Submucosal Cancer Research Articles

Diagnostic performance of the Japanese Narrow-band imaging expert team classification system using dual focus magnification in real-time Vietnamese setting.

The JNET classification, combined with magnified narrowband imaging (NBI), is essential for predicting the histology of colorectal polyps and guiding personalized treatment strategies. Despite its recognized utility, the diagnostic efficacy of JNET classification using NBI with dual focus (DF) magnification requires exploration in the Vietnamese context. This study aimed to investigate the diagnostic performance of the JNET classification with the NBI-DF mode in predicting the histology of colorectal polyps in Vietnam. A cross-sectional study was conducted at the University Medical Center in Ho Chi Minh City, Vietnam. During real-time endoscopy, endoscopists evaluated the lesion characteristics and recorded optical diagnoses using the dual focus mode magnification according to the JNET classification. En bloc lesion resection (endoscopic or surgical) provided the final pathology, serving as the reference standard for optical diagnoses. A total of 739 patients with 1353 lesions were recruited between October 2021 and March 2023. The overall concordance with the JNET classification was 86.9%. Specificities and positive predictive values for JNET types were: type 1 (95.7%, 88.3%); type 2A (81.4%, 90%); type 2B (96.6%, 54.7%); and type 3 (99.9%, 93.3%). The sensitivity and negative predictive value for differentiating neoplastic from non-neoplastic lesions were 97.8% and 88.3%, respectively. However, the sensitivity for distinguishing malignant from benign neoplasia was lower at 64.1%, despite a specificity of 95.9%. Notably, the specificity and positive predictive value for identifying deep submucosal cancer were high at 99.8% and 93.3%. In Vietnam, applying the JNET classification with NBI-DF demonstrates significant value in predicting the histology of colorectal polyps. This classification guides treatment decisions and prevents unnecessary surgeries.

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.

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.

Risk factors and a predictive nomogram for lymph node metastasis in superficial esophageal squamous cell carcinoma.

Superficial esophageal squamous cell carcinoma (ESCC) is defined as cancer infiltrating the mucosa and submucosa, regardless of regional lymph node metastasis (LNM). Endoscopic resection of superficial ESCC is suitable for lesions that have no or low risk of LNM. Patients with a high risk of LNM always need further treatment after endoscopic resection. Therefore, accurately assessing the risk of LNM is critical for additional treatment options. To analyze risk factors for LNM and develop a nomogram to predict LNM risk in superficial ESCC patients. Clinical and pathological data of superficial ESCC patients undergoing esophagectomy from January 1, 2009 to January 31, 2016 were collected. Logistic regression analysis was used to predict LNM risk factors, and a nomogram was developed based on risk factors derived from multivariate logistic regression analysis. The receiver operating characteristic (ROC) curve was used to obtain the accuracy of the nomogram model. A total of 4660 patients with esophageal cancer underwent esophagectomy. Of these, 474 superficial ESCC patients were enrolled in the final analysis, with 322 patients in the training set and 142 patients in the validation set. The prevalence of LNM was 3.29% (5/152) for intramucosal cancer and increased to 26.40% (85/322) for submucosal cancer. Multivariate logistic analysis showed that tumor size, invasive depth, tumor differentiation, infiltrative growth pattern, tumor budding, and lymphovascular invasion were significantly correlated with LNM. A nomogram using these six variables showed good discrimination with an area under the ROC curve of 0.789 (95%CI: 0.737-0.841) in the training set and 0.827 (95%CI: 0.755-0.899) in the validation set. We developed a useful nomogram model to predict LNM risk for superficial ESCC patients which will facilitate additional decision-making in treating patients who undergo endoscopic resection.

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.

Colonic de novo Clear Cell Adenocarcinoma of Intestinal-Type: A Case Report and Review of the Literature.

