PurposeEndoscopic submucosal dissection (ESD) is a minimally invasive treatment for early gastric cancer (EGC) with negligible risk of lymph node metastasis (LNM). When a patient is determined to have noncurative resection after ESD, additional surgical resection with lymph node dissection is recommended. Previous studies report that LNM is found in about 10% of these patients. It may be possible to avoid unnecessary surgical resection by selecting patients properly. We aimed to clarify the risk factors associated with LNM in EGC patients who underwent ESD and to develop a highly accurate diagnostic algorithm for LNM.Patients and methodsAmong 1005 patients with EGC who underwent ESD, 423 patients who could be followed up for more than 3 years after treatment or who underwent additional surgical resection were examined. We used the leave-one-out method to explore the combination of predictive factors of LNM and differentiated LNM by a unique classifier.ResultsCurative resection was achieved in 322 patients, whereas noncurative resection was achieved in 101 patients. In the noncurative resection group, LNM occurred in eight patients with additional surgical resection and one patient during follow-up. The combination of depth of invasion, lymphatic, and venous invasion showed the highest diagnostic performance and could differentiate LNM with 100% sensitivity, 86% specificity, and 86% diagnostic accuracy.ConclusionMore than 500 μm submucosal invasion and lymphatic and venous invasion will be useful in assessing LNM after ESD for patients with EGC. When these three factors are not observed, follow-up alone might be appropriate and it may be possible to reduce unnecessary surgical resection.

Purpose The utility of chromoendoscopy for early gastric cancer (GC) was determined by machine learning using data of color differences. Methods Eighteen histopathologically confirmed early GC lesions were examined. We prepared images from white light endoscopy (WL), indigo carmine (Indigo), and acetic acid-indigo carmine chromoendoscopy (AIM). A border between cancerous and non-cancerous areas on endoscopic images was established from post-treatment pathological findings, and 2000 pixels with equivalent luminance values were randomly extracted from each image of cancerous and non-cancerous areas. Each pixel was represented as a three-dimensional vector with RGB values and defined as a sample. We evaluated the Mahalanobis distance using RGB values, indicative of color differences between cancerous and non-cancerous areas. We then conducted diagnosis test using a support vector machine (SVM) for each image. SVM was trained using the 100 training samples per class and determined which area each of 1900 test samples per class came from. Results The means of the Mahalanobis distances for WL, Indigo, and AIM were 1.52, 1.32, and 2.53, respectively and there were no significant differences in the three modalities. Diagnosability per endoscopy technique was assessed using the F1 measure. The means of F1 measures for WL, Indigo, and AIM were 0.636, 0.618, and 0.687, respectively. AIM images were better than WL and Indigo images for the diagnosis of GC. Conclusion Objective assessment by SVM found AIM to be suitable for diagnosis of early GC based on color differences.

Aim. To investigate the effect of daikenchuto (TJ-100; DKT) for ulcerative colitis (UC) model mouse and assess its anti-inflammatory mechanisms. Methods. We evaluated the effects of DKT on dextran sulfate sodium- (DSS-) induced experimental colitis. First, we assessed the short-term effects of DKT using two groups: 5% DSS group and 5% DSS with DKT group. Colon length; histological scores; and interleukin- (IL-) 10, IL-1β, and tumor necrosis factor-α mRNA expression profiles were analyzed using real-time PCR. Second, we assessed the long-term effects of DKT, by comparing survival time between 2% DSS and 2% DSS with DKT groups. Results. After 7 days, the colon lengths of DSS + DKT group were longer than those of the DSS group (mean values: 6.11 versus 5.69 cm, p < 0.05). Furthermore, compared to DSS group, the DSS + DKT group maintained significantly higher levels of serum hemoglobin (13.1 versus 10.7 g/dL, p < 0.05) and exhibited significantly higher expression levels of IL-10 (p < 0.05). The 2% DSS + DKT group exhibited significantly longer survival time than the 2% DSS group (70 versus 44 days, p < 0.01). Conclusion. Our results indicate that DKT prevented inflammation in the colon, indicating its potential as a new therapeutic agent for UC.

PurposeTo investigate which colonoscopy (CS) cases should be presided over by endoscopists in training, using factors including obesity and metabolic syndrome.Patients and methodsItems investigated were sex, age, body mass index (BMI), waist circumference, hypertension, diabetes, hyperlipidemia, history of abdominal surgery (excluding colectomy), colon diverticulosis, prescription of antithrombotic agents, and quality of bowel preparation. Expert physicians were defined as those with at least 9 years of endoscopy experience; all other physicians were defined as being in training. In a retrospective analysis, cases in which a physician in training reached the cecum within 15 minutes without requiring the involvement of the supervising physician were defined as eligible cases over which a physician in training should preside, while other cases were defined as non-eligible.ResultsOverall, 813 CS cases were analyzed. Males (P<0.0001), cases started by an expert physician (P<0.0001), cases of no fellow physician involvement (P<0.0001), and cases with good bowel preparation (P<0.0001) had significantly shorter cecal intubation times. Of the 562 cases presided over by a physician in training, 194 were deemed eligible and 368 non-eligible. The eligible cases had a higher proportion of males (P=0.017), younger age (P=0.033), higher BMI (P=0.034), and higher rates of hypertension (P=0.001) and good bowel preparation (P=0.001). In analysis by sex, males demonstrated significantly more eligible cases among younger patients (P=0.009) and those with good bowel preparation (P=0.008), while there were significantly more eligible cases among females with hypertension (P=0.004).ConclusionIt may be useful to select CS cases for physicians considering sex, age, BMI, hypertension, and bowel preparation.

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