Effect of periodic endoscopy for gastric cancer on early detection and improvement of survival

Deep Learning Models for Anatomical Location Classification in Esophagogastroduodenoscopy Images and Videos: A Quantitative Evaluation with Clinical Data

BACKGROUND/OBJECTIVES

During gastroscopy, accurately identifying the anatomical locations of the gastrointestinal tract is crucial for developing diagnostic aids, such as lesion localization and blind spot alerts.

METHODS

This study utilized a dataset of 31,403 still images from 1000 patients with normal findings to annotate the anatomical locations within the images and develop a classification model. The model was then applied to videos of 20 esophagogastroduodenoscopy procedures, where it was validated for real-time location prediction. To address instability of predictions caused by independent frame-by-frame assessment, we implemented a hard-voting-based post-processing algorithm that aggregates results from seven consecutive frames, improving the overall accuracy.

RESULTS

Among the tested models, InceptionV3 demonstrated superior performance for still images, achieving an F1 score of 79.79%, precision of 80.57%, and recall of 80.08%. For video data, the InceptionResNetV2 model performed best, achieving an F1 score of 61.37%, precision of 73.08%, and recall of 57.21%. These results indicate that the deep learning models not only achieved high accuracy in position recognition for still images but also performed well on video data. Additionally, the post-processing algorithm effectively stabilized the predictions, highlighting its potential for real-time endoscopic applications.

CONCLUSIONS

This study demonstrates the feasibility of predicting the gastrointestinal tract locations during gastroscopy and suggests a promising path for the development of advanced diagnostic aids to assist clinicians. Furthermore, the location information generated by this model can be leveraged in future technologies, such as automated report generation and supporting follow-up examinations for patients.

Impact of endoscopic surveillance on the early diagnosis and endoscopic resection likelihood of gastric cancer

BACKGROUND

Endoscopy could help detect early gastric cancer (EGC) and improve the prognosis of patients. The aim of this study was to analyze the impact of endoscopy and endoscopic surveillance on the early detection of gastric cancer (GC), GC staging, and treatment selection.

METHODS

Patients with GC diagnosed at our center from 2010 to 2022 were retrospectively analyzed and allocated to the short-interval group (had received endoscopy within 3 years before diagnosis), the long-interval group (had received endoscopy more than 3 years before diagnosis), and the unchecked group (had not received endoscopy before diagnosis). The differences in GC staging and treatment modalities among the three groups were analyzed, and the differences in the clinical and pathological features of EGC were further analyzed.

RESULTS

One thousand and twenty-five GC patients were included, with 395 cases of EGC and 630 cases of advanced GC. The proportions of EGC in the short-interval, long-interval, and unchecked groups were 98.0%, 84.2%, and 29.8%, respectively (p < 0.001). Among the 387 lesions of 367 EGC patients were resected by endoscopic submucosal dissection (ESD), 341 (88.1%) exhibited curative resection, and 46 (11.9%) involved noncurative resections. Lesions of EGC differed significantly in diameter, depth of invasion, and curative resection rate (p = 0.033, 0.019, and 0.005, respectively). In the short-interval group, 87.8% of the lesions were ≤ 2 cm, 95.6% of the invasion depths were confined to the mucosal layer, and 96.7% of the eCura scores were A or B. Compared with the unchecked group, they had smaller diameters (RR = 0.419, 95% CI 0.234-0.752), shallower invasion depths (RR = 0.286, 95% CI 0.105-0.777), and a higher curative resection rate (RR = 0.215, 95% CI 0.068-0.676).

CONCLUSION

Endoscopic surveillance at 3-year intervals can help detect EGC, and the EGC lesions found have smaller diameters and shallower depths of invasion, helping improve the curative resection rate of ESD.

Increased Prevalence of Autoimmune Gastritis in Patients with a Gastric Precancerous Lesion

Background: Autoimmune gastritis (AIG), characterized with the presence of anti-parietal-cell antibodies (APCA), is a risk factor for gastric cancer. However, AIG may go underdiagnosed, especially in the case of H. pylori infection and the presence of gastric precancerous lesions (GPL), due to the ambiguous pathology and delayed symptom onset. Aim: Investigate the prevalence and characteristics of AIG in GPL patients. Methods: Prevalence of AIG was determined with the presence of APCA in patients with GPL (n = 256) and the control group (n = 70). Pathological characteristics and levels of gastrin 17 (G17), pepsinogen (PG) I and II and anti-Helicobacter pylori IgG were assessed in GPL cases, and the severity of intestinal metaplasia and gastric atrophy was scored by expert pathologists. Results: APCA positivity was observed in 18% of cases vs. 7% of controls (p = 0.033). Only 3/256 patients were previously diagnosed with AIG. The presence of APCA was associated with corpus-limited and extended GPL. A receiver operating curve analysis demonstrated that the G17 and PGI/II ratio could identify APCA-positive patients within GPL cases (AUC: 0.884). Conclusions: The prevalence of AIG is higher in patients with GPL but goes undiagnosed. Using G17 and PG I/II as diagnostic markers can help to identify patients with AIG and improve surveillance programs for patients with GPL.

Single and combined use of the platelet-lymphocyte ratio, neutrophil-lymphocyte ratio, and systemic immune-inflammation index in gastric cancer diagnosis

Introduction

The platelet-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR), and systemic immune-inflammation index (SII) are markers for systemic inflammatory responses and have been shown by numerous studies to correlate with the prognosis of gastric cancer (GC). However, the diagnostic value of these three markers in GC is unclear, and no research has examined them in combination. In this study, we investigated the value of the PLR, NLR, and SII individually or in combination for GC diagnosis and elucidated the connection of these three markers with GC patients' clinicopathological features.

Methods

This retrospective study was conducted on 125 patients diagnosed with GC and 125 healthy individuals, whose peripheral blood samples were obtained for analysis. The preoperative PLR, NLR, and SII values were subsequently calculated.

Results

The results suggest that the PLR, NLR, and SII values of the GC group were considerably higher than those of the healthy group (all P ≤ 0.001); moreover, all three parameters were notably higher in early GC patients (stage I/II) than in the healthy population. The diagnostic value of each index for GC was analyzed using receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) calculation. The diagnostic efficacy of the SII alone (AUC: 0.831; 95% confidence interval [CI], 0.777-0.885) was expressively better than those of the NLR (AUC: 0.821; 95% CI: 0.769-0.873, P = 0.017) and PLR (AUC: 0.783; 95% CI: 0.726-0.840; P = 0.020). The AUC value of the combination of the PLR, NLR, and SII (AUC: 0.843; 95% CI: 0.791-0.885) was significantly higher than that of the combination of the SII and NLR (0.837, 95% CI: 0.785-0.880, P≤0.05), PLR (P = 0.020), NLR (P = 0.017), or SII alone (P ≤ 0.001). The optimal cut-off values were determined for the PLR, NLR, and SII using ROC analysis (SII: 438.7; NLR: 2.1; PLR: 139.5). Additionally, the PLR, NLR, and SII values were all meaningfully connected with the tumor size, TNM stage, lymph node metastasis, and serosa invasion (all P ≤ 0.05). Elevated levels of the NLR and SII were linked to distant metastasis (all P ≤ 0.001).

Discussion

These data suggest that the preoperative PLR, NLR, and SII could thus be utilized as diagnostic markers for GC or even early GC. Among these three indicators, the SII had the best diagnostic efficacy for GC, and the combination of the three could further improve diagnostic efficiency.

Clinicopathological features and prognosis of gastric tube cancer after esophagectomy for esophageal cancer: a nationwide study in Japan

BACKGROUND

Survivors of esophageal cancer post-esophagectomy may sometimes develop gastric tube cancer (GTC). However, its clinical characteristics have not been elucidated. We conducted a retrospective nationwide survey of GTCs to clarify them.

METHODS

A questionnaire on GTCs was sent by e-mail and mail to 116 institutions certified by the Japan Esophageal Society. A total of 608 GTC cases diagnosed and treated between 2001 and 2015 were registered from 62 institutions.

