Diagnostic value of endoscopic ultrasonography for the depth of gastric cancer suspected of submucosal invasion: a multicenter prospective study.

BACKGROUND: Although the combination of conventional endoscopy (CE) and endoscopic ultrasonography (EUS) is useful for predicting the depth of early gastric cancer (EGC), the diagnostic value of EUS for submucosal (SM) invasive cancer has not been fully investigated. METHODS: We conducted a multicenter prospective study from May 2017 to January 2021 to evaluate the validity of a diagnostic strategy combining CE and EUS and to clarify the additional value of EUS for EGC suspected of SM invasion. In each case, the diagnosis was first made using CE, followed by EUS, and finally confirmed using a combination algorithm. RESULTS: A total of 180 patients with EGC were enrolled from 10 institutions, of which 175 were analyzed. The histopathological depths were M, SM1, SM2, and ≥ MP in 72, 16, 64, and 23 lesions, respectively. Treatment included 92 endoscopic submucosal dissection cases and 83 surgical cases. The overall diagnostic accuracy classified by M-SM1 or SM2-MP was 58.3% for CE, 75.7% for EUS, and 78.9% for the combination of CE and EUS; the latter two were significantly higher than that of CE alone (P < 0.001). The CE, EUS, and combination accuracy rates in 108 differentiated-type lesions were 51.9%, 77.4%, and 79.6%, respectively; the latter two were significantly higher than CE alone (P < 0.001). A significant additive effect of EUS was observed in CE-SM2 low-confidence lesions but not in CE-M-SM1 lesions or in CE-SM2 high-confidence lesions. Among the nine CE findings, irregular surface, submucosal tumor-like elevation, and non-extension signs were significant independent markers of pSM2-MP. Poorly delineated EUS lesions were misdiagnosed. CONCLUSIONS: EUS provides additional value for differentiated-type and CE-SM2 low-confidence EGCs in diagnosing invasion depth. CLINICAL REGISTRATION NUMBER: UMIN000025862.

Clinical and Histopathological Features of the Differentiated Type of Early Gastric Cancer with an Unclear Lateral Demarcation.

INTRODUCTION: Magnifying endoscopy with narrow-band imaging (M-NBI) is useful for determining lateral demarcation of early gastric cancers; however, this is sometimes difficult. Features related to an unclear lateral demarcation remain unknown. We evaluated the clinical and histopathological features of early gastric cancers with unclear lateral demarcation on M-NBI. METHODS: This single-center, retrospective, cohort study analyzed early gastric cancer treated by endoscopic submucosal dissection between January 2013 and August 2015. We evaluated the clinicopathological and immunohistochemical features using anti-p53, anti-Ki-67, anti-MUC5AC, anti-MUC6, anti-MUC2, and anti-CD10 antibody staining. We compared the lateral demarcation between the demarcation clear (DC) and the demarcation unclear (DU) lesions by using M-NBI. RESULTS: A total of 224 differentiated adenocarcinomas (DU group: 18 lesions; DC group: 206 lesions) were analyzed. A history of successful Helicobacter pylori eradication was significantly more frequent in the DU group (p = 0.001). We examined the tissues of 72 lesions (DU group: 18 lesions, DC group: 54 lesions [randomly selected]) immunohistochemically. The nonneoplastic superficial epithelium was observed more frequently in the DU group as compared to in the DC group (p = 0.006). Additionally, compared to the DC group, the DU group showed a significantly higher expression of the gastric phenotype markers (p = 0.023) and had lower p53 scores (p < 0.001) and Ki-67 labeling indexes (p = 0.029). Multivariate analysis revealed the nonneoplastic superficial epithelium and a low p53 score as the significant independent variables associated with an unclear lateral demarcation on M-NBI. CONCLUSIONS: The nonneoplastic superficial epithelium and a low p53 score were associated with difficulties in determining the lateral demarcation in early gastric cancers on M-NBI.

Geriatric nutritional risk index as a prognostic indicator in elderly patients with early colorectal cancer undergoing endoscopic submucosal dissection.

