Submucosal Invasive Cancer Research Articles

Efficacy of a whole slide image-based prediction model for lymph node metastasis in T1 colorectal cancer: A systematic review.

Accurate stratification of the risk of lymph node metastasis (LNM) following endoscopic resection of submucosal invasive (T1) colorectal cancer (CRC) is imperative for determining the necessity for additional surgery. In this systematic review, we evaluated the efficacy of prediction of LNM by artificial intelligence (AI) models utilizing whole slide image (WSI) in patients with T1 CRC. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review was conducted through searches in PubMed (MEDLINE), Embase, and the Cochrane Library for relevant studies published up to December 2023. The inclusion criteria were studies assessing the accuracy of hematoxylin and eosin-stained WSI-based AI models for predicting LNM in patients with T1 CRC. Four studies met the criteria for inclusion in this systematic review. The area under the receiver operating characteristic curve for these AI models ranged from 0.57 to 0.76. In the three studies in which AI performance was compared directly with current treatment guidelines, AI consistently exhibited a higher area under the receiver operating characteristic curve. At a fixed sensitivity of 100%, specificities ranged from 18.4% to 45.0%. Artificial intelligence models based on WSI can potentially address the issue of diagnostic variability between pathologists and exceed the predictive accuracy of current guidelines. However, these findings require confirmation by larger studies that incorporate external validation.

Accuracy Goals in Predicting Preoperative Lymph Node Metastasis for T1 Colorectal Cancer Resected Endoscopically.

Submucosal invasive (T1) colorectal cancer is a significant clinical management challenge, with an estimated 10% of patients developing extraintestinal lymph node metastasis. This condition necessitates surgical resection along with lymph node dissection to achieve a curative outcome. Thus, the precise preoperative assessment of lymph node metastasis risk is crucial to guide treatment decisions after endoscopic resection. Contemporary clinical guidelines strive to identify a low-risk cohort for whom endoscopic resection will suffice, applying stringent criteria to maximize patient safety. Those failing to meet these criteria are often recommended for surgical resection, with its associated mortality risks although it may still include patients with a low risk of metastasis. In the quest to enhance the precision of preoperative lymph node metastasis risk prediction, innovative models leveraging artificial intelligence or nomograms are being developed. Nevertheless, the debate over the ideal sensitivity and specificity for such models persists, with no consensus on target metrics. This review puts forth postoperative mortality rates as a practical benchmark for the sensitivity of predictive models. We underscore the importance of this method and advocate for research to amass data on surgical mortality in T1 colorectal cancer. Establishing specific benchmarks for predictive accuracy in lymph node metastasis risk assessment will hopefully optimize the treatment of T1 colorectal cancer.

Management of T1 colorectal cancer.

Approximately 10% of patients with submucosal invasive (T1) colorectal cancer (CRC) have lymph node metastasis (LNM). The risk of LNM can be stratified according to various histopathological factors, such as invasion depth, lymphovascular invasion, histological grade, and tumor budding. T1 CRC with a low risk of LNM can be cured by local excision via endoscopic resection (ER), whereas surgical resection (SR) with lymph node dissection is required for high-risk T1 CRC. Current guidelines raise concern that many patients receive unnecessary SR, even though most patients achieve a radical cure. Novel diagnostic techniques for LNM, such as nomograms, artificial intelligence systems, and genomic analysis, have been recently developed to identify more low-risk T1 CRC cases. Assessing the curability and the necessity of additional treatment, including SR with lymph node dissection and chemoradiotherapy, according to histopathological findings of the specimens resected using ER, is becoming an acceptable strategy for T1 CRC, particularly for rectal cancer. Therefore, complete resection with negative vertical and horizontal margins is necessary for this strategy. Advanced ER methods for resecting the muscle layer or full thickness, which may guarantee complete resection with negative vertical margins, have been developed. Although a necessary SR should not be delayed for T1 CRC given its unfavorable prognosis when SR with lymph node dissection is performed, the optimal treatment method should be chosen based on the risk of LNM and the patient's life expectancy, physical condition, social characteristics, and wishes.

Effect of optical diagnosis training on recognition and treatment of submucosal invasive colorectal cancer in community hospitals: a prospective multicenter intervention study.

