Comparison of effective imaging modalities for detecting gastric neoplasms: A randomized three-arm phase II trial.

OBJECTIVES: The early detection of gastric neoplasms (GNs) leads to favorable treatment outcomes. The latest endoscopic system, EVIS X1, includes third-generation narrowband imaging (3G-NBI), texture and color enhancement imaging (TXI), and high-definition white-light imaging (WLI). Therefore, this randomized phase II trial aimed to identify the most promising imaging modality for GN detection using 3G-NBI and TXI. METHODS: Patients with scheduled surveillance endoscopy after a history of esophageal cancer or GN or preoperative endoscopy for known esophageal cancer or GN were randomly assigned to the 3G-NBI, TXI, or WLI groups. Endoscopic observations were performed to detect new GN lesions, and all suspected lesions were biopsied. The primary endpoint was the GN detection rate during primary observation. Secondary endpoints were the rate of missed GNs, early gastric cancer (EGC) detection rate, and positive predictive value (PPV) for a GN diagnosis. The decision rule had a higher GN detection rate between 3G-NBI and TXI, outperforming WLI by >1.0%. RESULTS: Finally, 901 patients were enrolled and assigned to the 3G-NBI, TXI, and WLI groups (300, 300, and 301 patients, respectively). GN detection rates in the 3G-NBI, TXI, and WLI groups were 7.3, 5.0, and 5.6%, respectively. The rates of missed GNs were 1.0, 0.7, and 1.0%, the detection rates of EGC were 5.7, 4.0, and 5.6%, and the PPVs for the diagnosis of GN were 36.5, 21.3, and 36.8% in the 3G-NBI, TXI, and WLI groups, respectively. CONCLUSION: Compared to TXI and WLI, 3G-NBI is a more promising modality for GN detection.

Squamous cell papilloma of the hypopharynx with elongated villous projections.

Squamous cell papilloma with elongated villous projections may occur in the hypopharynx and present with symptoms observable on physical examination.

Laparoscopic transabdominal approach for resection of presacral epidermoid cyst in an obese man: a case report.

BACKGROUND: Complete resection of presacral epidermoid cysts is recommended due to the potential for infection or malignancy. Transsacral and transabdominal approaches have been used to treat presacral tumors. However, there are no standard surgical approaches to resection. We present the case of a presacral epidermoid cyst in an obese male patient who underwent laparoscopic transabdominal resection. CASE PRESENTATION: A 44-year-old man was referred to our hospital for treatment of a cystic tumor on the pelvic floor. Contrast-enhanced computed tomography revealed a 45 × 40-mm tumor on the left ventral side of the rectum, right side of the ischial spine, dorsal side of the seminal vesicles, and in front of the 5th sacrum. Enhanced magnetic resonance imaging revealed a multilocular cystic tumor with high and low signal intensities on T2-weighted images. The tumor was diagnosed as an epidermoid cyst. We considered the transsacral or laparoscopic approach and decided to perform a laparoscopic-assisted transabdominal resection since the tumor was in front of away from the sacrum, and a transsacral approach would result in a larger scar due to poor visibility from the thickness of the buttocks. The entire tumor was safely resected under laparoscopic guidance, because the laparoscopic transabdominal approach can provide a good and magnified field of view even in a narrow pelvic cavity with small skin incisions, allowing safe resection of the pelvic organs, vessels, and nerves while observing the tumor contour. CONCLUSIONS: The laparoscopic transabdominal approach is an effective method for treating presacral tumors in obese patients.

Parenchymatous glossitis: A case report.

We present a case of parenchymatous glossitis with unilateral severe inflammation of the hyoglossus muscle, resulting in laryngeal edema. The route of inflammation was unique. Contrast-enhanced CT was useful for diagnosis. Administration of sensitive antibiotics led to improvement. Creatine phosphokinase may be an indicator of diagnosis and treatment response.

Surgical management of secondary acquired cholesteatoma depends on its characteristics.