OBJECTIVES: Data on the long-term outcomes of endoscopic submucosal dissection (ESD) performed in elderly patients with early colorectal cancer (CRC) are limited. We analyzed the prognosis of elderly CRC patients, not only from the viewpoint of treatment curability but also from the patients' baseline physical condition assessed by several indexes. METHODS: A retrospective analysis of 729 patients aged ≥75 years who underwent ESD for Tis/T1 CRC in 16 institutions was conducted. The patients were classified into three groups based on curability: curative ESD (Group A, n = 582), non-curative ESD with additional surgery (Group B, n = 60), and non-curative ESD without additional surgery (Group C, n = 87). Overall survival (OS) was compared among the groups, and factors associated with reduced OS were investigated. RESULTS: The median follow-up periods in Groups A, B, and C were 41, 49, and 46 months, respectively (P = 0.62), during which 92 patients died. Two patients (0.3%) in Group A, none (0%) in Group B, and three (3.4%) in Group C died of CRC. Three-year OS rates in Groups A, B, and C were 93.9%, 96.1%, and 90.1%, respectively, without a significant difference (P = 0.07). Multivariate analysis indicated low (<96.3) geriatric nutritional risk index (GNRI) as the sole independent predictor for reduced OS (hazard ratio 3.37; 95% confidence interval 2.18-5.22; P < 0.0001). CONCLUSIONS: Low GNRI, but not the curability attained by ESD, was independently associated with reduced OS in patients with early CRC aged ≥75 years.

Exosomal microRNAs derived from colon cancer cells promote tumor progression by suppressing fibroblast TP53 expression.

The tumor microenvironment offers favorable conditions for tumor progression, and activated fibroblasts, known as cancer-associated fibroblasts, play a pivotal role. TP53-deficient cancer cells are known to induce strong fibroblast activation. We aimed to elucidate the oncogenic role of exosomes derived from TP53-deficient colon cancer cells in fibroblast proliferation and tumor growth. Cancer cell-derived exosomes (CDEs) were isolated from the conditioned media of cancer cells using a sequential ultracentrifugation method. The effects of exosomes on tumor growth were evaluated using human cell lines (TP53-WT colon cancer, HCT116; TP53-mutant colon cancer, HT29; and fibroblasts, CCD-18Co and WI-38) and an immune-deficient nude mouse xenograft model. HCT116 (HCT116sh p53 ) cells deficient in TP53 accelerated cocultured fibroblast proliferation compared to TP53-WT HCT116 (HCT116sh control ) cells in vitro. Exosomes from HCT116sh p53 cells suppressed TP53 expression of fibroblasts and promoted their proliferation. Xenografts of HCT116sh p53 cells grew significantly faster than those of HCT116sh control cells in the presence of co-injected fibroblasts, but this difference was diminished by CDE inhibition. Microarray analysis identified upregulation of several microRNAs (miR-1249-5p, miR-6737-5p, and miR-6819-5p) in TP53-deficient CDEs, which were functionally proven to suppress TP53 expression in fibroblasts. Exosomes derived from TP53-mutant HT29 cells also suppressed TP53 expression in fibroblasts and accelerated their growth. The proliferative effect of HT29 on cocultured fibroblasts was diminished by inhibition of these miRNAs in fibroblasts. Our results suggest that CDEs play a pivotal role in tumor progression by fibroblast modification. Cancer cell-derived exosomes might, therefore, represent a novel therapeutic target in colon cancer.

The heart's exposure to radiation increases the risk of cardiac toxicity after chemoradiotherapy for superficial esophageal cancer: a retrospective cohort study.

