Sexually dimorphic role of oxytocin in medaka mate choice.

Oxytocin is a central neuromodulator required for facilitating mate preferences for familiar individuals in a monogamous rodent (prairie vole), irrespective of sex. While the role of oxytocin in mate choice is only understood in a few monogamous species, its function in nonmonogamous species, comprising the vast majority of vertebrate species, remains unclear. To address this issue, we evaluated the involvement of an oxytocin homolog (isotocin, referred herein as oxt) in mate choice in medaka fish (Oryzias latipes). Female medaka prefer to choose familiar mates, whereas male medaka court indiscriminately, irrespective of familiarity. We generated mutants of the oxt ligand (oxt) and receptor genes (oxtr1 and oxtr2) and revealed that the oxt-oxtr1 signaling pathway was essential for eliciting female mate preference for familiar males. This pathway was also required for unrestricted and indiscriminate mating strategy in males. That is, either oxt or oxtr1 mutation in males decreased the number of courtship displays toward novel females, but not toward familiar females. Further, males with these mutations exhibited enhanced mate-guarding behaviors toward familiar females, but not toward novel females. In addition, RNA-sequencing (seq) analysis revealed that the transcription of genes involved in gamma-amino butyric acid metabolism as well as those encoding ion-transport ATPase are up-regulated in both oxt and oxtr1 mutants only in female medaka, potentially explaining the sex difference of the mutant phenotype. Our findings provide genetic evidence that oxt-oxtr1 signaling plays a role in the mate choice for familiar individuals in a sex-specific manner in medaka fish.

Magnifying endoscopy with crystal violet staining for immune checkpoint inhibitor-associated colitis.

BACKGROUND AND AIM: There exists no evidence on the relationship between endoscopic and histologic findings. Furthermore, even after multiple biopsy specimens were obtained, histologic examination usually fails to show the characteristic features of immune checkpoint inhibitor-associated colitis. In this study, we explored the endoscopic and histologic findings of immune checkpoint inhibitor-associated colitis. METHODS: Patients diagnosed with immune checkpoint inhibitor-associated colitis at our hospital between March 2018 and December 2018 were retrospectively assessed. The degree of mucosal inflammation was evaluated using endoscopic inflammation grade (inactive, mild, moderate, or severe disease) and further observed using magnifying endoscopy with crystal violet staining. Pit structures were classified into three types: regularly arranged pits with circular or elliptical shape (R type), irregularly arranged pits with inhomogeneous size and morphology (IR type), and pits with reduced density or pits that partially disappeared (AD type). RESULTS: Eleven patients (median age, 71 years; range, 44-83 years) were diagnosed with immune checkpoint inhibitor-associated colitis. All characteristic histologic findings, including crypt distortion, crypt abscesses, and apoptotic bodies, were observed at sites with moderate-to-severe endoscopic inflammation but not at sites with inactive-to-mild endoscopic inflammation. Characteristic histologic features were observed in 0%, 50%, and 100% of R-type, IR-type, and AD-type mucosa, respectively. CONCLUSIONS: We revealed the possible utility of endoscopic images for selecting suitable target sites for biopsy and showed that endoscopic findings could reduce the time lag associated with tissue diagnosis and sampling errors due to biopsy.

Long-term outcomes after endoscopic submucosal dissection for differentiated-type early gastric cancer that fulfilled expanded indication criteria: A prospective cohort study.

