receiver operating curves for CAD were 0.93-0.95, 0.86-0.89, and 0.89-0.91 for SP, BA/MSMC, and DSMC, respectively. The overall diagnostic accuracy of the CAD was 81.3-82.4%, which was significantly higher than that of the trainees (63.8-71.8%, P < 0.01) and comparable with that of experts (82.4-87.3%). The kappa value and diagnostic accuracies of the trainees improved with CAD assistance: that is, the kappa value increased from 0.368 to 0.655, and the overall diagnostic accuracy increased from 63.8-71.8% to 82.7-84.2%. CAD using a deep-learning model can accurately assess polyp histology and may facilitate the diagnosis of colorectal polyps by endoscopists.

Endoscopic Assessment of the Malignant Potential of the Nonpolypoid (Flat and Depressed) Colorectal Neoplasms: Thinking Fast, and Slow

Current endoscopy training methodology does not meet the learning traits, skills, and needs of the newer generation of gastroenterologists. This article provides information on assessment of the malignant potential of colorectal neoplasms. It takes a modern approach on the topic and integrates relevant information that aligns with the thinking process. The theory of thinking fast (reflex) and slow (rational) is used. By doing so, it is hoped that the learning process can be expedited and practiced immediately. The focus is on preresection assessment of nonpolypoid colorectal neoplasms. Assessment of polypoid, sessile-serrated adenoma/polyp, or inflammatory bowel disease dysplasia is briefly discussed.

Endoscopic full-thickness resection of colorectal lesions with the full-thickness resection device: clinical experience from two referral centers in Greece

Background:

Endoscopic full-thickness resection (EFTR) using the full-thickness resection device (FTRD^®) is an invasive treatment for colorectal lesions not resectable by conventional endoscopic techniques. This study presents the first Greek experience of the FTRD^® procedure, assessing the efficacy and safety of EFTR.

Methods:

We conducted a retrospective analysis of 17 consecutive patients treated with the FTRD^® at 2 referral centers from October 2015 through December 2018. The indications included difficult adenomas (non-lifting and/or at difficult locations), early adenocarcinomas and subepithelial tumors. Primary endpoints were technical success and R0 resection.

Results:

Technical success and R0 resection were achieved in 82.3% procedures (14/17) and in 87.5% of those with difficult adenomas (8 patients). In the subgroup with carcinomas (n=3), the rate of technical success and R0 resection was 66.6%, while in the subgroup with subepithelial tumors (n=6) the rate was 83.3%. Technical success and R0 resection were significantly lower for lesions >20 mm vs. ≤20 mm (P=0.0429). In the 17 patients a total of 3 adverse events occurred (17.6%) and one of the patients underwent laparoscopic appendectomy because of EFTR around the appendix.

Conclusions:

Our study showed favorable results concerning EFTR feasibility, efficacy and safety, especially for lesions ≤20 mm, non-lifting adenomas, and subepithelial tumors. Technical success, R0 resection, and adverse events rates were comparable with previously published data. Larger randomized studies are needed to better define the clinical benefit and long-term outcomes of EFTR in selected patients.

Magnetic bead-assisted endoscopic submucosal dissection: a gravity-based traction method for treating large superficial colorectal tumors

BACKGROUND

Colorectal endoscopic submucosal dissection (ESD) has always been challenging for endoscopists, but the procedure can be facilitated after adequate exposure of submucosal layer and cutting line. We developed a traction method based on gravity for facilitating colorectal ESD, referred as magnetic bead-assisted ESD (MBA-ESD). This study aimed to compare the safety and effectiveness of MBA-ESD and conventional ESD for treating large superficial colorectal tumors.

METHODS

This retrospective study included consecutive patients with large (≥ 20 mm in their maximal diameter) superficial colorectal tumors who underwent MBA-ESD or conventional ESD at our endoscopy center between June 2017 to January 2018. Each patient in the MBA-ESD group was matched to a patient in the conventional ESD group using propensity scores.

RESULTS

Thirteen patients in each group were matched for the analyses. The baseline characteristics were balanced after propensity matching. The incidence of overall complications was significantly lower in the matched MBA-ESD group (0% vs. 38.5%, P = 0.039), while similar rates of en bloc resection, R0 resection, curative resection, and tumor recurrence were noted. Although without statistic difference, dissection time and speed were improved when using MBA-ESD (33 min vs. 40 min, P = 0.111; and 21 mm²/min vs. 16 mm²/min, P = 0.143, respectively).

