Exploratory investigation of virtual lesions in gastrointestinal endoscopy using a novel phase-shift method for three-dimensional shape measurement.

Accurate measurement of the size of lesions or distances between any two points during endoscopic examination of the gastrointestinal tract is difficult owing to the fisheye lens used in endoscopy. To overcome this issue, we developed a phase-shift method to measure three-dimensional (3D) data on a curved surface, which we present herein. Our system allows the creation of 3D shapes on a curved surface by the phase-shift method using a stripe pattern projected from a small projecting device to an object. For evaluation, 88 measurement points were inserted in porcine stomach tissue, attached to a half-pipe jig, with an inner radius of 21 mm. The accuracy and precision of the measurement data for our shape measurement system were compared with the data obtained using an Olympus STM6 measurement microscope. The accuracy of the path length of a simulated protruded lesion was evaluated using a plaster model of the curved stomach and graph paper. The difference in height measures between the measurement microscope and measurement system data was 0.24 mm for the 88 measurement points on the curved surface of the porcine stomach. The error in the path length measurement for a lesion on an underlying curved surface was <1% for a 10-mm lesion. The software was developed for the automated calculation of the major and minor diameters of each lesion. The accuracy of our measurement system could improve the accuracy of determining the size of lesions, whether protruded or depressed, regardless of the curvature of the underlying surface.

Endoscopic features of synchronous multiple early gastric cancers: Findings from a nationwide cohort.

INTRODUCTION: We investigated the factors associated with synchronous multiple early gastric cancers and determined their localization. METHODS: We analyzed 8191 patients who underwent endoscopic submucosal dissection for early gastric cancers at 33 hospitals in Japan from November 2013 to October 2016. Background factors were compared between single-lesion (n=7221) and synchronous multi-lesion cases (n=970) using univariate and multivariate analyses. We extracted cases with two synchronous lesions (n=832) and evaluated their localization. RESULTS: Significant independent risk factors for synchronous multiple early gastric cancer were older age (≥75 years old) (OR=1.257), male sex (OR=1.385), severe mucosal atrophy (OR=1.400), tumor localization in the middle (OR=1.362) or lower region (OR=1.404), and submucosal invasion (OR=1.528 (SM1), 1.488 (SM2)). Depressed macroscopic type (OR=0.679) and pure undifferentiated histology OR=0.334) were more common in single early gastric cancers. When one lesion was in the upper region, the other was more frequently located in the lesser curvature of the middle region. When one lesion was in the middle region, the other was more frequently located in the middle region or the lesser curvature of the lower region. When one lesion was in the lower region, the other was more frequently located in the lesser curvature of the middle region or the lower region. CONCLUSION: Factors associated with synchronous multiple early gastric cancer included older age, male sex, severe mucosal atrophy, tumor localization in the middle or lower region, and tumor submucosal invasion. Our findings provide useful information regarding specific areas that should be examined carefully when one lesion is detected.

Risk factors for intraoperative and delayed perforation related with gastric endoscopic submucosal dissection.

BACKGROUND AND AIM: Perforation is one of the most important complications of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). Several studies have examined risk factors for intraoperative and delayed perforations, but most were retrospective analyses with small numbers of patients. METHODS: This study represents a secondary analysis of a Japanese multicenter prospective cohort study. We investigated the factors associated with each type of perforation using 9015 patients with 9975 EGCs undergoing ESD between July 2010 and June 2012. RESULTS: Intraoperative perforation occurred in 198 patients (2.2%) with 203 lesions (2.0%), necessitating emergency surgery for four lesions (0.04% [2.0%, 4/203]). Delayed perforation occurred in another 37 patients (0.4%) with 42 lesions (0.4%), requiring emergency surgery for 12 lesions (0.12% [28.6%, 12/42]). Factors showing significant independent correlations with intraoperative perforation were upper or middle third of the stomach; remnant stomach or gastric tube; procedure time ≥100 min; tumor size >35 mm; body mass index (BMI) < 18.5 kg/m2; and ≥72 years. Factors showing significant independent correlations with delayed perforation were procedure time ≥60 min; BMI < 18.5 kg/m2; ≥75 years; ulceration; and tumor size >20 mm. Intraoperative perforation occurred most frequently at the greater curvature in the upper third of the stomach (7.9%), whereas delayed perforation occurred most frequently at the greater curvature in the middle third (1.2%). CONCLUSION: This multicenter prospective cohort study clarified the risk and risk factors of intraoperative and delayed perforation related to ESD for EGCs, providing information to help endoscopists reduce perforation.