BACKGROUND AND AIM: Endoscopic resection for early gastric cancer (EGC) is widely performed. However, there is still a paucity of strong evidence regarding long-term outcomes after endoscopic submucosal dissection (ESD) for the expanded indication criteria of the Japanese guidelines (ver. 2010). METHODS: Endoscopic submucosal dissection was performed in patients with EGC that met the expanded indication criteria: (i) cT1a, differentiated-type EGC of 2 to 5 cm, ulcer negative or (ii) cT1a, differentiated-type EGC of ≤3 cm, ulcer positive. Patients whose pathological examination fulfilled the curative resection criteria were then enrolled in this cohort study: negative vertical margin, negative lymphovascular invasion, and (i) pT1a, differentiated-type, and ulcer negative; (ii) pT1a, differentiated-type, ≤3 cm, and ulcer positive; or (iii) pT1b1 (<500-µm submucosal invasion), differentiated-type, and ≤3 cm. Patients with only a positive horizontal margin as a noncurative factor were included for follow-up. RESULTS: From September 2003 to February 2012, a total of 356 patients underwent ESD, and 214 were enrolled in the survival analysis. One hundred twenty patients (56%) had >2 cm in diameter and ulcer-negative lesions, and 94 (44%) had ≤3 cm and ulcer-positive lesions. The vital status at 5 years after ESD was confirmed in all (100%) patients. No local or metastatic recurrence was detected; however, 26 metachronous gastric cancers developed, and 1 patient died of metachronous gastric cancer. The 5-year disease-specific and overall survival rates were 99.5% (95% confidence interval [CI], 97.2%-100%) and 93.9% (95% CI, 89.8%-96.4%), respectively. CONCLUSION: ESD for EGC that fulfills the expanded criteria is feasible and shows favorable long-term outcomes.

Narrow band imaging under less-air condition improves the visibility of superficial esophageal squamous cell carcinoma.

BACKGROUND: The current virtual chromoendoscopy equipment cannot completely detect superficial squamous cell carcinoma (SCC) in the esophagus, despite its development in the recent years. Thus, in this study, we aimed to elucidate the appropriate air volume during endoscopic observation to improve the visibility of esophageal SCC. METHODS: This retrospective study included a total of 101 flat type esophageal SCCs identified between April 2017 and January 2019 at the Department of Gastrointestinal Oncology, Osaka International Cancer Institute. Video images of narrow band imaging (NBI) under both less-air and standard-air conditions were recorded digitally. Videos were evaluated by five endoscopists. Relative visibility between less-air and standard-air conditions of the brownish area, brownish color change of the epithelium, and dilated intrapapillary capillary loop (IPCL) were graded as 5 (definitely better under less-air condition) to 1 (definitely worse under less-air condition), with 3 indicating average visibility (equivalent to standard-air observation). RESULTS: The mean (standard deviation) visibility score of the brownish area, brownish color change of the epithelium, and dilated IPCLs under less-air condition were 3.94 (0.58), 3.73 (0.57), and 4.13 (0.60), respectively, which were significantly better than that under standard-air condition (p < 0.0001). Esophageal SCC evaluated as ≥ 4 in the mean visibility score of the brownish area, brownish color change of the epithelium, and dilated IPCLs accounted for 50% (51/101 lesions), 34% (34/101 lesions), and 67% (68/101 lesions), respectively. CONCLUSIONS: The present results suggested that NBI with less air might improve the visibility of flat type esophageal SCC compared with NBI with standard air. Less-air NBI observation may facilitate the detection of flat type esophageal SCC. TRIAL REGISTRATION: The present study is a non-intervention trial.

Does cold snare polypectomy completely resect the mucosal layer? A prospective single-center observational trial.

BACKGROUND AND AIM: The true incidence of incomplete muscularis mucosa resection with cold snare polypectomy (CSP) is unknown. We examined the incidence of incomplete muscularis mucosa resection both with and without cold snare defect protrusion (CSDP). METHODS: We prospectively enrolled patients undergoing polypectomy for 4 to 9mm nonpedunculated polyps. We evaluated the presence of CSDP immediately following CSP and biopsied the CSDP or the center of the mucosal defect without CSDP. The presence of the muscularis mucosa and any residual polyp in the biopsies was evaluated histologically. The primary outcome was the incidence of incomplete mucosal layer resection defined as the presence of muscularis mucosa or residual polyp in the biopsies. RESULTS: From August 2017 to October 2018, 188 patients were screened, and 357 polyps were included. CSDP was detected in 122/355 (34%) evaluated mucosal defects. Excluding five lesions requiring hemostasis immediately following CSP, 352 mucosal defects were biopsied. After excluding 102 biopsies containing normal mucosa, we evaluated 250 biopsies. The overall incidence of incomplete mucosal layer resection was 63% (159/250), 76% (68/90) with CSDP and 57% (91/159) without CSDP (P < 0.01). Both univariate and multivariate analyses showed that size (≥ 6 mm), resection time (≥ 5 s), and serrated lesions were risk factors for CSDP. CONCLUSIONS: Cold snare defect protrusion (CSDP), which was present with 36%, was a good indicator for incomplete mucosal layer resection. Even in nonCSDP polypectomies, 57% of the mucosal layer was not removed completely. Thus, CSP should be used for intra-epithelial lesions only, and careful pretreatment evaluation is recommended.