BACKGROUND: Chemoradiotherapy effectively treats superficial esophageal cancer and is optimal to preserve organs. However, late toxicity, particularly in cardiac diseases, obstructs clinical outcomes. We revealed the risk factors for cardiac event development post-chemoradiotherapy. METHODS: Data from 80 patients who were diagnosed with submucosal invasive esophageal cancer without metastasis (confirmed using multiple modalities) and who underwent chemoradiotherapy between 2006 and 2014 were analyzed. Patients were 11% (9/80) female, and the median age and follow-up were 66.5 y and 73 mo, respectively. We calculated the individual radiation dose to the heart and analyzed relationships between the cardiac event occurrence rate and each clinical factor. RESULTS: The 5-y overall and recurrence-free survival rates were 74.6 and 62.4%, respectively. Among the total number of deaths, 34.6% was caused by esophageal cancer. During the follow-up, 13 patients developed severe cardiac events (ischemic heart diseases, n = 7; pericardial effusion, n = 3, atrial fibrillation, n = 1; and sudden death, n = 2). The significant risk factor for cardiac events post-chemoradiotherapy was the level of the heart's exposure to radiation, with higher exposure associated with greater occurrence. History of smoking, obesity, comorbidity, and history of cardiac disease were unrelated to cardiac event occurrence post-chemoradiotherapy. CONCLUSIONS: Chemoradiotherapy is a favorable intervention for superficial esophageal cancer. Reducing the radiation dose to the heart likely contributes to preventing cardiac toxicity post-chemoradiotherapy.

Adenoma of colorectal laterally spreading tumor nongranular type with biological phenotypic features similar to cancer.

BACKGROUND AND AIM: Colorectal laterally spreading tumors (LSTs) are morphologically subdivided into granular (LST-G) and nongranular (LST-NG) categories. We aimed to elucidate the differences in oncogenic characteristics between the two types. METHODS: Laterally spreading tumors resected by endoscopic submucosal dissection and surgery from March 2009 to May 2017 were examined for p53 positivity, Ki-67 labeling index (LI), microvessel density, degree of fibrosis, intensities of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT), and expression of acid mucins. We compared these factors between adenomas, noninvasive cancers, and invasive cancers, both LST-G and LST-NG. RESULTS: Ninety-three LST-G (53 adenomas [LST-GA] and 40 cancers [LST-GC]) and 55 LST-NG (24 adenomas [LST-NGA] and 31 cancers [LST-NGC]) were evaluated. Although p53 positivity was lower in LST-GA than in LST-NGA (P < 0.001), there was no difference between LST-GC and LST-NGC. Ki-67 LI was higher in LST-NGA than in LST-GA (P < 0.001) and higher in LST-NGC than in LST-GC of noninvasive cancers (P < 0.001). Microvessel density and degree of fibrosis were higher in LST-NGA than in LST-GA (P < 0.001), and intensities of iNOS and NT were also higher in LST-NGA than in LST-GA (P < 0.001). Expression of acid mucins was lower in LST-NGA than in LST-GA (P < 0.001). Although there were significant differences in p53 positivity, Ki-67 LI, microvessel density, degree of fibrosis, intensities of iNOS and NT, and expression of acid mucins between LST-GA and LST-NGA, these factors were only slightly different between LST-GC and LST-NGC of invasive cancers. CONCLUSIONS: Unlike LST-GA, LST-NGA possessed phenotypic features similar to cancer.

"Underwater" endoscopic submucosal dissection: a novel method for resection in saline with a bipolar needle knife for colorectal epithelial neoplasia.

BACKGROUND: Despite improvements in therapeutic strategy and instrumentation in colorectal endoscopic submucosal dissection (ESD), adverse events sometimes occur. Further advancements in available techniques are required to improve procedural success rates and safety. We developed a novel method for ESD in saline, referred to as "underwater" ESD (UESD). UESD involves using a bipolar needle knife and aims to enable complete resection while minimizing thermal damage to the muscle layer. In this study, we evaluated the safety and efficacy of this new technique. METHODS: This was a retrospective study using data from two referral centers and included 40 lesions diagnosed as colorectal epithelial neoplasia (> 20 mm in diameter or with severe fibrosis) and treated with UESD between December 2015 and March 2017. The main outcome measures were technical success rate, incidence of adverse events, and feasibility of histologic evaluation of the resected specimens. RESULTS: All 40 lesions, including those with submucosal fibrosis, underwent successful en bloc resection using the UESD technique. No procedural adverse events including perforation, delayed bleeding, and electrocoagulation syndrome were observed, and all patients had an uneventful clinical course associated with UESD. In all cases, UESD provided a resected specimen adequate for histological evaluation, without unwarranted burn effect to the tissues. CONCLUSIONS: Our UESD technique was safe and effective for complete resection of colorectal epithelial neoplasia.