RESULTS

The median age at diagnosis was 71 years, with 88.9% being diagnosed with stage I. Sixty percent of GTC cases were in the anal third of the gastric tube and 79.7% were differentiated adenocarcinomas. The median interval between esophagectomy and GTC diagnosis was 6 years, with approximately 25% of patients being diagnosed more than 10 years later. The 5-year overall survivals (5-OSs) after endoscopic and surgical treatments for GTC were 75.9% and 52.7%, respectively. Patients whose GTC was diagnosed without symptoms or by regular follow-up examination showed better 5-OSs compared to others (69.7% vs. 41.2%, p < 0.0001; and 71.4% vs. 41.8%, p < 0.0001, respectively). The prognosis of GTC cases diagnosed within 2 years of the preceding upper gastrointestinal endoscopy (UGI) was better than that in cases diagnosed longer than 2 years (5-OS: 73.4% vs. 48.8%, p < 0.05).

CONCLUSION

This nationwide survey revealed the clinicopathological features of GTCs for the first time. Early detection is important in improving the prognosis of GTC, and it is recommended that UGI endoscopy be continued every 2 years for 10 or more years after esophagectomy.

Effect of gastric cancer screening on long-term survival of gastric cancer patients: results of Korean national cancer screening program

BACKGROUND

Gastric cancer (GC) is the most common cancer type in Korea. Korean National Cancer Screening Program (KNCSP) offer either upper gastrointestinal series (UGIS) or upper endoscopy biennially for adults aged ≥ 40. This study aimed to investigate the effect of cancer screening program on the long-term survival among GC patients.

METHODS

A nationwide population-based cohort was constructed based on three national databases. Overall, 46,701 GC patients diagnosed in 2008 and 2009 were included in our final analysis, and they were followed-up until the end of 2019. Survival curves were estimated using the Kaplan-Meier analysis with the log-rank test. Cox proportional-hazards regression analysis was used to report the hazard ratios (HRs) with 95% confidence intervals.

RESULTS

A total of 18,614/46,701 (39.9%) patients died during the median follow-up time of 10.5 years. The survival rate was higher among screened patients (65.8%) than never-screened patients (49.1%). Screened patients had 53% (HR, 0.47; 95% CI 0.45-0.48) lower risk of death from GC. The HRs of GC-specific mortality was lower in upper endoscopy group (HR = 0.36; 95% CI = 0.34-0.37) compared with UGIS (HR = 0.69; 95% CI = 0.67-0.73). Screened patients within 2 years prior to cancer diagnosis had a 35% reduction in risk of GC death. The figure decline to approximately 19% among patients with interval time since last screening of > 3 years.

CONCLUSIONS

Our findings emphasized the positive effects of GC screening on long-term GC patient survival. Also, patients screened by upper endoscopy or within 2 years before diagnosis had the best survival outcomes.

Association of Regular Endoscopic Screening with Interval Gastric Cancer Incidence in the National Cancer Screening Program

Although regular endoscopic screening may help in early detection of gastric cancer, interval cancer remains a problem in the screening program. This study evaluated the association between regular endoscopic screening and interval cancer detection in the Korean National Cancer Screening Program (KNCSP). We defined three groups (regularly, irregularly, and not screened) according to the screening interval, and the trends in the interval cancer rate (ICR) between the groups were tested using the Cochran-Armitage test. The influence of regular endoscopic screening on the risk of interval cancer was evaluated using multivariable logistic regression. Among the 11,642,410 participants who underwent endoscopy, the overall ICR was 0.36 per 1000 negative screenings. The ICR of the not screened group (0.41) was the highest among the three groups and the risk of interval cancer in this group was 1.68 times higher (p < 0.001) than that in the regularly screened group. Women in their 40s who had regular screening with no history of intestinal metaplasia and gastric polyps would have the lowest probability of having interval cancer (0.005%). Regular participation in endoscopic screening programs for reducing the risk of interval cancer may help to improve the quality of screening programs.

Diagnostic Ability of High-definition Imaging Using Ultraslim Endoscopes in Early Gastric Cancer

Purpose

It is unclear whether high-definition (HD) imaging improves visibility and diagnostic ability in early gastric cancer (EGC) compared with standard-definition (SD) imaging. We aimed to compare the diagnostic performance and visibility scores of HD and SD ultraslim endoscopes in EGC.

Materials and Methods

We used HD and SD ultraslim endoscopes to obtain 60 images with similar compositions of gastric environments. Of the 60 images, 30 showed EGC (15 images for each modality) and 30 showed no EGC (15 images for each modality). Seventeen endoscopists evaluated the presence and location of the lesions in each image. Diagnostic ability was compared between modalities. The color difference between a lesion and the surrounding mucosa (ΔE) was measured and compared between the modalities.

Results

The ability of HD to detect EGC was significantly higher than that of SD (accuracy: 80.8% vs. 71.6%, P=0.017; sensitivity: 94.9% vs. 76.5%, P<0.001; positive predictive value, 76.2% vs. 55.3%, P<0.001; and negative predictive value (NPV), 94.1% vs. 73.5%, P<0.001). The ability of HD to determine the horizontal extent of EGC was significantly higher than that of SD (accuracy: 71.0% vs. 57.8%, P=0.004; sensitivity: 75.3% vs. 49.0%, P<0.001; NPV, 72.9% vs. 55.9%, P<0.001; and area under the curve: 0.891 vs. 0.631, P=0.038). The mean ΔE was significantly higher for HD than for SD (10.3 vs. 5.9, P=0.011).

Conclusions

The HD ultraslim endoscope showed a higher diagnostic performance in EGC than the SD endoscope because it provided good color contrast.

Artificial Intelligence in Gastric Cancer: Identifying Gastric Cancer Using Endoscopic Images with Convolutional Neural Network

Simple Summary

Gastric cancer (GC) is one of the most newly diagnosed cancers and the fifth leading cause of death globally. Previous studies reported that the detection rate of gastric cancer (EGC) at an earlier stage is low, and the overall false-negative rate with esophagogastroduodenoscopy (EGD) is up to 25.8%, which often leads to inappropriate treatment. Accurate diagnosis of EGC can reduce unnecessary interventions and benefits treatment planning. Convolutional neural network (CNN) models have recently shown promising performance in analyzing medical images, including endoscopy. This study shows that an automated tool based on the CNN model could improve EGC diagnosis and treatment decision.

Abstract

Gastric cancer (GC) is one of the most newly diagnosed cancers and the fifth leading cause of death globally. Identification of early gastric cancer (EGC) can ensure quick treatment and reduce significant mortality. Therefore, we aimed to conduct a systematic review with a meta-analysis of current literature to evaluate the performance of the CNN model in detecting EGC. We conducted a systematic search in the online databases (e.g., PubMed, Embase, and Web of Science) for all relevant original studies on the subject of CNN in EGC published between 1 January 2010, and 26 March 2021. The Quality Assessment of Diagnostic Accuracy Studies-2 was used to assess the risk of bias. Pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were calculated. Moreover, a summary receiver operating characteristic curve (SROC) was plotted. Of the 171 studies retrieved, 15 studies met inclusion criteria. The application of the CNN model in the diagnosis of EGC achieved a SROC of 0.95, with corresponding sensitivity of 0.89 (0.88–0.89), and specificity of 0.89 (0.89–0.90). Pooled sensitivity and specificity for experts endoscopists were 0.77 (0.76–0.78), and 0.92 (0.91–0.93), respectively. However, the overall SROC for the CNN model and expert endoscopists was 0.95 and 0.90. The findings of this comprehensive study show that CNN model exhibited comparable performance to endoscopists in the diagnosis of EGC using digital endoscopy images. Given its scalability, the CNN model could enhance the performance of endoscopists to correctly stratify EGC patients and reduce work load.