Recognition of submucosal invasive colorectal cancer (T1 CRC) is difficult, with sensitivities of 35 %-60 % in Western countries. We evaluated the real-life effects of training in the OPTICAL model, a recently developed structured and validated prediction model, in Dutch community hospitals. In this prospective multicenter study (OPTICAL II), 383 endoscopists from 40 hospitals were invited to follow an e-learning program on the OPTICAL model, to increase sensitivity in detecting T1 CRC in nonpedunculated polyps. Real-life recognition of T1 CRC was then evaluated in 25 hospitals. Endoscopic and pathologic reports of T1 CRCs detected during the next year were collected retrospectively, with endoscopists unaware of this evaluation. Sensitivity for T1 CRC recognition, R0 resection rate, and treatment modality were compared for trained vs. untrained endoscopists. 1 year after e-learning, 528 nonpedunculated T1 CRCs were recorded for endoscopies performed by 251 endoscopists (118 [47 %] trained). Median T1 CRC size was 20 mm. Lesions were mainly located in the distal colorectum (66 %). Trained endoscopists recognized T1 CRCs more frequently than untrained endoscopists (sensitivity 74 % vs. 62 %; mixed model analysis odds ratio [OR] 2.90, 95 %CI 1.54-5.45). R0 resection rate was higher for T1 CRCs detected by trained endoscopists (69 % vs. 56 %; OR 1.73, 95 %CI 1.03-2.91). Training in optical recognition of T1 CRCs in community hospitals was associated with increased recognition of T1 CRCs, leading to higher en bloc and R0 resection rates. This may be an important step toward more organ-preserving strategies.

Selection of endoscopic resection technique for large colorectal lesion treatment.

Large nonpedunculated colorectal polyps ≥ 20 mm (LNPCPs) comprise 1% of all colorectal lesions. LNPCPs are more likely to contain advanced histology such as high-grade dysplasia and submucosal invasive cancer (SMIC). Endoscopic resection is the first-line approach for management of these lesions. Endoscopic resection options include endoscopic mucosal resection (EMR), cold-snare EMR (EMR), endoscopic submucosal dissection (ESD) and endoscopic full-thickness resection (EFTR). This review aimed to critically evaluate current endoscopic resection techniques. Evidence-based selective resection algorithms should inform the most appropriate endoscopic resection technique. Most LNPCPs are removed by conventional EMR but there has been a trend toward C-EMR for endoscopic resection of LNPCPs. More high-quality trials are required to better define the limitations of C-EMR. Advances in our understanding of ESD technique, has clarified its role within the colorectum. More recently, the development of a full thickness resection device (FTRD) has allowed the curative endoscopic resection of select lesions. Endoscopic resection should be regarded as the principle approach for all LNPCPs. Underpinned by high-quality research, endoscopic resection has become more nuanced, leading to improved patient outcomes.

Management of complex colorectal lesions from the endoscopic tissue resection specialist perspective

Endoscopic resection (ER) is the standard of care for the management of large (≥20 mm) non-pedunculated colorectal polyps (LNPCP). Certain lesion characteristics increase the risk for incomplete ER, recurrence, harbouring submucosal invasive cancer and post ER adverse events. These include lesion location, morphology, difficult endoscopic access and prior attempts at resection. Such LNPCP are termed ‘complex’. Recognition of complexity is a crucial component of technique selection and resource allocation. Until recently, resection of complex lesions was dominated by surgery. Surgical resection of benign lesions is associated with prolonged hospital stay and post-operative recovery, stoma creation, post-operative complications and even death. Advances in ER techniques have enabled huge strides in the management of these lesions and is proven to be safer and more cost-effective than surgery.