Cardiac metastasis from colon cancer effectively treated with 5-fluorouracil, leucovorin, and oxaliplatin (modified FOLFOX6) plus panitumumab: a case report.

BACKGROUND: Cardiac metastasis from colorectal cancer is rare. There is little evidence supporting the effectiveness of chemotherapy, and standard therapy for metastatic cardiac tumors has not been established. CASE PRESENTATION: A 76-year-old woman presented with a right ventricle tumor that was detected incidentally on screening cardiac ultrasonography. The initial computed tomography (CT) scan showed the cardiac tumor, which was approximately 40 mm in size, and multiple pulmonary nodules. Serum levels of tumor markers CEA and CA19-9 were elevated aberrantly. The suspected primary tumor, a well-differentiated adenocarcinoma of the transverse colon with wild-type KRAS was found by colonoscopy, and treatment with 5-fluorouracil, leucovorin, and oxaliplatin (modified FOLFOX6) plus panitumumab was initiated. After 4 courses of the therapy, a CT scan showed that the cardiac tumor size had markedly decreased and the pulmonary nodules had diminished. The serum levels of CEA and CA19-9 were also markedly decreased. After 12 courses of chemotherapy during 10 months of treatment, the patient continued to show a partial response, and she remained asymptomatic with continuation of the treatment through 15 courses. CONCLUSION: To the best of our knowledge, this is the first report of the efficacy of combination therapy using cytotoxic and molecular targeted agents against cardiac metastasis from colon cancer.

Incomplete resection rate of cold snare polypectomy: a prospective single-arm observational study.

Background and study aims Cold snare polypectomy (CSP) is considered to be safe for the removal of subcentimeter colorectal polyps. This study aimed to determine the rate of incomplete CSP resection for subcentimeter neoplastic polyps at our center. Patients and methods Patients with small or diminutive adenomas (diameter 1 - 9 mm) were recruited to undergo CSP until no polyp was visible. After CSP, a 1 - 3 mm margin around the resection site was removed using endoscopic mucosal resection. The polyps and resection site marginal specimens were microscopically evaluated. Incomplete resection was defined as the presence of neoplastic tissue in the marginal specimen. We also calculated the frequency at which the polyp lateral margins could be assessed for completeness of resection. Results A total of 307 subcentimeter neoplastic polyps were removed from 120 patients. The incomplete resection rate was 3.9 % (95 % confidence interval [CI] 1.7 % - 6.1 %); incomplete resection was not associated with polyp size, location, morphology, or operator experience. The polyp lateral margins could not be assessed adequately for 206 polyps (67.1 %). Interobserver agreement between incomplete resection and lateral polyp margins that were inadequate for assessment was poor (κ = 0.029, 95 %CI 0 - 0.04). Female sex was an independent risk factor for incomplete resection (odds ratio 4.41, 95 %CI 1.26 - 15.48; P  = 0.02). Conclusions At our center, CSP resection was associated with a moderate rate of incomplete resection, which was not associated with polyp characteristics. However, adequate evaluation of resection may not be routinely possible using the lateral margin from subcentimeter polyps that were removed using CSP.Trial registered at University Hospital Medical Information Network (UMIN 000010879).

Scissor-type knife significantly improves self-completion rate of colorectal endoscopic submucosal dissection: Single-center prospective randomized trial.