Gastric cancer: lessons learned from high-incidence geographic regions

Gastric cancer is a global health concern. There is a marked geographical variability in the incidence of gastric cancer, with higher incidence in East and Central Asia followed by Latin America and Eastern Europe. Survival rates in gastric cancer are low and strongly stage dependent. Due to the limited survival benefit achieved from currently available therapeutic options, prevention and early diagnosis are essential to minimize morbidity and mortality from this disease. Countries with high incidence of gastric cancer have pioneered the development and implementation of prevention and screening programs. Helicobacter pylori (H. pylori) eradication and dietary modifications are the main preventive strategies. Upper gastrointestinal (UGI) endoscopy is the mainstay screening strategy for early diagnosis. In this article, we review the lessons learned for gastric cancer diagnosis and treatment from high-incidence areas and discuss their applicability for treatment in the Western world to reduce morbidity and mortality from this disease.

SCNET: A Novel UGI Cancer Screening Framework Based on Semantic-Level Multimodal Data Fusion

Upper gastrointestinal (UGI) cancer has been identified as one of the ten most common causes of cancer deaths globally. UGI cancer screening is critical to improving the survival rate of UGI cancer patients. While many approaches to UGI cancer screening rely on single-modality data such as gastroscope imaging, limited studies have been dedicated to UGI cancer screening exploiting multisource and multimodal medical data, which could potentially lead to improved screening results. In this paper, we propose semantic-level cancer-screening network (SCNET), a framework for UGI cancer screening based on semantic-level multimodal upper gastrointestinal data fusion. Specifically, the proposed SCNET consists of a gastrointestinal image recognition flow and a textual medical record processing flow. High-level features of upper gastrointestinal data are extracted by identifying effective feature channels according to the correlation between the textual features and the spatial structure of the image features. The final screening results are obtained after the data fusion step. The experimental results show that the improvement of our approach over the state-of-the-art ones reached 4.01% in average. The source code of SCNET is available at https://github.com/netflymachine/SCNET.

Deconvolution of diffuse gastric cancer and the suppression of CD34 on the BALB/c nude mice model

Background

Gastric cancer is a considerable burden for worldwide patients. And diffuse gastric cancer is the most insidious subgroup with poor survival. The phenotypic characterization of the diffuse gastric cancer cell line can be useful for gastric cancer researchers. In this article, we aimed to characterize the diffuse gastric cancer cells with MRI and transcriptomic data. We hypothesized that gene expression pattern is associated with the phenotype of the cells and that the heterogeneous enhancement pattern and the high tumorigenicity of SNU484 can be modulated by the perturbation of the highly expressed gene.

Methods

We evaluated the 9.4 T magnetic resonance imaging and transcriptomic data of the orthotopic mice models from diffuse gastric cancer cells such as SNU484, Hs746T, SNU668, and KATO III. We included MKN74 as an intestinal cancer control cell. After comprehensive analysis integrating MRI and transcriptomic data, we selected CD34 and validated the effect by shRNA in the BALB/c nude mice models.

Results

SNU484, SNU668, Hs746T, and MKN74 formed orthotopic tumors by the 5 weeks after cell injection. The diffuse phenotype was found in the SNU484 and Hs746T. SNU484 was the only tumor showing the heterogeneous enhancement pattern on T2 images with a high level of CD34 expression. Knockdown of CD34 decreased the round-void shape in the H&E staining (P = 0.028), the heterogeneous T2 enhancement, and orthotopic tumorigenicity (100% vs 66.7%). The RNAseq showed that the suppressed CD34 is associated with the downregulated gene-sets of the extracellular matrix remodeling.

Conclusion

Suppression of CD34 in the human-originated gastric cancer cell suggests that it is important for the round-void histologic shape, heterogeneous enhancement pattern on MRI, and the growth of gastric cancer cell line.

Three-year interval for endoscopic screening may reduce the mortality in patients with gastric cancer

BACKGROUND

Endoscopic screening has been adopted in South Korea for the national screening of gastric cancer (GC). This study aimed to assess the effect on overall survival of GC patients and determine the optimal endoscopic screening interval.

METHODS

The baseline characteristics and overall survival of GC patients treated at the National Cancer Center, Korea, between 2010 and 2016 were compared between those without a history of endoscopic evaluation (group N) and those in whom the interval between the last endoscopic evaluations and diagnosis of GC was ≤ 1, 1-2, 2-3, 3-4, or > 4 years (groups 1-5, respectively).

RESULTS

A total of 2362 patients met the criteria for the study (1060 in group N and 1302 in groups 1-5). More patients in groups 1-5 were diagnosed with stage I GC (83.7, 83.7, 71.8, 78.2, and 71.6%, respectively) than in group N (62.4%, P < 0.001) and were treated endoscopically (38.8, 33.8, 24.7, 21.8, and 15.5%, respectively, vs. 13.5%; P < 0.001). Group 2 had less-advanced tumor stages (P = 0.001) and was more likely to have received endoscopic treatments (P = 0.026) than group 3. Hazard ratios for death were significantly lower in groups 2 (0.45; 95% confidence interval [CI], 0.32-0.64) and 3 (0.57; 95% CI, 0.33-0.98) than in group N; the decrease was not significant in group 4 (0.49, 95% CI, 0.20-1.20).

CONCLUSIONS

Endoscopic screening every 3 years may reduce the mortality of GC patients, though screenings at least every 2 years may benefit patients with less-advanced stages.

Optimal Endoscopic Screening Interval for Early Detection of Gastric Cancer: a Single-Center Study

BACKGROUND

The optimal endoscopic screening interval for early gastric cancer (EGC) detection still remains controversial. Thus, we performed this prospective study to clarify the optimal interval between endoscopic examinations for EGC detection.

METHODS

A questionnaire survey for penultimate endoscopy and gastric cancer (GC) diagnosis interval was used; the findings were then analyzed. The patients were divided into two groups according to GC type and endoscopic examinations intervals.

RESULTS

A total of 843 patients were enrolled. The endoscopic GC detection interval (P < 0.001), tumor location (P < 0.001), tumor size (P < 0.001), histology (P < 0.001), tumor stage (P < 0.001), and treatment modality (P < 0.001) showed significant differences in the univariate analysis between EGC and advanced gastric cancer (AGC). Endoscopic examination intervals below 2 years and 3 years were associated with higher proportions of EGC detection (adjusted odds ratio, 2.458 and 3.022, respectively) (P < 0.001). The patients with endoscopic examination to GC diagnosis interval of < 2 years showed significant differences in tumor size (P < 0.001), tumor stage (P < 0.001), and treatment modality (P < 0.001) compared to those with intervals of > 2 years and without screening. Similar results were observed in those with < 3-year intervals.

CONCLUSION

Triennial endoscopic screening might be as effective as biennial screening in increasing the detection rate of EGC and the risk of subsequent curable endoscopic resections.

Effectiveness of Gastric Cancer Screening on Gastric Cancer Incidence and Mortality in a Community-Based Prospective Cohort

Purpose

This study was performed to investigate the effectiveness of gastric cancer (GC) screening methods in a community-based prospective cohort of the Korean Multi-center Cancer Cohort (KMCC) with over a 10-year follow-up.

Materials and Methods

A total 10,909 and 4,773 subjects from the KMCC with information on gastroendoscopy (GE) and upper gastrointestinal series (UGIS) were included in this study. Cox proportional hazard model adjusted for age, sex, Helicobacter pylori infection, cigarette smoking, and alcohol drinking was used to estimate the hazard ratios (HRs) and 95% confidence interval (CI).