Feasibility of underwater endoscopic mucosal resection and management of residues for superficial non-ampullary duodenal epithelial neoplasms.

BACKGROUND AND AIM: Underwater endoscopic mucosal resection (UEMR) is effective for superficial non-ampullary duodenal epithelial neoplasms (SNADEN). However, the incidence of residual lesion after UEMR, especially for large lesions (≥20 mm), and their prognosis remain unclear. We aimed to assess the incidence of residual lesions and further outcomes after UEMR for SNADEN. METHODS: We carried out a retrospective study at a tertiary cancer institute. Candidates for the study were systematically retrieved from an endoscopic and pathological database from January 2013 to April 2018. RESULTS: A total of 162 SNADEN resected with UEMR were analyzed. Median (range) procedure time was 5 (1-70) min. En bloc resection rates for large lesions (≥20 mm) and small lesions (<20 mm) were 14% and 79%, respectively. Intraprocedural bleeding occurred in one (0.6%) case, but no intraprocedural perforation occurred during the study. Delayed bleeding occurred in two (1.2%) cases and delayed perforation occurred in one (0.6%) case. A total of 157 (97%) lesions were followed up by at least one endoscopic examination. Of these lesions, residual lesions were recognized in seven cases (5%). Additional UEMR was carried out in five lesions and underwater cold snare polypectomy in one lesion. One lesion was observed without additional treatment. After salvage intervention, no cases experienced further residual lesions. CONCLUSION: Although UEMR for SNADEN can be relevant when other efficacious procedures are unavailable, careful follow up for residual lesions is required especially after piecemeal resection for large lesions.

Impact of age at diagnosis of head and neck cancer on incidence of metachronous cancer.

BACKGROUND: Metachronous cancer in patients with head and neck cancer (HNC) is common and is associated with a poor prognosis. We aimed to evaluate the incidence of metachronous cancer at different sites according to age at diagnosis of index HNC. METHODS: We collected data on 2011 patients with oral cancer, oropharynx cancer, hypopharyngeal cancer, and laryngeal cancer as index cancers using the Osaka International Cancer Institute Cancer Registry database between 2005 and 2016. Among these, we analyzed 1953 patients after excluding 5 patients who were not followed-up and 53 patients with simultaneous multiple index cancers. We evaluated the cumulative incidence of metachronous cancer in the esophagus, lung, and other sites according to age at diagnosis of the index HNC using the Kaplan-Meier method. Multivariate logistic regression analysis was performed to identify factors that influenced the incidence of metachronous cancers following HNC. RESULTS: The cumulative incidence of metachronous esophageal cancer in young patients (< 65 years) was significantly higher than that in old patients (≥ 65 years) (12.1% vs 8.5% at 5 years, and 16.5% vs 11.2% at 10 years; p = 0.015). On the other hand, the cumulative incidence of the other cancers in young patients was significantly lower than that in old patients (7.8% vs 12.2% at 5 years, and 13.9% vs 15.3% at 10 years; p = 0.017). The cumulative incidence of lung cancer was not significance according to age at diagnosis of the index HNC. In the multivariate analysis, histological type (squamous cell carcinoma) and lesion location (hypopharynx and larynx) were independently associated with metachronous cancers. Moreover, age at diagnosis of the index HNC (< 65 years), histological type (squamous cell carcinoma) and lesion location (hypopharynx) were significant predictors of metachronous esophageal cancer incidence and lesion location (hypopharynx) was a significant predictor of metachronous lung cancer incidence. CONCLUSION: Risk stratification of metachronous cancers with age and other predictors may help to properly manage patients with HNC. TRIAL REGISTRATION: The present study is a non-intervention trial.

Differences in Clinical Course of Intraprocedural and Delayed Perforation Caused by Endoscopic Submucosal Dissection for Colorectal Neoplasms: A Retrospective Study.