BACKGROUND AND AIM: Colorectal endoscopic submucosal dissection (C-ESD) is recognized as a difficult procedure. Recently, scissors-type knives were launched to reduce the difficulty of C-ESD. The aim of this study was to evaluate the efficacy and safety of the combined use of a scissors-type knife and a needle-type knife with a water-jet function (WJ needle-knife) for C-ESD compared with using the WJ needle-knife alone. METHODS: This was a prospective randomized controlled trial in a referral center. Eighty-five patients with superficial colorectal neoplasms were enrolled and randomly assigned to undergo C-ESD using a WJ needle-knife alone (Flush group) or a scissor-type knife-supported WJ needle-knife (SB Jr group). Procedures were conducted by two supervised residents. Primary endpoint was self-completion rate by the residents. RESULTS: Self-completion rate was 67% in the SB Jr group, which was significantly higher than that in the Flush group (39%, P = 0.01). Even after exclusion of four patients in the SB Jr group in whom C-ESD was completed using the WJ needle-knife alone, the self-completion rate was significantly higher (63% vs 39%; P = 0.03). Median procedure time among the self-completion cases did not differ significantly between the two groups (59 vs 51 min; P = 0.14). No fatal adverse events were observed in either group. CONCLUSIONS: In this single-center phase II trial, scissor-type knife significantly improved residents' self-completion rate for C-ESD, with no increase in procedure time or adverse events. A multicenter trial would be warranted to confirm the validity of the present study.

Integrated diagnostic strategy for the invasion depth of early gastric cancer by conventional endoscopy and EUS.

BACKGROUND: Although conventional endoscopy (CE) and EUS are considered useful for predicting the invasion depth (T-staging) in early gastric cancer (EGC), no effective diagnostic strategy has been established. OBJECTIVE: To produce simple CE criteria and to elucidate an efficient diagnostic method by combining CE and EUS for accurate T-staging. DESIGN: Single-center retrospective analysis. SETTING: Academic university hospital. PATIENTS: Consecutive patients with EGC from April 2007 to March 2012 who underwent CE and EUS before treatment. INTERVENTIONS: Recorded endoscopic images were independently reviewed by 3 observers. The CE criteria for massive invasion were defined, and their utility and the additional value of EUS were assessed. MAIN OUTCOME MEASUREMENTS: The accuracy of CE based on the criteria and the accuracy of EUS. RESULTS: Two hundred thirty patients were enrolled: 195 with mucosal cancer or cancer in the submucosa less than 500 µm from the muscularis mucosae and 35 with invasive cancers. Multivariate analysis of the CE findings by 1 observer revealed that an irregular surface and a submucosal tumor-like marginal elevation were significantly associated with massive invasion. The simple CE criteria, consisting of those 2 features, had an overall accuracy of 73% to 82% and no significant differences in the diagnostic yield compared with EUS in all observers. CE accurately revealed mucosal cancer, and EUS efficiently salvaged the lesions that were over-diagnosed by CE. With our strategy, which involved the CE criteria and the optimal use of EUS, the comprehensive accuracy exceeded 85% in each observer. LIMITATIONS: Retrospective, single-center study. CONCLUSIONS: We demonstrated a practical strategy for T-staging in EGC using simple CE criteria and EUS.

Diagnostic features of sessile serrated adenoma/polyps on magnifying narrow band imaging: a prospective study of diagnostic accuracy.

BACKGROUND AND AIMS: The narrow band imaging classification system (NBI International Colorectal Endoscopic [NICE] classification) classifies colorectal polyps very accurately. However, sessile serrated adenoma/polyps (SSA/Ps) pathologically resembles hyperplastic polyp and has a possibility to be left in situ on NICE classification. The aim of this study was to establish and evaluate new simple diagnostic features for SSA/Ps using magnifying narrow band imaging (M-NBI). METHODS: We performed a single-arm observational study of diagnostic accuracy in two stages, as follows: seeking stage, development of simple diagnostic features for SSA/P and definition of diagnostic criteria based on retrospective assessments of M-NBI; and validation stage, prospective validation and evaluation of the new diagnostic criteria. RESULTS: In the seeking stage, we identified brownish, oval, expanded crypt openings and thick-branched vessels on the surfaces of SSA/Ps. We named these "expanded crypt openings" (ECOs) and "thick and branched vessels" (TBVs), respectively. In the validation stage, we enrolled 796 polyps in 261 patients, and classified 126 polyps as NICE type 1; all these lesions were endoscopically removed and assessed histopathologically. The sensitivity, specificity, and accuracy of ECOs for SSA/Ps were 84.3%, 81.1%, and 82.4%, whereas those of TBVs were 45.1%, 68.9%, and 59.2%, respectively. M-NBI provided a sensitivity of 98% and specificity of 59.5% for discrimination of SSA/Ps from other lesions classified as NICE type 1. CONCLUSIONS: Identification of ECOs, supplemented with TBVs, has high sensitivity for the diagnosis of SSA/P. These findings may facilitate the use of endoscopic optical diagnosis in clinical practice.

