Performance evaluation of a computer-aided polyp detection system with artificial intelligence for colonoscopy.

OBJECTIVES: A computer-aided detection (CAD) system was developed to support the detection of colorectal lesions by deep learning using video images of lesions and normal mucosa recorded during colonoscopy. The study's purpose was to evaluate the stand-alone performance of this device under blinded conditions. METHODS: This multicenter prospective observational study was conducted at four Japanese institutions. We used 326 videos of colonoscopies recorded with patient consent at institutions in which the Ethics Committees approved the study. The sensitivity of successful detection of the CAD system was calculated using the target lesions, which were detected by adjudicators from two facilities for each lesion appearance frame; inconsistencies were settled by consensus. Successful detection was defined as display of the detection flag on the lesion for more than 0.5 s within 3 s of appearance. RESULTS: Of the 556 target lesions from 185 cases, detection success sensitivity was 97.5% (95% confidence interval [CI] 95.8-98.5%). The "successful detection sensitivity per colonoscopy" was 93% (95% CI 88.3-95.8%). For the frame-based sensitivity, specificity, positive predictive value, and negative predictive value were 86.6% (95% CI 84.8-88.4%), 84.7% (95% CI 83.8-85.6%), 34.9% (95% CI 32.3-37.4%), and 98.2% (95% CI 97.8-98.5%), respectively. TRIAL REGISTRATION: University Hospital Medical Information Network (UMIN000044622).

Artificial Intelligence System to Determine Risk of T1 Colorectal Cancer Metastasis to Lymph Node.

BACKGROUND & AIMS: In accordance with guidelines, most patients with T1 colorectal cancers (CRC) undergo surgical resection with lymph node dissection, despite the low incidence (∼10%) of metastasis to lymph nodes. To reduce unnecessary surgical resections, we used artificial intelligence to build a model to identify T1 colorectal tumors at risk for metastasis to lymph node and validated the model in a separate set of patients. METHODS: We collected data from 3134 patients with T1 CRC treated at 6 hospitals in Japan from April 1997 through September 2017 (training cohort). We developed a machine-learning artificial neural network (ANN) using data on patients' age and sex, as well as tumor size, location, morphology, lymphatic and vascular invasion, and histologic grade. We then conducted the external validation on the ANN model using independent 939 patients at another hospital during the same period (validation cohort). We calculated areas under the receiver operator characteristics curves (AUCs) for the ability of the model and US guidelines to identify patients with lymph node metastases. RESULTS: Lymph node metastases were found in 319 (10.2%) of 3134 patients in the training cohort and 79 (8.4%) of /939 patients in the validation cohort. In the validation cohort, the ANN model identified patients with lymph node metastases with an AUC of 0.83, whereas the guidelines identified patients with lymph node metastases with an AUC of 0.73 (P < .001). When the analysis was limited to patients with initial endoscopic resection (n = 517), the ANN model identified patients with lymph node metastases with an AUC of 0.84 and the guidelines identified these patients with an AUC of 0.77 (P = .005). CONCLUSIONS: The ANN model outperformed guidelines in identifying patients with T1 CRCs who had lymph node metastases. This model might be used to determine which patients require additional surgery after endoscopic resection of T1 CRCs. UMIN Clinical Trials Registry no: UMIN000038609.

Risk factors for vertical incomplete resection in endoscopic submucosal dissection of deep invasive submucosal colorectal cancer.

INTRODUCTION: It has been recently reported that deep invasive submucosal (T1b) colorectal cancer (CRC) without other pathological risk factors for lymph node metastasis has a low rate of lymph node metastasis, increasing the possibility of endoscopic submucosal dissection (ESD) in the future. However, ESD for T1b CRC is technically difficult, and some lesions cannot be resected en bloc. This study aimed to identify the risk factors associated with vertical incomplete ESD in T1b CRC. METHODS: We retrospectively studied 140 pathological T1b CRC lesions that underwent initial ESD at our institution between January 2011 and October 2020, and categorized them into positive vertical margin (PVM) and negative vertical margin (NVM) groups. The risk factors for PVM were examined using univariate and multivariate analyses, and a subgroup analysis for T1b CRC with an obvious depressed surface was performed. RESULTS: Multivariate analysis revealed obvious depression (hazard ratio [HR]: 7.4; 95% confidence interval [CI]: 2.47-22.5) and severe fibrosis (HR: 11.4; 95% CI: 3.95-33.0) as significant risk factors for PVM. Length of depressed surface ≥12 mm (HR: 6.19; 95% CI: 1.56 -24.6) was identified as an independent predictor of PVM for T1b CRC with an obvious depression. CONCLUSION: Pathological T1b CRC cases with an obvious depression and severe fibrosis are at a high risk of vertical incomplete ESD.