BACKGROUND: Although the use of endoscopic submucosal dissection (ESD) as a minimally invasive treatment for large superficial colorectal neoplasms is increasing, colorectal ESD remains technically challenging. As perforation in the colorectum is generally considered to be associated with a higher risk of complications, the aim of this study was to investigate the characteristics of perforation caused by colorectal ESD. METHODS: This retrospective study included 635 lesions treated with colorectal ESD, between February 2011 and December 2015, in a tertiary cancer center. We evaluated and compared the clinical course and short-term outcomes of the intraprocedural perforation group with those of the delayed perforation and no perforation groups. RESULTS: Perforation occurred in 45 (7.1%) of the 635 cases. Thirty-six cases were intraprocedural perforation (5.7%), all of which were successfully closed with endoclips during the procedure. Nine cases of delayed perforation occurred (1.4%). No emergency surgery was performed in the intraprocedural perforation group; however, 5 of 9 cases underwent emergency surgery in the delayed perforation group (56%, p < 0.0001). There were statistically significant differences between the intraprocedural and delayed perforation groups with regard to the hospitalization period, fasting period, abdominal pain scale, peak white blood cell (WBC) count, and peak C-reactive protein (CRP), and between the intraprocedural and no perforation groups with regard to the location of the lesion, hospitalization period, fasting period, abdominal pain scale, peak WBC, peak CRP, and en bloc resection rate. CONCLUSIONS: While intraprocedural perforation due to colorectal ESD can be managed conservatively, delayed perforation can lead to serious adverse events.

Pulley Traction-Assisted Colonic Endoscopic Submucosal Dissection: A Retrospective Case Series.

BACKGROUND AND STUDY AIMS: We have reported the usefulness of traction-assisted colorectal endoscopic submucosal dissection (TAC-ESD) to overcome the technical difficulty of colorectal ESD. However, the direction of traction is toward the anal side only. We retrospectively evaluate the safety and efficacy of "pulley" TAC-ESD. PATIENTS AND METHODS: We retrospectively analyzed patients diagnosed with colorectal polyps and treated by "pulley" TAC-ESD at Osaka International Cancer Institute from December 2017 to June 2018. RESULTS: During the study period, 79 patients with 81 lesions were treated by ESD, and 54 of these patients were treated by traction-assisted ESD. Among them, 7 underwent "pulley" traction-assisted ESD (6 men, 1 woman; age, 48-69 years), resulting in en bloc resection with no complications. This afforded good visibility of the submucosal layer in 6 patients, but it was not effective in the remaining patient with the muscle-retracting sign. CONCLUSION: The "pulley" method affords good visibility of the submucosal layer by changing the traction direction in cases that are difficult to manage by conventional traction-assisted ESD.

Risk stratification for lymph node metastasis using Epstein-Barr virus status in submucosal invasive (pT1) gastric cancer without lymphovascular invasion: a multicenter observational study.

BACKGROUND: Lymphovascular invasion (LVI) is a strong predictive factor for lymph node metastasis (LNM) in early gastric cancer (GC). This study investigated the risk for LNM in pT1b GC without LVI based on Epstein-Barr virus (EBV) status in addition to conventional clinicopathological parameters. METHODS: In total, 847 consecutive patients of pT1b GC without LVI who underwent surgery at three high-volume centers between 2005 and 2014 were retrospectively analyzed. Clinicopathological parameters and EBV status were evaluated, and univariate and multivariate analyses were performed to estimate LNM risk. With regard to the presence of those three parameters, risk stratification for LNM was performed and compared with a previously proposed risk classification that included low-risk (LNM < 3.0%), intermediate-risk (LNM ≥ 3.0 and < 19.6%), and high-risk (LNM ≥ 19.6%) groups. RESULTS: EBV-positive GC (EBVGC) accounted for 11.3% (96 of 847) of cases; LNM was lower in EBVGC than in non-EBVGC (1 of 96, 1.0% vs. 71/751, 9.5%). In the multivariate analysis, non-EBVGC [odds ratio (OR) 10.8, 95% confidence interval (CI) 1.48-78.9], age < 65 years (OR 2.13, 95% CI 1.30-3.48), and tumor diameter > 3 cm (OR 2.26, 95% CI 1.36-3.74) were independent risk factors for LNM. Patients with EBVGC were at low risk for LNM whereas those with all of three independent risk factors were at high risk (36 of 168, 21.4%, 95% CI 15.5-28.4). CONCLUSION: LNM risk stratification that includes EBV status is useful for clinical decision-making in pT1b GC cases without LVI.