A132 A COLON-SPECIFIC SELECTIVE RESECTION ALGORITHM FOR LARGE NON-PEDUNCULATED POLYPS OPTIMIZES EFFICIENCY WITH HIGH TECHNICAL AND CLINICAL SUCCESS: A PROSPECTIVE COHORT STUDY

Abstract Background Endoscopic resection is now the first line treatment strategy for most large (≥20 mm) non-pedunculated colonic polyps (LNPCPs); which includes endoscopic mucosal resection (EMR), cold snare resection (CSR), and endoscopic submucosal dissection (ESD). A selective resection algorithm incorporating EMR and ESD is cost effective and optimizes oncologic outcomes in the rectum. However, a focused evaluation for colonic lesions has not been described. Aims Assess the performance of a colon-specific selective resection algorithm for LNPCPs. Methods Consecutive patients ampersand:003E 18 years of age who underwent endoscopic resection for a LNPCP were enrolled in a prospective single center observation cohort study (clinicaltrials.gov ID: NCT05402696). Modality selection was determined by optical evaluation using the Paris and the Japan NBI Expert Team (JNET) classifications: 1) JNET I – CSR; 2) JNET IIA – EMR; 3) JNET IIB or Paris 0-IIC morphology – en bloc resection (EMR/ESD); 4) JNET III – referral to surgery/multi-disciplinary team review. Algorithm performance was evaluated by technical success (all neoplastic tissue removed at index procedure), procedure-related adverse events, referral to surgery, and recurrence at first surveillance colonoscopy (SC1). Results From 06/2022-09/2023, 230 patients underwent 244 procedures for 295 lesions. Median age was 67 years (IQR 61-74 years) and 127 (55.2%) were male. Median lesion size was 30mm (IQR 20-40mm). Cancer was identified in 12 (4.1%) LNPCPs. Based on pre-resection optical evaluation, 204 (69.2%), 86 (29.2%) and 5 (1.7%) LNPCPs underwent EMR, CSR and ESD, respectively. Technical success was 97.1%, 100.0% and 100.0% for EMR, CSR and ESD, respectively (p=0.245). Procedure duration was significantly shorter for CSR (10 min; IQR 8-15 min) compared to EMR (15 min; IQR 10-25 min) and ESD (30 min; IQR 30-60 min) (P ampersand:003C 0.001). There was no significant difference in intra-procedural perforation, clinically significant post-endoscopic resection bleeding, delayed perforation or serositis, with overall frequencies of 3.4%, 5.2%, 0% and 0.4% respectively. Surgery was performed for 15 lesions (11 submucosal invasive cancer (SMIC); 3 synchronous SMIC; 1 technical failure). Of LNPCPs completing SC1, there was 1 recurrence (1.2%) in the CSR group (p=0.366), which was successfully managed endoscopically. Conclusions A colon-specific selective resection algorithm optimizes procedural efficiency and the risk-benefit profiles of EMR, CSR and ESD for LNPCPs. Funding Agencies None

Short-term and long-term outcomes of submucosal dissection for residual or recurrent colorectal tumors after endoscopic resection: Analysis of a multicenter prospective study.

We previously demonstrated that a favorable long-term prognosis indicated that endoscopic submucosal dissection (ESD) could be the standard treatment for large colorectal epithelial neoplasms, but the usefulness of ESD for local residual or recurrent tumors with submucosal fibrosis has not been fully demonstrated. The aim of the present study was to assess the usefulness of ESD for local residual or recurrent colorectal tumors. We conducted a nationwide multicenter prospective study to evaluate the outcomes of ESD for colorectal tumors. In this post hoc analysis, a total of 54 local residual or recurrent colorectal tumors in 54 patients were included, and we analyzed the short-term and long-term outcomes of ESD for these lesions. The median size of the lesions was 16.0 (interquartile range [IQR] 11-25) mm. ESD was completed in 53 cases (98.1%) with a median procedure time of 65.0 min, but it was discontinued in one case because of submucosal cancer invasion. En bloc resection was achieved in 52 cases (96.3%), whereas R0 resection was achieved in 45 cases (83.3%). Intraoperative perforation was observed in four cases (7.4%) and delayed perforation in one (1.9%), but all cases could be managed conservatively. Delayed bleeding was not observed. There were no significant differences in short-term outcomes between the rectal and colonic lesions. There was no recurrence of the tumor during the median follow-up period of 60 (IQR50-64) months. An analysis of our multicenter prospective study suggests that ESD is an effective salvage management for local residual or recurrent colorectal lesions.

Concordance between nice classification and histopathology in colonic polyps: a tertiary center experience.