Colorectal clear cell adenocarcinomas are rare tumors. They can be divided into two types: intestinal- and Müllerian-type. Most intestinal-type clear cell adenocarcinomas show a composite morphology, and most early-stage (T1) intestinal-type clear cell adenocarcinomas have an adenoma component. We report an additional early-stage (T1) colonic clear cell adenocarcinoma that was a de novo adenocarcinoma without any adenoma component. It had a pure morphology and the smallest size (0.6 cm) ever reported. Immunohistochemical results demonstrated an intestinal phenotype (KRT20+, KRT7-, CEA+, and CDX2+). Periodic acid-schiff and alcian blue stains were both negative, which demonstrated decrease in mucin expression in the clear tumor cells. Enteroblastic differentiation was observed in a few colorectal clear cell adenocarcinomas in the literature, while it had not been observed in the present tumor. The tumor did not have deep submucosal invasion and cancer embolus, endoscopic submucosal dissection with regular follow-up was an appropriate treatment for the patient. Due to the rarity and diversity of primary colorectal clear cell adenocarcinomas, the cause of clear cytoplasm change and the impact on patient prognosis remain unknown. Accumulating evidence indicates that clear cell adenocarcinomas of intestinal-type is a histological variant of colorectal adenocarcinoma.

Usage trends of colorectal endoscopic submucosal dissection according to hospital types based on nationwide claims data.

Although the use of colorectal endoscopic submucosal dissection (ESD) for colorectal lesions has increased, there is a lack of analysis of the recent usage trends of ESD. Thus, this study aimed to identify changes in the annual utilization of ESD and determine the proportion of surgeries after ESD according to hospital types. Using Health Insurance Review and Assessment data from 2012 to 2019, 26,502 colorectal ESD cases were analyzed to assess the annual usage trends of ESD according to hospital type, additional early and late surgeries after ESD, changes in the distribution of colorectal lesions, and factors associated with early and late surgery. Trend analysis was performed using the chi-squared test for trend in proportions. Colorectal ESD increased from 2046 in 2012 to 5319 in 2019. Additional early and late surgeries rose from 135 (6.6%) in 2012 to 441 (8.2%) in 2019 (P < .05) and from 9 (0.3%) in 2013 to 52 (1.0%) in 2019 (P < .05), respectively. In tertiary and general hospitals, the proportion of submucosal cancers decreased, whereas the proportion of intramucosal cancers increased. Submucosal cancer was associated with early (odds ratio: 108.90, 95% confidence interval: 61.67-192.35) and late surgery (odds ratio: 3.55, 95% confidence interval: 2.27-5.56). Using nationwide data, our study identified the clinical usage trends of colorectal ESD based on the annual increase in utilization and the proportion of additional surgeries after ESD.

Prevalence and clinical significance of the muscle retracting sign during endoscopic submucosal dissection of large macronodular colorectal lesions (with videos)

The muscle retracting sign (MRS) can be present during endoscopic submucosal dissection (ESD) of macronodular colorectal lesions. The prevalence of MRS and its pathologic and clinical implications is unclear. This study evaluated the effect of MRS on the technical and clinical outcomes of ESD. All patients referred for ESD of protruding lesions or granular mixed lesions with >10mm macronodule granular mixed laterally spreading tumors (LST-GMs) in 2 academic centers from January 2017 to October 2022 were prospectively included. Size of the macronodule was analyzed retrospectively. The primary outcome was the curative resection rate according to MRS status. Secondary outcomes were R0 resection, perforation, secondary surgery rate, and risk factors for MRS. Of 694 lesions, 84 (12%) had MRS (MRS+). The curative resection rate was decreased by MRS (MRS+ 41.6% vs lesions without MRS [MRS-] 81.3%), whereas the perforation (MRS+ 22.6% vs MRS- 9.2%), submucosal cancer (MRS+ 34.9% vs MRS- 9.2%), and surgery (MRS+ 45.2% vs MRS- 6%) rates were increased. The R0 resection rate of MRS+ colonic lesions was lower than that of rectal lesions (53% vs 74.3%). In multivariate analysis, protruding lesions (odds ratio, 2.47; 95% confidence interval, 1.27-4.80) and macronodules >4 cm (odds ratio, 4.24; 95% confidence interval, 2.23-8.05) were risk factors for MRS. MRS reduces oncologic outcomes and increases the perforation rate. Consequently, procedures in the colon should be stopped if MRS is detected, and those in the rectum should be continued due to the morbidity of alternative therapy.