Endoscopic findings corresponding to multiple Lugol-voiding lesions in the esophageal background mucosa.

BACKGROUND AND AIM: Multiple Lugol-voiding lesions (LVLs) on Lugol chromoendoscopy can predict the development of metachronous multiple cancers in the esophagus and the head and neck regions. However, Lugol chromoendoscopy sometimes causes adverse events such as chest pain and discomfort. We therefore investigated the endoscopic findings on narrow band imaging (NBI) or blue laser imaging (BLI) that correspond to the presence of multiple LVLs in patients with esophageal squamous cell carcinoma. METHODS: First, we investigated the NBI/BLI findings corresponding to individual small LVLs (one-to-one correspondence). Second, we investigated the association between the grade of multiple LVLs and the five endoscopic findings, including multiple foci of dilated vessels (MDV), multiple small brownish areas without microvascular irregularity, and a nonuniform color tone. RESULTS: One-to-one correspondence of endoscopic findings was analyzed in 106 small LVLs. The main findings matched with small LVLs were a focus of dilated vessels (44 lesions), a small brownish area (17 lesions), and a small brownish area with a focus of dilated vessels (19 lesions). The relationship between multiple LVLs and each finding assessed by NBI/BLI was assessed in 155 patients. Multivariate logistic regression indicated that the presence of MDV was the only finding independently associated with multiple LVLs (P < 0.01). CONCLUSIONS: The presence of MDV in the noncancerous background esophageal mucosa was significantly associated with multiple LVLs. This pilot study demonstrates that MDV has the potential to be a new risk factor for the development of metachronous multiple esophageal squamous cell carcinoma.

Pharyngeal observation via transoral endoscopy using a lip cover-type mouthpiece.

BACKGROUND AND AIM: Simultaneous and metachronous head and neck cancers are likely to develop in patients with current or previous esophageal cancer. The Valsalva maneuver facilitates the visualization of the hypopharyngeal area during endoscopic observation, but it requires transnasal endoscopy. We developed a novel Valsalva maneuver using transoral endoscopy with a lip cover-type mouthpiece. METHODS: Between March 2018 and July 2018, 107 patients with current or previous esophageal cancer who were scheduled to undergo upper gastrointestinal endoscopy were included in our pilot study. We performed the Valsalva maneuver using our newly developed mouthpiece and transoral endoscopy in the patients and evaluated the hypopharyngeal region, including the postcricoid area and the posterior wall of the hypopharynx. The outcome measure was procedural success rate, which was graded as "complete," "incomplete," and "none." RESULTS: Observation of the hypopharyngeal area was "complete" in 81 patients (76%) using the Valsalva maneuver. However, in 25 patients and in 1 patient, observation was "incomplete" and "none," respectively. Seven lesions were newly detected in seven patients during the study period. CONCLUSIONS: The Valsalva maneuver using transoral endoscopy with a lip cover-type mouthpiece is feasible for the visualization of the postcricoid area and the posterior wall of the hypopharynx. Particularly, this technique would contribute to early detection of head and neck cancers.

An evolutionarily distinct Hmgn2 variant influences shape recognition in Medaka Fish.

Protein sequence diversification significantly impacts physiological traits. In this study, using medaka fish (Oryzias latipes), we identify a novel protein variant affecting shape preference behavior. Re-analysis of sequencing data reveals that LOC101156433 encodes a unique Hmgn2 variant with unusual subnuclear localization, clustered separately from the Hmgn2 clades of other species. Medaka mutants with this variant showed reduce telencephalic regions and altered shape preference, suggesting a link between protein sequence variation and behavioral changes. Additionally, this Hmgn2 variant is common in Acanthopterygii fishes, which are adapted to a variety of environments, indicating its potential evolutionary significance. Our findings highlight the relationship between amino acid sequence variation and the development of new molecular and behavioral adaptations, providing insights into the visual shape perception system in fish.

Usefulness of epinephrine-added injection solution to reduce procedure time for gastric endoscopic submucosal dissection.