Prospective multicenter trial of the cryoballoon ablation system for superficial esophageal squamous cell carcinoma on the post-endoscopic resection scar. A CRYO-SCAR study (EPOC1902).

BACKGROUND AND AIMS: Endoscopic resection (ER) is a minimally invasive treatment for superficial esophageal squamous cell carcinoma (SESCC). Post-ER scars complicate en bloc resection, even with advanced techniques, such as endoscopic submucosal dissection. The cryoballoon ablation system (CBAS) effectively manages Barrett's esophagus but has limited evidence in SESCC treatment, particularly on post-ER scars. This study aimed to evaluate the efficacy and safety of the CBAS for treating SESCC on post-ER scars. METHODS: This prospective study was conducted at two tertiary referral centers in Japan in patients endoscopically diagnosed with T1a SESCC on the post-ER scar. Focal CBAS was used for cryoablation, with specific criteria for lesion selection and treatment method. The primary endpoint was local complete response (L-CR) rate of the primary lesion 48 weeks after the first cryoablation as evaluated by an independent central evaluation committee. RESULTS: From October 2020 to October 2021, 15 patients with 17 lesions underwent cryoablation, with two requiring repeat cryoablation. The L-CR rate for primary and all lesions evaluated by the central evaluation committee was 100%. The endoscopist's evaluation was consistent with these results. The median procedure time was 9 min. Eight patients experienced no pain, and the highest pain score reported on a numeric 1-10 rating scale was 3. The technical success rate was 94.7% (18/19). Throughout the median follow-up period of 14.3 months, recurrences, deaths, or severe treatment-related adverse events were not reported. CONCLUSIONS: CBAS is a potentially safe and effective approach for SESCC on post-ER scars and represents an encouraging alternative to traditional endoscopic treatments.

Long-term outcomes after non-curative endoscopic resection for esophageal squamous cell carcinoma followed by additional chemoradiotherapy.

Endoscopic resection (ER) of esophageal squamous cell carcinoma (ESCC) is evaluated pathologically, and additional treatment is recommended for cases resulting in non-curative resection, defined as pMM with lymphovascular invasion (LVI), pSM, or positive vertical margin. This study aimed to assess long-term outcomes and risk factors for recurrence in patients with ESCC treated with non-curative ER followed by additional chemoradiotherapy (CRT). We retrospectively reviewed the clinical courses of patients who underwent non-curative ER followed by additional CRT for ESCCs between August 2007 and December 2017. Recurrence rates and risk factors for recurrence were analyzed. Among 97 patients with non-curative ER, 73 underwent additional CRT. With a median follow-up period of 71 months, recurrences were observed in 10 (14%) of 73 patients, with a median interval of 24.5 (1-59 months). The 3- and 5-year recurrence-free survival were 89 and 85%, respectively, and the 3- and 5-year overall survival rates were 96 and 91%, respectively. Multivariate analysis showed that lymphatic invasion was an independent risk factor for recurrence in patients with non-curative ESCC receiving additional CRT. Among the 10 patients with recurrence, 4, 3, 2, and 1 underwent surgery, chemotherapy, supportive care, and CRT, respectively. Notably, all four patients who underwent surgery survived, regardless of regional and/or distant lymph node metastasis. Lymphatic invasion is an independent risk factor for the recurrence of non-curative ESCCs. Careful follow-up is required for at least 5 years after ER with additional CRT.

Potential for expanding indications and curability criteria of endoscopic resection for early gastric cancer in elderly patients: results from a Japanese multicenter prospective cohort study.