Training program using a traction device improves trainees' learning curve of colorectal endoscopic submucosal dissection.

BACKGROUND: Colorectal endoscopic submucosal dissection (ESD) requires advanced endoscopic skill. For safer and more reliable ESD implementation, various traction devices have been developed in recent years. The purpose of this research was to evaluate whether an ESD training program using a traction device (TD) would contribute to the improvement of trainees' skill acquisition. METHODS: The differences in treatment outcomes and learning curves by the training program were compared before and after the introduction of TD (control group: January 2014 to March 2016; TD group: April 2016 to June 2018). RESULTS: A total of 316 patients were included in the analysis (TD group: 202 cases; control group: 114 cases). The number of cases required to achieve proficiency in ESD techniques was 10 in the TD group and 21 in the control group. Compared to the control group, the TD group had a significant advantage in ESD self-completion rate (73.8% vs. 58.8%), dissection speed (19.5 mm2/min vs. 15.9 mm2/min), en bloc resection rate (100% vs. 90%), and R0 resection rate (96% vs. 83%). CONCLUSIONS: The rate of colorectal ESD self-completion by trainees improved immediately after the start of the training program using a traction device compared to the conventional method, and the dissection speed tended to increase linearly with ESD experience. We believe that ESD training using a traction device will help ESD techniques to be performed safely and reliably among trainees.

Adding Narrow-Band Imaging to Chromoendoscopy for the Evaluation of Tumor Response to Neoadjuvant Therapy in Rectal Cancer.