Results

The GE screened subjects had almost half the risk of GC-specific death than that of unscreened subjects (HR, 0.58; 95% CI, 0.36 to 0.94). Among the GC patients, GE screenees had a 2.24-fold higher survival rate than that of the non-screenees (95% CI, 1.61 to 3.11). In particular, GE screenees who underwent two or more screening episodes had a higher survival rate than that of the non-screenees (HR, 13.11; 95% CI, 7.38 to 23.30). The effectiveness of GE screening on reduced GC mortality and increased survival rate of GC patients was better in elderly subjects (≥ 65 years old) (HR, 0.47; 95% CI, 0.24 to 0.95 and HR, 8.84; 95% CI, 3.63 to 21.57, respectively) than that in younger subjects (< 65 years old) (HR, 0.66; 95% CI, 0.34 to 1.29 and HR, 1.83; 95% CI, 1.24 to 2.68, respectively). In contrast, UGIS screening had no significant relation to GC mortality and survival.

Conclusion

The findings of this study suggest that a decreased GC-specific mortality and improved survival rate in GC patients can be achieved through GE screening.

When public health intervention is not successful: Cost sharing, crowd-out, and selection in Korea's National Cancer Screening Program

This study investigates the impact of and behavioral responses to cost sharing in Korea's National Cancer Screening Program, which provides free stomach and breast cancer screenings to those with an income below a certain cutoff. Free cancer screening substantially increases the screening take up rate, yielding more cancer detections. However, the increase in cancer detection is quickly crowded out by cancer detection through other channels such as diagnostic testing and private cancer screening. Further, compliers are much less likely to have cancer than never takers. Crowd-out and selection help explain why the program has been unable to reduce cancer mortality.

Does the interval of screening endoscopy affect survival in gastric cancer patients?: A cross-sectional study

Gastric cancer remains the second most common cancer in Korea; however, its mortality has decreased due to earlier diagnosis. In Korea, screening endoscopy has been performed nationwide since 1999. The aim of this study was to elucidate the benefit of screening endoscopy on actual survival in gastric cancer patients and to determine the optimal interval of screening endoscopy.We analyzed 1651 patients diagnosed with gastric adenocarcinoma who underwent surgical treatment between June 2008 and December 2014. Patients were divided into 4 groups according to the interval of screening endoscopy prior to their gastric cancer diagnosis. (Group I = within 1 year, Group II = >1 but <2 years, Group III = more than 2 years, Group IV = no prior endoscopic examination). Patient demographics, clinicopathologic characteristics, and postoperative surgical outcomes including overall survival were compared.The 5-year gastric cancer-specific survival rates of groups I and II were significantly higher than groups III and IV (90.9% vs 85.4%, P = 0.002, respectively). Multivariate analysis showed that screening interval was an independent factor for the diagnosis of advanced gastric cancer. The risk of advanced gastric cancer decreased in group I (odds ratio: 0.515, 95% confidence interval [CI] 0.369-0.719; P < 0.001) and group II (odds ratio: 0.678, 95% CI 0.517-0.889, P = 0.005).Screening endoscopy was helpful in increasing the survival of gastric cancer patients. A 2-year endoscopic screening interval is suitable to detect early-stage gastric cancer.

Gastric cancer and family history

Gastric cancer is associated with high morbidity and mortality rates worldwide. Identifying individuals at high risk is important for surveillance and prevention of gastric cancer. Having first-degree relatives diagnosed with gastric cancer is a strong and consistent risk factor for gastric cancer, but the pathogenic mechanisms behind this familial aggregation are unclear. Against this background, we reviewed the risk factors for gastric cancer in those with a first-degree relative with gastric cancer, and the possible causes for familial clustering of gastric cancer including bacterial factors, inherited genetic susceptibility, environmental factors or a combination thereof. Among individuals with a family history, current or past Helicobacter pylori infection, having two or more first-degree affected relatives or female gender was associated with an increased risk of developing gastric cancer. To date, no specific single nucleotide polymorphism has been shown to be associated with familial clustering of gastric cancer. H. pylori eradication is the most important strategy for preventing gastric cancer in first-degree relatives of gastric cancer patients, particularly those in their 20s and 30s. Early H. pylori eradication could prevent the progression to intestinal metaplasia and reduce the synergistic effect on gastric carcinogenesis in individuals with both H. pylori infection and a family history. Endoscopic surveillance is also expected to benefit individuals with a family history. Further large-scale, prospective studies are warranted to evaluate the cost-effectiveness and optimal time point for endoscopy in this population. Moreover, genome-wide association studies that incorporate environmental and dietary factors on a 'big data' basis will increase our understanding of the pathogenesis of gastric cancer.

Screening and surveillance for gastric cancer in the United States: Is it needed?

BACKGROUND AND AIMS

Although the incidence of gastric cancer in the United States is relatively low, the incidence of gastric cancer is higher than for esophageal cancer, for which clear guidelines for screening and surveillance exist. With the increasing availability of endoscopic therapy, such as endoscopic submucosal dissection, for treating advanced dysplasia and early gastric cancer, establishing guidelines for screening and surveillance of patients who are at high risk of developing gastric cancer has the potential to diagnose and treat gastric cancer at an earlier stage and improve mortality from gastric cancer. The aims of this article were to review the data regarding the risk factors for developing gastric cancer, methods for gastric cancer screening, and results of national screening programs.

METHODS

A review of the existing literature related to the aims was performed.

RESULTS

Risk factors for gastric cancer that were identified include race/ethnicity (East Asian, Russian, or South American), first-degree relative diagnosed with gastric cancer, positive Helicobacter pylori status, and presence of atrophic gastritis or intestinal metaplasia. Endoscopy has the highest rate of detecting gastric cancer compared with other gastric cancer screening methods. The national screening program in Japan has demonstrated a mortality reduction from gastric cancer based on cohort data.

CONCLUSIONS

Gastric cancer screening with endoscopy should be considered in individuals who are immigrants from regions associated with a high risk of gastric cancer (East Asia, Russia, or South America) or who have a family history of gastric cancer. Those with findings of atrophic gastritis or intestinal metaplasia on screening endoscopy should undergo surveillance endoscopy every 1 to 2 years. Large prospective multicenter studies are needed to further identify additional risk factors for developing gastric cancer and to assess whether gastric cancer screening programs for high-risk populations in the United States would result in improved mortality.

Pathological characteristics of gastric epithelial mucosa of patients with interval gastric cancer

AIM: To evaluate the clinicopathologic characteristics of interval gastric cancer (IGC) and the optimal frequency of endoscopy for gastric cancer screening.

METHODS: A retrospective analysis was performed of 41 patients with interval gastric cancer treated at the First Affiliated Hospital of Zhengzhou University from January 1, 2012 to December 31, 2014. We compared the differences between the missed cancers and the latent cancers.

RESULTS: A total of 41 IGC patients were identified, with a mean age of 52.56 years ± 10.60 years and a mean interval time of 18.9 mo. There were 33 IGC patients with poorly differentiated adenocarcinoma (80.5%), 18 IGC patients with tumor located in the gastric antrum (43.9%), and 24 IGC patients exhibited endoscopic ulcer morphology (58.5%).

CONCLUSION: IGCs tend to be poorly differentiated, located in gastric antrum and exhibit endoscopic ulcer morphology. The optimal frequency of endoscopy for gastric cancer screening may be 3 years. The patients with missed cancer are generally younger than the patients with latent cancer.

Clinicopathologic characteristics of interval gastric cancer in Korea

Background/Aims

Interval gastric cancer (IGC) is defined as cancer that is diagnosed between the time of screening and postscreening esophagogastroduodenoscopy (EGD). Unfortunately, little is known about the characteristics of IGC in Korea, a country with a high incidence of gastric cancer. The aim of this study was to evaluate the clinicopathologic characteristics of IGCs in Korea.

Methods

From January 2006 to July 2011, a total of 81,762 subjects underwent screening EGD at Yonsei University Health Promotion Center, Seoul, Korea. We defined missed cancer as cancer diagnosed within 1 year of screening EGD and latent cancer as cancer diagnosed more than 1 year after EGD.