BACKGROUND AND AIMS: Evidence for endoscopic resection (ER) in elderly patients with early gastric cancer (EGC) is limited. We assessed its clinical outcomes, and explored new indications and curability criteria. METHODS: We analyzed data from a Japanese multicenter prospective cohort study. Patients aged ≥75 years with EGC treated with ER were included. We classified "eCuraC-2 (corresponding to noncurative ER, defined in the Japanese gastric cancer treatment guidelines)" into "elderly-high (EL-H)" (>10% estimated metastatic risk) and "elderly-low (EL-L)" (≤10%). RESULTS: In total, 3,371 patients with 3,821 EGCs were included; endoscopic submucosal dissection (ESD) was the prominent treatment choice. Among them, 3,586 lesions met the guidelines' ER indications and 235 did not. The proportions of en bloc and R0 resections and perforations were 98.9%, 94.4%, and 0.8%, respectively, in EGCs within the indications. In EGCs beyond the indications, they were 99.5%, 85.4%, and 5.9%, respectively, for lesions diagnosed as ≤3 cm, and 96.0%, 64.0%, and 18.0% for those >3 cm. Curative ER ("eCuraA/B") and EL-L were observed in 83.6% and 6.2% of lesions within the indications, respectively, and in 44.2% and 16.8% of lesions <3 cm beyond the indications, respectively. The 5-year cumulative gastric cancer death rates following eCuraA/B and EL-H were 0.3% (95% CI, 0.2-0.6) and 3.5% (2.0-5.7), respectively. Following EL-L, the rate was 0.9% (0.2-3.5) even without subsequent treatment. CONCLUSIONS: Usefulness of ESD for elderly EGC patients was confirmed by their clinical outcomes. Lesions ≤3 cm and EL-L emerged as new ER indication and curability criterion, respectively.

Association between continuous cessation or reduction of drinking alcohol and improvement of multiple dysplastic lesions in patients with esophageal squamous cell carcinoma after endoscopic resection.

BACKGROUND: Multiple development of squamous cell carcinoma (SCC) in the upper aerodigestive tract has been explained by the 'field cancerization phenomenon' associated with alcohol drinking. Squamous dysplastic lesion is clinically visualised as a Lugol-voiding lesion (LVL) by chromoendoscopy. Whether cessation or reduction of alcohol drinking improves multiple LVL and reduces the risk of field cancerization has not been elucidated. METHODS: We analysed 330 patients with newly diagnosed superficial esophageal SCC (ESCC) enrolled in the cohort study. The grade of LVL was assessed in all patients every 6 months. We instructed the patients to stop smoking and drinking and recorded their drinking and smoking status every 6 months. RESULTS: Among 330 patients, we excluded 98 with no LVL or no drinking habit. Of the remaining 232 patients, 158 continuously ceased or reduced their drinking habit. Patients who ceased or reduced their drinking habit significantly showed improvement in the grade of LVL. Multivariate analysis showed that continuous cessation or reduction of drinking habit improved the grade of LVL (hazard ratio [HR] = 8.5, 95% confidence interval [CI] 1.7-153.8, p = 0.0053). Higher grade of LVL carried a high risk of multiple ESCC and head and neck SCC (HNSCC) (HR = 3.7, 95% CI 2.2-6.4, p < 0.0001). Improvement in LVL significantly decreased the risk of multiple ESCC and HNSCC (HR = 0.2, 95% CI 0.04-0.7, p = 0.009). CONCLUSIONS: This is the first report indicating that field cancerization was reversible and cessation or reduction of drinking alcohol could prevent multiple squamous dysplastic lesion and multiple ESCC and HNSCC development. CLINICAL TRIALS REGISTRY NUMBER: UMIN000001676.

A discrimination model by machine learning to avoid gastrectomy for early gastric cancer.