OBJECTIVE: Cholesteatoma secondary to tympanic perforation, known as "secondary acquired cholesteatoma" may progress slower than a retraction pocket cholesteatoma, with less bone destruction and fewer intracranial complications. However, complete surgical removal remains difficult because the pathological epithelium on the marginal side of the extension is not covered by the subepithelial layer of the cholesteatoma matrix, making the boundary with the middle ear mucosa difficult to identify. Therefore, considering the pathophysiology of secondary acquired cholesteatoma, suitable preoperative evaluation and surgical techniques are required. In this study, we aimed to evaluate (i) the extension of secondary acquired cholesteatoma according to the size and location of tympanic membrane perforation; and (ii) the microscopic surgical outcomes, including the rate of residual cholesteatoma, requirement for specialized surgical management, and changes in hearing. METHODS: This retrospective study included data of cases with secondary acquired cholesteatoma (n = 66; 66 ears of 64 patients, 2 patients had bilateral ear involvement), including those who underwent a staged operation (n = 25). RESULTS: The perforation level of the tympanic membrane was associated with the cholesteatoma extension. When the cholesteatoma extended around the stapes, staged operation was chosen. Six cases of spontaneous resolution of stapes lesions at the time of staged surgery were observed. A significant postoperative improvement in hearing was observed; however, five cases experienced sensorineural hearing loss. CONCLUSION: Surgery, including staged surgery of the stapes lesions, along with careful observation of the perforation, is required in secondary acquired cholesteatoma. For lesions that are visible yet challenging to remove, it is imperative to exercise prudent judgment, taking into account the possibility of spontaneous resolution.

Procedural characteristics and cardiovascular outcomes in patients undergoing drug-coated balloon angioplasty for de novo lesions in large coronary arteries: an observational study.

Limited data exist regarding drug-coated balloon (DCB) treatment in de novo large coronary arteries. We sought to demonstrate procedural characteristics, residual stenosis, and clinical outcomes following DCB angioplasty for de novo lesions in large versus small coronary arteries. The study included 184 consecutive patients with 223 de novo coronary lesions undergoing paclitaxel DCB angioplasty between January 2019 and August 2020, who were divided according to whether the DCB diameter was ≥ 3.0 mm (large group, n = 58) or < 3.0 mm (small group, n = 125). The large group had a higher proportion of acute coronary syndrome more commonly with ostial, bifurcation, and calcified lesions in large vessels and received lesion preparation with more frequent use of scoring or cutting balloons and atherectomy devices compared to the small group. Postprocedural angiographic diameter stenosis was smaller in the large group compared to the small group (31% [22-37] vs. 35% [26-42], p = 0.032), and intravascular ultrasound revealed no significant difference in postprocedural area stenosis between the groups (66.2 ± 7.7% vs. 67.9 ± 7.8%; p = 0.26). The median follow-up duration was 995 days. The incidence of a composite of all-cause death, myocardial infarction, stroke, or target lesion revascularization was similar between the groups (log-rank p = 0.41) and was influenced by the presence of acute coronary syndrome and anemia but not by DCB diameter. The rate of cardiovascular outcomes after DCB treatment was comparable in de novo large and small coronary arteries. Notably, well-planned lesion preparation with intravascular imaging guidance was prevalent in large vessels.

A manual of Eustachian tube function tests-illustration of representative test results obtained from healthy subjects and typical disorders with suggestion of the appropriate test method of choice.

In the 19th century, Politzer devised a method to measure passage of the Eustachian tube (ET) by pressurizing the nasopharyngeal cavity, which marked the beginning of the ET function test. Since then, various examination methods have been developed. While ET function testing is important, recent advancements in diagnostic imaging and treatments have renewed interest on its importance. In Japan, the main objective methods used for examining ET function include tubotympanoaero-dynamic graphy (TTAG), sonotubometry, and the inflation-deflation test. The Japan Otological Society (JOS) Eustachian Tube Committee has proposed a manual of ET function tests, which presents typical patterns of the normal ear and typical diseases and suggests the ET function test of choice for each disease. However, the diagnosis of each disease should be made based on a comprehensive history and various examination findings, with ET function tests playing a supplemental role in the diagnosis.