Narrow-Band imaging International Colorectal Endoscopic (NICE) could reduce histopathology study requirements in colorectal polyp evaluation. Local and regional studies are required to validate its utility. To evaluate concordance between NICE classification and histopathology. Prospective analytic study performed in the Hospital Universitario San Ignacio, Bogotá (Colombia) between 2021 and 2022. Concordance between NICE I, II and III classification and histopathology [Hyperplastic Polyp (HP), adenoma and deep submucosal invasive cancer (DSIC)] was evaluated using weighted kappa. Diagnostic performance was evaluated for NICE I-II versus NICE III for DSIC versus adenoma/HP. A subgroup analysis was performed for polyps ⩾10 mm and those located in the rectum, sigmoid, and left colon. A total of 238 polyps from 135 patients were evaluated. Median age 67 years (IQR 58.5-74.5), 54.4% males. 23 (17.1%) had ⩾3 polyps. Of polyps, 52.1% were located on rectum, sigmoid and left colon. A total of 182 (76.5%) were <10 mm. NICE and histopathology evidenced a fair-moderate concordance (quadratic weighted kappa 0.36, linear weighted kappa 0.43). NICE classification (NICE I-II versus III) compared to histopathology (DSIC versus adenoma/HP) evidenced a sensitivity of 90.9% and specificity of 99.1%. For DSIC diagnosis specificity was ⩾95% on polyps ⩾10 mm and those left sided located. NICE and histopathology concordance is suboptimal. However, NICE III for DSIC diagnosis evidence good specificity. Therefore, NICE III polyps require a prompt histopathological evaluation and follow-up. Good operative characteristics stand in polyps ⩾10 mm and left sided located. NBI formal training is recommended in gastroenterology units in Latin America.

Prediction of the invasion depth of superficial nonampullary duodenal adenocarcinoma.

Distinguishing between intramucosal cancer and submucosal invasive cancer is vital for optimal treatment selection for patients with superficial nonampullary duodenal adenocarcinoma (SNADAC); however, standard diagnostic systems for diagnosing invasion depth are as yet undetermined. Of 205 patients with SNADAC who underwent treatment at our institution between 2006 and 2022, 188 had intramucosal cancer and 17 had submucosal invasive cancer. The clinical, endoscopic, and pathological features used in the preoperative diagnosis of invasion depth and the diagnostic performance of endoscopic ultrasonography (EUS) were retrospectively analyzed in 85 patients. The oral side of the papilla tumor location, protruded or mixed macroscopic type, and moderately-to-poorly differentiated adenocarcinoma based on biopsy specimens were significantly more frequent in submucosal invasive cancer than in intramucosal cancer (88% vs. 48%; 94% vs. 42%; 47% vs. 0%, respectively). From the relationship between the endoscopic features and the submucosal invasive cancer incidence, submucosal invasion risk was stratified as: (i) low-risk (risk, 2%), all lesions located on the anal side of the papilla and superficial macroscopic type on the oral side of the papilla; and (ii) high-risk (risk, 23%), protruded or mixed macroscopic type on the oral side of the papilla. Based on the biopsy specimens, all eight patients with moderately-to-poorly differentiated adenocarcinoma had submucosal invasive cancer. Furthermore, EUS was not associated with invasion depth's diagnostic accuracy improvements. Optimal treatment indications for SNADAC can be selected based on the risk factors of submucosal invasion by tumor location, macroscopic type, and biopsy diagnosis.

Unified Magnifying Endoscopic Classification (UMEC) of Gastrointestinal Lesions: A North American Validation Study.