Aim: Gastrectomy is recommended for patients with early gastric cancer (EGC) because the possibility of lymph node metastasis (LNM) cannot be completely denied. The aim of this study was to develop a discrimination model to select patients who do not require surgery using machine learning. Methods: Data from 382 patients who received gastrectomy for gastric cancer and who were diagnosed with pT1b were extracted for developing a discrimination model. For the validation of this discrimination model, data from 140 consecutive patients who underwent endoscopic resection followed by gastrectomy, with a diagnosis of pT1b EGC, were extracted. We applied XGBoost to develop a discrimination model for clinical and pathological variables. The performance of the discrimination model was evaluated based on the number of cases classified as true negatives for LNM, with no false negatives for LNM allowed. Results: Lymph node metastasis was observed in 95 patients (25%) in the development cohort and 11 patients (8%) in the validation cohort. The discrimination model was developed to identify 27 (7%) patients with no indications for additional surgery due to the prediction of an LNM-negative status with no false negatives. In the validation cohort, 13 (9%) patients were identified as having no indications for additional surgery and no patients with LNM were classified into this group. Conclusion: The discrimination model using XGBoost algorithms could select patients with no risk of LNM from patients with pT1b EGC. This discrimination model was considered promising for clinical decision-making in relation to patients with EGC.

Complications of endoscopic resection in the upper gastrointestinal tract.

Endoscopic resection (ER) is widely utilized as a minimally invasive treatment for upper gastrointestinal tumors; however, complications could occur during and after the procedure. Post-ER mucosal defect leads to delayed perforation and bleeding; therefore, endoscopic closure methods (endoscopic hand-suturing, the endoloop and endoclip closure method, and over-the-scope clip method) and tissue shielding methods (polyglycolic acid sheets and fibrin glue) are developed to prevent these complications. During duodenal ER, complete closure of the mucosal defect significantly reduces delayed bleeding and should be performed. An extensive mucosal defect that comprises three-quarters of the circumference in the esophagus, gastric antrum, or cardia is a significant risk factor for post-ER stricture. Steroid therapy is considered the first-line option for the prevention of esophageal stricture, but its efficacy for gastric stricture remains unclear. Methods for the prevention and management of ER-related complications in the esophagus, stomach, and duodenum differ according to the organ; therefore, endoscopists should be familiar with ways of preventing and managing organ-specific complications.

Metachronous primary gastric cancer after endoscopic resection in patients with esophageal squamous cell carcinoma.

BACKGROUND: This study aimed to evaluate the risk factors for developing metachronous primary Gastric Cancer (GC) after Endoscopic Resection (ER) for esophageal Squamous Cell Carcinoma (SCC). METHODS: We studied 283 patients with esophageal SCC who underwent ER. The study outcomes were as follows: (1) incidence of metachronous primary GC after ER; and (2) predictors for the development of metachronous primary GC after ER by the Cox proportional hazards model. RESULTS: The median follow-up was 43.1 months (1.81-79.1), and the 3-year cumulative incidence of metachronous primary GC was 6.5% (95%CI: 4.1-10.4). The incidence of metachronous primary GC during the follow-up period was 2.31 per 100 person-years. The frequencies of severe gastric atrophy and macrocytosis at the timing of ER were significantly higher in patients with than without metachronous primary GC (91.7% vs. 73.2%, p = 0.0422, 20.8% vs. 5.2%, p = 0.0046, respectively). Severe gastric atrophy was associated with the development of metachronous primary GC (sex-and-age adjusted hazard ratio (HR) [95%CI] = 4.12 [0.95-27.78], p = 0.0093). Macrocytosis was associated with the development of metachronous primary GC (sex-and-age adjusted HR = 4.76 [1.75-13.0], p = 0.0012) and found to be an independent predictor for metachronous primary GC by multivariate Cox proportional hazards analysis (HR [95%CI] = 4.35 [1.60-11.84], p = 0.004). CONCLUSIONS: Severe gastric atrophy and macrocytosis should be noted in the development of metachronous primary GC after ER for esophageal SCC. In particular, macrocytosis at the timing of ER was considered an important predictor. CLINICAL TRIALS REGISTRY NUMBER: UMIN000001676.

Clinical and endoscopic features of metachronous gastric cancer with possible lymph node metastasis after endoscopic submucosal dissection and Helicobacter pylori eradication.