Impact of prolonged drug-coated balloon inflation on residual stenosis and clinical outcomes in coronary artery disease patients: A propensity score matched analysis.

BACKGROUND: There is a paucity of data regarding the optimal duration of drug-coated balloon (DCB) inflation for coronary lesions. We sought to explore the effect of DCB angioplasty with versus without long inflation time on residual stenosis and clinical outcomes in patients with coronary artery disease. METHODS: This study included 314 consecutive patients with 445 lesions undergoing paclitaxel DCB angioplasty using different inflation time, divided according to whether the total inflation time of the DCB was ≥180 s (prolonged group) or <180 s (standard group). The primary clinical endpoint, defined as a composite of all-cause death, myocardial infarction, stroke, or target lesion revascularization, was examined in 92 propensity score matched pairs. RESULTS: In the matched cohort, the median clinical follow-up period was 947 days. Postprocedural angiographic diameter stenosis was smaller in the prolonged group than in the standard group (30.0% [22.0-37.0] vs. 33.5% [25.5-40.5]; p = 0.042). Intravascular ultrasound measurements revealed that longer DCB inflation time resulted in smaller area stenosis (66.6 ± 7.8% vs. 69.4 ± 7.0%; p = 0.044) and a less mean increase in percent atheroma volume (-11.2 ± 7.1% vs. -7.4 ± 5.9%; p = 0.004) after angioplasty. The rate of the primary endpoint was lower in the prolonged group than in the standard group (log-rank p = 0.025). The efficacy of prolonged DCB inflation was prominent in patients with in-stent restenosis and longer lesions. CONCLUSION: Prolonged DCB inflation was associated with reduced residual stenosis and improved clinical outcomes in patients with coronary artery disease undergoing percutaneous coronary intervention. Prospective randomized trials are warranted to validate the benefits of DCB angioplasty with long inflation time.

Isotopic Evidence for Microbial Nitrogen Cycling in a Glacier Interior of High-Mountain Asia.

Glaciers are now acknowledged as an important biome globally, but biological processes in the interior of the glacier (englacial) are thought to be slow and to play only a minor role in biogeochemical cycles. In this study, we demonstrate extensive, microbially driven englacial nitrogen cycling in an Asian glacier using the stable isotopes (δ15N, δ18O, and Δ17O values) of nitrate. Apparent decreases in Δ17O values of nitrate in an 8 m shallow firn core from the accumulation area indicate that nitrifiers gradually replaced ∼80% of atmospheric nitrate with nitrate from microbial nitrification on a decadal scale. Nitrate concentrations did not increase with depth in this core, suggesting the presence of nitrate sinks by microbial assimilation and denitrification within the firn layers. The estimated englacial metabolic rate using isotopic mass balance was classified as growth metabolism, which is approximately 2 orders of magnitude more active than previously known cold-environment metabolisms. In a 56 m ice core from the interior of the ablation area, we found less nitrification but continued microbial nitrate consumption, implying that organic matter is microbially accumulated over centuries before appearing on the ablating surface. Such englacial microbial products may support supraglacial microbes, potentially promoting glacial darkening and melting. With predicted global warming and higher nitrogen loads, englacial nutrient cycling and its roles may become increasingly important in the future.

Association of probiotic use with nivolumab effectiveness against various cancers: A multicenter retrospective cohort study.

BACKGROUND: Previous studies have revealed an association between probiotic use and effectiveness of immune checkpoint inhibitors in renal and lung cancers. However, little is known regarding other cancers, including gastrointestinal cancer. METHODS: To address this issue, we conducted a multicenter retrospective cohort study and the duration of nivolumab treatment for various cancers was compared between probiotic users and non-users. RESULTS AND CONCLUSIONS: In total, 488 patients who received nivolumab therapy were included. In all cancers, no significant differences in treatment duration of nivolumab were observed between probiotic users and non-users (median 62.0 vs. 56.0, hazard ratio = 1.02, p = 0.825), whereas probiotic use, compared with non-use, in patients with gastric cancer was significantly associated with a longer duration of nivolumab treatment (55.0 vs. 31.0 days, hazard ratio = 0.69, p = 0.039). In conclusion, probiotics may improve the response to nivolumab and potentially prolong progression-free survival in patients with gastric cancer.