Magnifying endoscopy enables the diagnosis of advanced neoplasia throughout the gastrointestinal tract. The unified magnifying endoscopic classification (UMEC) framework unifies optical diagnosis criteria in the esophagus, stomach, and colon, dividing lesions into three categories: non-neoplastic, intramucosal neoplasia, and deep submucosal invasive cancer. This study aims to ascertain the performance of North American endoscopists when using the UMEC. In this retrospective cohort study, five North American endoscopists without prior training in magnifying endoscopy independently diagnosed images of gastrointestinal tract lesions using UMEC. All endoscopists were blinded to endoscopic findings and histopathological diagnosis. Using histopathology as the gold standard, the endoscopists' diagnostic performances using UMEC were evaluated. A total of 299 lesions (77 esophagus, 92 stomach, and 130 colon) were assessed. For esophageal squamous cell carcinoma, the sensitivity, specificity, and accuracy ranged from 65.2% (95%CI: 50.9-77.9) to 87.0% (95%CI: 75.3-94.6), 77.4% (95%CI: 60.9-89.6) to 96.8% (95%CI: 86.8-99.8), and 75.3% to 87.0%, respectively. For gastric adenocarcinoma, the sensitivity, specificity, and accuracy ranged from 94.9% (95%CI: 85.0-99.1) to 100%, 52.9% (95%CI: 39.4-66.2) to 92.2% (95%CI: 82.7-97.5), and 73.3% to 93.3%. For colorectal adenocarcinoma, the sensitivity, specificity, and accuracy ranged from 76.2% (95%CI: 62.0-87.3) to 83.3% (95%CI: 70.3-92.5), 89.7% (95%CI: 82.1-94.9) to 97.7% (95%CI: 93.1-99.6), and 86.8% to 90.7%. Intraclass correlation coefficients indicated good to excellent reliability. UMEC is a simple classification that may be used to introduce endoscopists to magnifying narrow-band imaging and optical diagnosis, yielding satisfactory diagnostic accuracy.

Investigating the Role of Tumor-Infiltrating Lymphocytes as Predictors of Lymph Node Metastasis in Deep Submucosal Invasive Colorectal Cancer: A Retrospective Cross-Sectional Study.

The role of tumor-infiltrating T cells (TILs) in colorectal cancer (CRC) and their significance in early-stage CRC remain unknown. We investigated the role of TILs in early-stage CRC, particularly in deep submucosal invasive (T1b) CRC. Sixty patients with CRC (20 each with intramucosal [IM group], submucosal invasive [SM group], and advanced cancer [AD group]) were randomly selected. We examined changes in TILs with tumor invasion and the relationship between TILs and LN metastasis risk. Eighty-four patients with T1b CRC who underwent initial surgical resection with LN dissection or additional surgical resection with LN dissection after endoscopic resection were then selected. TIL phenotype and number were evaluated using triple immunofluorescence for CD4, CD8, and Foxp3. All subtypes were more numerous according to the degree of CRC invasion and more abundant at the invasive front of the tumor (IF) than in the center of the tumor (CT) in the SM and AD groups. The increased Foxp3 cells at the IF and high ratios of Foxp3/CD4 and Foxp3/CD8 positively correlated with LN metastasis. In conclusion, tumor invasion positively correlated with the number of TILs in CRC. The number and ratio of Foxp3 cells at the IF may predict LN metastasis in T1b CRC.

Importance of preoperative total colonoscopy and endoscopic resection after self-expandable metallic stent placement for obstructive colorectal cancer as a bridge-to-surgery

Background and aimColonic self-expandable metallic stent (SEMS) placement enables preoperative total colonoscopy (TCS) in patients with obstructive colorectal cancer. Following SEMS placement, it is possible to assess the presence or absence of synchronous proximal colon cancers and perform preoperative endoscopic resection (ER) for neoplastic lesions proximal to the primary lesion. The objective of this study was to determine the usefulness and safety of preoperative TCS and ER after SEMS placement in patients with obstructive colorectal cancer.MethodsFrom April 2016 to March 2022, we enrolled 100 patients with obstructive colorectal cancer who underwent SEMS placement, including 86 patients who underwent preoperative TCS after SEMS placement. Complications associated with preoperative TCS and ER after SEMS placement and the characteristics of the neoplastic lesions were assessed.ResultsThe success rate of SEMS placement as bridge-to-surgery was 98.0%; six patients had associated complications. Preoperative TCS was performed 8 (range: 1–30) days after SEMS placement. Four patients had synchronous advanced cancers. Nine non-advanced synchronous cancers, 116 adenomas, and 18 sessile-serrated lesions were treated by preoperative TCS and ER after SEMS placement. No procedure-related complications, namely stent migration, bleeding, and perforation were observed. Forty-five patients underwent follow-up TCS 1 year after surgery. Only one patient with submucosal invasive cancer required a second surgery.ConclusionsPreoperative TCS and ER after SEMS placement was performed with no complications. This approach allows preoperative evaluation of the entire colon and the treatment of precancerous lesions. (240 words)

Diagnostic accuracy of magnifying chromoendoscopy in the assessment of tumor invasion depth in early colorectal cancer: a systematic review and meta-analysis.