CONCLUSIONS

MBA-ESD is a feasible, safe, and effective method for treating large superficial colorectal tumors. Further large, prospective and controlled studies are needed to fully assess this method.

Colo-rectal endoscopic full-thickness resection (EFTR) with the over-the-scope device (FTRD®): A multicenter Italian experience

BACKGROUND AND AIM

Endoscopic full-thickness resection(EFTR) with FTRD^® in colo-rectum may be useful for several indications.The aim was to assess its efficacy and safety.

MATERIAL AND METHODS

In this retrospective multicenter study 114 patients were screened; 110 (61M/49F, mean age 68 ± 11 years, range 20-90) underwent EFTR using FTRD^®. Indications were:residual/recurrent adenoma (39), incomplete resection at histology (R1 resection) (26), non-lifting lesion (12), adenoma involving the appendix (2) or diverticulum (2), subepithelial lesions(10), suspected T1 carcinoma (16), diagnostic resection (3). Technical success (TS: lesion reached and resected), R0 resection (negative lateral and deep margins),EFTR rate(all layers documented in the specimen) and safety have been evaluated.

RESULTS

TS was achieved in 94.4% of cases. EFTR was achieved in 91% with lateral and deep R0 resection in 90% and 92%. Mean size of specimens was 20 mm (range 6-42). In residual/recurrent adenomas, final analysis revealed: low-risk T1 (11), adenoma with low-grade dysplasia (LGD) (24) and high-grade dysplasia (HGD) (3), scar tissue (1). Histology reports of R1 resections were: adenoma with LGD (6), with HGD (1), low-risk (6) and high-risk (1) T1, scar tissue (12). Non-lifting lesions were diagnosed as: adenoma with HGD (3), low-risk (7) and high risk (2) T1. Adverse clinical events occurred in 12 patients (11%),while adverse technical events in11%. Three-months follow-up was available in 100 cases and residual disease was evident in only seven patients.

CONCLUSIONS

EFTR using FTRD^® seems to be a feasible, effective and safe technique for treating selected colo-rectal lesions. Comparative prospective studies are needed to confirm these promising results.

Quality of life and fear of cancer recurrence in T1 colorectal cancer patients treated with endoscopic or surgical tumor resection

BACKGROUND AND AIMS

To optimize therapeutic decision-making in early invasive colorectal cancer (T1 CRC) patients, it is important to elicit the patient's perspective next to considering medical outcome. Because empirical data on patient-reported impact of different treatment options are lacking, we evaluated patients' quality of life, perceived time to recovery, and fear of cancer recurrence after endoscopic or surgical treatment for T1 CRC.

METHODS

In this cross-sectional study, we selected patients with histologically confirmed T1 CRC who participated in the Dutch Bowel Cancer Screening Programme and received endoscopic or surgical treatment between January 2014 and July 2017. Quality of life was measured using the European Organization for Research and Treatment 30-item Core Quality of Life Questionnaire and the 5-level EuroQoL 5-dimension questionnaire. We used the Cancer Worry Scale (CWS) to evaluate patients' fear of cancer recurrence. A question on perceived time to recovery after treatment was also included in the set of questionnaires sent to patients.

RESULTS

Of all 119 eligible patients, 92.4% responded to the questionnaire (endoscopy group, 55/62; surgery group, 55/57). Compared with the surgery group, perceived time to recovery was on average 3 months shorter in endoscopically treated patients after adjustment for confounders (19.9 days vs 111.3 days; P = .001). The 2 treatment groups were comparable with regard to global quality of life, functioning domains, and symptom severity scores. Moreover, patients in the endoscopy group did not report more fear of cancer recurrence than those in the surgery group (CWS score, 0-40; endoscopy 7.6 vs surgery 9.7; P = .140).

CONCLUSIONS

From the patient's perspective, endoscopic treatment provides a quicker recovery than surgery, without provoking more fear of cancer recurrence or any deterioration in quality of life. These results contribute to the shared therapeutic decision-making process of clinicians and T1 CRC patients.