BACKGROUND: Several studies have reported the metachronous gastric cancers (MGCs) with possible lymph node metastasis (LNM) after endoscopic submucosal dissection (ESD) and Helicobacter pylori (H. pylori) eradication in which a curative ESD had not been achieved. There have been no published reports of evaluations of the features of patients with MGC with possible LNM after ESD and H. pylori eradication. METHODS: We identified 264 patients with 369 MGCs after H. pylori eradication among the 4354 patients with 5059 early gastric cancers (EGCs) who underwent ESD between 1999 and 2017 and divided them into two groups: patients with MGCs with possible LNM (Group I) and patients with MGCs undergone curative ESD (Group II). We retrospectively compared the features of patients with MGCs and patients with EGCs at index ESD in the two groups. RESULT: Group I consisted of 20 patients with 21 MGCs, and Group II consisted of 244 patients with 348 MGCs. Group I lesions were significantly more common in the posterior wall than in the lesser curvature (odds ratio [OR] = 3.97; 95% confidence intervals [CI] 1.20-13.10). Development of Group I was significantly more common in patients with a body mass index (BMI) < 19.0 kg/m2 than in patients with a BMI ≥ 19.0 kg/m2 at index ESD (OR = 4.44; 95% CI 1.30-15.20). CONCLUSIONS: During surveillance endoscopy after gastric ESD and H. pylori eradication, the posterior wall should be carefully examined to detect MGCs early. Lower BMI may be associated with the development of MGCs with possible LNM.

Oncologic significance of lymphovascular invasion in patients with superficial esophageal squamous cell carcinoma reaching the muscularis mucosae or with slight invasion of the submucosa.

BACKGROUND: The clinicopathological features and the distribution of lymph node metastasis in patients with T1a-MM and T1b-SM1 superficial esophageal squamous cell carcinoma remain unclear; therefore, the optimal treatment strategy is still controversial. METHODS: One hundred and ninety-one patients who had undergone a thoracic esophagectomy with 3-field lymphadenectomy and who were pathologically confirmed to have thoracic superficial esophageal squamous cell carcinoma that had reached the T1a-MM or T1b-SM1 stage were retrospectively reviewed. Risk factors of lymph node metastasis, the distribution of lymph node metastasis, and long-term outcomes were evaluated. RESULTS: A multivariate analysis revealed that lymphovascular invasion was the only independent risk factor of lymph node metastasis (odds ratio: 6.410, P < .001). Patients with primary tumors in the middle thoracic region had lymph node metastasis in all 3 fields, whereas patients with primary tumors in the upper or lower thoracic region did not have distant lymph node metastasis. The frequencies of neck (P = .045) and abdominal (P < .001) lymph node metastasis were significantly higher in lymphovascular invasion-positive patients than those in lymphovascular invasion-negative patients in all cohort. MM/lymphovascular invasion-positive patients with middle thoracic tumors had lymph node metastasis spread from the neck to the abdomen. SM1/lymphovascular invasion-negative patients with middle thoracic tumors did not have lymph node metastasis in the abdominal region. The SM1/pN+ group had a significantly poorer overall survival and relapse-free survival than the other groups. CONCLUSION: The present study revealed that lymphovascular invasion was associated with not only the frequency of lymph node metastasis, but also the distribution of lymph node metastasis. It also suggested that superficial esophageal squamous cell carcinoma patients with T1b-SM1 and lymph node metastasis had a significantly poorer outcome than those with T1a-MM and lymph node metastasis.

Endoscopic Resection of Undifferentiated Early Gastric Cancer.

Endoscopic resection (ER) is widely performed for early gastric cancer (EGC) with a negligible risk of lymph node metastasis (LNM) in Eastern Asian countries. In particular, endoscopic submucosal dissection (ESD) leads to a high en bloc resection rate, enabling accurate pathological evaluation. As undifferentiated EGC (UD-EGC) is known to result in a higher incidence of LNM and infiltrative growth than differentiated EGC (D-EGC), the indications for ER are limited compared with those for D-EGC. Previously, clinical staging as intramucosal UD-EGC ≤2 cm, without ulceration, was presented as 'weakly recommended' or 'expanded indications' for ER in the guidelines of the United States, Europe, Korea, and Japan. Based on promising long-term outcomes from a prospective multicenter study by the Japan Clinical Oncology Group (JCOG) 1009/1010, the status of this indication has expanded and is now considered 'absolute indications' in the latest Japanese guidelines published in 2021. In this study, which comprised 275 patients with UD-EGC (cT1a, ≤2 cm, without ulceration) treated with ESD, the 5-year overall survival (OS) was 99.3% (95% confidence interval, 97.1%-99.8%), which was higher than the threshold 5-year OS (89.9%). Currently, the levels of evidence grades and recommendations for ER of UD-EGC differ among Japan, Korea, and Western countries. Therefore, a further discussion is warranted to generalize the indications for ER of UD-EGC in countries besides Japan.