Deep Subseafloor Biogeochemical Processes and Microbial Populations Potentially Associated with the 2011 Tohoku-oki Earthquake at the Japan Trench Accretionary Wedge (IODP Expedition 343).

Post-mega-earthquake geochemical and microbiological properties in subseafloor sediments of the Japan Trench accretionary wedge were investigated using core samples from Hole C0019E, which was drilled down to 851| |m below seafloor (mbsf) at a water depth of 6,890 m. Methane was abundant throughout accretionary prism sediments; however, its concentration decreased close to the plate boundary decollement. Methane isotope systematics indicated a biogenic origin. The content of mole-cular hydrogen (H2) was low throughout core samples, but markedly increased at specific depths that were close to potential faults predicted by logging-while-drilling ana-lyses. Based on isotopic systematics, H2 appeared to have been abundantly produced via a low-temperature interaction between pore water and the fresh surface of crushed rock induced by earthquakes. Subseafloor microbial cell density remained constant at approximately 105| |cells| |mL-1. Amplicon sequences revealed that predominant members at the phylum level were common throughout the units tested, which also included members frequently found in anoxic subseafloor sediments. Metabolic potential assays using radioactive isotopes as tracers revealed homoacetogenic activity in H2-enriched core samples collected near the fault. Furthermore, homoacetogenic bacteria, including Acetobacterium carbinolicum, were isolated from similar samples. Therefore, post-earthquake subseafloor microbial communities in the Japan Trench accretionary prism appear to be episodically dominated by homoacetogenic populations and potentially function due to the earthquake-induced low-temperature generation of H2. These post-earthquake microbial communities may eventually return to the steady-state communities dominated by oligotrophic heterotrophs and hydrogenotrophic and methylotrophic methanogens that are dependent on refractory organic matter in the sediment.

Comparison of long-term quality of life based on surgical procedure in patients with rectal cancer.

Introduction: Reports on the long-term quality of life (QOL) over 3 years after surgery in patients who have undergone surgery for rectal cancer are limited. Therefore, we aimed to evaluate the long-term QOL of patients who underwent high anterior resection (HAR), low anterior resection (LAR), internal sphincter resection (ISR), or abdominoperineal resection (APR) for rectal cancer. Methods: A questionnaire regarding QOL was sent to 360 patients with rectal cancer who underwent curative resection by HAR, LAR, ISR, or APR between January 2005 and December 2015. QOL was assessed using the short-form 36 (SF-36) and modified fecal incontinence QOL (mFIQL) questionnaire. QOL between surgical procedures was analyzed using a multivariate model adjusted for age, sex, and postoperative time. Results: A total of 144 patients responded with a median follow-up period of 94 months (range 38-233 months). According to surgical procedure, HAR was performed in 26 patients, LAR in 80 patients, ISR in 32 patients, and APR in 6 patients. Patients who underwent HAR had significantly better mFIQL scores than those who underwent LAR and ISR (p=0.013 and p=0004, respectively) and significantly better role/social component summary scores on the SF-36 subscales (p=0.007). No difference was observed in the mFIQL scores between patients who underwent ISR and those who underwent APR (p=0.8423). In addition, postoperative anastomotic leakage sutures did not influence the mFIQL and SF-36 scores after surgery. Conclusion: The QOL of patients who underwent anus-preserving surgery was best in the HAR group, with the QOL of other groups similar to the APR group. These results suggest that anus- preserving surgery is acceptable from a QOL standpoint. However, a colostomy may be a more satisfactory procedure in some patients.

Application of elemental analysis-coupled isotope ratio mass spectrometry for protein turnover analysis using deuterium labeling: Purification and analysis of hydrogen isotope ratio of non-derivatized protein-bound alanine.