Endoscopic intermuscular dissection (EID) for removing early rectal cancers and benign fibrotic rectal lesions.

In the current era of screening colonoscopy and increasing incidence of early rectal cancer, interventional endoscopy moves toward resections in deeper planes than the submucosal layer. Several reports support the use of endoscopic intermuscular dissection (EID) instead of endoscopic submucosal dissection (ESD) for the removal of deeply invasive rectal submucosal cancers. The resection plane into the intermuscular space, the space between the longitudinal (external) and circular (internal) muscle layer, allows radical removal of rectal invasive submucosal cancers. Furthermore, the technique offers the potential for dissection of scarred and severe fibrotic lesions in the rectum by cutting deeper and performing a partial myectomy avoiding the narrow submucosal space. We present 23 cases ofEIDs both for deeply invasive rectal cancers and benign rectal lesions. This is the first report in the literature of EID resections for malignant and benign disease, including cases of severely fibrotic rectal lesions.

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.

Chicken skin mucosa surrounding small colorectal cancer could be an endoscopic predictive marker of submucosal invasion.

Chicken skin mucosa (CSM) surrounding colon polyps is a common endoscopic finding with pale yellow-speckled mucosa during a colonoscopy screening. Although reports about CSM surrounding small colorectal cancer are scarce, and its clinical significance in intramucosal and submucosal cancers is unclear, previous studies have suggested it could be an endoscopic predictive marker for colonic neoplastic and advanced polyps. Currently, because of the inaccurate preoperative evaluation by endoscopists, many small colorectal cancers, particularly lesions with a diameter < 2 cm, are improperly treated. Therefore, more effective methods are required to better assess the depth of the lesion before treatment. To explore potential markers of small colorectal cancer early invasion under white light endoscopy, providing patients with better treatment alternatives. This retrospective cross-sectional study included 198 consecutive patients [233 early colorectal cancers (ECCs)] who underwent endoscopy or surgical procedures at the Digestive Endoscopy Center of Chengdu Second People's Hospital between January 2021 and August 2022. The participants had pathologically confirmed colorectal cancer with a lesion diameter < 2 cm and received endoscopic or surgical treatment, including endoscopic mucosal resection and submucosal dissection. Clinical pathology and endoscopy parameters, including tumor size, invasion depth, anatomical position, and morphology, were reviewed. Fisher's exact test, the χ2 test, and Student's t-test were used to analyze the patient's basic characteristics. Logistic regression analysis was used to examine the relationship between morphological characteristics, size, CSM prevalence, and ECC invasion depth under white light endoscopy. Statistical significance was set at P < 0.05. The submucosal carcinoma (SM stage) was larger than the mucosal carcinoma (M stage) with a significant difference (17.2 ± 4.1 vs 13.4 ± 4.6 mm, P < 0.01). M- and SM-stage cancers were common in the left colon; however, no significant differences were found between them (151/196, 77% and 32/37, 86.5%, respectively, P = 0.199). The endoscopic features of colorectal cancer revealed that CSM, depressed areas with clear boundaries, and erosion or ulcer bleeding were more common in the SM-stage cancer group than in the M-stage cancer group (59.5% vs 26.2%, 46% vs 8.7%, and 27.3% vs 4.1%, respectively, P < 0.05). CSM prevalence in this study was 31.3% (73/233). The positive rates of CSM in flat, protruded, and sessile lesions were 18% (11/61), 30.6% (30/98), and 43.2% (32/74), respectively, with significant differences (P = 0.007). CSM-related small colorectal cancer was primarily located in the left colon and could be a predictive marker of submucosal invasion in the left colon.

A case of chronic gastric anisakiasis coexisting with early gastric cancer.