Results

A total of 16 IGC patients (17 lesions; three missed cancers and 14 latent cancers) were identified, with a mean age of 60.68 years and a mean interval time of 19.64 months. IGCs tended to be undifferentiated (12/17, 70.6%), located in the lower body of the stomach (12/17, 70.6%) and exhibited flat/depressed endoscopic morphology (11/17, 64.7%). The patients with missed cancer were generally younger than the patients with latent cancer (51.3 years vs 62.8 years, p=0.037), and the patients with undifferentiated cancer were significantly younger than those with differentiated cancer (57.0 years vs 68.8 years, p=0.008).

Conclusions

IGCs tended to be undifferentiated, located in the lower body of the stomach, and exhibited flat/depressed endoscopic morphology.

Diagnosis and management of high risk group for gastric cancer

Gastric cancer is associated with high morbidity and mortality worldwide. To reduce the socioeconomic burden related to gastric cancer, it is very important to identify and manage high risk group for gastric cancer. In this review, we describe the general risk factors for gastric cancer and define high risk group for gastric cancer. We discuss strategies for the effective management of patients for the prevention and early detection of gastric cancer. Atrophic gastritis (AG) and intestinal metaplasia (IM) are the most significant risk factors for gastric cancer. Therefore, the accurate selection of individuals with AG and IM may be a key strategy for the prevention and/or early detection of gastric cancer. Although endoscopic evaluation using enhanced technologies such as narrow band imaging-magnification, the serum pepsinogen test, Helicobacter pylori serology, and trefoil factor 3 have been evaluated, a gold standard method to accurately select individuals with AG and IM has not emerged. In terms of managing patients at high risk of gastric cancer, it remains uncertain whether H. pylori eradication reverses and/or prevents the progression of AG and IM. Although endoscopic surveillance in high risk patients is expected to be beneficial, further prospective studies in large populations are needed to determine the optimal surveillance interval.

Review of atrophic gastritis and intestinal metaplasia as a premalignant lesion of gastric cancer

Atrophic gastritis (AG) and intestinal metaplasia (IM) are the main precursor lesions of gastric cancer as the incidence of gastric cancer increases in the gastric mucosa involved with AG and IM. The prevalence of AG and IM vary depending on countries, even it represents diverse results in the same nation. Usually AG is antecedent of IM but the etiologies of AG and IM are not always the same. The sensitivity and specificity of diagnostic methods to detect AG and IM are different. Furthermore, the management strategy of AG and IM has not been established, yet. Helicobacter pylori infection has been proved as the most important cause of AG and IM. Thus the eradication of H. pylori is very important to prevent the progression to gastric cancer which is still placed in the high rank in morbidity and mortality among cancers. However, the reversibility of AG and IM by eradication of H. pylori which was assumed to be certain by meta-analysis is; however, controversial now. Therefore, the understanding and early diagnosis of AG and IM are very important, especially, in high incidence area of gastric cancer such as Republic of Korea.

Impact of periodic endoscopy on incidentally diagnosed gastric gastrointestinal stromal tumors: findings in surgically resected and confirmed lesions

BACKGROUND

Although gastric gastrointestinal stromal tumors (GISTs) are usually identified by endoscopic examinations, the diagnostic value of endoscopy has not been fully evaluated. We assessed the diagnostic performance of endoscopy for gastric GISTs according to lesion characteristics. Furthermore, the benefits of periodic endoscopy prior to diagnosis of gastric GISTs were evaluated.

METHODS

We reviewed patients who underwent surgery for gastric GISTs at Severance Hospital, Seoul, Korea, between January 2008 and April 2014. In addition, we administered a questionnaire to determine the usage of periodic endoscopic inspection and the period from the penultimate endoscopy to the diagnosis.

RESULTS

Of 174 included patients, 109 (62.4 %) showed intraluminally growing GISTs and 65 (37.4 %) showed extraluminally growing GISTs. The proportions of lesions that were initially diagnosed via endoscopy were 99.1 % for intraluminally growing GISTs and 49.2 % for extraluminally growing GISTs (P < 0.001). In patients with intraluminally growing GISTs, patients who had undergone endoscopy within 3 years prior to the diagnosis showed smaller tumor sizes (P = 0.015) and fewer tumors with ulceration (7.1 vs. 28.4 %, P = 0.021). The proportion of GISTs with a high mitotic index did not differ according to the usage of periodic endoscopy (P = 0.639). In contrast, lesion characteristics of the extraluminally growing GISTs did not differ according to whether an endoscopy was performed within 3 years prior to the diagnosis.

CONCLUSIONS

Endoscopic examinations had a limited role in the diagnosis of extraluminally growing GISTs. However, periodic endoscopy was associated with relatively earlier detection of growth in intraluminal gastric GISTs.

Optimal Interval for Repeated Gastric Cancer Screening in Normal-Risk Healthy Korean Adults: A Retrospective Cohort Study

PURPOSE

This retrospective cohort study was conducted to estimate the optimal interval for gastric cancer screening in Korean adults with initial negative screening results.

MATERIALS AND METHODS

This study consisted of voluntary Korean screenees aged 40 to 69 years who underwent subsequent screening gastroscopies after testing negative in the baseline screening performed between January 2007 and December 2011. A new case was defined as the presence of gastric cancer cells in biopsy specimens obtained upon gastroscopy. The follow-up periods were calculated during the months between the date of baseline screening gastroscopy and positive findings upon subsequent screenings, stratified by sex and age group. The mean sojourn time (MST) for determining the screening interval was estimated using the prevalence/incidence ratio.

RESULTS

Of the 293,520 voluntary screenees for the gastric cancer screening program, 91,850 (31.29%) underwent subsequent screening gastroscopies between January 2007 and December 2011. The MSTs in men and women were 21.67 months (95% confidence intervals [CI], 17.64 to 26.88 months) and 15.14 months (95% CI, 9.44 to 25.85 months), respectively.

CONCLUSION

These findings suggest that the optimal interval for subsequent gastric screening in both men and women is 24 months, supporting the 2-year interval recommended by the nationwide gastric cancer screening program.

Prevalence of Precancerous Conditions and Gastric Cancer Based upon the National Cancer Screening Program in Korea for 7 Years, Single Center Experience

Aims. Gastric cancer is the second most prevalent cancer and the third leading cause of cancer-related deaths in Korea. The National Cancer Screening Program (NCSP) has implemented esophagogastroduodenoscopy (EGD) biennially for all Koreans starting in their 40s. This study was conducted to estimate the clinical relevance of NCSP through identifying the prevalence of gastric disease, including cancer. Materials and Methods. Data from 40,821 subjects who received the screening EGD in the single center for 7 years were retrospectively investigated. Results. The overall prevalence of nonatrophic/atrophic/metaplastic gastritis, peptic ulcer, adenoma, early gastric cancer (EGC), and advanced gastric cancer (AGC) was 44.28%, 27.97%, 14.95%, 0.59%, 0.43%, 0.21%, and 0.09%, respectively. The prevalence of metaplastic gastritis, peptic ulcer, adenoma, EGC, and AGC was significantly higher in men than in women. The prevalence of preneoplastic/neoplastic disease significantly increased with age. Judged from the ratio of EGC to AGC, the proportion of EGC made up to 70% of all cancers. Conclusions. Screening endoscopy starting for people in their 40s should be strongly recommended for the elderly. Through the NCSP, the early detection of gastric cancer might contribute to the decreased mortality rate due to gastric cancer in Korea.