RATIONALE: Heavy water can be used as a tracer for the evaluation of protein turnover. By adding heavy water (D2 O) to the precursor pool, nonessential amino acids, including alanine, can be isotopically labeled in vivo. Protein turnover can then be quantified by measuring the hydrogen isotope ratio of protein-bound alanine. METHODS: In this study, we constructed a novel method to apply deuterium labeling of alanine to the evaluation of protein turnover using elemental analysis-coupled isotope ratio mass spectrometry (EA-IRMS). We established a preparative high-performance liquid chromatography method to isolate alanine from protein hydrolysates. EA-IRMS was then used to determine the hydrogen isotope ratio of alanine isolated from hydrolysates of protein from mouse myoblast C2C12 cells that had been treated with D2 O over the course of 72 h. RESULTS: In cells treated with 4% D2 O, the deuterium enrichment of alanine increased to approximately 0.9% over time, while that of cells treated with 0.017% D2 O increased to approximately 0.006%. The rate of protein synthesis calculated by fitting the increase of deuterium excess to rise-to-plateau kinetics was similar regardless of the concentration of D2 O. When C2C12 cells treated with insulin and rapamycin were analyzed 24 h after the addition of 0.017% D2 O, protein turnover was found to be accelerated by insulin, but this effect was offset by co-treatment with rapamycin. CONCLUSION: The derivative-free measurement of the hydrogen isotope ratio of protein-bound alanine using EA-IRMS can be applied to the evaluation of protein turnover. The proposed method is an accessible option for many laboratories to perform highly sensitive IRMS-based evaluations of protein metabolic turnover.

Ecological Dynamics of Broad- and Narrow-Host-Range Viruses Infecting the Bloom-Forming Toxic Cyanobacterium Microcystis aeruginosa.

Microcystis aeruginosa is predicted to interact and coexist with diverse broad- and narrow-host-range viruses within a bloom; however, little is known about their affects on Microcystis population dynamics. Here, we developed a real-time PCR assay for the quantification of these viruses that have different host ranges. During the sampling period, total Microcystis abundance showed two peaks in May and August with a temporary decrease in June. The Microcystis population is largely divided into three phylotypes based on internal transcribed sequences (ITS; ITS types I to III). ITS I was the dominant phylotype (66% to 88%) except in June. Although the ITS II and III phylotypes were mostly less abundant, these phylotypes temporarily increased to approximately equivalent abundances of the ITS I population in June. During the same sampling period, the abundances of the broad-host-range virus MVGF_NODE331 increased from April to May and from July to October with a temporary decrease in June, in which its dynamics were in proportion to the increase of total Microcystis abundances regardless of changes in host ITS population composition. In contrast, the narrow-host-range viruses MVG_NODE620 and Ma-LMM01 were considerably less abundant than the broad-host-range virus and generally did not fluctuate in the environment. Considering that M. aeruginosa could increase the abundance and sustain the bloom under the prevalence of the broad-host-range virus, host abundant and diverse antiviral mechanisms might contribute to coexistence with its viruses. IMPORTANCE The bloom-forming toxic cyanobacterium Microcystis aeruginosa interacts with diverse broad- and narrow-host-range viruses. However, the dynamics of the Microcystis population (at the intraspecies level) and viruses with different host ranges remain unknown. Our real-time PCR assays unveiled that the broad-host-range virus gradually increased in abundance over the sampling period, in proportion to the increase in total Microcystis abundance regardless of changes in genotypic composition. The narrow-host-range viruses were considerably less abundant than the broad-host-range virus and did not generally fluctuate in the environment. The expansion and maintenance of the Microcystis bloom even under the increased infection by the broad-host-range virus suggested that highly abundant and diverse antiviral mechanisms allowed them to coexist with viruses under selective pressure. This paper expands our knowledge about the ecological dynamics of Microcystis viruses and provides potential insights into their coexistence with their host.

Usefulness of third-generation narrow band imaging and texture and color enhancement imaging in improving visibility of superficial early gastric cancer: A study using color difference.