The aim of the study was to evaluate the ability of magnifying chromoendoscopy (MCE) to correctly differentiate early colorectal cancer (CRC) lesions with massively invasive submucosal cancer (SMm) from lesions without submucosal massive invasion (polyp, adenoma, dysplasia, intramucosal cancer, slightly invasive submucosal cancer (SMs)). We searched PubMed, Embase, the Cochrane Library from the time of the establishment of each database to 5April 2023. Stata15 software was used to perform the meta-analysis for sensitivity, specificity, positive likelihood ratio (LR), and negative LR, diagnostic odds ratio, and 95%CI. A summary receiver-operating characteristic (SROC) curve was constructed, the area under the curve (AUC) was calculated, and the diagnostic value was evaluated. Furthermore, to explore the potential sources of heterogeneity, we used meta-regression to estimate the influencing factors of these studies and their impact on the diagnostic accuracy. MCE was used to evaluate the diagnostic accuracy in differentiating CRC lesions with SMm from lesions without submucosal massive invasion (polyp, adenoma, dysplasia, intramucosal cancer, SMs). Subgroup analysis was conducted as well. Deeks' funnel plots were also used to assess publication bias. A total of 11,387 colorectal lesions were included in 19 articles, including polyp, adenoma, dysplasia, and early cancer (intramucosal cancer, SMs, and SMm). The aggregate sensitivity, specificity, positive LR, negative LR, and diagnostic advantage scores of MCE in the diagnosis of differentiating CRC lesions with SMm from lesions without submucosal massive invasion (polyp, adenoma, dysplasia, intramucosal cancer, SMs) were 0.78 (95%CI 0.72-0.83), 0.95 (0.95%CI 0.91-0.97), 15.4 (0.95%CI 8.7-27.4), 0.23 (0.95%CI 0.18-0.30), and 66 (0.95%CI 32-136), respectively. The AUC of the SROC curve was 0.91 (0.95%CI 0.88-0.93). No significant publication bias was found with Deeks' funnel plot. The results showed significant heterogeneity due to the different objects included. MCE can differentiate CRC lesions with SMm from lesions without submucosal massive invasion (polyp, adenoma, dysplasia, intramucosal cancer, SMs) with high accuracy and it can guide assessment of invasion depth of SMm in T1 early CRCs to help us select the most appropriate treatment.