BACKGROUND: Endoscopic assessment is crucial in diagnosing clinical complete response after neoadjuvant therapy in rectal cancer. OBJECTIVE: The purpose of this research was to evaluate the benefits of adding narrow-band imaging endoscopy to conventional chromoendoscopy in predicting pathologic complete response in the surgical specimen. DESIGN: This was a prospective nonrandomized study. SETTINGS: This was an ad hoc study of a prospective phase II trial at a single comprehensive cancer center that evaluated oncologic outcomes of a neoadjuvant therapy for rectal cancer. PATIENTS: Patients with high-risk stage II to III low rectal cancer who received neoadjuvant modified folinic acid, fluorouracil, and oxaliplatin plus bevacizumab followed by chemoradiotherapy and surgery were included. INTERVENTION: Tumor response after neoadjuvant therapy was evaluated using conventional white light endoscopy plus chromoendoscopy then followed by using narrow-band imaging based on a predefined diagnostic protocol. MAIN OUTCOME MEASURES: Diagnostic accuracy for predicting pathologic complete response and inter-rater agreement between an expert and trainee endoscopists were compared between the assessments using conventional white light endoscopy plus chromoendoscopy and the assessment adding narrow-band imaging. RESULTS: In total, 61 patients were eligible for the study, and 19 had pathologic complete response (31.1%). Although the addition of narrow-band imaging correctly converted the diagnosis in 3 patients, overall diagnostic improvement in predicting pathologic complete response was limited (conventional chromoendoscopy vs adding narrow-band imaging: accuracy, 70.5% vs 75.4%; sensitivity, 63.2% vs 73.7%; specificity, 73.8% vs 76.2%; positive predictive value, 52.2% vs 58.3%; and negative predictive value, 81.6% vs 86.5%). A κ value for the inter-rater agreement improved from 0.599 to 0.756 by adding narrow-band imaging. LIMITATIONS: This was a single-center study with a relatively small sample size. CONCLUSIONS: Despite the limited improvement in diagnostic accuracy, adding narrow-band imaging to chromoendoscopy improved inter-rater agreement between the expert and nonexpert endoscopists. Narrow-band imaging is a reliable and promising modality for universal standardization of the diagnosis of clinical complete response. See Video Abstract at http://links.lww.com/DCR/B275. ADICIÓN DE IMÁGENES DE BANDA ESTRECHA A LA CROMOENDOSCOPÍA PARA LA EVALUACIÓN DE LA RESPUESTA TUMORAL A LA TERAPIA NEOADYUVANTE EN EL CÁNCER DE RECTO: La evaluación endoscópica es fundamental para valorar la respuesta clínica completa después de la terapia neoadyuvante en el cáncer de recto.Evaluar los beneficios de agregar endoscopia de imagen de banda estrecha a la cromoendoscopía convencional para predecir la respuesta patológica completa en la muestra quirúrgica.Estudio prospectivo no aleatorizado.Un estudio ad hoc de un ensayo prospectivo de fase II en un solo centro integral de cáncer que evaluó los resultados oncológicos de una terapia neoadyuvante para el cáncer rectal.Pacientes con cáncer rectal bajo de alto riesgo en estadio II-III que recibieron ácido folínico neoadyuvante modificado, fluorouracilo y oxaliplatino más bevacizumab seguido de quimiorradioterapia y cirugía.La respuesta tumoral después de la terapia neoadyuvante se evaluó mediante endoscopia de luz blanca convencional más cromoendoscopía, seguido de imágenes de banda estrecha basadas en un protocolo de diagnóstico predefinido.La precisión diagnóstica para predecir la respuesta patológica completa y el acuerdo entre evaluadores entre un experto y un endoscopista en entrenamiento se compararon entre las evaluaciones utilizando endoscopia de luz blanca convencional más cromoendoscopía y la evaluación agregando imágenes de banda estrecha.En total, 61 pacientes fueron elegibles para el estudio, y 19 tuvieron una respuesta patológica completa (31.1%). Aunque la adición de imágenes de banda estrecha convirtió correctamente el diagnóstico en 3 pacientes, la mejora diagnóstica general en la predicción de la respuesta patológica completa fue limitada (cromoendoscopía convencional versus adición de imágenes de banda estrecha: precisión, 70.5% versus 75.4%; sensibilidad, 63.2% versus 73.7%; especificidad, 73.8% versus 76.2%; valor predictivo positivo, 52.2% versus 58.3%; y valor predictivo negativo, 81.6% versus 86.5%). Un valor de kappa para el acuerdo entre evaluadores mejoró de 0.599 a 0.756 al agregar imágenes de banda estrecha.Un estudio de centro único con un tamaño de muestra relativamente pequeño.A pesar de la mejora limitada en la precisión diagnóstica, agregar imágenes de banda estrecha a la cromoendoscopía mejoró el acuerdo entre evaluadores entre los endoscopistas expertos y no expertos. La imagenología de banda estrecha es una modalidad confiable y prometedora para la estandarización universal del diagnóstico de respuesta clínica completa. Consulte Video Resumen en http://links.lww.com/DCR/B275.

Malignant potential of colorectal neoplasms in Lynch syndrome: an analysis of 325 lesions endoscopically treated at a single institute.

BACKGROUND: Patients with Lynch syndrome are at an increased risk of developing colorectal cancer, and the adenoma-carcinoma sequence is accelerated in these patients. However, the clinicopathological characteristics of colorectal neoplasms in Lynch syndrome patients are not well-known. METHODS: A total of 325 consecutive colorectal neoplasms were endoscopically removed from 68 patients with Lynch syndrome between June 2005 and May 2018 and retrospectively reviewed. RESULTS: Of the 325 lesions, 94 (29%), 220 (68%) and 11 (3%) were from patients with MLH1, MSH2 and MSH6 mutations, respectively. The median lesion size was 5 mm (range 2-40 mm), with 229 (71%) lesions having a non-polypoid morphology. The frequencies of advanced neoplasms, including high-grade adenomas, intramucosal carcinomas and submucosal invasive carcinomas were 14, 34, 97 and 93% for lesions with diameters of <5, ≥5 and <10, ≥10 and <20, and ≥20 mm, respectively. The frequencies of advanced neoplasms in the proximal colon, distal colon and rectum did not significantly differ (36, 35 and 41%, respectively). CONCLUSIONS: Our results suggest that the malignant transformation interval from low-grade adenomas to advanced neoplasms is similar in all parts of the colon. Furthermore, since one-third of neoplastic lesions with diameters of ≥5 and <10 mm and most of those ≥10 mm were advanced neoplasms, we recommend that in Lynch syndrome patients, careful colonoscopic surveillance should be performed throughout the colon, and all neoplastic lesions, regardless of the size, should be subjected to detailed endoscopic examination, complete resection and detailed pathological examination.