Anisakiasis is a parasitic disease caused by the consumption of raw or undercooked fish that is infected with Anisakis third-stage larvae. In countries, such as Japan, Italy, and Spain, where people have a custom of eating raw or marinated fish, anisakiasis is a common infection. Although anisakiasis has been reported in the gastrointestinal tract in several countries, reports of anisakiasis accompanied by cancer are rare. We present the rare case of a 40-year-old male patient with anisakiasis coexisting with mucosal gastric cancer. Submucosal gastric cancer was suspected on gastric endoscopy and endoscopic ultrasonography. After laparoscopic distal gastrectomy, granulomatous inflammation with Anisakis larvae in the submucosa was pathologically revealed beneath mucosal tubular adenocarcinoma. Histological and immunohistochemical investigation showed cancer cells as intestinal absorptive-type cells that did not produce mucin. Anisakis larvae could have invaded the cancer cells selectively because of the lack of mucin in the cancerous epithelium. Anisakiasis coexisting with cancer is considered reasonable rather than coincidental. In cancer with anisakiasis, preoperative diagnosis may be difficult because anisakiasis leads to morphological changes in the cancer.

Clinical and endoscopic characteristics of sessile serrated lesions with dysplasia/carcinoma.

Some sessile serrated lesions (SSLs) progress into dysplasia and colorectal cancer, however, the clinical and endoscopic characteristics of SSLs with dysplasia remain to be determined. In this study, we elucidated these characteristics in SSLs with dysplasia/carcinoma, compared with those of SSLs without dysplasia. We retrospectively collected the clinical, endoscopic, and pathological data of 254 SSLs from 216 patients endoscopically resected between January 2009 and December 2020. All SSLs included 179 without dysplasia and 75 with dysplasia/carcinoma, including 55 with low-grade dysplasia, 10 with high-grade dysplasia, and 10 with submucosal cancer. In clinical characteristics, SSLs with dysplasia/carcinoma were significantly associated with advanced age, metabolic diseases, and high-risk adenomas. In endoscopic characteristics, SSLs with dysplasia/carcinoma were significantly associated with the distal colon, large size, polypoid morphology, surface-changes, no mucus cap, and narrow-band imaging international colorectal endoscopic classification (NICE) type 2/3. In the multivariate analysis, high-risk adenomas (odds ratio [OR], 2.98; p = 0.01), large size (OR, 1.18; p < 0.01), depression (OR, 11.74; p = 0.03), and NICE type 2/3 (OR, 14.97; p < 0.01) were significantly associated with SSLs with dysplasia/carcinoma. SSLs had a higher risk of dysplasia in the distal colon than in the proximal colon. SSLs with large size, depression, and adenomatous surface-patterns, as well as those in patients with high-risk adenomas, increased the risk of dysplasia/ carcinoma. This suggests that the clinical and endoscopic characteristics can aid in the diagnosis and management of SSLs with dysplasia/carcinoma.

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

Tumor-infiltrating T cells as a risk factor for lymph node metastasis in patients with submucosal colorectal cancer

Approximately 10% of patients with colorectal cancer with submucosal invasion have lymph node metastasis. Pathological risk factors for lymph node metastasis have varying sensitivities and specificities. To predict the risk of lymph node metastasis, the identification of new risk factors is vital. Tumor-infiltrating T cells have been reported to improve the prognosis of many solid tumors. Therefore, the purpose of this study was to examine the relationship between lymph node metastasis and tumor-infiltrating T cells in patients with colorectal cancer with submucosal invasion. We examined CD8+ tumor-infiltrating T cells level as a risk factor for lymph node metastasis in patients with colorectal cancer with submucosal invasion. Using immunohistochemical staining, we identified CD8 + T cells in surgically resected specimens from 98 patients with SM-CRC. We showed that low CD8+ tumor-infiltrating T cells levels are positively correlated with lymph node metastasis. Furthermore, by combining the number of CD8+ tumor-infiltrating T cell and the number of CD103+ tumor-infiltrating T cells, the results showed a high positive predictive value for lymph node metastasis in cases with low numbers of both types of tumor-infiltrating T cells and a high negative predictive value in cases with high numbers of both types of tumor-infiltrating T cells.