A114 UNIFIED MAGNIFYING ENDOSCOPIC CLASSIFICATION (UMEC) FOR GASTROINTESTINAL LESIONS: A NORTH AMERICAN EDUCATION STUDY

Abstract Background Magnification endoscopy and magnification narrow-band imaging are image enhanced endoscopy technologies that may allow for the diagnosis of advanced neoplasia in the GI tract on the basis of imaging characteristics. Recently, the Unified Magnifying Endoscopic Classification (UMEC) has been developed, which unified the criteria for the esophagus, stomach, and colon. UMEC divides optical diagnosis into one of the three categories: non-neoplastic, intramucosal neoplasia, and deep submucosal invasive cancer. Purpose The objective of this study is to educate North American endoscopists on the use of the UMEC schema, and to ascertain performance of the UMEC framework among North American endoscopists. Method Using UMEC, five North American endoscopists (&amp;gt;1000 procedures) without prior training in magnifying endoscopy independently diagnosed previously collected endoscopic image set of the esophagus, stomach, and colon. The endoscopists were trained on the use of UMEC via an eleven-minute training video with exemplars of each element of UMEC from esophagus, stomach, and colon. All endoscopists were blinded to white-light and non-magnifying NBI findings as well as histopathological diagnosis. The diagnostic performance of UMEC was assessed while using the gold standard histopathology as a reference. Result(s) A total of 299 gastrointestinal lesions (77 esophagus, 92 stomach, and 130 colon) were assessed using UMEC. For esophageal squamous cell carcinoma, the sensitivity, specificity, and accuracy for all 5 endoscopists ranged from 65.2% (95% CI: 50.9–77.9) to 87.0% (95% CI: 75.3–94.6), 77.4% (95% CI: 60.9–89.6) to 96.8% (95% CI: 86.8–99.8), and 75.3% to 87.0%, respectively. For gastric adenocarcinoma, the sensitivity, specificity, and accuracy for all 5 endoscopists ranged from 94.9% (95% CI: 85.0–99.1) to 100%, 52.9% (95% CI: 39.4–66.2) to 92.2% (95% CI: 82.7–97.5), and 73.3% to 93.3%, respectively. For colorectal adenocarcinoma, the sensitivity, specificity, and accuracy for all 5 endoscopists ranged from 76.2% (95% CI: 62.0–87.3) to 83.3% (95% CI: 70.3–92.5), 89.7% (95% CI: 82.1–94.9) to 97.7% (95% CI: 93.1–99.6), and 86.8% to 90.7%, respectively. Image Conclusion(s) UMEC is a simple and practical classification that can be used to introduce and educate endoscopists to magnification narrow-band imaging and optical diagnosis. Please acknowledge all funding agencies by checking the applicable boxes below CAG Disclosure of Interest M. R. A. Fujiyoshi Grant / Research support from: 2022 CAG/AbbVie Education Research Grant, Y. Fujiyoshi: None Declared, N. Gimpaya: None Declared, R. Bechara: None Declared, T. Jeyalingam: None Declared, N. Calo: None Declared, N. Forbes: None Declared, R. Khan: None Declared, M. Atalla: None Declared, A. Toshimori: None Declared, Y. Shimamura: None Declared, M. Tanabe: None Declared, J. Mosko: None Declared, H. Inoue: None Declared, S. Grover: None Declared

Colorectal submucosa thickness in specimens obtained by EMR versus ESD: a retrospective pilot study.

AbstractAccurate histopathology is the mainstay for reliable classification of resected early colorectal cancer lesions in terms of potential risk of lymph node metastasis. In particular, thickness of resected submucosa is important in cases of submucosal invasive cancer. Nevertheless, little is known about the quality and thickness of submucosal tissue obtained using different endoscopic resection techniques. In this small pilot study, we performed morphometric analysis of submucosal thickness in specimens obtained from right-sided colorectal lesions using endoscopic mucosal resection (EMR) versus endoscopic submucosal resection (ESD). Comparative measurements showed significant differences in submucosal area ≥ 1000 μm and minimum submucosal thickness per tissue section analyzed (EMR vs. ESD: 91.2 % ± 6.6 vs. 47.1 % ± 10.6, P = 0.018; 933.7 µm ± 125.1 vs. 319.0 µm ± 123.6, P = 0.009). In contrast, no significant differences were observed in variation coefficient and mean maximum submucosal thickness. Thus, unexpectedly, in this small retrospective pilot study, specimens obtained using EMR had a better preserved submucosal layer than those obtained using ESD – possibly due to the different methods of specimen acquisition. The findings should be kept in mind when attempting to resect lesions suspicious for submucosal invasive cancer.

Assessment of tumor extension to the ductal system of submucosal glands in patients with superficial esophageal squamous neoplasms: Implications for endoscopic resection.