Clinical utility of the pocket-creation method with a traction device for colorectal endoscopic submucosal dissection.

BACKGROUND: Colorectal endoscopic submucosal dissection (ESD) is technically demanding while ensuring safety, especially in cases with fibrosis and/or poor maneuverability. To overcome such difficulties, we developed a novel method called the pocket-creation method with a traction device (PCM with TD). We then evaluated the effectiveness and safety of PCM with TD in colorectal ESD compared to other conventional methods. METHODS: In total, 324 colorectal lesions treated with ESD from July 2018 to June 2019 were included. The following three treatment strategies were used: conventional ESD (CE), CE with TD, and PCM with TD. Patient backgrounds and treatment outcomes were retrospectively compared and analyzed. RESULTS: As ESD methods, CE, CE with TD, and PCM with TD account for 58% (187/324), 24% (78/324), and 18% (59/324), respectively. No significant difference was observed among the three groups in en bloc and R0 resection rates or adverse events. The rate of lesions with fibrosis and poor maneuverability was significantly higher in the PCM with TD group (CE group vs CE with TD group vs PCM with TD group: fibrosis, 24% vs 47% vs 64%, p < 0.001; poor maneuverability, 5.3% vs 13% vs 20%, p = 0.002). Dissection speed was significantly higher in the PCM with TD than in the CE with TD group (p = 0.003). CONCLUSIONS: PCM with TD can achieve a stable en bloc resection rate and R0 dissection rate without adverse events even in the hands of trainees, irrespective of the size and location of the lesion, presence of fibrosis, and under poor maneuverability conditions.

Macroscopic and microscopic morphology and molecular profiling to distinguish heterogeneous traditional serrated adenomas of the colorectum.

OBJECTIVES: Serrated lesions of the colorectum often have complex histological morphology, and some groups include subtypes with different molecular biology. This study aimed to characterize serrated lesions with heterogeneous histology that was dominated by a traditional serrated adenoma (TSA) component. METHODS: Representative lesions were selected based on both endoscopic and histological features. If a lesion had more than one component, each of the different structural parts was considered as a separate sample. DNA was extracted from 177 samples of 60 lesions and amplified to screen for BRAF and K/NRAS mutations. RESULTS: Heterogeneous TSA samples were classified into four categories: sessile serrated lesion with TSA (SA-1); TSAs with microvesicular hyperplastic polyp (SA-2); TSAs with unclassified adenoma, characterized by tubulo-serrated histology (SA-3); and TSAs with conventional adenomas (SA-4). On endoscopy, SA-1 lesions had sessile-elevated morphology with the small reddish elevations; SA-2 lesions had a pedunculated appearance with a whitish mucosal component at the stalk; SA-3 lesions had a sessile-elevated component surrounded by flat spreading margins; and SA-4 lesions had mixed adenomatous morphology. Eighteen of the 19 category SA-1 and -2 lesions (95%) had BRAF mutations, and all of the SA-3 and -4 lesions had K/NRAS mutations. CONCLUSIONS: Traditional serrated adenomas were classified into two phenotypes according to their molecular characteristics: microvesicular serrated subtypes with BRAF mutations (SA-1 and -2 lesions) and subtypes containing tubulo-serrated/conventional adenoma with K/NRAS mutations (SA-3 and -4 lesions). Each subtype had characteristic macroscopic and microscopic morphologies and was distinct on endoscopy.

Phenotypic variations of gastric neoplasms in familial adenomatous polyposis are associated with endoscopic status of atrophic gastritis.