[Effectiveness of anti-tumor necrosis factor-α therapy in Crohn's disease with abscesses around the sigmoid colon: a case report].

We report the case of a man in his 50s who was diagnosed with Crohn's colitis in his 30s and who presented with post-prandial lower abdominal pain in January, 20XX. Colonoscopy and abdominal contrast-enhanced computed tomography revealed abscesses around the sigmoid colon. Although his response to antibiotics was poor, treatment with a combination of antibiotics and adalimumab resolved the abscesses. Nine months later, however, the abscesses around the sigmoid colon recurred. Treatment comprising bowel rest and antibiotics led to immediate improvement of the symptoms. We report a case of effective anti-tumor necrosis factor-α therapy in Crohn's colitis with abscesses around the sigmoid colon.

Endoscopic optical diagnosis provides high diagnostic accuracy of esophageal squamous cell carcinoma.

BACKGROUND: Recent technological advances have stimulated the development of endoscopic optical biopsy technologies. This study compared the accuracy of endoscopic diagnosis using magnifying narrow-band imaging (NBI) and histologic diagnosis of esophageal squamous lesions. METHODS: Patients at high risk for esophageal squamous cell carcinoma were examined with endoscopy and subsequent biopsy. The lesions diagnosed as cancer on NBI and the lesions diagnosed as cancer on biopsy were resected endoscopically or surgically. Histological diagnoses of resected specimens, the reference standards in this study, were made by a pathologist who was blind to both the endoscopic and biopsy diagnoses. The primary outcome was the accuracy of endoscopic and biopsy diagnosis. A noninferiority trial design with a noninferiority margin of -10% was chosen to investigate the accuracy of endoscopic diagnosis using magnifying NBI. RESULTS: Between November 2010 and October 2012, a total of 111 lesions in 85 patients were included in the analysis. The accuracy of endoscopic diagnosis and biopsy diagnosis for all lesions was 91.0% (101/111) and 85.6% (95/111), respectively. The difference in diagnostic accuracy was 5.4% (95% confidence interval: -2.9%-13.7%). The accuracy of endoscopic diagnosis and biopsy diagnosis of invasive cancers was 94.9% (74/78) and 84.6% (66/78), respectively. The difference was 10.3% (95% confidence interval: 1.6%-19.0%) for invasive cancers. The lower bound of the 95% confidence interval was above the prestated -10% in both cases. CONCLUSION: Noninferiority of endoscopic diagnosis by magnifying NBI to histologic diagnosis by biopsy was established in this study (p = 0.0001). TRIAL REGISTRATION: The study was registered on 9th November 2010 in the University Hospital Medical Network Clinical Trials Registry as number: UMIN000004529.

Utility and advantage of the unroofing technique for gastrointestinal subepithelial tumors: A multicenter retrospective cohort study.

Background and aim: Various techniques for direct biopsy from gastrointestinal subepithelial tumors (SETs) have been reported, although no standard method has been established. A common feature of these techniques is the removal of overlaying mucosa to enable direct biopsies from the SETs. These methods have been synthesized under the collective term "unroofing technique". We conducted a multicenter retrospective study to assess its efficacy and identify potential complications. Methods: This study was conducted in 10 hospitals and involved all eligible patients who underwent unroofing techniques to obtain biopsies for gastrointestinal SETs between April 2015 and March 2021. The primary endpoint was the diagnostic accuracy of the unroofing technique, and the secondary endpoints were the incidence of adverse events and the factors contributing to the accurate diagnosis. Results: The study included 61 patients with 61 gastrointestinal SETs. The median tumor size was 20 mm, and the median procedure time was 38 min, with 82% successful tumor exposure. The rate of pathological diagnosis was 72.1%. In 44 patients with a pathological diagnosis, two showed discrepancies with the postresection pathological diagnosis. No factors, including facility experience, organ, tumor size, or tumor exposure, significantly affected the diagnostic accuracy. There was one case of delayed bleeding and two cases of perforation. Conclusion: The diagnostic yield of the unroofing technique was acceptable. The unroofing technique was beneficial regardless of institutional experience, organ, tumor size, or actual tumor exposure.