Clinical characteristics and long-term prognosis of type 1 gastric neuroendocrine tumors in a large Japanese national cohort.

OBJECTIVES: Optimal management of type 1 gastric neuroendocrine tumors (T1-GNETs) remains unknown, with few reports on their long-term prognosis. This study investigated the clinical characteristics and long-term prognosis of T1-GNETs. METHODS: We reviewed the medical records of patients diagnosed with T1-GNET during 1991-2019 at 40 institutions in Japan. RESULTS: Among 172 patients, endoscopic resection (ER), endoscopic surveillance, and surgery were performed in 84, 61, and 27, respectively, including 27, 77, and 2 patients with pT1a-M, pT1b-SM, and pT2 tumors, respectively. The median tumor diameter was 5 (range 0.8-55) mm. Four (2.9%) patients had lymph node metastasis (LNM); none had liver metastasis. LNM rates were significantly higher in tumors with lymphovascular invasion (LVI) (15.8%; 3/19) than in those without (1.1%; 1/92) (P = 0.016). For tumors <10 mm, LVI and LNM rates were 18.4% (14/76) and 2.2% (2/90), respectively, which were not significantly different from those of tumors 10-20 mm (LVI 13.3%; 2/15, P = 0.211; and LNM 0%; 0/17, P = 1.0). However, these rates were significantly lower than those of tumors >20 mm (LVI 60%; 3/5, P = 0.021; and LNM 40%; 2/5, P = 0.039). No tumor recurrence or cause-specific death occurred during the median follow-up of 10.1 (1-25) years. The 10-year overall survival rate was 97%. CONCLUSIONS: Type 1 gastric neuroendocrine tumors showed indolent nature and favorable long-term prognoses. LVI could be useful in indicating the need for additional treatments. ER for risk prediction of LNM should be considered for tumors <10 mm and may be feasible for tumors 10-20 mm. TRIAL REGISTRATION: The study protocol was registered in the University Hospital Medical Information Network (UMIN) under the identifier UMIN000029927.

Association between perioperative management of antiplatelet agents and risk of post-endoscopic submucosal dissection bleeding in early gastric cancer: analysis of a nationwide multicenter study.

BACKGROUND AND AIMS: Data are lacking regarding post-endoscopic submucosal dissection (ESD) bleeding in patients with early gastric cancer (EGC) who take antiplatelet agents (APAs), particularly in those taking thienopyridine and cilostazol. We aimed to clarify the association between the status of APA medication and post-ESD bleeding risk. METHODS: This study is a secondary analysis using data from a recently conducted nationwide multicenter study in Japan. We retrospectively reviewed patients treated with APAs or on no antithrombotic therapy recruited from 33 institutions who underwent ESD for EGC between November 2013 and October 2016. The primary outcome of this study was the relationship between the rate of post-ESD bleeding and the status of each APA medication. RESULTS: A total of 9736 patients were included in the analysis. Among 665 aspirin users, the continuation group was significantly associated with post-ESD bleeding (odds ratio [OR], 2.79; 95% confidence interval [CI], 1.77-4.37). Among 227 thienopyridine users, the aspirin or cilostazol replacement group was not significantly associated with post-ESD bleeding (OR, 1.85; 95% CI, .72-4.78). Among 158 cilostazol users, there was no significant association with post-ESD bleeding, irrespective of medication status. The rate of post-ESD bleeding was approximately 10% to 20% irrespective of the status of APA administration among dual-antiplatelet therapy users. No patients experienced thromboembolic events in this study. CONCLUSIONS: Replacement of thienopyridine with aspirin or cilostazol may be acceptable for minimizing both the risk of post-ESD bleeding and thromboembolism in patients with EGC. In patients on cilostazol monotherapy undergoing ESD, continuation of therapy may be acceptable.