BACKGROUND AND AIM: Gastric neoplasms (GN), including gastric adenoma and carcinoma, are well known as extracolonic manifestations of familial adenomatous polyposis (FAP). We aimed to investigate the clinicopathological features of GN in FAP patients and to clarify their relationship with the endoscopic status of the background mucosa. METHODS: We analyzed the records of 39 patients who were diagnosed with FAP and underwent esophagogastroduodenoscopy between April 2005 and July 2016. Patients were divided into two groups according to atrophic gastritis (AG) status. Endoscopic findings of GN and background mucosa, and histopathological findings, including phenotypic expression of GN and mutation locus of adenomatous polyposis coli (APC) gene, were evaluated. RESULTS: Gastric neoplasms were more predominant in the AG-positive group than in the AG-negative group (6/9, 66.7% vs 7/30, 23.3%; P = 0.039). Of 36 GN detected in 13 patients, six GN in five patients were followed and 30 GN in eight patients were endoscopically resected and analyzed. GN in the AG-negative group frequently showed whitish color, were located in the proximal stomach, and presented the gastric immunophenotype compared to GN in the AG-positive group. All GN were intramucosal lesions and were curatively resected regardless of AG status. APC germline mutations were identified in 32 patients. In patients with GN, a significantly higher number of mutation loci were among exons 10-15 (codons 564-1465). CONCLUSION: Clinicopathological characteristics and phenotypic expressions of GN in FAP patients depend on background mucosa status with or without AG. These findings are useful for detecting GN in FAP patients.

Clinicopathological characteristics and frequency of multiple rectal neuroendocrine tumors: a single-center retrospective study.

BACKGROUND: Rectal multiple neuroendocrine tumors (M-NETs) are rare, with only few epidemiologic reports on the topic. Therefore, their clinicopathological features are not completely known, and the appropriate treatment strategy has not been established. PURPOSE: This study aimed to compare the clinicopathological malignant potential (lymphatic or venous invasion-positive and lymph node metastasis rates) of M-NETs with that of solitary NETs (S-NETs). METHODS: We retrospectively investigated 369 patients with NETs of the rectum. Patients who underwent colonoscopy at the Cancer Institute Hospital between January 1979 and 2016 and diagnosed with S-NETs were included, and S-NETs were found in 348 patients. Patients with M-NETs were classified into two groups as follows: patients with < 8 tumors (several (S) group, n = 21) and those with ≥ 8 tumors (numerous (N) group, n = 3). RESULTS: The overall frequency of M-NETs was 5.7% and that of the N group was 0.8%. The mean tumor diameter in the N group was 6.0 mm (range, 4-8 mm). The lymphatic invasion rates of the S-NETs, and S and N groups of the M-NETs were 8.9%, 5.6%, and 66.7%, respectively. Moreover, the lymph node metastasis rates were 9.2%, 11.1%, and 33.3, respectively. CONCLUSIONS: While M-NETs in the S and N groups had different characteristics, they were rarer in the N group. The N group may have higher rates of lymphatic invasion and lymph node metastasis regardless of tumor size.

Exploring substituent diversity on pyrrolidine-aryltriazole iminosugars: Structural basis of ß-glucocerebrosidase inhibition.

The synthesis of a library of pyrrolidine-aryltriazole hybrids through CuAAC between two epimeric dihydroxylated azidomethylpyrrolidines and differently substituted phenylacetylenes is reported. The evaluation of the new compounds as inhibitors of lysosomal ß-glucocerebrosidase showed the importance of the substitution pattern of the phenyl moiety in the inhibition. Crystallization and docking studies revealed key interactions of the pyrrolidine motif with aminoacid residues of the catalytic site while the aryltriazole moiety extended along a hydrophobic surface groove. Some of these compounds were able to increase the enzyme activity in Gaucher patient fibroblasts, acting as a new type of chemical chaperone for Gaucher disease.

[Spontaneous regression of primary gastric EBV-positive diffuse large B-cell lymphoma].