Endoscopic submucosal dissection (ESD) has become the standard treatment for superficial esophageal squamous cell neoplasia (SESCN); however, local recurrence still occurs occasionally even in patients who meet the current curative criteria. Esophageal ducts of the submucosal gland may serve as a pathway for the spread of SESCN to a deeper layer. However, the clinical impact of ductal involvement (DI) in patients undergoing ESD has yet to be investigated. We consecutively enrolled patients with SESCN who were treated with ESD. The resected specimens were meticulously reviewed in multiple section slices for the presence and resected margins of DI, and their correlations with clinical factors were evaluated. A total of 210 lesions were analyzed, of which 78 (37.1%) presented with DI. The presence of submucosal invasion, lymphovascular invasion (LVI), and DI were indicators of worse prognosis (P<.05). Deep extended DIs were misdiagnosed as deep submucosal invasive cancer in 4 cases (2%). Of the 185 patients who met the criteria for curative ESD (ie, R0 resection and no deep submucosal invasion or LVI), 11 (5.9%) developed local recurrence/metastasis during a mean follow-up of 55.2months (range, 6 to 140) months. Compared with patients with without DI, patients with DI had worse recurrence-free survival (P=.008, log-rank test) and a higher local risk of recurrence (12.7% vs 2.5%) after curative ESD (hazard ratio, 4.20; P=.038). A precise histological assessment of DI in SESCN is crucial after ESD, given that DI is common and associated with worse outcome. Whether total removal of esophageal glands/ducts can improve outcome requires future study.

Endoscopic intermuscular dissection for deep submucosal invasive cancer in the rectum. Is this the dawn of the endoscopic cancer surgeon?

Endoscopic intermuscular dissection for deep submucosal invasive cancer in the rectum. Is this the dawn of the endoscopic cancer surgeon?

A Rectum-Specific Selective Resection Algorithm Optimizes Oncologic Outcomes for Large Nonpedunculated Rectal Polyps

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are complementary techniques for large (≥20 mm) nonpedunculated rectal polyps (LNPRPs). A mechanism for appropriate technique selection has not been described. We evaluated the performance of a selective resection algorithm (SRA) (August 2017 to April 2021) compared with a universal EMR algorithm (UEA) (July 2008 to July 2017) for LNPRPs within a prospective observational study. In the SRA, LNPRPs with features of superficial submucosal invasive cancer (SMIC) (<1000 μm; Kudo pit pattern Vi), or with an increased risk of SMIC (Paris 0-Is or 0-IIa+Is nongranular, 0-IIa+Is granular with a dominant nodule ≥10 mm) underwent ESD. The remaining LNPRPs underwent EMR. Algorithm performance was evaluated by SMIC identified after EMR, curative oncologic resection (R0 resection, superficial SMIC, absence of negative histologic features), technical success, adverse events, and recurrence at first surveillance colonoscopy. A total of 480 LNPRPs were evaluated (290 UEA, 190 SRA). Median lesion size was 40 (interquartile range, 30-60) mm. SMIC was identified in 56 (11.7%) LNPRPs. Significant differences in SMIC after EMR (SRA 1 [1.0%] vs UEA 35 [12.1%]; P= .001) and curative oncologic resection (SRA n= 7 [33.3%] vs UEA n= 2 [5.7%]; P= .010) were identified. No significant differences in technical success or adverse events were identified (all P > .137). Among LNPRPs with SMIC amenable to curative oncologic resection and which underwent ESD, 100% (n= 7 of 7) were cured. A rectum-specific SRA optimizes oncologic outcomes for LNPRPs and mitigates the risk of piecemeal resection of cancers.

Endoscopic intermuscular dissection for deep submucosal invasive cancer in the rectum: a new endoscopic approach.

The risk of lymph node metastasis associated with deep submucosal invasion should be balanced against the mortality and morbidity of total mesorectal excision (TME). Dissection through the submucosa hinders radical deep resection, and full-thickness resection may influence the outcome of completion TME. Endoscopic intermuscular dissection (EID) in between the circular and longitudinal part of the muscularis propria could potentially provide an R0 resection while leaving the rectal wall intact. In this prospective cohort study, the data of patients treated with EID for suspected deep submucosal invasive rectal cancer between 2018 and 2020 were analyzed. Study outcomes were the percentages of technical success, R0 resection, curative resection, and adverse events. 67 patients (median age 67 years; 73 % men) were included. The median lesion size was 25 mm (interquartile range 20-33 mm). The rates of overall technical success, R0 resection, and curative resection were 96 % (95 %CI 89 %-99 %), 81 % (95 %CI 70 %-89 %), and 45 % (95 %CI 33 %-57 %). Only minor adverse events occurred in eight patients (12 %). EID for deep invasive T1 rectal cancer appears to be feasible and safe, and the high R0 resection rate creates the potential of rectal preserving therapy in 45 % of patients.