Current strategies for malignant pedunculated colorectal polyps

Despite significant advances in imaging techniques, the incidence of colorectal cancer has been increasing in recent years, with many cases still being diagnosed in advanced stages. Early detection and accurate staging remain the main factors that lead to a decrease in the cost and invasiveness of the curative techniques, significantly improving the outcome. However, the diagnosis of pedunculated early colorectal malignancy remains a current challenge. Data on the management of pedunculated cancer precursors, apart from data on nonpolypoid lesions, are still limited. An adequate technique for complete resection, which provides the best long-term outcome, is mandatory for curative intent. In this context, a discussion regarding the diagnosis of malignancy of pedunculated polyps, separate from non-pedunculated variants, is necessary. The purpose of this review is to provide a critical review of the most recent literature reporting the different features of malignant pedunculated colorectal polyps, including diagnosis and management strategies.

Endoscopic Submucosal Dissection Decreases Additional Colorectal Resection for T1 Colorectal Cancer

Background

There are 3 methods of treating T1 colorectal cancer (T1 CRC), which include endoscopic resection, endoscopic resection followed by additional colorectal resection, and surgical resection. In this retrospective study, changes in the management of T1 CRC after introduction of endoscopic submucosal dissection (ESD) were investigated by comparison with the 10-year period before introduction of ESD.

Material/Methods

During a 20-year period from 1996 to 2015, 835 patients with T1 CRC were treated, including 331 patients before introduction of ESD (Group A) and 504 patients after introduction of ESD (Group B). Clinicopathological findings and treatment methods were compared between these 2 groups.

Results

As the initial treatment, endoscopic treatment was performed in 185 patients (55.9%) in Group A and 288 (57.1%) in Group B. In Group B, ESD was performed in 161 patients (55.9%), accounting for more than half of the T1 CRC patients receiving endoscopic treatment. In Groups A and B, observation after endoscopic resection was selected for 54.2% and 67.3% of T1a patients, respectively (p=0.04). A similar trend was noted for T1b patients, and there was no significant difference of the treatment approach. Among all T1 CRC patients, the percentage undergoing observation after endoscopic resection was significantly higher in Group B than in Group A (34.3% vs. 26.9%, p=0.02), and the percentage of patients undergoing additional colorectal resection was significantly lower in Group B (22.8% vs. 29.0%, p=0.04).

Conclusions

After introduction of ESD, it was performed in more than half of all patients with T1 CRC undergoing endoscopic treatment. The percentage of patients undergoing observation following endoscopic resection of T1 CRC increased after introduction of ESD.

Endoscopic submucosal dissection of malignant non-pedunculated colorectal lesions

BACKGROUND AND STUDY AIMS

 Endoscopic submucosal dissection (ESD) is an established method for en bloc resection of large non-pedunculated colorectal lesions in Asia but dissemination of ESD in Western countries is limited. The aim of this study was to evaluate the role of ESD in the management of malignant non-pedunculated colorectal lesions in a European center.

PATIENTS AND METHODS

Among 255 patients undergoing colorectal ESD between 2014 and 2016, 29 cases were identified as submucosal invasive cancers and included in this study. The main outcomes were en bloc, R0 and curative resection as well as procedural time, complications and recurrence.

RESULTS

Median tumor size was 40 mm (range 20 - 70 mm). Thirteen cancers were located in the colon and 16 were located in the rectum. Procedural time was 89 minutes (range 18 - 594 minutes). Complete resection was achieved in 28 cases, en bloc and R0 resection rates were 83 % and 69 %, respectively. Curative resection rate was 38 %. One case had a perforation in the sigmoid colon requiring emergency surgery. No significant bleeding occurred. Six patients underwent additional surgery after ESD, one of whom had residual tumor. One recurrence was detected in 20 patients that were followed-up endoscopically, median follow-up time was 13 months (range 2 - 30 months).

CONCLUSION

ESD seems to be a safe and effective method for treating non-pedunculated malignant colorectal lesions after careful patient selection and proper endoscopic training.

Long-term outcomes of endoscopic submucosal dissection for high-grade dysplasia and early-stage carcinoma in the colorectum

Background

Colorectal carcinomas (CRCs) arise from premalignant precursors in an adenoma-carcinoma sequence, in which adenoma with high-grade dysplasia (HGD) and early-stage carcinoma are defined as advanced neoplasia. A limited number of studies have evaluated the long-term outcomes of endoscopic submucosal dissection (ESD) for advanced colorectal neoplasia. This study aimed to assess the efficacy and safety of ESD for advanced colorectal neoplasia as well as the long-term outcomes, including local recurrence and metastasis.