Objectives: Overlooking early gastric cancer (EGC) during endoscopy is an issue to be resolved. Image-enhanced endoscopy is expected to improve EGC detection. This study investigated the usefulness of third-generation narrow band imaging (3G-NBI) and texture and color enhancement imaging (TXI) in improving the visibility of EGC using the color difference between EGC and its surrounding gastric mucosa. Methods: In this retrospective observational study, we examined 51 superficial EGCs that underwent endoscopic submucosal dissection and were observed by all three methods: 3G-NBI, TXI, and white light imaging (WLI). The primary endpoint was to compare the color difference of each method. For each EGC, we prepared one non-magnifying image for each method so that the location and size of the lesion in each image were the same. The L*a*b* color space was used to evaluate the color values. When the color values of the cancerous lesion and its surrounding mucosa were (L*c, a*c, b*c) and (L*s, a*s, b*s), respectively, the color difference was defined to be [(L*c-L*s)2+(a*c-a*s)2+(b*c-b*s)2]1/2. Results: The median color difference was 9.2 (interquartile range, 5.3-15.7) in WLI, 13.5 (interquartile range, 9.4-19.5) in 3G-NBI, and 15.3 (interquartile range, 9.1-22.1) in TXI. Statistically, the color difference was significantly larger in 3G-NBI than in WLI (p < 0.001) and TXI compared with WLI (p < 0.001). However, there was no significant difference between 3G-NBI and TXI (p = 0.330). Conclusions: Regarding color difference, both 3G-NBI and TXI were estimated to be more useful than WLI in improving the visibility of superficial EGC.

Intractable otitis media - Pathogenesis and treatment of Eosinophilic otitis media (EOM) and otitis media with Antineutrophil cytoplasmic antibody (ANCA) -associated vasculitis (OMAAV).

Intractable otitis media is resistant to antimicrobial therapy, tympanostomy ventilation tube insertion, and surgery. In children, intractable acute otitis media, pathological tympanic membrane due to prolonged otitis media with effusion (OME), tympanic membrane atelectasis, and adhesive otitis media are common. Contrarily, in adults, otitis media caused by drug-resistant pathogens, tuberculous otitis media, cholesterol granuloma, malignant otitis externa (skull base osteomyelitis), eosinophilic otitis media (EOM), and otitis media with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (OMAAV) are common and require differentiation. Among them, EOM is increasing along with eosinophilic upper respiratory tract diseases, such as bronchial asthma and eosinophilic chronic rhinosinusitis (ECRS), a subgroup of chronic rhinosinusitis with nasal polyps (CRSwNP). EOM is associated with adult-onset bronchial asthma and is characterized by viscous middle ear effusion and middle ear mucosa thickness with eosinophilic infiltration, which requires treatment with glucocorticoids according to disease activity and symptoms. Recently, OMAAV was proposed because of the similarities in clinical features and therapeutic effects. The clinical course of OMAAV is characterized by a relatively rapid increase in the bone conductive hearing threshold, which progresses over 1-2 months, without response to antimicrobial agents or tympanostomy ventilation tube insertion, and in some cases, is complicated by facial paralysis and hypertrophic pachymeningitis. This new concept may explain the pathogenesis and clinical presentation of many cases of intractable otitis media, the cause of which was previously unknown. Although making a diagnosis of OMAAV is relatively easy based on the clinical course, such as vascular dilatation of the tympanic membrane and positive ANCA titer, it is often difficult because the ANCA titer becomes negative with previous administration of glucocorticoids. In adults with intractable otitis media, ANCA titers must be measured before glucocorticoid administration. Treatment consisted of remission induction therapy with a combination of glucocorticoids and immunosuppressive drugs.

Role of Dust and Iron Solubility in Sulfate Formation during the Long-Range Transport in East Asia Evidenced by 17O-Excess Signatures.