Long-term Survival After Endoscopic Resection For Gastric Cancer: Real-world Evidence From a Multicenter Prospective Cohort.

BACKGROUND & AIMS: We aimed to clarify the long-term outcomes of endoscopic resection (ER) for early gastric cancers (EGCs) based on pathological curability in a multicenter prospective cohort study. METHODS: We analyzed the long-term outcomes of 9054 patients with 10,021 EGCs undergoing ER between July 2010 and June 2012. Primary endpoint was the 5-year overall survival (OS). The hazard ratio for all-cause mortality was calculated using the Cox proportional hazards model. We also compared the 5-year OS with the expected one calculated for the surgically resected patients with EGC. If the lower limit of the 95% confidence interval (CI) of the 5-year OS exceeded the expected 5-year OS minus a margin of 5% (threshold 5-year OS), ER was considered to be effective. Pathological curability was categorized into en bloc resection, negative margins, and negative lymphovascular invasion: differentiated-type, pT1a, ulcer negative, ≤2 cm (Category A1); differentiated-type, pT1a, ulcer negative, >2 cm or ulcer positive, ≤3 cm (Category A2); undifferentiated-type, pT1a, ulcer negative, ≤2 cm (Category A3); differentiated-type, pT1b (SM1), ≤3 cm (Category B); or noncurative resections (Category C). RESULTS: Overall, the 5-year OS was 89.0% (95% CI, 88.3%-89.6%). In a multivariate analysis, no significant differences were observed when the hazard ratio of Categories A2, A3, and B were compared with that of A1. In all the pathological curability categories, the lower limit of the 95% CI for the 5-year OS exceeded the threshold 5-year OS. CONCLUSION: ER can be recommended as a standard treatment for patients with EGCs fulfilling Category A2, A3, and B, as well as A1 (UMIN Clinical Trial Registry, UMIN000005871).

Bleeding following Endoscopic Submucosal Dissection for Early Gastric Cancer in Surgically Altered Stomach.

INTRODUCTION: Few studies have focused on bleeding following endoscopic submucosal dissection (ESD) in surgically altered stomach. We aimed to reveal the bleeding risk in surgically altered stomach following ESD for early gastric cancer (EGC). METHODS: We enrolled patients with ESD for EGC at 33 institutions between 2013 and 2016. In study 1, we evaluated bleeding risk following ESD in surgically altered stomach, compared with whole stomach. In study 2, we evaluated factors associated with bleeding following ESD in patients with surgically altered stomach. RESULTS: Of 11,452 patients, 445 patients had surgically altered stomach with the bleeding rate following ESD of 4.9%. In study 1, the bleeding risk in surgically altered stomach was not significant (odds ratio [OR], 1.37; 95% confidence interval [CI], 0.87-2.17) in the multivariate logistic regression analysis. No significant results were obtained when the surgically altered stomach was subdivided into various types. In study 2, the multivariate logistic regression analysis revealed that independent risk factors for bleeding following ESD were ischemic heart disease (OR, 7.52; 95% CI, 2.00-28.25) and P2Y12 receptor antagonist (OR, 4.81; 95% CI, 1.21-19.14). DISCUSSION/CONCLUSION: In this nationwide study, we found that the bleeding risk of surgically altered stomach following ESD for EGC did not significantly differ from that of whole stomach. The risk factors for ESD in patients with surgically altered stomach were ischemic heart disease and P2Y12 receptor antagonist.

A retrospective 5-year survival analysis of surgically resected gastric cancer cases from the Japanese Gastric Cancer Association nationwide registry (2001-2013).

BACKGROUND: The nationwide registry of the Japanese Gastric Cancer Association collected data of surgically resected cases of gastric cancer between 2001 and 2013. These retrospective analyses aimed to delineate tumor characteristics, surgical history, and survival distribution. METHODS: Data from 254,706 patients with primary gastric cancer were included. The 5-year survival rates were calculated for various subsets of prognostic factors. RESULTS: The number of patients over 70 years old increased from 2001 to 2013. The frequency with which laparoscopic gastrectomy was opted for increased dramatically (from 3.5 to 40.8%) in 13 years. We focused on the patients registered between 2010 and 2013, for whom data collection was based on the 3rd edition of the Japanese classification and guidelines. Five-year overall survival (OS) rate among 92,305 patients with resected tumors was 70.6%. The 5-year OS rates of patients with pathological stage IA, IB, IIA, IIB, IIIA, IIIB, IIIC, and IV disease were 89.6%, 83.2%, 77.6%, 68.1%, 59.3%, 45.6%, 29.9%, and 14.0%, respectively. CONCLUSION: Our detailed analysis highlights the historical changes in outcomes of surgically treated gastric malignancies in Japan, and provides robust dataset for future analysis.