Background and study aims Epinephrine-added submucosal injection solution is used to facilitate hemostasis of non-variceal upper gastrointestinal bleeding and to prevent delayed bleeding of large pedunculated colorectal lesions. However, its benefit in gastric endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) is unclear. The effectiveness of epinephrine-added injection solution for outcomes of gastric ESD was examined using propensity score matching analysis. Patients and methods A total of 1,599 patients with solitary EGC (83 with non-epinephrine-added solution and 1,516 with epinephrine-added solution) between 2011 and 2018 were enrolled. Propensity scores were calculated to balance the distribution of baseline characteristics: age, sex, tumor location, specimen size, presence of ulcer scar, tumor depth, histological tumor type, and operators' experience, and 1:3 matching was performed. En bloc resection rate, mean procedure time, delayed bleeding rate, and perforation rate were compared between the non-epinephrine (n = 79) and epinephrine (n = 237) groups. Results Mean procedure time was significantly shorter in the epinephrine group than in the non-epinephrine group (60 vs. 78 min, P  < 0.001). No significant difference was found in the rate of en bloc resection (both 99 %), incidence of delayed bleeding (both 6 %), or perforation (0 vs. 0.8 %) between the two groups. In multiple linear regression analysis, use of epinephrine-added solution was independently associated with short procedure time ( P  < 0.001) after adjustment for other covariates. Conclusion The results suggest that epinephrine-added injection solution is useful for reduction of gastric ESD procedure time, warranting validation in a randomized controlled trial.

Effect of horizontal margin status and risk of local recurrence after endoscopic submucosal dissection for superficial esophageal cancer.

BACKGROUND AND AIM: Endoscopic submucosal dissection (ESD) sometimes results in en bloc resection with a positive or inconclusive horizontal margin (HM1 or HMX, respectively) on histological evaluation. The specific risk for such situations is unclear. We therefore investigated the outcome of ESD with HM1 or HMX. METHODS: This single-center retrospective study was performed at Osaka International Cancer Institute. A total of 886 esophageal squamous cell carcinoma lesions in 749 patients treated from April 2005 to June 2015 were evaluated according to the following inclusion criteria: en bloc resection with no residual lesion, HM1 or HMX status, no prior treatment, and no additional treatment. We classified HM1 and HMX into type A, in which cancer was exposed on the HM, and type B, in which the HM status was unclear because of mechanical or thermal damage. We further classified type B according to the distance between the cancer and the edge of the specimen: type B1, <1 mm and type B2, ≥1 mm. RESULTS: The resection margin was judged as HM1 or HMX in 5.0% (39/767; 95% confidence interval, 3.5-6.6%) of the en bloc resected specimens. Of 39 lesions, 30 fulfilled the inclusion criteria. Local recurrence developed in 8 of 30 lesions (26.7%). The local recurrence rates for types A, B1, and B2 were 40% (6/15 lesions), 28.5% (2/7 lesions), and 0.0% (0/8 lesions), respectively. CONCLUSIONS: Although a statistical analysis was not conducted because of the limited events, the pathological HM status may be a useful predictor of local recurrence.

Application of Convolutional Neural Networks for Detection of Superficial Nonampullary Duodenal Epithelial Tumors in Esophagogastroduodenoscopic Images.

OBJECTIVES: A superficial nonampullary duodenal epithelial tumor (SNADET) is defined as a mucosal or submucosal sporadic tumor of the duodenum that does not arise from the papilla of Vater. SNADETs rarely metastasize to the lymph nodes, and most can be treated endoscopically. However, SNADETs are sometimes missed during esophagogastroduodenoscopic examination. In this study, we constructed a convolutional neural network (CNN) and evaluated its ability to detect SNADETs. METHODS: A deep CNN was pretrained and fine-tuned using a training data set of the endoscopic images of SNADETs (duodenal adenomas [N = 65] and high-grade dysplasias [HGDs] [N = 31] [total 531 images]). The CNN evaluated a separate set of images from 26 adenomas, 8 HGDs, and 681 normal tissue (total 1,080 images). The gold standard for both the training data set and test data set was a "true diagnosis" made by board-certified endoscopists and pathologists. A detected tumor was marked with a rectangular frame on the endoscopic image. If it overlapped at least a part of the "true tumor" diagnosed by board-certified endoscopists, the CNN was considered to have "detected" the SNADET. RESULTS: The trained CNN detected 94.7% (378 of 399) of SNADETs on an image basis (94% [280 of 298] of adenomas and 100% [101 of 101] of HGDs) and 100% on a tumor basis. The time needed for screening the 399 images containing SNADETs and all 1,080 images (including normal images) was 12 and 31 seconds, respectively. DISCUSSION: We used a novel algorithm to construct a CNN for detecting SNADETs in a short time.