In vivo molecular imaging of gastric cancer in human-murine xenograft models with confocal laser endomicroscopy using a tumor vascular homing peptide

The early detection of premalignant lesions and cancers are very important for improving the survival of patients with gastric malignancies. Confocal laser endomicroscopy (CLE) is a novel imaging tool for achieving real-time microscopy during the ongoing endoscopy at subcellular resolution. In the present study, to evaluate the feasibility of real-time molecular imaging of GEBP11 by CLE in gastric cancer, CLE was performed on two types of tumor-bearing mice models, as well as surgical specimens of patients with gastric cancer, after the application of GEBP11. A whole-body fluorescent imaging device was first used to screen for the strongest specific fluorescent signal in xenograft models. Next, the tumor sites, as well as human tissues, were scanned with CLE. After this, targeted specimens were obtained for fluorescence microscopy and histology. We confirmed that GEBP11 could specifically bind to co-HUVECs by means of CLE in cell experiments. Thereafter, a specific signal was observed in both subcutaneous and orthotopic xenograft models in vivo after the injection of FITC-GEBP11 via tail vein, whereas the group injected with FITC-URP showed no fluorescent signals. In human tissues, a specific signal of GEBP11 was observed in 26/28 neoplastic specimens and in 8/28 samples of non-neoplastic specimens from the patients (p < 0.01). The findings from ex vivo immunofluorescence microscopy of cryostat sections correlated well with that obtained by CLE. These findings indicate that the peptide, GEBP11, might be a potential candidate for the molecular imaging of gastric cancer.

Risk factors of atrophic gastritis and intestinal metaplasia in first-degree relatives of gastric cancer patients compared with age-sex matched controls

Background:

To identify whether first-degree relatives (FDRs) of gastric cancer (GC) patients have increased risk for atrophic gastritis (AG) and intestinal metaplasia (IM) in relation to other risk factors of GC.

Methods:

The study cohort consisted of 224 pairs of age-sex matched controls and FDRs. AG and IM in the gastric mucosa were scored histologically using the updated Sydney classification. Risk of having AG and IM was studied by comparing FDRs to controls. Impacts of age, H. pylori infection, smoking, dietary and socioeconomic factors on the presence of AG and IM were studied.

Results:

In multivariate regression analysis, FDRs had adjusted OR of 2.69 (95% CI 1.06–6.80, P=0.037) for antral IM in male population. Adjusted OR for antral AG and IM were 9.28 (95% CI 4.73–18.18, P<0.001) and 7.81 (95% CI 3.72–16.40, P<0.001) for the H. pylori infected subjects in total population. Getting old by 5 years increased the ORs of having AG and IM by approximately 1.25 fold (P<0.001). Spicy food increased the OR of antral IM by 2.28 fold (95% CI 1.36–3.84, P=0.002).

Conclusions:

Family history of GC was an independent risk factor for antral IM in male in our study, which could be one reason for the increase of gastric cancer in the family member of gastric cancer. It could be an evidence for the necessity of frequent endoscopy in the presence of family history of GC compared to general population in male.

The optimal endoscopic screening interval for detecting early gastric neoplasms

BACKGROUND

The optimal interval between endoscopic examinations for detecting early gastric neoplasms, including gastric adenomas, has not previously been studied.

OBJECTIVE

To clarify the optimal interval between endoscopic examinations for the early diagnosis of both gastric cancers and adenomas.

DESIGN

Retrospective study.

SETTING

University-affiliated tertiary-care hospital, Seoul, Korea.

PATIENTS

Patients who were treated for gastric neoplasms between January 2008 and August 2013.

INTERVENTIONS

Questionnaire survey for interval between the penultimate endoscopy and diagnosis of a gastric neoplasm. A total of 846 patients were divided into 5 groups according to the interval between endoscopic examinations.

MAIN OUTCOME MEASUREMENTS

The proportion of gastric neoplasms treated with endoscopic submucosal dissection and the proportion of advanced gastric cancers according to the interval between endoscopic examinations.

RESULTS

In total, 197, 430, and 219 patients were diagnosed with gastric adenoma, early gastric cancer, and advanced gastric cancer, respectively. In multivariate analysis, the proportion of gastric neoplasms treated with endoscopic submucosal dissection was significantly higher in the ≤12 months, 12 to 24 months, and 24 to 36 months endoscopy interval groups than in the no endoscopy within 5 years group (all P < .001). In addition, the proportion of advanced gastric cancers was significantly lower in the ≤12 months and 12 to 24 months endoscopy interval groups than in the no endoscopy within 5 years group (all P < .001).

LIMITATIONS

Retrospective study and recall bias.

CONCLUSION

Annual endoscopy cannot facilitate the detection of endoscopically treatable gastric neoplasms compared with biennial or triennial endoscopy. We recommend biennial endoscopic screening for gastric neoplasms in order to increase the proportion of lesions discovered while they are still endoscopically treatable and to reduce the number of lesions that progress to advanced gastric cancer.

Methodological issues for determining intervals of subsequent cancer screening

The gap between nationwide recommendations of cancer screening and the related evidences obtained from Korean adults should be filled. Estimation of the mean sojourn time (MST) in a specific cancer is important to determine the intervals of subsequent screening. This author arranged the methods for calculating MST into 5 categories based on the parameters used. Under the legal barrier for protection of individual privacy and confidentiality in a Korean academic situation, the methods involving the use of transition rates or prevalence/incidence ratio would be applicable among these methods.

Li-Fraumeni syndrome: cancer risk assessment and clinical management

Carriers of germline mutations in the TP53 gene, encoding the cell-cycle regulator and tumour suppressor p53, have a markedly increased risk of cancer-related morbidity and mortality during both childhood and adulthood, and thus require appropriate and effective cancer risk management. However, the predisposition of such patients to multiorgan tumorigenesis presents a specific challenge for cancer risk management programmes. Herein, we review the clinical implications of germline mutations in TP53 and the evidence for cancer screening and prevention strategies in individuals carrying such mutations, as well as examining the potential psychosocial implications of lifelong management for a ubiquitous cancer risk. In addition, we propose an evidence-based framework for the clinical management of TP53 mutation carriers and provide a platform for addressing the management of other cancer predisposition syndromes that can affect multiple organs.

Risk factors and clinical outcomes of gastric cancer identified by screening endoscopy: a case-control study

BACKGROUND AND AIM

A customized screening program for gastric cancer would optimize the benefits of screening endoscopy. This study investigated the risk factors for gastric cancer detected during screening and factors affecting clinical outcomes.

METHODS

From April 2000 to December 2010, subjects who underwent screening endoscopy at Asan Medical Center were included. To investigate risk factors, age- and sex-matched control group was selected. The clinical outcomes of gastric cancer identified during screening (screening group) were compared with age, sex, and date of diagnosis-matched subjects who were diagnosed with gastric cancer in the outpatient clinic (outpatient group).

RESULTS

Of 109 530 subjects, 327 were diagnosed with gastric cancer. The median age of the screening group was 63.6 years (interquartile range 56-71 years), and the male-to-female ratio was 2.4:1. When comparing with the control group, Helicobacter pylori seropositivity (odds ratio [OR] 2.933, P < 0.001), carcinoembryonic antigen (OR 8.633, P = 0.004), family history of gastric cancer (OR 2.254, P = 0.007), and drinking (OR 3.312, P < 0.001) were independent positive risk factors, and the use of aspirin a negative risk factor for gastric cancer (OR 0.445, P = 0.012) in multivariate analysis. Low-density lipoprotein cholesterol (hazard ratio [HR] 0.987, P = 0.005), cancer antigen 19-9 (HR 21.713, P < 0.001), resectability (HR 59.833, P < 0.001), and family history (HR 0.308, P = 0.009) were independent risk factors for death. The 5-year survival rate was significantly higher in the screening group than in the outpatient group (P < 0.001).

CONCLUSIONS

Early detection of gastric cancer by screening endoscopy while asymptomatic enhances patient outcomes, especially in high-risk groups.

Effect of endoscopic screening at 1-year intervals on the clinicopathologic characteristics and treatment of gastric cancer in South Korea

BACKGROUND AND AIM

The recommended interval of endoscopic screening for gastric cancer (GC) in a general population is 2 years in Korea. However, it has not been determined whether endoscopic screening with a shorter interval is beneficial, especially for high-risk groups.

METHODS

A total of 415 patients with GC were categorized according to whether they had (vigilant screening group) or not (non-vigilant screening group) undergone endoscopic screening within 1 year before being diagnosed with GC. Clinicopathologic GC characteristics of the two groups were compared. Next, the same analyses were conducted in subgroups of patients with high risk for GC including males, current smokers, first-degree relatives of GC; and patients with Helicobacter pylori infection, gastric atrophy, or intestinal metaplasia (IM).