Endoscopic resection of esophageal squamous cell carcinoma: Current indications and treatment outcomes.

Endoscopic resection (ER) is an alternate minimally invasive treatment for superficial esophageal squamous cell carcinoma (SESCC). We aimed to review the clinical indications and treatment outcomes of ER for SESCC. Endoscopic mucosal resection is relatively easy and efficient for SESCC ≤ 15 mm. In contrast, endoscopic submucosal dissection (ESD) is recommended to achieve en bloc resection for lesions >15 mm, in view of the accurate pathological evaluation. The Japan Gastroenterological Endoscopy Society guidelines recommend ER for non-circumferential cT1a-EP/LPM (epithelium/lamina propria mucosae), cT1a-MM/T1b-SM1 (muscularis mucosa/superficial submucosa ≤ 200µm) SESCC, and whole-circumferential T1a-EP/LPM SESCC ≤ 50 mm (upon implementing preventive measures for stenosis), considering the risk-benefit balance of ER. It defines pT1a-EP/LPM without lymphovascular invasion as a curative endoscopic resection. The guidelines recommend additional esophagectomy or chemoradiotherapy for pT1b SESCC or any SESCC, with lymphovascular invasion. However, there is no recommendation for or against the administration of additional treatments for pT1a-MM without lymphovascular invasion, owing to limited evidence. Researchers have reported on high en bloc and R0 resection rates of ESD, and a randomized controlled trial demonstrated that clip-line traction-assisted ESD could significantly reduce the ESD procedural time. Moreover, steroid treatment has been developed to prevent post-ESD esophageal strictures. There have been reports on favorable long-term outcomes of ESD. However, most of them are retrospective studies. Further robust data in prospective trials are warranted to achieve a definitive evidence of ESD, which will be beneficial to patients with SESCC.

Visibility of early gastric cancer in texture and color enhancement imaging.

Objective: There are little data regarding the efficacy of texture and color enhancement imaging (TXI) for early gastric cancer (EGC) diagnosis. This study aimed to compare the color difference and visibility of EGC between white light imaging (WLI) and TXI. Methods: This study included 20 EGCs of 18 patients undergoing endoscopic submucosal dissection. Still images of EGC in WLI, TXI mode 1 (with color enhancement), and TXI mode 2 (without color enhancement), which were consistent in distance, angle, and air insufflation, were constructed by computer simulation. The center of the lesion, eight equal peripheral points 5 mm outside the lesion, and eight inner points two-thirds of the distance from peripheral points to the EGC lesion center were annotated. Mean color differences (ΔE) of the area between peripheral and inner points per lesion in WLI, TXI mode 1, and TXI mode 2 were analyzed. In addition, four endoscopists independently scored the visibility of EGC images of TXI mode 1 and 2 compared with WLI. Results: Clinicopathological characteristics were as follows: 0-IIa/0-IIb/0-IIc/0-IIa+IIc = 6/1/11/2, reddish/pale = 10/10, differentiated/undifferentiated = 18/2, median tumor size = 13.5 mm. Mean ΔE ± SD = WLI/TXI mode1/TXI mode2 = 10.3 ± 4.7, 15.5 ± 7.8, and 12.7 ± 6.1, respectively. Mean ΔE was significantly higher in TXI mode 1 than in WLI. Visibility (improved/no change/decreased) was 7/13/0 and 4/16/0 in TXI mode 1 and 2, respectively. The visibility was significantly more commonly improved in the macroscopic type 0-IIc or 0-IIb than in 0-IIa or IIa+IIc in TXI mode 1. Conclusions: TXI could improve the visibility of EGC compared with WLI.