High incidence of head and neck cancers after endoscopic resection for esophageal cancer in younger patients.

BACKGROUND: Second cancers in patients with esophageal cancer (EC) are common and have a poor prognosis. We evaluated the incidence of second cancers at different sites by patients' ages when their index ECs were diagnosed. METHODS: This study included patients who underwent endoscopic resection for superficial EC at our hospital between September 1994 and September 2011. Patients' data, including sex, age at diagnosis, sequence of cancer incidence, cancer histology, and cancer site, were extracted from the cancer registry. RESULTS: Of 544 patients, 255 developed second cancers. Simultaneous head and neck cancers (HNCs) and other organ cancers (OCs) were, respectively, present in 15% (80/544) and 9.6% (52/544) of patients; and 30% (162/544) developed metachronous second cancers over a median follow-up period of 79.5 months (range 2-120), including 44 metachronous HNCs and 70 OCs. The cumulative incidence of metachronous HNCs was significantly higher in younger patients (< 60 years) than in older patients (≥ 60 years; P = 0.001), whereas the cumulative incidence of OCs was significantly higher in older patients than in younger patients (P = 0.03). CONCLUSIONS: The incidence of second HNC after index EC was higher in younger-onset patients than in older-onset patients. We suggest that younger patients with EC should be carefully monitored for early detection of second HNC.

Stratification of gastric cancer risk using a deep neural network.

BACKGROUND AND AIM: Stratifying gastric cancer (GC) risk and endoscopy findings in high-risk individuals may provide effective surveillance for GC. We developed a computerized image- analysis system for endoscopic images to stratify the risk of GC. METHODS: The system was trained using images taken during endoscopic examinations with non-magnified white-light imaging. Patients were classified as high-risk (patients with GC), moderate-risk (patients with current or past Helicobacter pylori infection or gastric atrophy), or low-risk (patients with no history of H. pylori infection or gastric atrophy). After selection, 20,960, 17,404, and 68,920 images were collected as training images for the high-, moderate-, and low-risk groups, respectively. RESULTS: Performance of the artificial intelligence (AI) system was evaluated by the prevalence of GC in each group using an independent validation dataset of patients who underwent endoscopic examination and H. pylori serum antibody testing. In total, 12,824 images from 454 patients were included in the analysis. The time required for diagnosing all the images was 345 seconds. The AI system diagnosed 46, 250, and 158 patients as low-, moderate-, and high risk, respectively. The prevalence of GC in the low-, moderate-, and high-risk groups was 2.2, 8.8, and 16.4%, respectively (P = 0.0017). Three experienced endoscopists also successfully stratified the risk; however, interobserver agreement was not satisfactory (kappa value of 0.27, indicating fair agreement). CONCLUSION: The current AI system detected significant differences in the prevalence of GC among the low-, moderate-, and high-risk groups, suggesting its potential for stratifying GC risk.

Natural history of early gastric cancer: series of 21 cases.

Background and study aims While knowledge of the natural history of early gastric cancer (EGC) may be useful in relevant clinical situations, few relevant reports are available. Therefore, we investigated the progression of EGC. We gathered data regarding 114 cases of EGC from 2005 to 2015 from a hospital cancer registry and analyzed 21 lesions that fulfilled five inclusion criteria. Deep progression was defined as submucosal invasion by a mucosal tumor and proper muscle invasion by a submucosal tumor. Lateral progression was defined as ≥ 20 % increase in size. During median follow-up of 23 months, one of 18 mucosal tumors showed deep progression and six showed lateral progression. Of three submucosal tumors, two showed deep progression and three showed lateral progression. Our study suggests that a certain proportion of mucosal cancers can lie dormant for several years. Further large-scale studies in a multicenter setting should overcome the limitations of this study.