RESULTS

The proportion of vigilant screening patients was 36.1%. Early gastric cancer (EGC) was more frequently observed in the vigilant screening group than the non-vigilant screening group (62.7% vs 49.4%, P = 0.009). In the high-risk factor analyses, EGC was more frequently detected among patients with severe IM in the vigilant screening group than the non-vigilant screening group (66.7% vs 35.5%, P = 0.047). In addition, more patients in the vigilant screening group had undergone endoscopic submucosal dissection (ESD; 26.7% vs 0%, P = 0.008) and had stage I (84.6% vs 41.7%, P = 0.012) than in the non-vigilant screening group.

CONCLUSIONS

Endoscopic screening for GC at 1-year intervals would be beneficial for patients with severe IM in South Korea; this method could detect EGC for which the curative modality would be ESD.

Effect of annual endoscopic screening on clinicopathologic characteristics and treatment modality of gastric cancer in a high-incidence region of Korea

We investigated risk factors for gastric cancer (GC) and effect of annual endoscopic screening on detection and treatment modality of GC. Asymptomatic adults who underwent upper endoscopy during health checkups at Seoul National University Hospital Healthcare System Gangnam Center were enrolled. We compared clinicopathologic characteristics of GC according to screening interval (repeated vs. infrequent, annual vs. biennial). After age- and sex-matching, relative risk was computed by hazard ratio (HR) using Cox proportional regression with multivariate adjustment. Of the 58,849 subjects who received screening endoscopy, 277 (0.47%) were found to have GC. Intestinal type comprised 55.4% (102/184) followed by diffuse type (n = 65, 35.3%). Age ≥ 50 years, family history and smoking independently increased the risk of GC for both types, whereas male gender [HR = 4.81, 95% confidence interval (CI): 2.72-8.03] and intestinal metaplasia (IM) (HR = 10.87, 95% CI: 3.36-22.30) were significant predictors for intestinal type only. Proportion of early gastric cancer (EGC) was 98.6% (71/72) in annual screening group and 80.7% (46/57) in biennial screening group (p < 0.01). In the former, tumor size was smaller (1.7 ± 1.3 vs. 2.3 ± 1.8 cm; p < 0.01] and proportion of intramucosal cancer was larger (75.0 vs. 56.1%; p = 0.04). Endoscopic resection was performed more frequently in annual screening group (56.9 vs. 33.3%; p = 0.02). IM along with male gender and older age was a strong risk factor for intestinal type GC. Annual screening group improved detection of early-stage and endoscopically treatable GC suggesting that intensive screening and surveillance may be useful for high-risk subpopulations with epidemiologic risk factors or premalignant lesions such as IM.

Surveillance strategy of atrophic gastritis and intestinal metaplasia in a country with a high prevalence of gastric cancer

BACKGROUND

It is not clear which screening examinations are best suited for gastric cancer prevention, especially in patients with atrophic gastritis and intestinal metaplasia. Therefore, we investigated the gastric cancer screening methods and intervals that are performed in clinical practice in an area with a high prevalence of gastric cancer.

METHODS

Eighty-seven physicians voted by keypad and discussed the consistency of endoscopic diagnosis of atrophic gastritis and intestinal metaplasia at the Annual Symposium of the Korean College of Helicobacter and Upper Gastrointestinal Research. Additionally, 100 core members of this academic society were asked via e-mail to complete the questionnaires related to screening strategies for gastric cancer.

RESULTS

The most common recommendation for the subjects with intestinal metaplasia was an annual endoscopic follow-up (95.5% vs. 80.4% in the expert and non-expert groups, respectively; P = 0.118). Annual endoscopic follow-up was also the most predominant recommendation for atrophic gastritis (95.5% vs. 76.5%; P = 0.092), regardless of the physicians' endoscopic experience, position, and degree of the hospital. However, the correct answer rate for the diagnosis of normal endoscopic findings was only 16.7 and 14.1% in the expert and non-expert groups, respectively (P = 0.883).

CONCLUSIONS

The most common practical screening strategy for patients with atrophic gastritis and intestinal metaplasia in Korea was annual endoscopic examination. However, a new program estimating individualized gastric cancer risk might be needed because of the low inter-observer agreement in the endoscopic diagnosis of atrophic gastritis and intestinal metaplasia.

Who participates in the gastric cancer screening and on-time rescreening in the National Cancer Screening Program? A population-based study in Korea

Gastric cancer (GC) screening is a major challenge in countries where the disease is highly prevalent. This study was conducted to identify the factors associated with participation in GC screening and on-time rescreening among the average-risk population in Korea. The study population was derived from the National Cancer Screening Program database. The population for this study was 22 913 618 individuals aged ≥40 years who had been invited to participate in a GC screening program from 2005 to 2006. We determined whether these individuals had attended the GC screening program and which method - an upper gastrointestinal series (UGIS) or endoscopy-they underwent. We followed the participants to determine whether they had a second GC screening after 2 years. The overall participation rate in the GC screening was 20.5%. More people underwent UGIS than endoscopy. Individuals who had been screened by endoscopy rather than UGIS were more likely to be younger, male, or those who were National Health Insurance (NHI) beneficiaries with a higher premium rate. Of those who underwent baseline screening, 59.4% participated in a rescreening program 2 years later. NHI beneficiaries with a higher premium rate were significantly more likely to be rescreened than medical aid recipients. The results from this study showed that the UGIS were more commonly used in organized GC screenings in Korea, and those who underwent UGIS were more likely to return for subsequent screening compared to those who underwent an endoscopy.

[Gastric cancer screening and diagnosis]

Gastric cancer is the most common cancer in Korea and has overall survival rate of around 50%. Gastric cancer detected in early stage can be cured by endoscopic resection or less invasive surgical treatment and the subsequent prognosis is excellent. National cancer screening program for gastric cancer has been available for several years. The evaluation for efficacy of our screening strategy is strongly needed in terms of mortality reduction and cost-effectiveness. Accurate diagnosis and staging evaluation is important for proper management and prediction of a patients prognosis. It is recommended to understand the advantages and limitations of currently available guidelines and diagnostic modalities. The 7th edition of gastric cancer staging system from AJCC may have significant effect on our knowledge and patient management.

Effect of repeated endoscopic screening on the incidence and treatment of gastric cancer in health screenees

OBJECTIVES

Early gastric cancer (EGC) can be treated by minimally invasive endoscopic resection and has an excellent prognosis. The aim of this study was to investigate whether repeated esophagogastroduodenoscopy (EGD) screening is an effective method for detecting EGC that can be treated by endoscopic resection.

METHODS

For patients diagnosed with gastric cancer in the Korean National Cancer Center screening program, we analyzed the incidence of gastric cancer, clinicopathological characteristics, and treatment modality according to whether they had (repeated screening group) or not (infrequent screening group) undergone EGD screening within 2 years before diagnosis.

RESULTS

Of the 18,414 patients who underwent EGD, 81 (0.44%) were found to have gastric cancer. Incidence of gastric cancer in repeated screening group was lower than that of infrequent screening group (multiple adjusted odds ratio=0.45, 95% confidence interval: 0.26-0.77, P=0.004). The proportion of EGCs was 96% (25 of 26) n the repeated screening group and 71% (34 of 48) in the infrequent screening group (P=0.01). Mean (SD) tumor size was smaller [1.9 (1.2) vs. 3.0 (1.6) cm, P=0.01] and the proportion of intramucosal cancer was higher [81% (21 of 26) vs. 50% (24 of 48), P=0.02] in the former than in the latter. Endoscopic resection was performed more frequently in the repeated screening group [54% (14 of 26) vs. 23% (11 of 48), P=0.007].

CONCLUSION

Repeated endoscopic screening within 2 years decreased the incidence of gastric cancer and endoscopic resection could be applied to more patients who underwent EGD screening within 2 years.