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) in the elderly was revised from the category EBV-positive DLBCL not otherwise specified in WHO 2017. The prognosis of this lymphoma is very poor. We report a case of an 82-year-old woman diagnosed with gastric EBV-positive DLBCL (WHO 2008). Gastroduodenoscopy revealed multiple ulcers and fold thickening. She was followed-up without any treatment because of her old age. Repeat endoscopy one year and eight months later revealed a single ulcer with no lymphoma cells found in a biopsy specimen. Two years later, the lesion had spontaneously disappeared.

Discovery of a Potent α-Galactosidase Inhibitor by in Situ Analysis of a Library of Pyrrolizidine-(Thio)urea Hybrid Molecules Generated via Click Chemistry.

The parallel synthesis of a 26-membered-library of aromatic/aliphatic-(thio)urea-linked pyrrolizidines followed by in situ biological evaluation toward α-galactosidases has been carried out. The combination of the (thio)urea-forming click reaction and the in situ screening is pioneer in the search for glycosidase inhibitors and has allowed the discovery of a potent coffee bean α-galactosidase inhibitor (IC50 = 0.37 µM, Ki = 0.12 µM) that has also showed inhibition against human lysosomal α-galactosidase (α-Gal A, IC50 = 5.3 µM, Ki = 4.2 µM).

Divergent synthesis of new α-glucosidase inhibitors obtained through a vinyl Grignard-mediated carbocyclisation.

Four new α-glucosidase inhibitors have been synthesised through 5-8 synthetic steps from a common synthetic intermediate obtained through a recently developed carbocyclisation. The compounds were designed as hybrids of the known glucosidase inhibitors valienamine, voglibose and miglitol. All four compounds showed activity against rat intestinal sucrase with the most potent inhibitor acting at low micromolar concentration. The newly synthesised compounds were not as potent as miglitol against sucrase but showed greater selectivity towards the tested glycosidases. The most potent inhibitors were docked into a homology model built for this study of rat intestinal sucrase explaining the difference in potency between two diastereoisomers with varying orientation of a secondary amine.

Multivalency To Inhibit and Discriminate Hexosaminidases.

A set of multivalent polyhydroxylated acetamidoazepanes based on ethylene glycol, glucoside, or cyclodextrin scaffolds was prepared. The compounds were assessed against plant, mammalian, and therapeutically relevant hexosaminidases. Multimerization was shown to improve the inhibitory potency with synergy, and to fine tune the selectivity profile between related hexosaminidases.

Efficacy of hyperbaric oxygen therapy in patients with radiation-induced rectal ulcers: Report of five cases.

For decades, hyperbaric oxygen therapy has been considered a treatment option in patients with chronic radiation-induced proctitis after pelvic radiation therapy. Refractory cases of chronic radiation-induced proctitis include ulceration, stenosis, and intestinal fistulas with perforation. Appropriate treatment needs to be given. In the present study, we assessed the efficacy of hyperbaric oxygen therapy in five patients with radiation-induced rectal ulcers. Significant improvement and complete ulcer resolution were observed in all treated patients; no side-effects were reported. Hyperbaric oxygen therapy has a low toxicity profile and appears to be highly effective in patients with radiation-induced rectal ulcers. However, hyperbaric oxygen therapy alone failed to improve telangiectasia and easy bleeding in four of the five patients; these patients were further treated with argon plasma coagulation (APC). Although hyperbaric oxygen therapy may be effective in healing patients with ulcers, it seems inadequate in cases with easy bleeding. Altogether, these data suggest that combination therapy with hyperbaric oxygen therapy and APC may be an effective and safe treatment strategy in patients with radiation-induced rectal ulcers.

[Blood Transfusion Inspection].

Nearly one-half of all hematopoietic progenitor cell transplantation (HCT) procedures involve recipient- donor ABO incompatibility. ABO-incompatible HCT places the recipient at an increased risk of acute and delayed hemolytic reactions, delayed RBC engraftment, and pure red blood cell aplasia. Additionally, clinical and laboratory evaluations for potential non-ABO, minor RBC antigen-antibody discrepancies may be benefi- cial to facilitate safe transfusions before, during, and after transplantation. It is important for medical tech- nologists to play a role in ABO-incompatible HCT as members of the medical team. Medical technologists should obtain accurate laboratory data and analyze the outcomes in patients receiving ABO-incompatible HCT.