Methods

We analyzed data collected from 610 consecutive patients with 616 advanced colorectal neoplasia lesions treated with ESD between January 2007 and December 2013. Clinical, endoscopic, and histological data were collected over a median follow-up period of 58 months to determine tumor stage and type, resection status, complications, tumor recurrence, and distant metastasis.

Results

The overall rates of en bloc resection, histological complete resection, and major complications were 94.3%, 89.4%, and 2.3%, respectively. Hybrid ESD was an independent factor of piecemeal resection. Tumor location in the colon was associated with increased risk of ESD-related complications. During the follow-up period, all patients remained free of metastasis. However, local recurrence occurred in 4 patients (0.8%); piecemeal resection was a risk factor.

Conclusions

ESD is effective and safe for resection of advanced colorectal neoplasia, with a high en bloc resection rate and favorable long-term outcomes. ESD is indicated for the treatment of HGD and early-stage CRC to obtain curative resection and reduce local recurrence rate.

Efficacy and safety of additional surgery after non-curative endoscopic submucosal dissection for early colorectal cancer

Background

Additional surgery is recommended when early colorectal cancer (ECRC) is resected by non-curative endoscopic submucosal dissection (ESD) and there is significant risk of lymph node metastasis (LNM). The aim of this study was to investigate the efficacy and safety of additional surgery after non-curative ESD for ECRC and evaluate long-term outcomes.

Methods

Patients with ECRC who underwent ESD and additional surgery between July 2007 and November 2013 were identified. Histology and patient data were collected during an average period of more than 5 years to determine tumor stage and type, resection status, complications, tumor recurrence, and distant metastasis.

Results

Fifty-one patients who underwent additional surgery were eligible for analysis. Overall, regional LNM was detected in 5 patients (9.8%) and presence of lymphovascular infiltration was a significant risk factor. Surgery-related complications occurred in 3 patients (5.9%). During a median follow-up period of 59 months, no metastasis or local recurrence was observed. Three patients died of other diseases and no CRC-related deaths took place.

Conclusions

Additional surgery after non-curative ESD for ECRC is effective and safe and should be encouraged to foster curative treatment and better long-term outcomes.

Endoscopic full-thickness resection for T1 early rectal cancer: a case series and video report

BACKGROUND AND STUDY AIMS

 Endoscopic treatment of malignant colorectal polyps is often challenging, especially for early rectal cancer (ERC) localized close to the dentate line. Conversely, the surgical approach may result in temporary or definitive stoma and in frequent post-surgical complications. The Full-Thickness Resection Device (FTRD ^® ) System (Ovesco Endoscopy, Tübingen, Germany) is a novel system that, besides having other indications, appears to be promising for wall-thickness excision of intestinal T1 carcinoma following incomplete endoscopic resection. However, follow-up data on patients treated with this device are scarce, particularly for ERC.

PATIENTS AND METHODS

 Six consecutive patients with incomplete endoscopic resection of T1-ERC were treated with the FTRD and their long-term outcomes were evaluated based on a detailed clinical and instrumental assessment.

RESULTS

 The endoscopic en bloc full-thickness resection was technically feasible in all patients. The histopathologic analysis showed a complete endoscopic resection in all cases, and a full-thickness excision in four. Neither complications, nor disease recurrence were observed during the 1-year follow-up period.

CONCLUSIONS

 The FTRD System is a promising tool for treating ERC featuring a residual risk of disease recurrence after incomplete endoscopic mucosal resection in patients unfit for surgery or refusing a surgical approach.

Recent traction methods for endoscopic submucosal dissection

Endoscopic mucosal resection (EMR) is problematic with regard to en bloc and curable resection rates. Advancements in endoscopic techniques have enabled novel endoscopic approaches such as endoscopic submucosal dissection (ESD), which has overcome some EMR problems, and has become the standard treatment for gastrointestinal tumors. However, ESD is technically difficult. Procedure time is longer and complications such as intraoperative perforation and bleeding occur more frequently than in EMR. Recently various traction methods have been introduced to facilitate ESD procedures, such as clip with line, external forceps, clip and snare, internal traction, double scope, and magnetic anchor. Each method must be used appropriately according to the anatomical characteristics. In this review we discuss recently proposed traction methods for ESD based on the characteristics of various anatomical sites.