Numerical models have been developed to elucidate air pollution caused by sulfate aerosols (SO42-). However, typical models generally underestimate SO42-, and oxidation processes have not been validated. This study improves the modeling of SO42- formation processes using the mass-independent oxygen isotopic composition [17O-excess; Δ17O(SO42-)], which reflects pathways from sulfur dioxide (SO2) to SO42-, at the background site in Japan throughout 2015. The standard setting in the Community Multiscale Air Quality (CMAQ) model captured SO42- concentration, whereas Δ17O(SO42-) was underestimated, suggesting that oxidation processes were not correctly represented. The dust inline calculation improved Δ17O(SO42-) because dust-derived increases in cloud-water pH promoted acidity-driven SO42- production, but Δ17O(SO42-) was still overestimated during winter as a result. Increasing solubilities of the transition-metal ions, such as iron, which are a highly uncertain modeling parameter, decreased the overestimated Δ17O(SO42-) in winter. Thus, dust and high metal solubility are essential factors for SO42- formation in the region downstream of China. It was estimated that the remaining mismatch of Δ17O(SO42-) between the observation and model can be explained by the proposed SO42- formation mechanisms in Chinese pollution. These accurately modeled SO42- formation mechanisms validated by Δ17O(SO42-) will contribute to emission regulation strategies required for better air quality and precise climate change predictions over East Asia.

Assessment of Outcomes From 1-Year Surveillance After Detection of Early Gastric Cancer Among Patients at High Risk in Japan.

Importance: Single endoscopic examination often misses early gastric cancer (GC), even when both high-definition white light imaging and narrow-band imaging are used. It is unknown whether new GC can be detected approximately 1 year after intensive index endoscopic examination. Objective: To examine whether new GC can be detected approximately 1 year after intensive index endoscopic examination using both white light and narrow-band imaging. Design, Setting, and Participants: This case-control study was a preplanned secondary analysis of a randomized clinical trial involving 4523 patients with a high risk of GC who were enrolled between October 1, 2014, and September 22, 2017. Data were analyzed from December 26, 2019, to April 21, 2021. Participants in the clinical trial received index endoscopy to detect early GC via 2 examinations of the entire stomach using white light and narrow-band imaging. The duration of follow-up was 15 months. The secondary analysis included 107 patients with newly detected GC (case group) and 107 matched patients without newly detected GC (control group) within 15 months after index endoscopy. Interventions: Surveillance endoscopy was scheduled between 9 and 15 months after index endoscopy. If new lesions suspected of being early GC were detected during surveillance endoscopy, biopsies were obtained to confirm the presence of cancer. Main Outcomes and Measures: The primary end point was the rate of new GC detected within 15 months after index endoscopy. The main secondary end point was identification of risk factors associated with new GC detected within 15 months after index endoscopy. Results: Among 4523 patients (mean [SD] age, 70.6 [7.5] years; 3527 men [78.0%]; all of Japanese ethnicity) enrolled in the clinical trial, 4472 received index endoscopy; the rate of early GC detected on index endoscopy was 3.0% (133 patients). Surveillance endoscopy was performed in 4146 of 4472 patients (92.7%) who received an index endoscopy; the rate of new GC detected within 15 months after index endoscopy was 2.6% (107 patients). Among 133 patients for whom early GC was detected during index endoscopy, 110 patients (82.7%) received surveillance endoscopy within 15 months after index endoscopy; the rate of newly detected GC was 10.9% (12 patients). For the secondary analysis of risk factors associated with newly detected GC, characteristics were well balanced between the 107 patients included in the case group vs the 107 patients included in the matched control group (mean [SD] age, 71.7 [7.2] years vs 71.8 [7.0] years; 94 men [87.9%] in each group; 82 patients [76.6%] vs 87 patients [81.3%] with a history of gastric neoplasm). Multivariate analysis revealed that the presence of open-type atrophic gastritis (odds ratio, 6.00; 95% CI, 2.25-16.01; P < .001) and early GC detection by index endoscopy (odds ratio, 4.67; 95% CI, 1.08-20.21; P = .04) were independent risk factors associated with new GC detection. Conclusions and Relevance: In this study, the rate of new GC detected by surveillance endoscopy approximately 1 year after index endoscopy was similar to that of early GC detected by index endoscopy. These findings suggest that 1-year surveillance is warranted for patients at high risk of GC.