A novel artificial intelligence-based endoscopic ultrasonography diagnostic system for diagnosing the invasion depth of early gastric cancer.

BACKGROUND: We developed an artificial intelligence (AI)-based endoscopic ultrasonography (EUS) system for diagnosing the invasion depth of early gastric cancer (EGC), and we evaluated the performance of this system. METHODS: A total of 8280 EUS images from 559 EGC cases were collected from 11 institutions. Within this dataset, 3451 images (285 cases) from one institution were used as a development dataset. The AI model consisted of segmentation and classification steps, followed by the CycleGAN method to bridge differences in EUS images captured by different equipment. AI model performance was evaluated using an internal validation dataset collected from the same institution as the development dataset (1726 images, 135 cases). External validation was conducted using images collected from the other 10 institutions (3103 images, 139 cases). RESULTS: The area under the curve (AUC) of the AI model in the internal validation dataset was 0.870 (95% CI: 0.796-0.944). Regarding diagnostic performance, the accuracy/sensitivity/specificity values of the AI model, experts (n = 6), and nonexperts (n = 8) were 82.2/63.4/90.4%, 81.9/66.3/88.7%, and 68.3/60.9/71.5%, respectively. The AUC of the AI model in the external validation dataset was 0.815 (95% CI: 0.743-0.886). The accuracy/sensitivity/specificity values of the AI model (74.1/73.1/75.0%) and the real-time diagnoses of experts (75.5/79.1/72.2%) in the external validation dataset were comparable. CONCLUSIONS: Our AI model demonstrated a diagnostic performance equivalent to that of experts.

Long-term outcome and metastatic risk after endoscopic resection of superficial esophageal squamous cell carcinoma.

OBJECTIVES: Long-term outcomes after endoscopic resection (ER) provide important information for the treatment of esophageal carcinoma. This study aimed to investigate the rates of survival and metastasis after ER of esophageal carcinoma. METHODS: From 1995 to 2010, 570 patients with esophageal carcinoma were treated by ER. Of these, the 402 patients with squamous cell carcinoma (280 epithelial (EP) or lamina propria (LPM) cancer, 70 muscularis mucosa (MM) cancer, and 52 submucosal (SM) cancer) were included in our analysis. Seventeen patients had cancer invading into the submucosa up to 0.2 mm (SM1) and 35 patients had cancer invading into the submucosa more than 0.2 mm (SM2). RESULTS: The mean (range) follow-up time was 50 (4-187) months. The 5-year overall survival rates of patients with EP/LPM, MM, and SM cancer were 90.5, 71.1, and 70.8%, respectively (P=0.007). Multivariate analysis identified depth of invasion and age as independent predictors of survival, with hazard ratios of 3.6 for MM cancer and 3.2 for SM cancer compared with EP/LPM cancer, and 1.07 per year of age. The cumulative 5-year metastasis rates in patients with EP/LPM, MM, SM1, and SM2 cancer were 0.4, 8.7, 7.7, and 36.2%, respectively (P<0.001). Multivariate analysis identified depth of invasion as an independent risk factor for metastasis, with hazard ratios of 13.1 for MM, 40.2 for SM1, and 196.3 for SM2 cancer compared with EP/LPM cancer. The cumulative 5-year metastasis rates in patients with mucosal cancer with and without lymphovascular involvement were 46.7 and 0.7%, respectively (P<0.0001). CONCLUSIONS: The long-term risk of metastasis after ER was mainly associated with the depth of invasion. This risk should be taken into account when considering the indications for ER.