Laparoscopy-assisted distal gastrectomy for gastric cancer

OBJECTIVE

The purpose of this study was to evaluate the safety and value of laparoscopy-assisted distal gastrectomy (LADG) for early stage gastric cancer (stages IA, IB, and II).

MATERIALS AND METHODS

We retrospectively assessed 101 cases treated by LADG and compared to 49 contemporaneous cases treated by open distal gastrectomy (DG) between 2001 and 2006. Clinical variables, such as tumor diameter, operation time, blood loss, number of lymph nodes dissected, and length of stay were investigated.

RESULTS

Tumor size (mm) was significantly smaller in the LADG group (p < 0.0001). Although operation time (min) in the two groups was similar (278 +/- 57 vs. 268 +/- 55), mean blood loss was significantly higher in the DG group (139 +/- 181 vs. 460 +/- 301, p < 0.0001). Fewer lymph nodes were harvested in the LADG group (27 +/- 14 vs. 34 +/- 19, p = 0.012). Hospital stay was longer in the DG group (13.3 +/- 8.5 vs. 16.7 +/- 10.5, p = 0.034). There was no mortality in either group. Postoperative surgical complications occurred in six (6%) of the LADG and four (8%) of the DG.

CONCLUSIONS

The authors conclude that laparoscopy-assisted distal gastrectomy is a safe and useful operation for early-stage gastric cancers. If patients are selected properly, laparoscopy-assisted distal gastrectomy can be a curative and minimally invasive treatment for gastric cancer.

Significance of long-term follow-up of early gastric cancer

BACKGROUND

Therapeutic outcomes for most patients with early gastric cancer are favorable. However, mortality among these patients remains a concern. Improvements in therapeutic outcomes are being sought by studying the timing and causes of death. Here, the results of surgery were evaluated to assess the appropriate treatment and follow-up schedule for early gastric cancer.

METHODS

A total of 1169 patients with early gastric cancer underwent curative gastrectomy between 1992 and 1999. Survival time, prognostic factors, cause of death, and time of death were evaluated retrospectively.

RESULTS

Multivariate analysis of disease-specific survival identified lymph node metastasis as an independent prognostic factor. The anatomical extent of lymph node metastasis and the number of metastatic lymph nodes influenced the rate of recurrence. Multivariate analysis of overall survival identified age as a prognostic factor. A total of 91 patients (7.8%) from the study group died: 56 from comorbid diseases, 21 from gastric cancer, and 14 from other second primary cancers. Death from gastric cancer was frequently observed within 5 years of surgical resection, whereas death from other diseases usually occurred after 5 years. Patients who died as a result of diseases other than gastric cancer tended to be older.

CONCLUSIONS

Appropriate lymph node dissection is necessary for patients with early gastric cancer, particularly those with risk factors associated with lymph node metastasis. Meticulous follow-up protocols that can detect second primary cancers, together with the development of treatments for comorbid diseases, are required to improve survival.

Outcomes of mass screening for gastric carcinoma

BACKGROUND

Therapeutic results of gastric cancer have been improved by early detection of gastric cancer with the mass screening system in Japan. The objective of our study was to assess the efficacy of mass screening for gastric cancer by using a barium meal.

METHODS

A series of 1050 patients (364 in the screened group and 686 in the nonscreened group) were included in this study from April 1992 to March 2000. Patient characteristics, therapeutic results, and prognostic factors were compared in the two groups.

RESULTS

The screened patients tended to be younger and male, with tumors in the middle third of the stomach that were of a macroscopically superficial type, with a smaller diameter, and at an earlier stage. They had fewer metastatic lymph nodes and underwent more frequent curative resection. Among the screened patients with curatively resected disease, tumors tended to be of a smaller diameter, and there were fewer metastatic lymph nodes in both early and advanced cases. Disease-specific survival was significantly better in the screened cases among all registered and curatively resected patients. Mass screening achieved significantly better surgical results in early or advanced gastric cancer patients who received curative resection. Multivariate analysis revealed that mass screening was an independent prognostic factor (hazard ratio, .3949; P < .0001), together with depth of invasion, lymph node metastasis, age, and tumor diameter.

CONCLUSIONS

Mass screening by using barium meal examination for gastric cancer detects cancer at an early stage and produces good therapeutic results.

Evaluation of the diagnostic accuracy of gastroscopy to detect gastric tumours: clinicopathological features and prognosis of patients with gastric cancer missed on endoscopy

OBJECTIVES

Some gastric cancers are missed during diagnostic gastroscopy, but data are sparse on the clinical characteristics of patients with missed gastric cancers and on the accuracy of gastroscopy for detecting these tumours. We evaluated the number, clinicopathological characteristics, and survival of patients with missed gastric cancers, and the sensitivity and specificity of gastroscopy to detect these tumours.

METHODS

Data on gastric cancers detected in 1996-2001 in a single hospital referral area were obtained from the National Cancer Registry. Patient files were examined to identify those who underwent gastroscopy less than 3.5 years before a cancer diagnosis.

RESULTS

Of the 284 gastric cancer patients, 13 (4.6%) had undergone gastroscopy in the previous 3.5 years; their mean age was 72.4 years at the time of the first gastroscopy. The median delay in cancer diagnosis was 11.5 months. Histologically, all patients had gastric carcinoma. The sensitivity and specificity of gastroscopy for diagnosing gastric cancer were 0.93 and 1.00, respectively. Among the deceased patients, no difference was observed in the survival of cases with non-missed (n = 191) and missed (n = 10) carcinoma: 9.4 versus 7.3 months (P = 0.15).

CONCLUSION

A small proportion of gastric carcinomas are missed on gastroscopy, causing a significant delay in diagnosis. However, the prognoses of patients with missed and non-missed gastric carcinoma were equally poor.

[Surgical treatment of gastric remnant-stump cancer]

The aim of this study was to evaluate the characteristics, and treatment of gastric remnant cancer based on an analysis of the surgical results of Nippon Medical School over the past 18 years. Thirty seven patients (27 males and 10 females, mean age 60 years) underwent surgery for gastric remnant cancer. Patients who had undergone gastrectomy with Billroth II anastomosis for benign disorder underwent re-gastrectomy for the cancer of gastric remnant 20 years after the first gastrectomy. While, patients who had undergone gastrectomy with Billroth I anastomosis for malignant disorder underwent re-gastrectomy within 10 years after the first gastrectomy. Early-type gastric remnant cancers were not observed in the suture line or gastric stump region, while advanced-type cancers were observed in the anastomotic region. Surgical treatment was carried out by the method of total gastrectomy with Roux-en-Y esophago-jejunal anastomosis. The 5 year survival rates were 77%for early cancer and 14%for advanced cancer. Periodic follow-up endoscopies in gastrectomized patients may be useful for the early detection of gastric remnant cancer after operations for gastric cancer.

Myosin heavy chain kinase from developed Dictyostelium cells. Purification and characterization

Background:

Although gastric cancer screening is common among countries with a high prevalence of gastric cancer, there is little data to support the effectiveness of this screening. This study was designed to determine the differences in stage at diagnosis of gastric cancer according to the screening history and screening method (upper gastrointestinal series (UGIS) vs endoscopy).

Methods:

The study population was derived from the National Cancer Screening Programme (NCSP), a nationwide organised screening programme in Korea. The study cohort consisted of 19 168 gastric cancer patients who had been diagnosed in 2007 and who were invited to undergo gastric cancer screening via the NCSP between 2002 and 2007.

Results:

Compared with never-screened patients, the odds ratios for being diagnosed with localised gastric cancer in endoscopy-screened patients and UGIS-screened patients were 2.10 (95% CI=1.90–2.33) and 1.24 (95% CI=1.13–1.36), respectively.

Conclusions:

Screening by endoscopy was more strongly associated with a diagnosis of localised stage gastric cancer compared with screening by UGIS.